July 15, 2015
RPA Inc. T55 University Ave. Suite 501 I Toronto, ON, Canada M5J 2H7 I + 1 (416) 947 0907 www.rpacan.com
PREMIER GOLD MINES LIMITED
TECHNICAL REPORT ON THESOUTH ARTURO , ELKO COUNTY,MINESTATE OF NEVADA, U.S.A.
NI 43-101 Report
Qualified Persons:Wayne W. Valliant, P.Geo.Stuart E. Collins, P.E.Brenna J.Y. Scholey, P.Eng.
Report Control Form Document Title Technical Report on the South Arturo Mine, Elko County,
State of Nevada, U.S.A.
Client Name & Address
Premier Gold Mines Limited Suite 200, 1100 Russell Street Thunder Bay, Ontario P7B 5N2
Document Reference
Project # 2499
Status & Issue No.
Final Version
Issue Date July 15, 2015 Lead Author Wayne W. Valliant, P.Geo.
Stuart E. Collins, P.E. Brenna J.Y. Scholey, P.Eng.
(Signed) (Signed) (Signed)
Peer Reviewer Richard J. Lambert
(Signed)
Project Manager Approval Wayne W. Valliant
(Signed)
Project Director Approval Deborah A. McCombe
(Signed)
Report Distribution Name No. of Copies Client RPA Filing 1 (project box)
Roscoe Postle Associates Inc.
55 University Avenue, Suite 501 Toronto, ON M5J 2H7
Canada Tel: +1 416 947 0907
Fax: +1 416 947 0395 [email protected]
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Premier Gold Mines Limited – South Arturo Mine, Project #2499
Technical Report NI 43-101 – July 15, 2015 Page i
TABLE OF CONTENTS PAGE
1 SUMMARY ........................................................................................................................ 1-1 Executive Summary ......................................................................................................... 1-1 Economic Analysis ........................................................................................................... 1-6 Technical Summary ....................................................................................................... 1-11
2 INTRODUCTION ............................................................................................................... 2-1
3 RELIANCE ON OTHER EXPERTS ................................................................................... 3-1
4 PROPERTY DESCRIPTION AND LOCATION ................................................................. 4-1 Land Tenure .................................................................................................................... 4-1 Royalties .......................................................................................................................... 4-2
5 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY ................................................................................................................. 5-1
Accessibility ..................................................................................................................... 5-1 Climate ............................................................................................................................. 5-1 Local Resources .............................................................................................................. 5-1 Infrastructure .................................................................................................................... 5-1 Physiography ................................................................................................................... 5-2
6 HISTORY ........................................................................................................................... 6-1 Prior Ownership ............................................................................................................... 6-1 Exploration and Development History ............................................................................. 6-1 Historical Resource Estimates ......................................................................................... 6-3 Past Production ............................................................................................................... 6-4
7 GEOLOGICAL SETTING AND MINERALIZATION ........................................................... 7-1 Regional Geology ............................................................................................................ 7-1 Local and Property Geology ............................................................................................ 7-3 Mineralization ................................................................................................................... 7-6
8 DEPOSIT TYPES .............................................................................................................. 8-1
9 EXPLORATION ................................................................................................................. 9-1 Exploration Potential ........................................................................................................ 9-1
10 DRILLING ...................................................................................................................... 10-1 Sampling Method and Approach ................................................................................... 10-4
11 SAMPLE PREPARATION, ANALYSES, AND SECURITY ............................................ 11-1 Sample Preparation and Analyses ................................................................................ 11-1 Sample Security ............................................................................................................. 11-3 Quality Assurance and Quality Control .......................................................................... 11-3 Twinned Hole Data ........................................................................................................ 11-6 RPA Opinion .................................................................................................................. 11-9
12 DATA VERIFICATION ................................................................................................... 12-1
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Premier Gold Mines Limited – South Arturo Mine, Project #2499
Technical Report NI 43-101 – July 15, 2015 Page ii
Barrick Samples ............................................................................................................. 12-1 Meridian Samples .......................................................................................................... 12-1 Dee/Glamis Samples ..................................................................................................... 12-2
13 MINERAL PROCESSING AND METALLURGICAL TESTING ...................................... 13-1 Metallurgical Samples .................................................................................................... 13-1 Mineralogical Study ....................................................................................................... 13-6 Column Leach Tests ...................................................................................................... 13-6 CIL Bottle Roll Tests ...................................................................................................... 13-8 Bench Top Roaster/CIL Tests ....................................................................................... 13-9 Bond Work Index ......................................................................................................... 13-10 Historical Dee Mine Data ............................................................................................. 13-10 Conclusions and Recommendations ........................................................................... 13-10
14 MINERAL RESOURCE ESTIMATE .............................................................................. 14-1 Data ............................................................................................................................... 14-3 Geological Modelling ..................................................................................................... 14-3 Mineralization Modelling ................................................................................................ 14-3 Indicator Interpolation .................................................................................................... 14-5 Grade Capping and Compositing .................................................................................. 14-6 Variography ................................................................................................................... 14-7 Block Model Construction .............................................................................................. 14-7 Grade Interpolation ........................................................................................................ 14-7 Density ........................................................................................................................... 14-9 Classification .................................................................................................................. 14-9 Post Processing ........................................................................................................... 14-10 Model Validation .......................................................................................................... 14-10
15 MINERAL RESERVE ESTIMATE ................................................................................. 15-1 Whittle Analysis and Block Value inputs ........................................................................ 15-4 Dilution ........................................................................................................................... 15-7 Cut-off Grades ............................................................................................................... 15-7
16 MINING METHODS ....................................................................................................... 16-1 Mine Design, Mining Method ......................................................................................... 16-1 Open Pit Mining ............................................................................................................. 16-1 Ore Control .................................................................................................................... 16-3 Overburden/Waste Storage Design Discussion ............................................................ 16-4 Geomechanics ............................................................................................................... 16-5 Life of Mine Plan .......................................................................................................... 16-10 Mine Equipment ........................................................................................................... 16-10
17 RECOVERY METHODS ............................................................................................... 17-1 Heap Leaching............................................................................................................... 17-1 Oxide Ore Milling/CIL ..................................................................................................... 17-1 Roaster/CIL .................................................................................................................... 17-2 POX/TCM Leaching ....................................................................................................... 17-2
18 PROJECT INFRASTRUCTURE .................................................................................... 18-1
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Premier Gold Mines Limited – South Arturo Mine, Project #2499
Technical Report NI 43-101 – July 15, 2015 Page iii
19 MARKET STUDIES AND CONTRACTS ....................................................................... 19-1 Contracts ....................................................................................................................... 19-1
20 ENVIRONMENTAL STUDIES, PERMITTING, AND SOCIAL OR COMMUNITY IMPACT ............................................................................................................................................ 20-1
Environmental Studies ................................................................................................... 20-1 Tailings Storage Facility ................................................................................................. 20-1 Permitting ....................................................................................................................... 20-1 Social or Community Requirements .............................................................................. 20-2 Mine Closure Requirements .......................................................................................... 20-3
21 CAPITAL AND OPERATING COSTS ............................................................................ 21-1 Capital Cost ................................................................................................................... 21-1 Operating Costs ............................................................................................................. 21-1
22 ECONOMIC ANALYSIS ................................................................................................ 22-1
23 ADJACENT PROPERTIES ........................................................................................... 23-1
24 OTHER RELEVANT DATA AND INFORMATION ......................................................... 24-1
25 INTERPRETATION AND CONCLUSIONS ................................................................... 25-1
26 RECOMMENDATIONS ................................................................................................. 26-1
27 REFERENCES .............................................................................................................. 27-1
28 DATE AND SIGNATURE PAGE.................................................................................... 28-1
29 CERTIFICATE OF QUALIFIED PERSON ..................................................................... 29-1
LIST OF TABLES PAGE
Table 1-1 Mineral Resources - 40% Basis - December 31, 2014 ....................................... 1-2 Table 1-2 Mineral Reserves - 40% Basis - December 31, 2014 ......................................... 1-2 Table 1-3 Cash Flow Summary .......................................................................................... 1-8 Table 1-4 Sensitivity Analyses .......................................................................................... 1-11 Table 1-5 LOM Capital Costs (excludes Pre-stripping) .................................................... 1-18 Table 1-6 LOM (2015-2022) Operating Costs .................................................................. 1-18 Table 4-1 Royalties on Dee Joint Venture .......................................................................... 4-2 Table 6-1 Previous Mineral Resource Estimates (40% basis)............................................ 6-4 Table 6-2 Annual Production from Dee Mine ..................................................................... 6-5 Table 10-1 Drilling Summary ............................................................................................ 10-1 Table 11-1 Drilling QA/QC Sampling Summary –2013-2014 ........................................... 11-4 Table 11-2 Standard Reference Samples ........................................................................ 11-5 Table 11-3 Twinned Holes of Interest ............................................................................... 11-7 Table 13-1 Metallurgical Sample Distribution ................................................................... 13-2 Table 14-1 Summary of Mineral Resources (40% - PREMIER) – December 31, 2014 .. 14-2 Table 14-2 Summary of Indicator Grade Thresholds ........................................................ 14-6 Table 14-3 Gold and Silver Grade Caps .......................................................................... 14-6 Table 14-4 Summary of Composite Weights .................................................................... 14-8 Table 14-5 Density Values by Rock Type......................................................................... 14-9
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Premier Gold Mines Limited – South Arturo Mine, Project #2499
Technical Report NI 43-101 – July 15, 2015 Page iv
Table 14-6 Comparison of composite and block grades ................................................ 14-12 Table 15-1 Mineral Reserves (100%) - December 31, 2014 ............................................ 15-1 Table 15-2 Mineral Reserves (40% Premier) - December 31, 2014 ................................. 15-2 Table 15-3 Whittle and Block Value Input Parameter Summary ...................................... 15-5 Table 15-4 Effective Recoveries at Cut-off Grade ............................................................ 15-7 Table 15-5 Cut-off Grade Summary ................................................................................. 15-7 Table 16-1 Pit Design Parameters and Dimensions Summary ........................................ 16-1 Table 16-2 Button Hill PIt Slope Recommendations ......................................................... 16-7 Table 16-3 Waste Rock Disposal Facility Material Properties .......................................... 16-9 Table 16-4 Life of Mine – Mine Production ..................................................................... 16-10 Table 16-5 Mining Equipment ......................................................................................... 16-11 Table 20-1 Major Permits and Approvals ......................................................................... 20-3 Table 21-1 LOM Sustaining Capital Costs (2015-2017) ................................................... 21-1 Table 21-2 LOM (2015-2022) Operating Costs ................................................................ 21-2 Table 21-3 LOM (2015-2017) Manpower ......................................................................... 21-2 Table 22-1 Cash Flow Summary ...................................................................................... 22-3 Table 22-2 Sensitivity Analyses ........................................................................................ 22-6
LIST OF FIGURES PAGE
Figure 1-1 Sensitivity Analysis .......................................................................................... 1-10 Figure 4-1 Location Map ..................................................................................................... 4-3 Figure 4-2 Claim Map ......................................................................................................... 4-4 Figure 7-1 Regional Geology .............................................................................................. 7-2 Figure 7-2 Property Geology .............................................................................................. 7-5 Figure 10-1 Drill Hole Location Map ................................................................................. 10-3 Figure 11-1 Locations of Twinned Drill Holes ................................................................... 11-8 Figure 11-2 RC vs. Core Twinned Hole Comparisons ...................................................... 11-9 Figure 13-1 Sample Distribution for Column Leach Tests ................................................ 13-3 Figure 13-2 Sample Distribution for CIL and Roaster Tests ............................................. 13-4 Figure 13-3 Sample Distribution for Dee Bottle Roll Tests ............................................... 13-5 Figure 13-4 Crushed Ore Heap Leach Gold Recovery Data ............................................ 13-7 Figure 13-5 CIL Gold Recovery Data ............................................................................... 13-8 Figure 13-6 Roaster Gold Recovery Data ........................................................................ 13-9 Figure 14-1 Search Domains Used in Grade Interpolation ............................................... 14-4 Figure 14-2 Comparison of Block and Composite Gold Grades at South Arturo ........... 14-13 Figure 14-3 Block Classification ..................................................................................... 14-14 Figure 15-1 West Button Hill Ultimate Pit ......................................................................... 15-3 Figure 17-1 ROM Heap Leach Process Flowsheet .......................................................... 17-3 Figure 17-2 Oxide Ore Treatment - Cortez ....................................................................... 17-4 Figure 17-3 Barrick Goldstrike Roaster Process Flowsheet ............................................. 17-5 Figure 17-4 Barrick Goldstrike Pressure Oxidation - TCM Leach FlowSheet ................... 17-6 Figure 18-1 Site Layout and Utilities ................................................................................. 18-4 Figure 22-1 Sensitivity Analysis ........................................................................................ 22-5
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-1
1 SUMMARY EXECUTIVE SUMMARY
Roscoe Postle Associates Inc. (RPA) was retained by Premier Gold Mines Limited (Premier)
to prepare an independent Technical Report on the South Arturo Mine (South Arturo or the
Mine), in Elko County, Nevada, USA. The purpose of this report is to support public disclosure
of Mineral Resources and Mineral Reserves at South Arturo as of December 31, 2014. This
Technical Report conforms to NI 43-101 Standards of Disclosure for Mineral Projects. RPA
visited the operations on June 24, 2015.
Premier Gold Mines is a Canadian publicly-traded mining company with a portfolio of
exploration, development, and operating mines and projects across North America. The South
Arturo Operations are located in northeastern Nevada approximately 48 km northwest of
Carlin, Nevada, and 4.8 km northwest of Barrick Gold Corporation’s (Barrick) Goldstrike
operation. The South Arturo Mine contains the historical Dee pit that produced approximately
605,000 ounces of gold in the 1980s and 1990s.
The South Arturo Mine is a joint venture between Barrick’s wholly-owned subsidiary Barrick
Gold Exploration Inc. (60%) and Premier (40%). Mineralization is found throughout the South
Arturo Mine area, however, Mineral Reserves are confined to the West Button Hill area.
Current infrastructure includes an open pit mine, waste rock storage facilities, roads, a 120 kV
powerline with substation, vertical dewatering wells, explosive storage facilities, and main gate.
The open pit is a large-scale operation utilizing a conventional truck and shovel fleet and mining
approximately 130,000 tonnes per day (tpd) of ore and waste. Oxide ore will be treated at an
oxide mill at Barrick’s Cortez site and the refractory ore will be treated at Barrick’s Goldstrike
operation. Heap leach mineralization will be stockpiled at the South Arturo site for future
processing.
Table 1-1 summarizes the South Arturo Mineral Resources as of December 31, 2014.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-2
TABLE 1-1 MINERAL RESOURCES - 40% BASIS - DECEMBER 31, 2014 Premier Gold Mines Limited – South Arturo Mine
Category Tonnes Grade Contained Gold Grade Contained Silver
(000 t) (g/t Au) (000 oz) (g/t Ag) (000 oz) Measured 3.4 2.69 0.3 9.19 1.0 Indicated 19,128 1.35 831 7.05 4,337 Measured + Indicated 19,132 1.35 831 7.05 4,338 Inferred 3,866 0.68 84 3.46 430
Notes:
1. CIM definitions were followed for Mineral Resources. 2. Mineral Resources are estimated using a long-term gold price of US$1,400 per ounce, a long term silver
price of US$19, and a C$/US$ exchange rate of 1.10. 3. Mineral Resources are reported using cut-off grades of 0.79 g/t Au, 1.20 g/t Au, and 1.89 g/t Au for the
oxide mill, refractory roaster and total carbonaceous material (TCM), respectively, and a grade range from 0.14 g/t Au to 0.79 g/t Au for heap leach material.
4. Mineral Resources represent attributable ounces to Premier, equal to 40% of the Joint Venture controlled ounces. Material from the Rossi property has been excluded.
5. Bulk density is specific to geological formation and varies from 2.00 t/m3 to 2.67 t/m3. 6. Mineral Resources are exclusive of Mineral Reserves. 7. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. 8. Numbers may not add due to rounding.
Table 1-2 summarizes Premier’s 40% portion of the South Arturo Mineral Reserves as of
December 31, 2014.
TABLE 1-2 MINERAL RESERVES - 40% BASIS - DECEMBER 31, 2014 Premier Gold Mines Limited - South Arturo Mine
Category/ Process
Type
Tonnes Gold Grade
Contained Gold
Silver Grade
Contained Silver
(000 t) (g/t Au) (000 oz) (g/t Ag) (000 oz) Probable Reserves ROM Leach 309 0.74 7 3.39 34 Mill Oxide 184 2.48 15 11.23 60 TCM 128 10.09 42 11.83 44 Roaster 519 5.86 98 6.90 104 Total 1,141 4.40 161 6.62 243
Notes:
1. Mineral Reserves estimated according to CIM definitions. 2. Stockpile reserves include open pit material. 3. Mineral Reserves estimated at $1,100/oz Au and $17/oz Ag. 4. Silver ounces are reported in the Barrick LOM cash flow, but only represent 3.8% of gross revenue. 5. Cut-off grades are incorporated into the net block value calculation, which was used to determine the
processing method for each block. 6. ROM – run of mine; TCM – total carbonaceous material
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-3
CONCLUSIONS Based on the site visit and subsequent review, RPA offers the following conclusions:
GEOLOGY AND MINERAL RESOURCES
• The South Arturo deposits are Carlin-type deposits located in the north end of the Carlin Trend.
• The drilling, sampling, sample preparation, analyses, security, and data verification meet or exceed industry standards and are appropriate for Mineral Resource estimation.
• The parameters, assumptions, and methodology used for Mineral Resource estimation are appropriate for the style of mineralization.
• Mineral Resources, at December 31, 2014, for the South Arturo Mine, exclusive of Mineral Reserves and adjusted to reflect 40% ownership by Premier, include Measured and Indicated Resources of 19.1 million tonnes, grading 1.35 g/t Au and 7.05 g/t Ag, containing 831,000 ounces of gold and 4,338,000 ounces of silver. Inferred Resources total 3.9 million tonnes grading 0.68 g/t Au and 3.46 g/t Ag, containing 80,000 oz of gold and 430,000 oz of silver.
• The current drill hole database is reasonable for supporting a resource model for use in Mineral Resource and Mineral Reserve estimation.
• Mineral Resource estimates have been prepared using acceptable interpolation strategies. The classification of Measured, Indicated, and Inferred Resources conform to Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves dated May 10, 2014 (CIM definitions). Restricting the Measured component of the Mineral Resource to those blocks directly intersected by drill holes is considered by RPA to be conservative, and not practical for mine design purposes.
• Gold and silver grades are not overly smoothed in higher grade areas. MINERAL RESERVES AND MINING
• The South Arturo Mine is located less than five kilometres from Barrick’s Goldstrike operation.
• Mining is by open pit at 130,000 tpd ore and waste.
• All Barrick Goldstrike systems (safety, geological control, mining, processing, administration, environmental) have been implemented for mining at South Arturo and they are operating efficiently.
• Mineral Reserves are restricted to the West Button Hill area.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-4
• Probable Mineral Reserves for the South Arturo Mine, adjusted to reflect Premier’s 40% basis, as of December 31, 2014, total 1.14 million tonnes grading 4.40 g/t Au and 6.62 g/t Ag, containing 161,000 oz of gold and 243,000 oz of silver, respectively.
• Mining of the West Button Hill area began on March 26, 2015, and the Mine’s current mine life is estimated to be less than three years (2015-2017).
MINERAL PROCESSING AND METALLURGICAL TESTING
• Ore will be processed via one of four routes: o Carbon-in-leach (CIL) milling at Cortez for the oxide ores o Roasting and CIL at Goldstrike o Pressure Oxidation (POX) and total carbonaceous material (TCM) leach at
Goldstrike o Stockpiling and future run-of-mine (ROM) heap leaching at South Arturo
• Ore trucks hauling refractory ore from Barrick’s Cortez operation to Goldstrike will be
used to backhaul oxide mill material to Cortez.
• Historical operating data from the Dee mine and the recent metallurgical test work indicate that the ore is amenable to processing. Processing of siliceous, carbonaceous, and sulphidic materials that are extracted from new deposits and deeper areas of existing deposits may not result in metallurgical responses that are similar to historical operations.
• The metallurgical test results determined the following: o Sulphide ore and ore containing preg-robbing organic carbon above the target
cut-off gold grade would be roasted. o Oxide ore above the target cut-off gold grade would be processed via ROM
heap leach. o Ore containing preg-robbing organic carbon below the cut-off grade gold grade
for roasting will be considered waste.
• The mill recovery ranges from 48% to 79% depending on the process employed. Recovery may be higher than predicted if the ore is ground finer than 74 µm in size. A gold deportment study completed by AMTEL Ltd. (AMTEL) and metallurgical test results indicated that a large portion of the gold is most likely encapsulated in silica, therefore, finer grinding could assist with improved gold liberation.
• The heap leach recovery and relationships between particle sizes and recovery may be different from the estimates because the samples tested are not in the same area of the mineralization that will be processed on the heap leach pads.
• Additional sampling and column leach tests of material from the West Button Hill deposit would provide additional metallurgical data for analysis.
ENVIRONMENTAL CONSIDERATIONS
• During the mining operations the Mine will undertake concurrent reclamation on inactive portions of the waste rock facility.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-5
• Cultural sites were identified near the proposed mine area. The necessary mitigation was completed and approved prior to issuance of the Record of Decision.
• It is expected that the two major, long-term environmental liabilities that will impact on the Mine are the mitigation of damage to cultural sites within planned, disturbed areas and the presence of a pit lake that will be created from passive water inflow after the dewatering pumps are removed.
• Approximately 343 ha of disturbance will be created within the permit boundary for waste storage facilities and a heap leach pad.
• It is recognized that proper construction, operation, and closure techniques should minimize the long-term environmental liability.
RECOMMENDATIONS RPA makes the following recommendations:
GEOLOGY AND MINERAL RESOURCES
• Investigate the use of traditional grade wireframes and mineralization trend surfaces in favour of indicator grade domains and search domains in future resource model updates.
• Grade capping at South Arturo has been performed appropriately, and could be further improved by considering grade caps by grade domain in addition to search domain.
• Collect additional density samples and incorporate into the Mineral Resource model.
• Develop a classification script based on drill hole spacing and geological confidence for the property to prevent the loss of Measured Resources during reblocking.
MINERAL RESERVES AND MINING
• Create an overall Mine development schedule for tracking all of the significant South Arturo milestones.
• Closely monitor the controlled blasting and begin implementing a highwall slope monitoring program in the Carlin Formation.
• Investigate the use of blast movement monitoring for accurately locating the post blast location of all ore and waste material types.
MINERAL PROCESSING AND METALLURGICAL TESTING
• Representative samples of each ore type should be collected and confirmatory test work conducted using these samples to ensure that the gold and silver recovery and anticipated operating costs are accurate. Particular emphasis should be placed on a range of gold and silver head grades for each of the ore types to be processed and test work at a range of particle sizes for both heap leaching and CIL processing.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-6
• After additional metallurgical data is available, appropriate trade-off studies should be completed in order to determine the optimum processing alternatives under changes in gold and silver prices.
ENVIRONMENTAL CONSIDERATIONS
• Monitor sites to effectively manage potential environmental and geochemical issues.
ECONOMIC ANALYSIS
A Cash Flow Projection has been generated from the Life of Mine production schedule and
capital and operating cost estimates, and is summarized in Table 1-3. This cash flow is based
on revenue and costs for the Mine on a 100% basis. A summary of the key criteria is provided
below.
ECONOMIC CRITERIA REVENUE
• 130,000 tonnes per day mining of ore and waste from the West Button Hill pit only.
• Mill recovery by zone, as indicated by testwork, averaging 86.1%.
• Reduction in ounces for gold entrained in mill circuit.
• Gold at refinery 99.965% payable.
• Silver revenue was not included, and it is assumed to be non-material to the cash flow.
• Metal price: US$1,250 per ounce gold, except for 2015 that used US$1,200 per ounce gold.
• Revenue from 353,000 tonnes of lower-grade, stockpiled oxide mill ore was assumed to be realized in 2020.
• Heap leach mineralization revenue was assumed to be realized in 2022; this material is being stockpiled for future processing.
• Net Smelter Return includes doré refining, transport, and insurance costs.
• Revenue is recognized at the time of production.
COSTS
• Pre-production period: none, mining was initiated on March 26, 2015.
• Mine life: less than three years (2015 to 2017).
• Life of Mine production plan as summarized in Table 1-3.
• Mine life capital totals US$213 million.
• Capital cost contingency estimated to be 10%, which excludes capitalized pre-stripping.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-7
• Costs from 353,000 tonnes of lower-grade, stockpiled oxide mill ore was assumed to be realized in 2020.
• Heap leach ore will not be processed during the first three years of mining, however, it will be stockpiled. RPA assumed a processing date of 2022 in the cash flow.
• Average operating cost over the mine life is $29.87 per tonne milled.
• All In Sustaining Cost (AISC) is US$950/oz.
TAXATION AND ROYALTIES Nevada Net Proceeds tax was applied to the cash flow. An average royalty of 4.9% was
applied to the Gross Revenue. RPA relied on Premier for the taxes applied to the Mine.
CASH FLOW ANALYSIS Considering the Project on a stand-alone basis, the undiscounted pre-tax cash flow totals $84
million over the mine life, and simple payback occurs approximately 2.5 years from start of
production.
The World Gold Council Adjusted Operating Cost (AOC) is US$316 per ounce of gold. The
mine life capital cost, including both pre-production and sustaining unit cost, is US$634 per
ounce, for an AISC of US$950 per ounce of gold. Average annual gold production during mine
operation (2015-2017) is approximately 104,000 ounces on a 100% basis.
The after-tax Net Present Value (NPV) at a 5% discount rate is $25 million, and the Internal
Rate of Return (IRR) is 12.5%.
A summary of the cash flow analysis is presented in Table 1-3.
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INPUTS UNITS TOTAL 2015 2016 2017 2018 2019 2020 2021 2022 2023MININGOpen Pit
Mine Operating Days 365 days 746 281 365 100Stacking Operating Days days - - - -Leaching Operating Days days - - - -Tonnes moved per day tonnes / day 130,418 195,884 101,583 51,705
'000 tonnes 2,853 240 809 1,803g/t 4.40 0.92 2.34 5.79
'000 tonnes 3,367 - - 3,367'000 tonnes 91,072 54,804 36,269 -'000 tonnes 97,292 55,043 37,078 5,171
ProductionAu GradeWasteWaste - CapitalizedTotal MovedStripping Ratio 33.1 228.4 44.8 1.9
Total Production'000 tonnes 2,853 240 809 1,803Total Tonnes Mined
Average Grade Au g/t 4.40 0.92 2.34 5.79
PROCESSING
'000 tonnes 321 - 50 270oz 104,002 - 10,209 93,794oz 92,873 - 8,984 83,889
g/t Au 10.09 - 6.293 10.798% 89.3% 0.0% 88.0% 89.4%
10.21 93.80'000 tonnes 1,298 2 265 1,031
oz 244,656 829 34,616 209,211oz 209,357 740 28,221 180,396
g/t Au 5.86 12.137 4.066 6.312% 85.6% 89.3% 81.5% 86.2%
'000 tonnes 461 - 36 72 353oz 36,738 - 5,455 10,248 21,035oz 24,673 - 4,281 6,680 13,712
g/t Au 2.48 - 4.711 4.406 1.853% 67.2% 0.0% 78.5% 65.2% 65.2%
'000 tonnes 773 - - - 773oz 18,300 - - - 18,300oz 8,378 - - - 8,378
g/t Au 0.74 - - - 0.737% 45.8% 0.0% 0.0% 0.0% 45.8%
'000 tonnes 2,853 2 351 1,373 353 773oz 403,696 829 50,280 313,253 21,035 18,300oz 335,282 740 41,486 270,965 13,712 8,378
g/t Au 4.40 12.137 4.452 7.094 1.853 0.737
AutoclaveTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery RateRoasterTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery RateMillTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery RateLeachTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery RateTotalTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery Rate % 83.1% 89.3% 82.5% 86.6% 65.0% 45.8%
REVENUEMetal Prices Input UnitsAu 1,250$ US$/oz Au $1,250 $1,200 $1,250 $1,250 $1,250 $1,250 $1,250 $1,250 $1,250 $1,250Total Contained Revenue US$ '000 $419,065 $888 $51,858 $338,707 $0 $0 $17,140 $0 $10,472 $0Total Payable Revenue 99.97% US$ '000 $418,918 $888 $51,840 $338,588 $0 $0 $17,134 $0 $10,469 $0
Transport $0.000 US$/oz Au US$ '000 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Refining cost $0.583 US$/oz Au US$ '000 $195 $0 $24 $158 $0 $0 $8 $0 $5 $0Treatment $0.000 US$/oz Au US$ '000 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Total Charges US$ '000 $195 $0 $24 $158 $0 $0 $8 $0 $5 $0Net Smelter Return US$ '000 $418,723 $887 $51,815 $338,430 $0 $0 $17,126 $0 $10,464 $0Nevada Net Proceeds US$ '000 $16,675 $20 $1,916 $13,718 $0 $0 $598 $0 $424 $0Royalty NSR Input Rate Into US$ '000 $20,515 $43 $2,539 $16,581 $0 $0 $839 $0 $513 $0Net Revenue US$ '000 $381,533 $824 $47,361 $308,132 $0 $0 $15,690 $0 $9,527 $0Unit NSR US$/t milled $1,190 $388 $135 $224 $0 $0 $44 $0 $12 $0
TABLE 1-3 CASH FLOW SUMMARY Premier Gold Mines Limited - South Arturo Mine
Prem
ier Go
ld M
ines L
imited
– So
uth
Artu
ro P
roject, P
roject #2499
Tech
nical R
epo
rt NI 43-101 – Ju
ly 15, 2015 P
age 1-9
INPUTS UNITS TOTAL 2015 2016 2017 2018 2019 2020 2021 2022 2023OPERATING COST
US$/t moved $ 2.99 $ 1.69 $ 1.69 $ 3.25 $ 3.25 $ 3.25 $ 3.25 $ 3.25 $ 3.253.25 $Mining CostProcessing 23.36$
59.91US$/t Autoclave $ $0.00 $59.89 $59.91 $59.91 $59.91 $59.91 $59.91 $59.91 $59.91US$/t Roaster 29.91$ $36.76 $32.52 $29.15 $29.15 $29.15 $29.15 $29.15 $29.15 $29.15US$/t milled 3.23$ $0.00 $13.96 $14.22 $14.22 $14.66 $14.66 $14.66 $14.22 $14.22
AutoclaveRoasterMillLeach US$/t Leach 2.57$ $2.57 $2.57 $2.57 $2.57 $2.57 $2.57 $2.57 $2.57 $2.57
US$/t milled -$ $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00G&ATotal Unit Operating Cost US$/t milled 29.87$ $227 $38 $47 $0 $0 $15 $0 $3 $0
Mining Cost US$ '000 $18,583 $405 $1,365 $16,814 $0 $0 $0 $0 $0 $0Processing US$ '000 $66,636 $78 $12,135 $47,263 $0 $0 $5,175 $0 $1,985 $0
Autoclave US$ '000 $19,209 $0 $3,022 $16,187 $0 $0 $0 $0 $0 $0Roaster US$ '000 $38,736 $78 $8,610 $30,047 $0 $0 $0 $0 $0 $0Mill US$ '000 $6,707 $0 $503 $1,029 $0 $0 $5,175 $0 $0 $0Leach US$ '000 $1,985 $0 $0 $0 $0 $0 $0 $0 $1,985 $0
G&A US$ '000 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Total Operating Cost US$ '000 $85,219 $483 $13,500 $64,076 $0 $0 $5,175 $0 $1,985 $0
Operating Cashflow US$ '000 $296,314 $341 $33,861 $244,055 $0 $0 $10,514 $0 $7,542 $0
CAPITAL COSTDirect Cost
US$ '000 $153,596 $ 92,428 $ -61,168 $US$ '000 $29,334 $22,054 $4,062 $3,218US$ '000 $13,727 $0 $550 $12,868 $309 $0US$ '000 $3,137 $1,637 $1,000 $500
Capitalized StrippingMiningProcessingInfrastructureInfill Drilling & Condemnation Drilling US$ '000 $5,123 $973 $2,000 $2,150
Total Direct Cost US$ '000 $204,917 $117,092 $68,780 $18,736 $0 $0 $0 $0 $309 $010% US$ '000 $5,132 $2,466 $761 $1,874 $0 $0 $0 $0 $30.91 $0.00Contingency (Stripping not included)
Initial Capital Cost US$ '000 $210,049 $119,558 $69,541 $20,610 $0 $0 $0 $0 $340 $0US$ '000 $0US$ '000 $2,602 $ 551 $ 569 $ 587 $ 289 606 $
SustainingReclamation and ClosureWorking Captial US$ '000 $0 $2,422 $4,897 $21,751 -$24,909 $17 $1,140 -$5,318 $4,952 -$4,952
Total Capital Cost US$ '000 $212,651 $122,531 $75,008 $42,948 -$24,303 $306 $1,140 -$5,318 $5,292 -$4,952
PRE-TAX CASH FLOWUS$ '000 $83,663 ($ 122,190) ($ 41,146) $ 201,107 $ 24,303 ($ 306) $ 9,374 $ 5,318 $ 2,250 $ 4,952US$ '000 ($ 122,190) ($ 163,337) $ 37,771 $ 62,074 $ 61,768 $ 71,142 $ 76,461 $ 78,711 $ 83,663US$ '000 $35,118 $ 0 $ 3,968 $ 29,813 $ 0 $ 0 $ 529 $ 0 $ 808 $ 0US$ '000 $48,545 ($ 122,190) ($ 45,114) $ 171,294 $ 24,303 ($ 306) $ 8,845 $ 5,318 $ 1,442 $ 4,952
Net Pre-Tax CashflowCumulative Pre-Tax Cashflow
TaxesAfter-Tax CashflowCumulative After-Tax Cashflow US$ '000 ($ 122,190) ($ 167,305) $ 3,990 $ 28,293 $ 27,987 $ 36,832 $ 42,150 $ 43,592 $ 48,545
Total Cash Cost US$/oz $316 $712 $387 $298 $0 $0 $439 $0 $299 $0Capital Cost US$/oz $634Total Production Cost US$/oz $950
PROJECT ECONOMICS% 21.7%
5.00% US$ '000 $55,2767.50% US$ '000 $43,722
Pre-Tax IRRPre-tax NPV at 5.0% discountingPre-tax NPV at 7.5% discountingPre-tax NPV at 10.0% discounting 10.00% US$ '000 $33,588
% 12.5%5.00% US$ '000 $24,9827.50% US$ '000 $15,494
After-Tax IRRAfter-Tax NPV at 5.0% discountingAfter-Tax NPV at 7.5% discountingAfter-tax NPV at 10.0% discounting 10.00% US$ '000 $7,234
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SENSITIVITY ANALYSIS Project risks can be identified in both economic and non-economic terms. Key economic risks
were examined by running cash flow sensitivities:
• Gold price
• Contained gold ounces
• Operating costs
• Capital costs
• Recovery
NPV sensitivity over the base case has been calculated for -20% to +20% variations. The
sensitivities are shown in Figure 1-1 and Table 1-4.
FIGURE 1-1 SENSITIVITY ANALYSIS
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TABLE 1-4 SENSITIVITY ANALYSES Premier Gold Mines Limited – South Arturo Mine
Parameter Variables Units -20% -10% Base 10% 20%
Gold Price US$/oz 1,000 1,125 1,250 1,375 1,500 Contained Au Ounces oz (000) 327 365 404 442 481
Operating Cost US$ millions 68.18 76.70 85.22 93.74 102.26 Capital Cost US$ millions 170 191 213 234 255
Recovery % 71% 76% 80% 85% 90%
Pre-tax NPV @ 5% Units -20% -10% Base 10% 20% Gold Price US$ millions (9.35) 22.96 55.28 87.59 119.91
Contained Au Ounces US$ millions (8.05) 23.61 55.28 86.94 118.61 Operating Cost US$ millions 69.20 62.24 55.28 48.32 41.36
Capital Cost US$ millions 95.18 75.23 55.28 35.32 15.37 Recovery US$ millions 18.00 36.64 55.28 73.91 92.55
TECHNICAL SUMMARY
PROPERTY DESCRIPTION AND LOCATION The Mine is located approximately 48 km northwest of Carlin, Nevada, on federal lands
administered by the U.S. Department of the Interior, Bureau of Land Management (BLM). The
Project includes development of an open pit mine on the former Dee open pit mine site. Barrick
is the manager and operator of the Mine. All resources are on mining claims held on federal
lands.
LAND TENURE The South Arturo mineral deposits occur on the Dee and Rossi properties consisting of
unpatented mining claims owned or controlled by two separate mining ventures, in which
Barrick Gold Exploration Inc., a wholly owned subsidiary of Barrick, has a fully vested 60%
participating interest. The Barrick/Premier Venture, the previous joint venture between Barrick
and Goldcorp Inc. (Goldcorp), controls the mining claims known as the Dee property and the
Barrick/Barrick Storm Venture (previously known as the Barrick/Meridian Venture) controls the
mining claims known as the Rossi Property. The majority of the resources occur on the Dee
Property.
The Barrick/Premier Venture portions of the South Arturo deposits reside on leased claims and
therefore are subject to royalties. Royalties are paid to Franco Nevada Corporation ranging
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-12
from 4% to 9% of gross proceeds indexed to ore values, daily production rates, ore
characteristics, and other factors.
EXISTING INFRASTRUCTURE The Mine is located on the site of the reclaimed Dee open pit mine. Most site facilities were
removed or reclaimed after cessation of mining activities in the late 1990s, except for the power
and water supply systems.
Power is supplied from Nevada Energy to an existing mine substation. Surface rights are
sufficient for mine waste stockpiles, heap leach pads, and processing plants sites.
HISTORY Exploration work for barite and gold began in the Mine area in 1975. Prospecting exposed
barite in several trenches. Cordex Exploration Company conducted exploration activities in
the area from 1981 to 1983. While no economic barite was identified, two gold deposits were
discovered.
Within the South Arturo Mine area, four major companies, i.e., FMC Gold/Meridian Gold
Corporation (further on referred to as Meridian), Dee Gold Mine/Rayrock Mines Inc. (Dee),
Glamis Gold Ltd. (Glamis), and Barrick, have been primarily responsible for exploration drilling,
geologic mapping, geophysics, and geochemistry that have defined the South Arturo
mineralization. Drilling consisted of a combination of core, mud rotary, and reverse circulation
(RC) methods for a total of approximately 55,000 m.
The Dee open pit mine was put into production by Rayrock in partnership with Dee Gold Mining
Co. (Dee Gold) in 1984. Over 16 years from 1984 to 1999, the Dee mine produced
approximately 605,000 ounces of gold from oxide ore. Underground production started in 1999
and continued until December 2000, when both open pit and underground operations were
shut down and surface facilities were reclaimed.
The South Arturo deposit was discovered by Barrick in July 2005 as a result of drilling beneath
the waste disposal facilities of the Dee open pit mine.
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In 1997, The Barrick Dee Mining Venture (BDMV) was formed when Barrick Gold Exploration
Inc. entered into an exploration agreement with Dee Gold (then a subsidiary of Glamis),
whereby Barrick held 60% and Dee Gold 40%, to explore the Dee mine property outside of the
active mining area. In 1999, Glamis acquired Rayrock, and became the operator of the Dee
mine. In 2007, Glamis was acquired by Marigold Mining Company (Marigold), a wholly owned
subsidiary of Goldcorp. Marigold/Goldcorp is the successor of Dee Gold.
On June 2, 2015, Premier completed its acquisition of Goldcorp's 40% interest in the South
Arturo Mine.
GEOLOGY AND MINERALIZATION The Mine is located within the northern Carlin Trend in the Basin and Range physiographic
province in northeastern Nevada. A sequence of tectonic events have transformed the district
into large scale, north-northwest trending folds and northwest to northeast trending faults,
which expose “windows” of the lower plate rocks within the upper plate. The northern Carlin
Trend is defined by a north-northwest trending alignment of gold deposits in a series of these
windows. The windows in the Carlin Trend from south to north are the Carlin, Lynn, and
Bootstrap. The Mine is located within the Bootstrap Window.
The oldest formation known near the Mine is the Ordovician Hanson Creek dolomite,
intersected in a deep drill hole west of the deposit. A 700 ft thick section of Silurian-Devonian
Roberts Mountains limestone occurs above the Hanson Creek dolomite. The Bootstrap
limestone is a grey, massive limestone deposited in a reef margin environment. The Bootstrap
limestone is overlain by the Devonian Popovich Formation, which is a carbonaceous
limestone. The contact between the Popovich Formation and Bootstrap limestone is
characterized by karst-type dissolution features and brecciation. The upper contact of the
Popovich Formation grades conformably into the Devonian Rodeo Creek Formation. The
Rodeo Creek Formation consists of siliceous mudstone and silty limestone. The top of the
Rodeo Creek is structurally terminated by the Roberts Mountain Thrust and is the top of the
lower Plate sequence.
Upper plate rocks at the Mine consist of a sequence of mudstone, argillite, and bedded cherts
of the Vinini, Elder, and Slaven Chert formations. The Tertiary Carlin Formation, a sequence
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-14
of tuffaceous sedimentary rocks and air-fall tuff, fills channels and depressions in the Dee mine
area.
While mineralization is widespread throughout the South Arturo Mine area, there are five zones
of high-grade gold mineralization, these zones are South Arturo, Dee Deep North, SW Dee,
West Button Hill, and Hinge.
EXPLORATION STATUS Barrick continues to conduct drilling programs to test for possible extensions to the South
Arturo mineralization at depth.
MINERAL RESOURCES The end of year 2014 Mineral Resources are summarized in Table 1-1. The resources were
estimated using a gold price of US$1,400 per ounce, and a silver price of US$19 per ounce.
RPA is of the opinion that the Mineral Resources are acceptable, reasonable, and conform to
CIM definitions.
The Mineral Resource model was prepared mid-year 2014 and is the same as the end of year
2014 model.
Wireframes were constructed to define geological boundaries, in addition to nine search
domains, representing areas of similar grade continuity and orientation. Inverse distance
squared (ID2) was employed to predict areas of low, medium and high grade areas for each
search domain using indicator thresholds specific to each domain. Gold and silver assays
were capped prior to compositing and were interpolated in six nested estimation runs for each
search/grade domain combination, using ID2. Search ellipse orientations and ranges were
defined using variogram models. Soft boundaries were used between search domains, and
weights were assigned to allow some influence of composites across grade domains. Density
was assigned by rock type. Blocks were classified by estimation run, and limited to 90%
(Inferred) and 80% (Indicated) of the variogram range for each search domain and to blocks
directly intersected by a drill hole (Measured).
The Mineral Resource estimate gold cut-off grades range from 0.14 g/t Au for ROM heap leach
material, to 1.89 g/t Au for TCM routed material. Blocks were divided into different material
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-15
types by assigning a revenue based on geology, process route costs, and mining costs for
each option, and optimized for maximum revenue.
MINERAL RESERVES The South Arturo Mineral Reserves stated for December 31, 2014 meet the necessary
Canadian and US requirements to be classified as Mineral Reserves.
On a 40% basis, the Proven and Probable Mineral Reserve estimate as of December 31, 2014
is 1.14 million tonnes grading 4.40 g/t Au and 6.62 g/t Ag containing 161,000 oz of Au and
243,000 oz of Ag (see Table 1-2). Mineral Reserves are for the West Button Hill pit only.
MINING METHOD South Arturo will be run mainly with current Goldstrike employees.
South Arturo is an open pit mine. Mineral Reserves are restricted to the West Button Hill area
where mining began on March 26, 2015. The geotechnical slope stability input for the mine
design was prepared by Piteau Associates Engineering Limited, and the mine design includes
three interconnected pits mined on 12.2 m waste benches and 6.1 m high ore benches.
The current pit highwalls appear to have good rock mass characteristics, and this information
has been incorporated into the open pit mine design. Slope stability situations similar to those
found at the Goldstrike operation may occur, especially in the Carlin Formation.
MINERAL PROCESSING Ore from South Arturo will be processed via one of four routes: ROM heap leaching, milling
and CIL, roasting and CIL, or POX and TCM leaching (previously CaTS, or calcium
thiosulphate leaching). Based on information from the Life of Mine plan, approximately 95%
of the contained gold in South Arturo ore will be processed off-site at the Barrick Cortez CIL
circuit or the Goldstrike TCM circuit or roasting circuit. The remainder of the gold will be
processed by ROM heap leaching on site.
ROM ore will be placed on a permanent leach pad by haul trucks. Cyanide solution will be
distributed by drip emitters. The pregnant solution will then be collected and pumped to a
carbon adsorption circuit. The cyanide concentration and pH of the barren solution will be
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 1-16
adjusted and the solution will be re-circulated via pumping to the heap leach pads. Loaded
carbon will be trucked to the existing autoclave carbon processing circuit for stripping and
refining to recover the precious metals and the carbon will be regenerated prior to being
returned to the carbon adsorption columns at South Arturo for reuse.
The grinding and CIL circuits in the existing circuit at Cortez will be utilized to process the
South Arturo ore on a campaign basis. The treatment plant currently includes crushing, semi-
autogenous grinding (SAG), ball milling, grind thickening, carbon-in-column (CIC) circuit for
the grind thickener overflow solution, CIL circuit, tailings countercurrent decantation (CCD)
wash thickener circuit, carbon stripping and reactivation circuits, and a refinery to produce gold
doré.
Ore that is scheduled for roaster/CIL processing will be toll processed in the existing roaster
circuit at Goldstrike on a campaign basis. The roaster pre-oxidizes ore that contains refractory
carbonaceous and sulphidic material so it can be effectively processed in a traditional CIL
circuit.
Some of the South Arturo ore is characterized as low quality roaster feed with sulphide
concentrations above oxide cut-off grades. It is expected that this material would be amenable
to thiosulphate leaching via the Goldstrike TCM leach process, which represents
approximately 8% of the material mined at South Arturo. Calcium thiosulphate is used to leach
the gold after pressure oxidation rather than using cyanide. Resin is used to collect the
dissolved gold in a resin-in-leach or RIL process rather than using activated carbon.
Metallurgical recovery is based on the existing TCM leach metallurgical testwork and recovery
curves.
PROJECT INFRASTRUCTURE Project infrastructure will include:
• Expansion of the open pit that began on March 26, 2015
• New Waste Rock Disposal Facilities
• Upgrades and widening segments of Bootstrap Haul Road, including light vehicle access, that are nearly complete
• Support facilities, including a communication site that has been installed
• New power transmission lines that have been installed
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MARKET STUDIES The principal commodities of gold and silver at South Arturo are freely traded, at prices that
are widely known, so that prospects for sale of any production are virtually assured. RPA used
a gold price of $1,250 per ounce gold for the Base Case cash flow, except for 2015 where a
gold price of US$1,200 per ounce gold was used.
ENVIRONMENTAL, PERMITTING AND SOCIAL CONSIDERATIONS On May 8, 2014, Barrick received a favourable Record of Decision from BLM to proceed with
the Mine. Even though the South Arturo Mine is on the site of the previously operated Dee
mine, there are no known environmental liabilities. It is important to note that the Dee mine
has been substantially reclaimed.
To date, the most significant environmental impact is the pit lake water quality after the
cessation of mining.
No storage of tailings is required on site since the mill grade ore will be processed off site. All
ore that requires mill processing will be treated at the Barrick Goldstrike or Cortez facilities.
Tailings associated with the roaster circuit are permitted for disposal in the North Block Tailings
Disposal Facility (NBTDF), or for delivery to the Rodeo paste backfill plant.
The mine closure costs have been estimated to total approximately US$2.6 million for the mine
plan from 2015 to 2017. During mining, concurrent reclamation will take place on inactive
portions of the waste rock facility when it is safe and practical. Final reclamation is expected
to be completed during the three-year mine life and one year after the end of mining operations.
CAPITAL AND OPERATING COST ESTIMATES CAPITAL COST
Pre-stripping capital for the period of 2015 to 2017 is estimated to be US$153.4 million.
The sustaining capital costs for the South Arturo Mine are developed and revised on an annual
basis as part of the budget cycle. The total direct capital expenditure in the LOM plan including
pre-stripping is approximately $205 million.
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The 2015 LOM capital plan for sustaining capital to support the LOM as developed at the site
for approval by the Barrick/Premier Venture is shown in Table 1-5.
TABLE 1-5 LOM CAPITAL COSTS (EXCLUDES PRE-STRIPPING) Premier Gold Mines Limited – South Arturo Mine
Capital Cost Totals 2015 2016 2017
US$(000) US$(000) US$(000) US$(000) Mine Capital 24,875 20,945 1,812 2,118 Process Capital 13,418 - 550 12,868 Dewatering Capital 4,459 1,109 2,250 1,100 Condemnation Drilling 973 973 - - Infill Drilling 4,150 - 2,000 2,150 Dee Capital 3,137 1,637 1,000 500 Totals 51,012 24,664 7,612 18,736
OPERATING COSTS The operating costs for South Arturo are developed annually as part of the Goldstrike site
budget process. The total direct operating costs estimated for the South Arturo Mine are
shown in Table 1-6 before inventory adjustments, deferred stripping, silver credits, and
adjustments.
TABLE 1-6 LOM (2015-2022) OPERATING COSTS Premier Gold Mines Limited – South Arturo Mine
Operation Unit 2015 2016 2017 2020 2022
Mining Cost US$/tonne mined 1.69 1.69 3.25 Autoclave US$/tonne processed - 59.89 59.91 Roaster US$/tonne processed 36.76 32.52 29.15 Mill US$/tonne processed - 13.96 14.22 14.66 14.66 Leach US$/tonne processed 2.57 2.57 2.57 2.57 2.57 G&A Included in mining cost
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2 INTRODUCTION Roscoe Postle Associates Inc. (RPA) was retained by Premier Gold Mines Limited (Premier)
to prepare an independent Technical Report on the South Arturo Mine (South Arturo or the
Mine), located in Nevada, U.S.A. The purpose of this report is to support the disclosure of
Mineral Resources and Mineral Reserves. This Technical Report conforms to NI 43-101
Standards of Disclosure for Mineral Projects.
Premier is a Canadian exploration and development company with gold projects in North
America including:
• 40% interest in the South Arturo Mine, Nevada, U.S.A.
• 50% interest in the Trans-Canada Property, Geraldton, Ontario.
• 44% interest in the Rahill-Bonanza Project, Red Lake, Ontario.
• 100% interest in the Hasaga Property, Red Lake, Ontario.
• 100% interest in the McCoy-Cove Project, Nevada, U.S.A.
RPA prepared a previous internal Technical Report on the South Arturo Mine Project in 2012.
SOURCES OF INFORMATION A site visit was carried out by Wayne W. Valliant, P.Geo., RPA Principal Geologist, and Stuart
E. Collins, P.E., RPA Principal Mining Engineer, on June 24, 2015.
Discussions were held with personnel from Barrick Goldstrike Mines Inc.:
• Jeremy Johnson, Open Pit, Technical Services Superintendent
• Katie Marten, Chief Planning Engineer
• Jim Bryar, Chief Geologist
• Kim Starr, Long Range Planning Engineer
• Gerry Griesel, Project Geologist, Drilling
• John Porter, Modeller
• Janna Linebarger, Chief Reserve/Resource Geologist
• Bill Zelinski, Ore Control Geologist
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Mr. Valliant is responsible for Sections 2 through 12, 14, 19, and 23 of this report and
contributed to Sections 1, 24, 25, 26, and 27. Mr. Collins is responsible for Sections 15, 16,
21, and 22 of this report and contributed to Sections 1, 24, 25, 26, and 27. Ms. Brenna Scholey,
P.Eng., RPA Principal Metallurgist, is responsible for Sections 13, 17, and 20 of this report and
contributed to Sections 1, 18, 24, 25, 26, and 27.
The documentation reviewed, and other sources of information, are listed at the end of this
report in Section 27 References.
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LIST OF ABBREVIATIONS
Units of measurement used in this report conform to the metric system unless otherwise
indicated. All currency in this report is US dollars (US$) unless otherwise noted.
a annum kWh kilowatt-hour A ampere L litre bbl barrels lb pound btu British thermal units L/s litres per second °C degree Celsius m metre C$ Canadian dollars M mega (million); molar cal calorie m2 square metre cfm cubic feet per minute m3 cubic metre cm centimetre µ micron cm2 square centimetre MASL metres above sea level d day µg microgram dia diameter m3/h cubic metres per hour dmt dry metric tonne mi mile dwt dead-weight ton min minute °F degree Fahrenheit µm micrometre ft foot mm millimetre ft2 square foot mph miles per hour ft3 cubic foot MVA megavolt-amperes ft/s foot per second MW megawatt g gram MWh megawatt-hour G giga (billion) oz Troy ounce (31.1035g) Gal Imperial gallon oz/st, opt ounce per short ton g/L gram per litre ppb part per billion Gpm Imperial gallons per minute ppm part per million g/t gram per tonne psia pound per square inch absolute gr/ft3 grain per cubic foot psig pound per square inch gauge gr/m3 grain per cubic metre RL relative elevation ha hectare s second hp horsepower st short ton hr hour stpa short ton per year Hz hertz stpd short ton per day in. inch t metric tonne in2 square inch tpa metric tonne per year J joule tpd metric tonne per day k kilo (thousand) US$ United States dollar kcal kilocalorie USg United States gallon kg kilogram USgpm US gallon per minute km kilometre V volt km2 square kilometre W watt km/h kilometre per hour wmt wet metric tonne kPa kilopascal wt% weight percent kVA kilovolt-amperes yd3 cubic yard kW kilowatt yr year
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3 RELIANCE ON OTHER EXPERTS This report has been prepared by RPA for Premier. The information, conclusions, opinions,
and estimates contained herein are based on:
• Information available to RPA at the time of preparation of this report, • Assumptions, conditions, and qualifications as set forth in this report, and • Data, reports, and other information supplied by Premier, Barrick, and other third
party sources.
For the purpose of this report, RPA has relied on ownership information provided by Premier
and Barrick. RPA has not researched property title or mineral rights for the Mine and
expresses no opinion as to the ownership status of the property.
RPA has relied on Premier for guidance on applicable taxes, royalties, and other government
levies or interests, applicable to revenue or income from the Mine.
Except for the purposes legislated under provincial securities laws, any use of this report by
any third party is at that party’s sole risk.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 4-1
4 PROPERTY DESCRIPTION AND LOCATION The Mine is located approximately 48 km northwest of Carlin, Nevada, on federal lands
administered by the U.S. Department of the Interior, Bureau of Land Management (BLM). The
Project comprises development of an open pit mine on the former Dee open pit mine site, in
the vicinity of the past producer, Storm underground mine. Barrick Gold Exploration Inc. is the
manager and operator of the Mine. All resources are on mining claims held on federal lands.
The property location is illustrated in Figure 4-1.
LAND TENURE
The South Arturo mineral deposits occur on the Dee and Rossi properties consisting of
unpatented mining claims owned or controlled by two separate mining ventures, in which
Barrick Gold Exploration Inc., a wholly owned subsidiary of Barrick (together Barrick), has a
fully vested 60% participating interest. The Barrick/Premier Venture, the previous joint venture
between Barrick and Goldcorp Inc. (Goldcorp), controls the mining claims known as the Dee
property and the Barrick/Barrick Storm Venture (previously known as the Barrick/Meridian
Venture) controls the mining claims known as the Rossi property. The majority of the Mineral
Resources occur on the Dee property and only the Dee property Mineral Resources are
included in this report. In 2007, Barrick acquired Meridian Gold Corporation’s (Meridian)
portion of the Barrick/Meridian Venture, which is now held by the Barrick wholly-owned
subsidiary Barrick Storm Inc. and thus is under full Barrick’s control. The claim boundaries are
illustrated in Figure 4-2.
On June 2, 2015, Premier announced that it had completed its acquisition of Goldcorp’s 40%
interest in the South Arturo Project.
Pursuant to the terms of the acquisition, Premier has paid US$20 million, has transferred to
Goldcorp 5% of its interest in the Rahill-Bonanza Joint Venture in Red Lake, and has granted
Goldcorp a right of first refusal for a period of three years on any proposed sale or joint venture
transaction by Premier of Premier's McCoy-Cove Project located in Nevada.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 4-2
In connection with the acquisition, Premier also reimbursed Goldcorp US$16.6 million for costs
and contributions paid by Goldcorp with respect to the South Arturo Mine since March 16,
2015. Goldcorp has agreed to contribute $12.5 million to Premier in a financing to be
completed within the one month period commencing on the closing date of the acquisition.
ROYALTIES
The Barrick/Premier Venture portions of the South Arturo deposits (the Dee Joint Venture)
reside on leased claims and therefore are subject to royalties. Royalties are paid to Franco
Nevada Corporation ranging from 4% to 9% of gross proceeds indexed to ore values, daily
production rates, ore characteristics, and other factors. Table 4-1 lists a range of likely royalties
for the Dee Joint Venture.
TABLE 4-1 ROYALTIES ON DEE JOINT VENTURE Premier Gold Mines Limited – South Arturo Mine
Ore Grade (oz/st) Royalty Percent By Ore Type
From To Oxide Non-Oxide 0.00 0.13 4% 6% 0.13 0.26 6% 6% 0.26 No Limit 9% 6%
From: Barrick, 2009
In order to maintain the lease in good standing, annual advanced royalty payments of
US$200,000 are required and are recoupable against future production royalties.
RPA is not aware of any environmental liabilities on the property. The Barrick/Premier Venture
has all required permits to conduct the proposed work on the property. RPA is not aware of
any other significant factors and risks that may affect access, title, or the right or ability to
perform the proposed work program on the property.
80Pershing
Washoe
Elko
EsmeraldaNye
Mineral
Clark
Eureka
White Pine
Lander
Churchill
Humboldt
Lincoln
Douglas
Lyon
Sto
rey
Wells
Tonopah
Hawthorne
Lovelock
Reno
CARSON CITY
Eureka
Ely
BattleMountain
ElkoWestWendover
Austin
McDermitt
Winnemucca
Carlin
Fallon
Las Vegas
N E V A D A
OREGON
CA
LIF
OR
NIA
CALIFO
RNIA
SOUTH ARTURO MINE
ARTURO
N
Major Highway
Legend:
County Boundary
Road
Town/City
Capital City
UTA
H
IDAHO
AR
IZO
NA
0 25 50 75 10 Miles0
0 50 200 Kilometres150100
N
July 2015
Premier Gold Mines Limited
South MineArturo
Location Map
Elko County State of Nevada, U.S.A.,
Figure 4-1
4-3
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BARRICK / BARRICK STORM
VENTURE
VENTURE
Dee Pit Outline
201924232221
27 26
3
18 17
3331
7
6
30
19
18
7
4
19
15 131416 18
125
8 9 10 11 12
13141516
8 9 10 11 12
1314151617
20 21 22 23 24
252829
32 34 35 36
7
18
19
30
31
6
7
18
T37N R49E
T36N R49E T36N R50E
T37N R50E
Elko
Eureka
BARRICK / DEE
0 2000 4000 6000 800 Feet0
0 500 200 Metres015001000
N
Patented - Private Lands
Legend:
USA - Public Lands
July 2015 Source: Barrick Gold Corporation, 2011.
Premier Gold Mines Limited
South MineArturo
Claim Map
Elko County State of Nevada, U.S.A.,
Figure 4-2
4-4
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 5-1
5 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY ACCESSIBILITY
Regional access from Elko and Reno, Nevada, is provided by Interstate Highway 80. Local
access to the South Arturo Mine is via paved and improved gravel roads. Gravel road access
is available from Barrick’s Goldstrike Mine property, approximately 4.8 km to the southeast.
Access is also available over gravel road from the Dunphy exit on Interstate Highway 80,
approximately 40 km to the south.
CLIMATE
The climate is semi-arid with an annual average precipitation of 255 mm. There are, on
average, 90 frost-free days, and the air temperature ranges from an average of -5oC in January
to an average of 21oC in July, producing a year-round operating climate.
LOCAL RESOURCES
Operating labour and mining services are available from Elko, located 56 km southeast of the
Mine, and several other communities within a 97 km radius.
INFRASTRUCTURE
The Mine is located on the site of the reclaimed Dee open pit mine. Most site facilities were
removed or reclaimed after cessation of mining activities in the late 1990s, except for the power
and water supply systems.
Power is supplied from Nevada Energy to an existing mine substation. Surface rights are
sufficient for mine waste stockpiles, heap leach pads, and processing plants sites.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 5-2
PHYSIOGRAPHY
The Mine is situated within an area of low, broad, northwest-southeast trending ridges. The
elevations in the area range from 1,615 MASL to 1,830 MASL. Within the Mine area, there
are several ephemeral stream drainages. Common vegetation found in the area includes
cheat grass, foxtail chess, mustard grass, shadscale, green rabbitbrush, sagebrush, western
wheatgrass, and sedge.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 6-1
6 HISTORY PRIOR OWNERSHIP
The South Arturo deposit is located on the site of the past producing Dee open pit mine which
was put into production by Rayrock Mines Ltd. (Rayrock) in partnership with Dee Gold Mining
Co. (Dee Gold) in 1984.
In 1997, The Barrick Dee Mining Venture (BDMV) was formed when Barrick entered into an
exploration agreement with Dee Gold (at the time, a subsidiary of Glamis Gold Ltd., or Glamis),
in which Barrick held 60% and Dee Gold held 40%, to explore the Dee mine property outside
of the active mining area. In 1999, Glamis acquired Rayrock and became the operator of the
Dee mine. In October 1999, the Glamis Dee Mining Company began underground production
from the Dee Deep North deposit, which is accessed by a decline from the bottom of the Dee
pit. Both the Dee open pit and the Dee Deep North underground operations were shut down
in December 2000 due to a period of low gold prices. Reclamation and closure activities were
initiated in 2000 on the heap leach pads, tailings disposal facilities, Waste Rock Disposal
Facility (WRDF), and ancillary facilities. At this time, all surface facilities have been reclaimed
except for the power and water supply systems.
In July 2005, drilling by Barrick beneath the dumps of the Dee open pit mine led to the discovery
of the South Arturo deposit. In 2007, Glamis was acquired by Marigold Mining Company
(Marigold), a wholly owned subsidiary of Goldcorp. Marigold/Goldcorp was the successor of
the Dee Gold Mining Company. On June 2, 2015, Premier acquired Goldcorp’s 40% interest
in the South Arturo Mine.
In 2009, the West Button Hill deposit was discovered. The Project consists of these new
discoveries and the remaining resources surrounding the Dee pit.
EXPLORATION AND DEVELOPMENT HISTORY
Exploration along the Carlin Trend has been ongoing since the early 1900s, and it is well
documented.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 6-2
Exploration work for barite and gold began in the Mine area in 1975. Prospecting exposed
barite in several trenches. Cordex Exploration Company conducted exploration activities in
the Mine area from 1981 to 1983. While no economic barite was identified, two gold deposits
were discovered.
Within the South Arturo Mine area, four major companies, i.e., FMC Gold/Meridian (further on
referred to as Meridian), Dee Gold, Glamis, and Barrick, have been primarily responsible for
exploration drilling, geologic mapping, geophysics, and geochemistry that have defined the
South Arturo mineralization. Geologic mapping has occurred via mapping the Dee open pit,
mapping and sampling of 1,200 m of trenches, mapping of nearby barite open pits, and
mapping of the Dee and Storm underground workings. Drilling consisted of a combination of
core, mud rotary, and reverse circulation (RC) methods conducted on the surface, within the
Dee open pit and from within the Storm underground workings.
The South Arturo Mine deposits lie primarily on the Dee Joint Venture side of the property, and
secondarily on the Rossi property. Barrick entered into the Dee Joint Venture in 1997. Barrick
entered into the Rossi Joint Venture in 1998, and acquired the remainder in 2007. Extensive
property-wide exploration had been carried out on both properties since the discovery of the
Dee deposit in 1981. These exploration activities included several generations of drill testing,
geologic mapping, geophysics, and geochemistry.
Barrick’s exploration activity since the inception of the Dee and Rossi Joint Ventures has
included:
• Re-evaluation and assembling pertinent data from both properties into a combined data set.
• Property wide detailed geologic mapping at a scale of 1:2400.
• Geologic mapping of the Dee open pit at a scale of 1:1200.
• Geologic mapping at 1:600 and sampling of approximately 12,000 m of trenches.
• Geologic mapping at 1:1200 and sampling the Queen and Sagehen Barite open pits.
• Geologic mapping of the Dee and Storm underground workings at 1:240.
• Acquisition and evaluation of 210 line km of magnetotelluric and Induced Polarization (MT/IP) data (property wide survey) on lines spaced 300 m apart.
• Acquisition and evaluation of 140 line km of ground magnetics.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 6-3
• Acquisition and evaluation of 27 line km of Controlled Source Audio-frequency Magnetotelluric (CSAMT) data, a frequency-based electromagnetic sounding geophysical survey technique that uses a remote synchronous signal source.
• Collection of 1,035 gravity stations on a 150 m x 150 m survey.
• Collection and analysis of more than 2,500 soil samples on various grid spacings.
• Completion of a 3D Vulcan/Geocad property wide geologic model.
• Reprocessing and detailed Geophysical analysis of property wide geophysical data.
• Detailed geochemical analysis of property wide geochemical data.
• More than 91,000 m of combined RC, mud rotary, and core drilling.
A description of the drilling programs is included in Section 10 Drilling.
HISTORICAL RESOURCE ESTIMATES
Table 6-1 summarizes the Mineral Resource estimates for the South Arturo Mine prepared by
Barrick from 2009 to 2013 exclusive of Mineral Reserves. The Mineral Resources are
expressed as 40% of the total, i.e., Premier’s share. The Mineral Resources in Table 6-1
should be considered relevant as they were prepared using Canadian Institute of Mining,
Metallurgy and Petroleum (CIM) definitions and guidelines. RPA notes, however, that they
should not be relied upon as they were prepared using operating costs and metal price
parameters for cut-off grades that are not current.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 6-4
TABLE 6-1 PREVIOUS MINERAL RESOURCE ESTIMATES (40% BASIS) Premier Gold Mines Limited - South Arturo Mine
Year Category Tonnes Grade Cont. Au Gold Price
(Mt) (g/t Au) (oz 000s) (US$/oz) 2009 Indicated 2.1 1.65 108 900
Inferred 0.5 1.54 24
2010 Indicated 9.7 1.47 461 1,200 Inferred 4.2 0.62 84
2011 Indicated 13.0 1.34 552 1,400 Inferred 6.4 0.79 157
2012 Indicated 9.9 1.54 487 1,650 Inferred 17.0 0.51 281
2013 Indicated 19.7 1.51 959 1,500 Inferred 9.4 0.48 147
PAST PRODUCTION
Over 16 years, the Dee mine produced approximately 605,000 ounces of gold from oxide ore.
Annual production from 1984 to 1999, when the Dee mine was shut down, is shown in Table
6-2.
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TABLE 6-2 ANNUAL PRODUCTION FROM DEE MINE Premier Gold Mines Limited - South Arturo Mine
Year Mill
(oz) Heap Leach
(oz) Total Gold
(oz) 1984 6,388 0 6,388 1985 42,613 7,019 49,632 1986 43,351 7,682 51,033 1987 43,657 9,377 53,034 1988 43,698 6,090 49,788 1989 35,193 10,467 45,660 1990 37,035 11,029 48,064 1991 37,058 4,988 42,046 1992 29,900 8,918 38,818 1993 6,568 19,204 25,772 1994 9,093 16,541 25,634 1995 28,829 14,954 43,782 1996 28,829 9,789 38,618 1997 33,977 5,655 39,632 1998 25,070 3,453 28,523 1999 17,224 841 18,065 Total 468,482 136,006 604,488
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 7-1
7 GEOLOGICAL SETTING AND MINERALIZATION REGIONAL GEOLOGY
The South Arturo Mine is located within the northern Carlin Trend in the Basin and Range
physiographic province in northeastern Nevada (Figure 7-1). Late Devonian-Mississippian
continental arc collision (Antler Orogeny) juxtaposed a siliceous deep-water assemblage over
the favourable shelf and slope facies carbonate assemblage. A sequence of compressional,
and later extensional, tectonic events have transformed the district into large scale, north-
northwest trending folds, and northwest to northeast trending faults, which expose “windows”
of the lower plate rocks within the upper plate. The northern Carlin Trend is defined by a north-
northwest trending alignment of gold deposits in a series of these windows. The windows in
the Carlin Trend from south to north are the Carlin, Lynn, and Bootstrap. The South Arturo
Mine is located within the Bootstrap Window.
Igneous activity along the Carlin Trend has occurred periodically from the Jurassic through the
Tertiary with the emplacement of medium size diorite stocks, diorite, dacite, and lamprophyre
dikes and sills, and a very large deep-seated intrusion at Mary’s Mountain. A two mile wide
northwest trending lamprophyre dike swarm defines the overall axis of the Carlin Trend.
Carlin Trend
Quaternary-Tertiary Cover
Mesozoic Intrusive Rocks
Tertiary Volcanics Undifferentiated
Mesozoic Sediments
Mesozoic Volcanics
Tertiary Intrusive Rocks
Paleozoic Overlap AssemblageSediment
Paleozoic Western AssemblageSedimentsSiliceous
Gold Deposits
Paleozoic Eastern AssemblageSedimentsCarbonate
0 1 2 3 Miles
0 4 Kilometres1 2 3
N
Source: Barrick Gold Corporation, 201 .5July 2015
Premier Gold Mines Limited
South MineArturo
Regional Geology
State of Nevada, U.S.A.
Figure 7-1
7-2
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 7-3
LOCAL AND PROPERTY GEOLOGY
In general, the South Arturo deposits are sediment- and intrusive-hosted gold and silver
deposits hosted mainly in silicified breccias. Oxide gold mineralization in the existing Dee pit
mine area is structurally controlled, dominantly paralleling the north-south striking Dee Fault
Zone. Gold was emplaced simultaneous to several pulses of silica alteration, which converted
mineralized wall rocks into massive silica or silica breccia. Enriched zones are found where
the Dee Fault Zone intersects northwest trending faults. Minor gold mineralization can be
traced along northwest, northeast, and east-west structures trending away from the Dee Fault
Zone.
The oldest formation known near the South Arturo Mine is the Ordovician Hanson Creek
dolomite, intersected in a deep drill hole west of the deposit. A 215 m thick section of the
Silurian-Devonian Roberts Mountains limestone occurs above the Hanson Creek dolomite.
There is a gradational contact between the Roberts Mountains Formation and the overlying
Silurian-Devonian Bootstrap limestone. The Bootstrap limestone is a grey, massive limestone
deposited in a reef margin environment. The thickness of the Bootstrap limestone ranges from
less than 60 m to more than 120 m along a north-northwest trend. West of the reef margin is
a full section of Devonian Popovich Formation slope-facies carbonates. East of the reef
margin, the Popovich carbonates thin to less than 30 m above the Bootstrap limestone. The
upper contact of the Popovich Formation grades conformably into the Devonian Rodeo Creek
siliceous argillite and mudstone sequence, which ranges in thickness from 60 m to 750 m north
of the Mine. The stratigraphic section west of the Mine is consistent with the type sections
described by Newmont Mining Corporation (Newmont) at Bootstrap/Capstone/Tara and with
the Popovich section described by Barrick at Rodeo/Goldstrike. The stratigraphic section east
of the Mine is consistent with the type section described by Barrick at Meikle (Barrick, 2009).
Upper plate rocks at the South Arturo Mine consist of a sequence of mudstone, argillite, and
bedded cherts of the Vinini, Elder, and Slaven Chert formations. The Tertiary Carlin Formation,
a sequence of tuffaceous sedimentary rocks and air-fall tuff, fills channels and depressions in
the Dee mine area.
At least three generations of dikes occur at South Arturo. The most notable zone is a 2.5 km
wide northwest trending lamprophyre dike swarm that includes the Jurassic Arturo dike. Other,
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 7-4
possibly Tertiary, intrusive rocks include a quartz-bearing biotite dacite dike in the Dee Fault
and an andesite dike along the northeast Flower structure.
North-south striking Basin and Range faulting is prominent throughout the deposit. The Dee
Fault Zone controls mineralization in the Dee area. Northeast and northwest striking faults act
as secondary controls on mineralization. The Hinge fault controls mineralization in the Hinge
zone; West Button Hill mineralization is coincident with the modelled BW1 fault.
Ovsc
Tc
Co
Tc
DSrmDpCo Tc
Tc
Deep
NorthWest
Button
Hill
Hinge
South
Arturo
Southwest
Dee
Plan of Operations Boundary
WRDF
Dumps
-4000
-4000
0
0
26000
26000
30000
30000
34000
34000
38000
38000
Arturo Pit - A41A Plan
Dumps\Ponds
Legend:
Tertiary Carlin Fm.
Quaternary/Alluvium
Upper Plate Siliciclastic
Rodeo Creek Fm.
Bootstrap Limestone
Popovich Fm.
Roberts Mtns Fm.
Conglomerate
0.035 opt Mineralization
Faults
0
0
1000 Metres500
1,000 2,000 3,000 Feet
Grid: Goldstrike Mine Grid, feet
N
July 2015 Source: Barrick Gold Corporation, 201 .5
Premier Gold Mines Limited
South MineArturo
Property Geology
State of Nevada, U.S.A.
Figure 7-2
7-5
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 7-6
MINERALIZATION
The South Arturo gold-silver deposits can be divided into five mineralized areas. These areas
are the South Arturo, West Button Hill, Southwest Dee pit, Deep North, and Hinge. The
majority of these deposits are classified as “Meikle Type” breccia-hosted Carlin-type deposits.
A complex set of breccias occur at the upper contact of the Bootstrap limestone. These
breccias can be generalized into four basic types: silicified heterolithic breccias, silica-sulphide
breccia, dolomite breccia, and cavity-fill breccia. The oldest breccias are the silicified
heterolithic breccias and the dolomite breccias which have been crosscut and replaced by
mineralized silica sulphide breccias. The youngest breccias are the post mineral cavity-fill
breccias.
While mineralization is widespread throughout the South Arturo Mine area, localized high-
grade gold mineralization drives the open pit economics and defines pit locations.
SOUTH ARTURO The northern extent of South Arturo mineralization lies approximately 60 m southeast of the
Dee pit and under 180 m of waste rock. An overall north-south orientation to mineralization is
inferred from the grade thickness contours, which define an area 520 m in a north-south
direction by 100 m to 115 m wide in an east-west direction. The mineralization and Tertiary
contact dip 15o to 20o to the south. Drilling has shown that rocks are oxidized to a depth of up
to 600 m. Paleozoic rocks host the mineralization mainly in multi-stage, multi-lithic breccias
with gold values ranging from 0.2 g/t Au to more than 35 g/t Au with an average grade of
approximately 2.0 g/t Au. These breccias are commonly formed by karsting or dissolution of
carbonate rock and subsequent collapse and cavity fill. In general, decalcification is followed
by weak to strong silicification with local argillization. Silver to gold ratios are generally 1:1 at
grades of greater than 2.06 g/t Au but increase to 5:1 at lower gold grade values.
DEE DEEP NORTH Dee Deep North is a north-northeast trending pod of mineralization that plunges slightly north
and is approximately 180 m long, 45 m wide, and 45 m thick. The majority of high-grade
refractory mineralization is in silica-sulphide breccia within a flat to west-dipping silicified, multi-
lithic breccia body above the Bootstrap limestone between 1,494 MASL and 1,554 MASL. The
principal controls are the north-northeast trending high angle EB fault and southwest dipping
low angle structures.
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SW DEE The SW Dee pit mineralization is along the north-northeast trending, west dipping Dee Fault
Zone. The mineralization is carbonaceous, partially oxidized, variably silicified mudstone/
siltstone breccia approximately 100 m in a north-south strike length, 30 m wide, and 45 m in
thickness. The mineralization sits between 1,494 MASL and 1,554 MASL, with a small portion
exposed along the southwest high wall at the bottom of the Dee pit.
WEST BUTTON HILL The West Button Hill mineralization trends north-northeast for over 600 m in strike length, in
pods that vary up to 120 m wide and 15 m thick. The majority of high-grade refractory
mineralization is in the lower Rodeo Creek Formation and multi-lithic breccias above the
Bootstrap limestone. The principal controls are the north-northeast and north-south trending
high angle structures and favourable host rocks.
HINGE The Hinge zone is a north-south striking zone that lies between the Arturo zone to the south
west and West Button Hill to the northeast, and is due east relative to the existing Dee pit. It
is approximately 425 m long and up to approximately 90 m wide, lying between elevations of
1,450 MASL to 1,600 MASL at depths from 100 m to 270 m below surface. Mineralization is
hosted in the lower portion of the Rodeo Creek Formation and silicified breccias of the Basal
Rodeo Creek and Popovich Upper Muds units. Breccia bodies drape the Bootstrap limestone.
Mineralization in the Hinge zone is controlled by the Hinge fault, a steeply east dipping north-
south structure that appears to be a northerly extension of faults in Newmont’s Bootstrap pit to
the south. Intersecting faults that influence mineralization have not been clearly identified.
Most mineralization is partially to completely oxidized, even in the more deeply buried zones.
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8 DEPOSIT TYPES The South Arturo Mine is located in the northern end of the Carlin Trend, a 60 km long north-
northwest alignment of sedimentary rock-hosted gold deposits. These deposits are generally
known as Carlin-type deposits named after the Carlin deposit. More than 50 million ounces of
gold have been mined from the Carlin Trend since 1980. Characteristically, the gold
mineralization in Carlin-type gold deposits is dispersed, micron-sized, and found commonly on
the rims of pyrite grains in predominately carbonate-bearing host rocks. Decalcification,
silicification, and dolomitization are the most dominant alteration features. Generally, there is
negligible base metal content, low silver to gold ratios, and a geochemical enrichment in
arsenic, antimony, and mercury.
Carlin-type gold deposits represent a spectrum of deposit types including the classic
stratigraphic hosted deposit end member, collapse breccia hosted deposit end member, and
structurally controlled deposit end member. Most, if not all, of these deposit types contain
individual components of the end members. Most of the South Arturo gold mineralization is
considered to be of the breccia hosted Carlin-type with structural controls, similar to Barrick’s
Meikle deposit located approximately 6.5 km to the southeast.
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9 EXPLORATION Premier has not conducted exploration at South Arturo. Exploration conducted by Barrick and
previous owners is summarized in Section 6 History and Section 10 Drilling.
EXPLORATION POTENTIAL
In addition to the Mineral Resources described in Section 14, the South Arturo property hosts
additional mineralization that is not economically extractable at the current gold price,
operating cost, and metallurgical recovery. There is potential to increase the Mineral
Resources if these conditions improve.
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10 DRILLING Barrick, Glamis (Dee Gold), and Meridian have completed most of the exploration and
development drilling for gold in the South Arturo Mine area, with most recent drilling conducted
by Barrick. Data from these drilling programs is stored in the South Arturo Mine database that
is maintained by Barrick. The database contains 3,203 drill holes with an aggregate length of
582,621 m in the Project area. Table 10-1 summarizes drilling activity by company and by
drilling method.
TABLE 10-1 DRILLING SUMMARY Premier Gold Mines Ltd - South Arturo Mine
Company Holes RC (m)
Core (m)
Rotary/Other (m)
Total (m)
Barrick 1,393 221,696 76,015 1,482 299,193 Glamis/Dee 1,754 98,534 4,130 64,321 166,985 Haliburton 29 3,566 1,377 - 4,943 Meridian/Rossi 364 78,801 11,175 12,137 102,113 Trio Gold 9 - 9,386 - 9,386 Total 3,203 402,598 102,083 77,940 582,621
Of the approximately 583,000 m drilled, approximately 16% was core and 80% was RC holes.
Overall, 96% of the holes within the potential pit had downhole surveys conducted. Drill
spacing varies throughout the Mine area with drilling density increasing in mineralized zones.
Drill spacing in the Dee Deep North area can be found as close as 15 m, while the nominal
drill spacing within the South Arturo area is approximately 50 m.
The drill hole database used to create the model originates from an acQuire database
maintained by the Barrick Exploration group based in Elko, Nevada. This acQuire database
contains holes for the entire district, including areas outside the South Arturo block model area.
Approximately 3,026 valid drill holes, within or immediately adjacent to the South Arturo block
model area, were extracted from this database for use in the Mineral Resource estimation.
Figure 10-1 shows the location of these drill holes.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 10-2
The acQuire database contains ten tables and associated fields and they are as follows:
Collar Fields: HOLEID, NORTH, EAST, ELEV, TD
Survey Fields: DEPTH, AZM, DIP
Assay Fields: FROM, TO, AUOPT, AUCAP, AGOPT, AGCAP, AUCN, AGCN, AURAT, AGRAT,
FLAG1, PIT, TYPE, MISC1, SAMPID, AUIND, MAUIND, AUIN2, MAUIN2, , DOMAIN,
SUBDOM, FORM, REDOX
Lithology Fields: FROM, TO, LITH, PROTO
Stratigraphy Fields: FROM, TO, FORM, UNIT, SBUNIT
ALTER1 Fields: FROM, TO, SIL, SIL2, ARG, CO3_LG, CCI, FEOX, REDOX, BRNZPY, BRSSPY
ALTER2 Fields: FROM, TO, QTZ, CCV, PYV
MET Fields: FROM, TO, ANP, BLCH, TPR, AS, HG
LECO Fields: SAMPID, FROM, TO, CO3, S2, TS, TC, TCM, ANP, APP, NCV
RMR Fields: FROM, TO, RQD, RMR, Q, METHOD, FF
38000 N
Drill Hole Trace
36000 N
34000 N
32000 N
30000 N
28000 N
26000 N
-8000 E
-4000 E
-6000 E
-2000 E
2000 E
0 E
38000 N
36000 N
34000 N
32000 N
30000 N
28000 N
26000 N
-8000 E
-4000 E
-6000 E
-2000 E
2000 E
0000 E
0 1000 2000 3000 400 Feet0
0 250 100 Metres0750500
N
July 2015
Note: Grid Coordinate System is in Imperial Units
Premier Gold Mines Limited
South MineArturo
Drill Hole Location Map
State of Nevada, U.S.A.
Figure 10-1
10-3
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 10-4
SAMPLING METHOD AND APPROACH
The following description of sampling methods of the various drill campaigns is taken largely
from Barrick’s internal procedures. In RPA’s opinion, the sample preparation, analyses, and
security are appropriate for the style of mineralization and for Mineral Resource estimation.
BARRICK DRILLING SURFACE REVERSE CIRCULATION DRILLING
1. Samples were collected from five-foot intervals in a five gallon bucket placed below the rotating wet splitter. The bucket was replaced with a clean bucket after each sample.
2. Samples were thoroughly mixed. A small representative sample was taken for inclusion in a chip box for geologic logging.
3. Remaining contents of the sample (approximately 7 lb to 10 lb) were poured into a 10
in. by 17 in. pre-numbered sample bag. Sample numbers were pre-assigned.
4. From 1999 to 2003, non-certified standards were inserted every 200 ft into the sample stream. From 2004 onward, certified standards and blanks purchased from Rock Labs, along with a field duplicate sample, were inserted randomly within every 30 samples in the sample stream.
5. Samples were delivered to the assay laboratory by a Barrick employee at the
completion of each hole.
6. The utmost care was taken to ensure clean, non-contaminated sampling at the drill rig. Holes were blown out every 20 ft (rod change) until discharge was clear and the rotating wet splitter was sprayed clean.
7. All collars were surveyed and all holes were downhole surveyed to measure deviation.
8. Holes were logged according to a convention developed by Barrick. The Header
included Drill Hole ID, Collar Information, Azimuth and Dip, Date Drilled, Contractor, and Logger. The body of the Log included Footage Intervals, Color, Codes for Intensity of Alteration and Veining, Fault Codes, Metallurgical Codes, Formation Codes, Lithology Codes, Graphic Logs for Lithology and Structure, and Lithologic Description.
SURFACE AND UNDERGROUND DIAMOND (CORE) DRILLING
1. Core was usually drilled at HQ size, although some minor reductions to NQ were necessary.
2. Core was placed in labelled boxes at the drill site; boxes were transported to logging facility.
3. Core was washed.
4. Sampling/assay intervals were assigned according to geologic boundaries.
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5. Sampling numbers were assigned to intervals. From 1999 to 2003, non-certified standards were inserted into the sampling stream approximately every 200 ft. From 2004 onward, certified standards and blanks purchased from Rock Labs as well as a half core field duplicate were inserted into the sampling stream.
6. Holes were logged according to Barrick convention. Header information included Hole
ID, Coordinate Information, Bearing and Dip, Logger, Total Depth, and Contractor. The Body of the Log included Depth, Intervals, Assays, Codes for Intensity of Alteration, Codes for Veins, Formation Codes, Protolith Codes, Metallurgical Codes, Lithology Codes, Graphic Logs for Structure, Lithology, Core Photos, Color, Percent Recovery, and Percent RQD.
7. Core was photographed by digital camera in natural light.
8. Samples were sawn in half at Barrick Goldstrike. One half of each sample was put in
a 10 in. by 17 in. sample bags and the other half was put back in the core box in its original orientation. Samples were delivered to the assay laboratory by a Barrick employee, while the remaining core was stored at the Rossi property logging facilities.
9. All drill hole collars were surveyed. Downhole surveys were completed for all surface
holes. Maxibore downhole surveys were completed for underground holes in excess of 300 ft in depth.
UNDERGROUND REVERSE CIRCULATION DRILLING The same procedures were followed as those described for surface RC drilling, however, the
holes were smaller diameter and samples were taken on six-foot intervals.
MERIDIAN DRILLING All of the drill holes completed by Meridian were collared at the surface and consisted primarily
of RC and minor conventional mud rotary (less than 3% of drill holes) drilling with some HQ
core tails in areas with suspected ore zones.
REVERSE CIRCULATION DRILLING
1. Samples were collected from five-foot intervals in a five-gallon bucket placed below the rotating wet splitter. The bucket was replaced with a clean bucket after each sample.
2. The sample was thoroughly mixed. A small representative sample was taken from the mix for inclusion into a chip box for geologic logging.
3. Remaining contents of the sample (5 lb to 7 lb) were poured into a 7.5 in. by 12 in.
sample bag.
4. An additional bag was filled every tenth sample (every 50 ft), and often through suspected ore zones, as a check sample.
5. Sample bags were pre-numbered, with the first five characters of the sample number
representing the hole number and the last three numbers, when multiplied by five,
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denoting the ending footage (e.g., RS150031 represented the sample from the drill footage of 150 ft to 155 ft from drill hole RS150).
6. Sample bags were placed on dry plywood. Samples were picked up by a laboratory
representative at the completion of the drill hole.
7. The utmost care was taken to ensure clean non-contaminated samples at the drill rig. The hole was blown out every 20 ft (rod change) until discharge was clear. The rotary wet splitter was sprayed off thoroughly.
8. All drill hole collars were surveyed. Most holes (more than 95%) were surveyed by
downhole survey companies using gyro methods for determination of deviation.
9. Drill cuttings were logged by Meridian geologists according to logs designed by Meridian. Header information includes Drilling Method, Location, Contractor, Driller, Rig, Hole Size, Start-Finish, Logger, Collar Coordinates, Sample Sequence, Mineralized Intervals, and Geologic Summary. The body of the log includes From-To (depth), Individual Sample Numbers, Assays, Graphic Logs of Alteration, Lithology, and Oxide/Sulphide, Comments, and Lithology and Intensity of Alteration and Mineralization Fields.
CONVENTIONAL MUD-ROTARY DRILLING
1. Samples were collected in an aluminum hopper below the shaker screen.
2. At conclusion of each five-foot drill interval, the shaker screen was rinsed into hopper and the contents split and diverted into a five-gallon bucket. Steps 3 through 9 were the same as those described for RC drilling.
DIAMOND (CORE) DRILLING
1. Core was usually drilled at HQ size, but some minor reductions to NQ were necessary.
2. Core was placed in labelled boxes at the drill site and the boxes were transported to the logging facility.
3. Core was washed.
4. Sampling/assay intervals were assigned according to geologic boundaries.
5. Sample numbers were sequential and continued from the end of the rotary precollar.
The last three numbers do not denote drill footage.
6. Core was logged according to a convention developed by Meridian. The same Header information as that described for RC drilling was noted for the precollar. The body of the Log includes Run Interval, Percent Recovery, Percent RQD, Assays, Alteration Description, Graphic Logs of Alteration, Structure, Lithology, Oxidation, Sulphides, Description of Metallization/Geology, Lithology Codes, and Codes for Intensity of Alteration and Mineralogy.
7. Core photos were taken for each box with colour film under natural light.
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8. Mineralized or otherwise interesting core was sawn in half. The remaining core was split using a hydraulic splitter. One half of the core was returned to the core box in its original orientation, while the other was placed in a 10 in. by 17 in. cloth sample bag with an appropriate number. These samples were shipped to the assay laboratory. The remaining core was stored at the Meridian warehouse. Barrick took custody of this core in 2002.
GLAMIS/DEE MINING COMPANY DRILLING Dee drill holes were labelled with the letter ”D”, then two numbers denoting year drilled and
three digits denoting the sequence of the hole drilled that year. For example, the third hole
drilled in 1997 would be labelled D97003 and the tenth hole drilled in 2000 would be labelled
D00010. Samples were labelled by drill hole and footage. Prior to 1999, RC holes were drilled
from surface with five-foot sampling intervals. In 1999 and 2000, underground RC drilling was
carried out. The same procedures were followed as in surface RC drilling, but the holes were
smaller diameter and samples were taken at six-foot intervals.
Sampling procedures for Dee drilling from 1992 through 2000 were similar to those used by
Barrick/Goldcorp at the Marigold mine (now operated by Silver Standard Resources Inc.). The
following is a brief summary of the Goldcorp procedures.
1. Prior to drilling, geological technicians label each bag with the hole number, sample
footage, and the consecutive sample number. Duplicate samples are collected from each five-foot interval down the hole; for example "MRA-1234, 0-5', 1". The smaller of these sample splits, nominally approximately 5 lb, is the "assay" sample, and the larger sample, approximately 10 lb, is the "bulk" sample.
2. When drilling dry, the drill cuttings pass through a riffle-type splitter and drop into a pan. Every five-foot sample in the pan must be stirred thoroughly before being scooped with a grain scoop and placed in the bags. After each pair of samples has been collected, the sampler places a second pan in the splitter for collection of the next samples and blows out the pan just used with high pressure air to be ready for the following sample.
3. When drilling wet, in areas of groundwater or broken ground where water injection may
be necessary, a hydraulically driven rotary cone wet-type splitter is used in place of the dry splitter. The retained split of the sample drops into a 12-gal heavy rubber feed bucket, where it is stirred and bagged as described in (2). A second tub is placed in the sample stream and the one used for the previous sample is washed with water.
4. A small split of every five feet of cuttings is washed in a sieve and placed into 20-
compartment hinged plastic chip-trays.
5. All reasonable efforts are made to minimize wet drilling but, in most cases, it is necessary in order to collect a suitable volume of sample.
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6. Samples are taken to the drilling field office trailers and ”blind” samples are inserted into the drill string as will be described below. The bulk bags are hauled to a nearby "bag dump" and lined up on the ground in order by sample and hole number.
7. Blind-Sample Program:
o Approximately 2% to 5% of “blind” samples are inserted. The purpose of the procedure is to check for possible laboratory sequence errors.
o The technician arbitrarily selects two to five samples per 100 in the assay string to be substituted with blind material. The original assay sample is transferred from the original bag into a new bag labelled with the hole number and identifier, such as B-1, B-2, B-3, etc. The original bag is refilled with “blind” material. This “blind” material is a truckload of low-grade material that has been run through a crusher to better resemble drill cuttings.
o The blinds and their associated samples are assayed in one job. If the “blind” values do not occur in proper sequence, the laboratory can either reassay the pulps for the range of samples in question or re-prep and assay the samples from the bulk bags.
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11 SAMPLE PREPARATION, ANALYSES, AND SECURITY In RPA’s opinion, the sample preparation, analysis, security, and Quality Assurance/Quality
Control (QA/QC) procedures at the South Arturo Mine are adequate for use in the estimation
of Mineral Resources.
SAMPLE PREPARATION AND ANALYSES
BARRICK SAMPLES The primary assay laboratories for the Mine were ALS Chemex Labs (ALS Chemex) and
American Assay Labs (American Assay). Minor assay work, including check assays, was
performed at Inspectorate Labs (Inspectorate). The following was the procedure used for
Barrick’s sample preparation and assay.
1. Submittal form was filled out by the geologist/geotechnician and submitted with
samples to the laboratory.
2. Samples were catalogued and checked against submittal sheet. Barrick geologists were notified of any discrepancies.
3. The entire sample was weighed and then oven dried.
4. The entire sample was crushed to 75% passing 10 mesh.
5. 250 g of material was riffle split from the –10 mesh material and pulverized to 80%
passing 200 mesh.
6. Pulps were assayed for gold using a 30 g aliquot by lead fire assay with an atomic absorption spectrometry finish (FA-AAS) and for silver by AAS after an aqua regia digestion.
7. Samples with FA-AAS gold assays greater than 7 ppm (0.146 oz/st) Au were reassayed
by fire assay with a gravimetric finish. Samples from 2004 to 2013 used a 5 ppm (0.204 oz/st) Au threshold for gravimetric fire assay.
8. Pulps were returned to Barrick and stored at the Rossi core shed. Mineralized coarse
rejects were returned or discarded after one year.
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MERIDIAN SAMPLES Meridian used Chemex Labs in Sparks, Nevada (Chemex), for the majority of assays. Assay
checks were run by Bondar Clegg, Monitor, and Assayers laboratories. The following was the
procedure used by Chemex for Meridian’s sample preparation and assay.
1. Submittal form was filled out by the Meridian geologist and delivered with the samples
to Chemex.
2. Samples were catalogued and the entire sample was oven dried.
3. A riffle split was taken to obtain a 250 g sub-sample, which was pulverized using a chrome-steel ring mill to greater than 90% passing 100 µm (150 mesh).
4. Standard fire assay methods using a 30 g pulp sample were utilized to determine total
gold content. Samples assaying greater than or equal to 5.0 ppm Au using FA-AAS were reassayed (FA) with a gravimetric finish for accuracy.
5. Selected sample intervals were composited into five samples for multi-element
geochemistry using a 32-element standard inductively coupled plasma atomic emission spectrometry (ICP-AES) package.
6. Pulps and mineralized coarse rejects (greater than 1.0 ppm Au) were returned to
Meridian and stored at a warehouse in Sparks, Nevada. Barrick took possession of the pulps and remaining core samples in 2002.
DEE/GLAMIS SAMPLES Dee drill samples were assayed on the mine site at the Dee laboratory. The Dee mine is
currently closed.
The analytical procedures used at the Dee laboratory were similar to those used by
Barrick/Goldcorp at the Marigold mine (now operated by Silver Standard Resources Inc.).
Since nearly all drilling at Marigold involves oxidized rocks, our standard exploration sample
procedure is to analyze visibly oxidized rocks using the atomic absorption (AA) method first.
For samples where 0.004 oz Au/st or higher is reported, the samples are fire assayed (FA).
Moreover, if the rock in the sample during sample prep is grey or black, samples are initially
fire assayed. If anomalous values appear in the results, the samples are analyzed by AA.
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SAMPLE SECURITY
BARRICK SAMPLES RC drilling samples are delivered to the assay laboratory by a Barrick employee. Prior to 2013,
RC drilling samples were picked up at the drill site by a representative of the assay laboratory.
Half core samples were picked up at the Goldstrike core shed at the completion of sawing.
MERIDIAN SAMPLES RC drilling samples were picked up at the completion of drilling by the laboratory and core
samples were delivered to the laboratory by Meridian geologists.
DEE/GLAMIS SAMPLES No documentation was available describing sample security for the Dee/Glamis samples.
QUALITY ASSURANCE AND QUALITY CONTROL
The following description of QA/QC is taken largely from Barrick’s internal procedures and
supplemented by discussions and data collected during the June 2015 site visit by RPA.
BARRICK SAMPLES The QA/QC system employed by Barrick at South Arturo included the insertion of standard
samples, blank samples, and duplicate samples into the sample stream. From 1999 to 2003,
non-certified standard and blank material was inserted approximately every 40 samples. Since
2004, certified standards, blanks, and field duplicates have randomly been inserted into the
sample stream. Assay results are electronically e-mailed from the assay laboratory to the
Barrick Exploration Office. Upon passing a QA/QC protocol, the results are downloaded into
Barrick’s assay database. Check analyses are done on pulps and/or rejects at American
Assay in Reno, Inspectorate in Reno, and ALS Chemex in Reno and Vancouver.
RPA reviewed the results of the 2013-2014 QA/QC program. During the two year drilling
campaign, 14,241 samples were received by the laboratory including 1,237 (8.7%) QA/QC
samples as summarized in Table 11-1.
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TABLE 11-1 DRILLING QA/QC SAMPLING SUMMARY –2013-2014 Premier Gold Mines Limited - South Arturo Mine
Sample Type Nominal
Frequency Action Limits
Source Total Failures
Blanks 1:50 0.06 g/t Au Barren Drill Core Rejects
269 1
Standards – Au 1:50 2 SD Rocklabs or CDN Resource Laboratory
294 10
Duplicates 1:20 Varies by grade range
RC & Lab Duplicates
674 31
STANDARD SAMPLES
Certified Reference Standard (CRM) samples were purchased from Rocklabs as pulps that
were assayed in a round robin of 28 laboratories or made from bulk samples sent from Barrick’s
Nevada operations to CDN Resource Laboratories Ltd. to make reference material after a 14
laboratory round robin. The average value and its standard deviation (SD) for the round robins
are certified. The variation from the standard’s mean value in standard deviations defines the
QA/QC variance and is used to determine acceptability of the standard sample assay.
Approximately 150 g of sample material is submitted per QA/QC sample. The database
administrator maintains documents for these samples. The criteria for pass or failure are as
follows.
• Assay value <certified mean ±2 SD → Pass
• Assay value ≥ mean ±2 SD and ≤mean ±3 SD → Warning or Failure
• Assay value > mean ±3 SD → Failure
A failure is declared when the same standard exceeds two consecutive ±2 SD warnings or
when an individual result exceeds ±3 SD from the expected result.
The geologist in charge is notified when a standard failure occurs. The geologist then
determines if the failure can be accepted or if the laboratory needs to re-run the failing batch.
The standard reference samples used for Barrick’s 2013-2014 drilling campaigns are
summarized in Table 11-2.
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TABLE 11-2 STANDARD REFERENCE SAMPLES Premier Gold Mines Limited - South Arturo Mine
Sample Number Expected Value Standard Deviation
(g/t Au) (g/t Au) BCH-OX-01 0.214 0.01 BCH-OX-02 0.338 0.011 BCH-DR-01 ~1.14 ~0.045 BCH-SR-02 4.26 0.11 BCH-SR-05 2.08 0.05 BCH-SR-06 4.13 0.11
Barrick inserted 294 standard reference samples, approximately 2% of the total 14,241
samples submitted. Six failures were reported.
BLANK SAMPLES
Blank QA/QC samples are used to assess the level of analytical “background noise” and to
identify “smearing” or sample carryover in subsequent samples caused by improper sample
preparation techniques and lack of equipment cleaning. Blanks are prepared from barren drill
hole reject cuttings of various colors and are submitted as one kilogram pulps. The blanks
contain no detectable gold (<0.005 ppm Au). They are assigned to the sample stream series
using a prescribed number of samples according to the anticipated mineralized intervals.
A warning occurs when a blank returns an assay in the range of 0.03 g/t Au to 0.06 g/t Au. A
failure is declared when a blank returns an assay greater than 0.06 g/t Au. Special attention
is paid to blanks inserted within or following mineralized samples.
The geologist in charge is notified when a blank failure occurs. The geologist then determines
if the failure can be ignored or if the laboratory needs to re-run the failing batch.
During the 2013-2014 drill campaign, 294 blank samples were inserted, approximately 2%,
and ten failures were recorded.
DUPLICATE SAMPLES
Duplicate or check samples are used primarily to identify problems with field sampling
procedures. A prescribed number of samples are allocated according to the anticipated
mineralized intervals. The RC drill crew collects duplicate samples in a five gallon bucket with
splitter baffles adjusted to allow for adequate sample collection. The sample is homogenized
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and then split in two equal, approximately three kilogram portions and placed in the assigned
sample bags.
The assay results of the duplicates are analyzed by preparing relative difference plots that
compare the difference of grade of the pairs to the mean grade of the pairs.
While there is no procedure in place now to flag problem holes, drill holes that have a large
assay discrepancy (e.g., 0.5 g/t Au to 2.0 g/t Au) and no other problems are flagged for metallic
screen assays, while problem sample intervals with larger discrepancies are re-assayed.
MERIDIAN SAMPLES No certified standards and blanks were used. Field duplicate samples were taken every 10th
sample at the rotary drill, mud rotary drill, or RC drill and submitted for analyses. No field
duplicate core samples were taken.
DEE/GLAMIS SAMPLES Approximately 5% to 10% of the samples were selected for re-assaying to check initial results,
usually while drilling was slow or inactive during the winter, however, for holes with significant
mineralization the check assaying was expedited. Samples for this procedure include a
combination of original assay pulps and ''bulk bag" samples. Generally, samples originally
sent through the Glamis laboratory were sent to off-site commercial laboratories, and samples
originally run off-site were run through the on-site assay laboratory. The blind sample
procedure was also employed for the checks.
The Glamis internal laboratory also participated in a round-robin assay checking arrangement
with several other commercial and mine laboratories, assaying known standard grade material
and comparing results. They routinely inserted known, low-level control samples at every
fifteenth sample in the AA string. Approximately 50 randomly chosen blast hole samples were
re-assayed by AA and FA each month and checked for reproducibility as internal checks.
TWINNED HOLE DATA
Two holes closely spaced together (twinned holes) can be used to examine the difference
between two drilling types. Within the Mine bounds, several twinned hole pairs can be found
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and examined. The twinned holes of interest are listed in Table 11-3 and Figure 11-1 shows
the location of some of these holes. For a select set of twinned holes, gold grades were visually
compared from relatively close spaced core and RC type exploration holes (Figure 11-2).
TABLE 11-3 TWINNED HOLES OF INTEREST Barrick Gold Corporation – South Arturo Mine
Core Hole RC Hole BD-283CW BD-283 BD-284CW BD-284 BD-285CW BD-285 BD-052CW BD-052
West
Bu� on
Hill
S. Arturo
SW Dee
Deep
North
BD-285
BD-284
BD-283
BD-052
-6000
-6000
-4000
-4000
-2000
-2000
0
0
30
00
0
30
00
0
32
00
0
32
00
0
34
00
0
34
00
0
Twinned Holes
Legend:
0.035 opt Mineralization
Arturo Pit - A41A Plan
Grid: Goldstrike Mine Grid, feet
0 500 1000 1500 200 Feet0
0 100 400 50 Metres0300200
N
July 2015
Source: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX,Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS UserCommunity.
Premier Gold Mines Limited
South MineArturo
Locations ofTwinned Drill Holes
State of Nevada, U.S.A.
Figure 11-1
11-8
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 11-9
FIGURE 11-2 RC VS. CORE TWINNED HOLE COMPARISONS
RPA OPINION
In RPA’s opinion, the sample preparation, analysis, and security procedures at the Mine are
adequate for use in the estimation of Mineral Resources.
00.020.040.060.08
0.10.120.140.160.18
0.2
1050 1070 1090 1110 1130 1150 1170 1190
Assa
y Va
lue
(oz/
st A
u)
Hole Depth (ft)
BD-052CW (Core)BD-052 (RC)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
950 1000 1050 1100 1150
Assa
y Va
lue
(oz/
st A
u)
Hole Depth (ft)
BD-283CW (Core)BD-283 (RC)
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12 DATA VERIFICATION RPA reviewed all available reports and interviewed the relevant personnel on site to verify data
collection procedures, QA/QC, and data analyses and is of the opinion that database
verification procedures for the Mine comply with industry standards and are adequate for the
purposes of Mineral Resource estimation. RPA did not collect independent samples as the
historical production of gold is considered sufficient demonstration of the presence of economic
mineralization.
The following description of previous data verification is taken largely from an internal Barrick
procedures. In RPA’s opinion, the data verification undertaken by the current and previous
owners was adequate for inclusion in this technical report.
The 2012 assay database was validated against laboratory certificates on file by M. Lechner,
Resource Modeling Inc. Of the 3,700 assay intervals checked, an error rate of 0.06% for gold
and 0.14% for silver was noted. It was also noted that 8.5% of the certificates could not be
found. RPA notes that missing certificates were from the older data, which is not uncommon
in a legacy database.
BARRICK SAMPLES
Lynda Bloom, a consultant with Analytical Solutions Ltd., reviewed Barrick’s Storm Resource
Area assay quality control program and results for 1999 through 2004. No evidence of serious
problems with accuracy, bias, or analytical procedures were noted (Bloom, 2005).
MERIDIAN SAMPLES
Meridian holes were assayed at Chemex in Sparks, Nevada. Meridian transmitted Barrick
assay results digitally and they were loaded into Barrick’s assay database. Original hard
copies of the assay results from the laboratory are available for most of the holes. Both
Chemex and Monitor commonly ran in-house checks. Chemex results for four holes (RS-107,
RS-108, RS-123, RS-125), all drilled in 1996, had every tenth sample sent to Bondar-Clegg
for check analyses. The results showed overall good correlation.
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DEE/GLAMIS SAMPLES
The 1992 through 2000 Dee drill samples were usually assayed at the Dee mine laboratory.
Dee mine transferred the assay results to Barrick digitally and they were loaded into Barrick’s
assay database. They are in binders in the Barrick open pit office, with Dee drill logs and hard
copies of the original Dee assay laboratory results. The Dee laboratory commonly ran in-
house QA/QC as well as outside laboratory check assays. The QA/QC results are not
available.
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13 MINERAL PROCESSING AND METALLURGICAL TESTING Background information on mineral processing and metallurgical testing for the Mine was
assembled from several sources:
• Barrick-Dee Mining Venture, South Arturo Project Feasibility Study or 2012 Feasibility Study (Barrick, 2012);
• Report on Arturo metallurgical re-assaying (Porter, 2013); and
• Presentation on sample pull for metallurgical assays (Barrick, 2014).
Ore samples from the South Arturo deposit were tested using gold processing technologies,
such as heap leaching, oxide milling, and roasting. The ore from the South Arturo deposit can
be categorized into four distinct types based on gold grade, sulphide grade, and expected
recovery. AMTEL Ltd. (AMTEL) completed a mineralogical study of the gold deportment in
2007. McClelland Labs, Inc. (McClelland) in Sparks, Nevada, performed column leach tests
to estimate the heap leaching performance and Barrick’s Goldstrike Metallurgical Lab
performed carbon-in-leach (CIL) and roaster/CIL tests to estimate the CIL and roaster/CIL
recovery for the South Arturo deposit.
METALLURGICAL SAMPLES
Gold recovery via cyanide leaching processes, i.e., heap leaching or CIL, is commonly a
function of cyanide solubility of the gold. Gold assaying using cyanide solubility assays (AA)
and fire assay (FA) methods are performed on drill core intervals. From these assays, the
cyanide solubility ratio (AA/FA) is used to estimate gold recovery for all ore samples. In the
case of the South Arturo Mine, gold recovery via cyanide leaching appears to be a function of
both the cyanide solubility ratio and the amount of silica contained in the samples based on
data generated from metallurgical testing. The roaster recovery is shown to be a function of
only the silica concentration.
The samples used for the column leaching tests were HQ (6.25 cm diameter) half core
uncrushed samples in 2006, and PQ (8.25 cm diameter) samples crushed to less than 3.13
cm in 2007. The column leaching tests were conducted by McClelland in Sparks, Nevada
(Barrick, 2012). The samples for the CIL/roaster tests were crushed reject material from the
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 13-2
assay laboratory. Bottle roll tests to assess oxide mill grade and roaster ore characterization
were conducted at the Goldstrike Metallurgical Lab. The samples for both test programs were
selected on the basis of location (Figures 13-1 and 13-2) in relation to the previous pit design
(Barrick, 2012), oxidation state, and degree of silicification. Table 13-1 shows the sample
distributions that were used for the testing programs as compared to the proportion of
contained gold in each of the classifications. Bond work index tests were also performed on a
number of the samples tested at the Goldstrike Metallurgical Lab.
TABLE 13-1 METALLURGICAL SAMPLE DISTRIBUTION Premier Gold Mines Limited - South Arturo Mine
Location Oxidation State Degree of Silicification
South Arturo
Deep North
West Button
Hill Oxide Non-oxide Carbon
None Code 0
Weak Code 1
Moderate Code 2
Strong Code 3
Heap Leach Column Tests Gold ounces, % 33 67 --- 86 14 --- 28 13 24 35 Column Tests 12 12 --- 18 6 --- 5 3 4 12 CIL and Roaster Tests Gold ounces, % 37 36 28 55 29 16 16 18 28 38 Bottle Roll Tests 25 16 21 27 26 9 12 11 17 22
The oxidation state refers to whether the sample is classified as oxide or non-oxide and the
degree of silicification refers to the potential for quartz encapsulation/attachment as signified
by the silica code (0 = none, 1 = weak, 2 = moderate, 3 = strong). As shown in Table 13-1, no
column tests were completed using samples from West Button Hill and the ratios of the
numbers of tests performed on each of the classifications of material shown in the table do not
necessarily correspond to the proportion of gold ounces that correspond to the same
classifications. This observation implies that the samples are not necessarily representative
of the ore that will be processed over the life of the mine.
Additional CIL bottle roll tests were performed during active Dee operations. The sources of
the samples were varied and were restricted to known resources on the north end of the
deposit (Figure 13-3). The tests were conducted at a grind target of 80% passing 400 mesh.
< 0.500
Drill: Rec Column
0.600 - 0.700
0.500 - 0.600
0.700 - 0.800
0.800 - 0.900
> 0.900
July 2015 Source: Barrick Gold Corporation, 201 .2
Premier Gold Mines Limited
South MineArturo
Sample Distribution forColumn Leach Tests
State of Nevada, U.S.A.
Figure 13-1
13-3
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< 0.500
Drill: Rec Bottle
0.600 - 0.700
0.500 - 0.600
0.700 - 0.800
0.800 - 0.900
> 0.900
< 0.500
Drill: Rec Bottle
0.600 - 0.700
0.500 - 0.600
0.700 - 0.800
0.800 - 0.900
> 0.900
July 2015 Source: Barrick Gold Corporation, 201 .2
Premier Gold Mines Limited
South MineArturo
Sample Distribution forCIL and Roaster Tests
State of Nevada, U.S.A.
Figure 13-2
13-4
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< 0.500
Drill: Rec Bottle
0.600 - 0.700
0.500 - 0.600
0.700 - 0.800
0.800 - 0.900
> 0.900
< 0.500
Drill: Rec Bottle
0.600 - 0.700
0.500 - 0.600
0.700 - 0.800
0.800 - 0.900
> 0.900
July 2015 Source: Barrick Gold Corporation, 201 .2
Premier Gold Mines Limited
South MineArturo
Sample Distribution forDee Bottle Roll Tests
State of Nevada, U.S.A.
Figure 13-3
13-5
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 13-6
Additional sample analysis was conducted in 2013 and 2014. Some 39 composite pulp
samples from previous 32 RC and diamond drill holes were re-analyzed and good correlation
between old and new assays were observed (Porter, 2013). In early 2014, the number of
LECO/metallurgical assays were increased for waste characterization and mineralogical study.
MINERALOGICAL STUDY
AMTEL analyzed a sample from South Arturo in 2007. The grade was 11.5 g/t Au, with 0.68%
total sulphur and the cyanide solubility ratio of 0.78. The sample had two major rock
components, quartz (70%), and mica/clays (25%). AMTEL’s gold deportment study concluded
that native gold accounts for 90% of the total gold in the sample. At 80% passing 125 µm, only
22% of the gold is liberated. The gold particles are predominantly small, averaging five microns
and ranging in size up to 36 µm.
Unliberated native gold, averaging two microns in size, is primarily associated with the host
rock while there is a minor association with pyrite (1%). Most of the unliberated gold (80%) is
partially exposed, while 20% is locked or enclosed in rock. The remaining 10% of the gold is
submicron gold which is mainly locked in pyrite.
Although the grade of the sample analyzed is significantly higher than the grades that will be
processed from South Arturo, the results appear to be consistent with the gold recovery results
seen in the metallurgical tests and historically experienced on the site. In order to confirm this
observation, RPA recommends that additional gold deportment analyses also be performed
on lower-grade samples.
COLUMN LEACH TESTS
Twenty-four column leach tests were performed at McClelland during 2006 and 2007. The
data from the column leach tests showed that the gold recovery demonstrated a moderate
correlation to cyanide solubility and a strong negative correlation to the degree of silicification.
When a multiple regression using both cyanide solubility and silica were used to predict
recovery, a strong correlation was noted, as shown in Figure 13-4. It was also observed that
head grade did not produce a meaningful correlation with gold recovery.
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FIGURE 13-4 CRUSHED ORE HEAP LEACH GOLD RECOVERY DATA
The resulting multi-regression formula for crushed ore heap leaching, as reported in the 2012
Feasibility Study is:
𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶ℎ − 𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿ℎ 𝐺𝐺𝐺𝐺𝐺𝐺𝐺𝐺 𝑅𝑅𝐿𝐿𝐿𝐿𝐺𝐺𝑅𝑅𝐿𝐿𝐶𝐶𝑅𝑅 = (0.801 × Cyanide Solubility Ratio) + (−0.142 × 𝐶𝐶𝑠𝑠𝐺𝐺𝑠𝑠𝐿𝐿𝐿𝐿) + 0.204
One run-of-mine (ROM) bulk column test in a three-foot diameter by ten-foot tall column was
completed by McClelland. It was not possible to access a typical leach feed bulk sample so
this sample had a high silica, low cyanide solubility, which resulted in a ROM recovery of 8.7%
compared to a crushed leach recovery of 12.7%. Therefore, an analysis of the historical Dee
mine operating data was used to estimate the recovery for ROM leaching. The ROM leach
recovery is estimated using 85% of the crushed ore heap leaching recovery. The resulting
formula is:
𝐺𝐺𝐺𝐺𝐺𝐺𝐺𝐺 𝑅𝑅𝐿𝐿𝐿𝐿𝐺𝐺𝑅𝑅𝐿𝐿𝐶𝐶𝑅𝑅 = 0.85 × [(0.801 × Cyanide Solubility Ratio) + (−0.142 × 𝐶𝐶𝑠𝑠𝐺𝐺𝑠𝑠𝐿𝐿𝐿𝐿)− 0.204]
Due to the near-refractory nature of the material, testwork on a bulk sample near the Storm
deposit did not respond well to either coarse (10 cm size) crush or two finer crush sizes
(Barrick, 2012). This formula must be confirmed with additional testing.
Silver recovery in the column leach tests is very low. The average silver recovery in the column
tests was 7%, which was used to model the leach pad silver production. RPA recommends
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 13-8
that additional ROM and crushed ore column tests be completed using samples that are
representative of the material that will be leached over the life of the mine.
CIL BOTTLE ROLL TESTS
The CIL bottle roll test work was performed at Barrick’s Goldstrike Metallurgical Lab in 2007,
2008, and 2009 using a targeted grind of 80% passing 74 µm. The gold recovery for the
samples tested showed a strong correlation to the cyanide solubility and a moderate negative
correlation to the degree of silicification. A multiple regression analysis that estimates gold
recovery as a function of both cyanide solubility and silica content results in a slightly stronger
correlation, as shown in Figure 13-5. It was also observed that head grade did not produce a
meaningful correlation with gold recovery.
FIGURE 13-5 CIL GOLD RECOVERY DATA
The resulting multi-regression formula for CIL leaching is:
𝐶𝐶𝐶𝐶𝐿𝐿 𝐺𝐺𝐺𝐺𝐺𝐺𝐺𝐺 𝑅𝑅𝐿𝐿𝐿𝐿𝐺𝐺𝑅𝑅𝐿𝐿𝐶𝐶𝑅𝑅 = (0.355 × Cyanide Solubility Ratio) + (−0.027 ×𝑆𝑆𝑠𝑠𝐺𝐺𝑠𝑠𝐿𝐿𝐿𝐿) + 0.601
The CIL bottle roll tests did not yield much information about silver recovery because the silver
head grades were low. The estimated silver recovery is based on bottle roll tests from samples
with the highest silver head grades and historic Dee data, as shown in the formula:
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𝐶𝐶𝐶𝐶𝐿𝐿 𝑆𝑆𝑠𝑠𝐺𝐺𝑅𝑅𝐿𝐿𝐶𝐶 𝑅𝑅𝐿𝐿𝐿𝐿𝐺𝐺𝑅𝑅𝐿𝐿𝐶𝐶𝑅𝑅 = (0.080 ×𝑆𝑆𝑠𝑠𝐺𝐺𝑅𝑅𝐿𝐿𝐶𝐶 𝐶𝐶𝑅𝑅𝐿𝐿𝐶𝐶𝑠𝑠𝐺𝐺𝐿𝐿 𝑆𝑆𝐺𝐺𝐺𝐺𝐶𝐶𝑆𝑆𝑠𝑠𝐺𝐺𝑠𝑠𝑆𝑆𝑅𝑅) + 0.298
Additional tests should be completed using samples that are representative of the material that
will be leached over the life of the mine.
BENCH TOP ROASTER/CIL TESTS
Bench top roaster (BTR) tests were performed at Barrick’s Goldstrike Metallurgical Lab on the
same sample set as the CIL test work using a targeted grind of -74 µm. In these tests, cyanide
solubility did not influence BTR gold recovery, as expected. It was also observed that head
grade did not produce a meaningful correlation with gold recovery. The data is shown in Figure
13-6.
FIGURE 13-6 ROASTER GOLD RECOVERY DATA
The resulting formula for predicting the roaster gold recovery is:
𝑅𝑅𝐺𝐺𝐿𝐿𝐶𝐶𝑆𝑆𝐿𝐿𝐶𝐶 𝐺𝐺𝐺𝐺𝐺𝐺𝐺𝐺 𝑅𝑅𝐿𝐿𝐿𝐿𝐺𝐺𝑅𝑅𝐿𝐿𝐶𝐶𝑅𝑅 = (−0.025 ×𝑆𝑆𝑠𝑠𝐺𝐺𝑠𝑠𝐿𝐿𝐿𝐿) + 0.879
Again, the silver head grade of the samples was so low that little information about silver
recovery was gained from the BTR/CIL tests. However, the tests which used the samples with
the 12 highest head grades yielded an average silver recovery of 36%, which is used to
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 13-10
estimate silver recovery in the model. Again, RPA recommends that additional tests should
be completed using representative samples.
BOND WORK INDEX
Bond work index (BWI) tests were performed at the Goldstrike Metallurgical Lab. The BWI
ranged from 15.4 kWh/t to 22.0 kWh/t, with an estimated average of 19.3 kWh/t.
HISTORICAL DEE MINE DATA
Historical operating data were also used in the evaluation of the South Arturo Mine, however,
data regarding the cyanide solubility and the silica content of the ore were not available.
Therefore, assumptions and estimates were needed to evaluate the data. Although no fatal
flaws were identified during the analysis due to missing relevant information, RPA is of the
opinion that the information has limited value in predicting future metallurgical performance.
CONCLUSIONS AND RECOMMENDATIONS
The metallurgical test results determined the following:
• Sulphide ore and ore containing pre-robbing organic carbon above the target cut-off gold grade would be roasted.
• Oxide ore above the target cut-off gold grade would be processed via ROM heap leach.
• Ore containing pre-robbing organic carbon below the cut-off grade gold grade for roasting will be considered waste.
• The mill recovery ranges from 48% to 79% depending on the process employed. Recovery may be higher than predicted if the ore is ground finer than 74 µm in size. A gold deportment study completed by AMTEL and metallurgical test results indicated that a large portion of the gold is most likely encapsulated in silica, therefore, finer grinding could assist with improved gold liberation.
• The heap leach recovery and relationships between particle sizes and recovery may be different from the estimates because the samples tested are not in the same area of the mineralization that will be processed on the heap leach pads.
• Additional sampling and column leach tests of material from the West Button Hill deposit would provide additional metallurgical data for analysis.
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14 MINERAL RESOURCE ESTIMATE A summary of the Mineral Resources, excluding Mineral Reserves, for South Arturo as of
December 31, 2014, is shown in Table 14-1. Cut-off grades for the Mineral Resources were
established using a gold price of US$1,400 per ounce and a silver price of US$19 per ounce.
Measured and Indicated Mineral Resources increased relative to 2013 due to additional drilling
conducted in 2014 which allowed the conversion of Inferred Resources to higher
classifications, as well as reclassification of Mineral Reserves to Mineral Resources following
a reduction in gold and silver prices.
Estimation of Mineral Resources was completed by Barrick personnel using Maptek’s Vulcan
software. All work was completed using imperial units, and has been converted to metric units
for this report, with the exception of the coordinate grid system, which has been retained in
imperial units.
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TABLE 14-1 SUMMARY OF MINERAL RESOURCES (40% - PREMIER) – DECEMBER 31, 2014
Premier Gold Mines Limited – South Arturo Mine
Category Tonnes Grade Contained Metal Grade Contained
Metal (000 t) (g/t Au) (000 oz Au) (g/t Ag) (000 oz Ag) Measured
ROM Leach 1.6 0.39 0.0 8.38 0.4 Oxide Mill 1.7 4.89 0.3 9.97 0.6
CATS Roaster
Total Measured 3.4 2.69 0.3 9.19 1.0 Indicated
ROM Leach 13,402 0.47 203 5.51 2,376 Oxide Mill 4,007 2.77 357 11.58 1,492
CATS 259 7.53 63 8.51 71 Roaster 1,459 4.41 207 8.48 398
Total Indicated 19,128 1.35 831 7.05 4,337 Measured + Indicated
ROM Leach 13,404 0.48 203 5.12 2,377 Oxide Mill 4,009 2.77 358 11.58 1,493
CATS 259 7.53 63 8.51 71 Roaster 1,459 4.41 207 8.48 398
Total Measured + Indicated 19,132 1.35 831 7.05 4,338 Inferred
ROM Leach 3,488 0.44 50 3.26 366 Oxide Mill 237 2.60 20 6.54 50
CATS 16 6.38 3 5.19 3 Roaster 124 2.86 11 2.80 11
Total Inferred 3,866 0.68 84 3.46 430 Notes:
1. CIM definitions were followed for Mineral Resources. 2. Mineral Resources are estimated using a long-term gold price of US$1,400 per ounce, a long term silver
price of US$19, and a C$/US$ exchange rate of 1.10. 3. Mineral Resources are reported using gold cut-off grades of 0.79 g/t, 1.20 g/t, and 1.89 g/t for the oxide
mill, refractory roaster and total carbonaceous material (TCM), respectively, and a grade range from 0.14 g/t Au to 0.79 g/t Au for heap leach material.
4. Mineral Resources represent attributable ounces to Premier, equal to 40% of the Joint Venture controlled ounces. Material from the Rossi property has been excluded.
5. Bulk density is specific to geological formation and varies from 2.00 t/m3 to 2.67 t/m3. 6. Mineral Resources are exclusive of Mineral Reserves. 7. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. 8. Numbers may not add due to rounding.
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DATA
For resource estimation, the drill hole data was limited to holes within or immediately adjacent
to the block model boundaries. The final resource database contains a total of 3,026 drill holes
over 506,076 m and containing 267,725 gold assays and 228,759 silver assays. The drill hole
database comprises surface RC, and surface and underground diamond drilling.
RPA reviewed the validation routines and outputs provided by Barrick. Several drill holes were
excluded or modified due to missing or poor quality data.
RPA conducted a limited number of checks on the resource database. RPA identified almost
6,000 assays (2%) with a cyanide assay value and no fire assay value, all of which were
excluded from the final resource composite file. RPA recommends consideration be given to
the use of cyanide gold values in place of missing fire assays values, where possible, to ensure
identification of low grade in the composite file. No other issues were identified. RPA is of the
opinion that the database is appropriate to support Mineral Resource estimation.
GEOLOGICAL MODELLING
Wireframes were constructed using Maptek’s Vulcan software for the Bootstrap Limestone
(Bootstrap), Devonian Rodeo Creek Formation (DRC), Vinini Formation (VF), Tertiary Carlin
Formation (TC), Tertiary Volcanics (TV), and the Breccia Zone. Redox surfaces were
constructed to define the oxide and refractory ore limits, and additional solids were built to
define low and high grade silica areas. A topographic surface limited the vertical extent of the
wireframe surfaces.
MINERALIZATION MODELLING
Mineralization is widespread throughout South Arturo, and the Mine area is broken into six
domains: Arturo, Dee, Hinge, West Button, Central, and Upper Dee. The Dee zone is further
broken into four subdomains: Discovery, Forty Niner, Dee, and End Zone, for a total of nine
domains. These domains represent areas of similar grade continuity and orientation and were
defined considering grade breaks derived from statistical analysis of gold distributions in
conjunction grade continuity analysis, and lithological and structural elements derived from
geological logs. An overview of the search domains at South Arturo are shown in Figure 14-1.
End Zone
Drill Hole Trace
Central
Upper Dee
DeeDiscovery
Forty Niner
Hinge
Arturo
West Button
1,500
metre
s
July 2015
Search Domains Used inGrade Interpolation
Premier Gold Mines Limited
South MineArturoState of Nevada, U.S.A.
Figure 14-1
14-4
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Within these search domains, there are five zones of high grade gold mineralization that drive
the open pit economics and define pit locations. These zones are South Arturo, End Zone,
Dee Deep North, SW Dee, and West Button Hill.
INDICATOR INTERPOLATION
Barrick applied Inverse Distance Squared (ID2) for the estimation of mineralized and
unmineralized, and high and low grade indicators at South Arturo. First, a mineralization
indicator was estimated within each search domain using gold and silver grade thresholds of
0.1 g/t and 5.14 g/t, respectively, and 6.1 m composites, capped prior to compositing, to
separate the block model into mineralized and unmineralized domains for each metal.
The initial (mineralized/unmineralized) indicator estimation was interpolated in a single pass
using variable search ellipse dimensions and orientations, in line with variography and domain
shape. A minimum of six and a maximum of 12 composites were required to estimate each
block, over at minimum three drill holes. Composite samples were not restricted by
subdomain. Blocks were divided into mineralized and unmineralized using a probability
threshold of 0.4. Domains were backflagged to the drill hole database.
Following the mineralization indicator estimation, a high grade indicator estimation was
interpolated within the mineralized area using 3.0 m composites and similar interpolation
criteria to the low grade indicator estimation. Grade thresholds are listed in Table 14-2. Search
ellipse dimensions were smaller, however, but also in line with variography. Mineralized blocks
were categorized into low and high grade domains at a probability of 0.4. Domains were
backflagged to the drill hole database.
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TABLE 14-2 SUMMARY OF INDICATOR GRADE THRESHOLDS Premier Gold Mines Limited – South Arturo Mine
Subdomain Mineralization Indicator Threshold High Grade Indicator Threshold Au (g/t) Ag (g/t) Au (g/t) Ag (g/t)
10 Arturo 0.10 5.14 1.54 34.28 22 Dee 0.10 5.14 3.43 17.14 23 Forty Niner 0.10 5.14 6.86 68.56 24 Discovery 0.10 5.14 6.86 68.56 25 End Zone 0.10 5.14 6.86 68.56 30 Hinge 0.10 5.14 3.09 13.71 40 West Button 0.10 5.14 2.40 20.57 50 Central 0.10 5.14 1.71 12.00 60 Upper Dee 0.10 5.14 1.37 12.00
GRADE CAPPING AND COMPOSITING
Raw gold and silver assays were capped for outliers based on examination of cumulative
probability plots and histograms by Barrick. The capped assays were composited using
downhole 3.0 m lengths in the mineralized zone and 6.1 m lengths in the unmineralized zone.
Composites were flagged by search domain and grade domain from the block model. A
summary of gold grade caps is shown in Table 14-3.
TABLE 14-3 GOLD AND SILVER GRADE CAPS Premier Gold Mines Limited – South Arturo Mine
Subdomain Au (g/t) Ag (g/t)
0 Default 10.28 24.00
10 Arturo 30.85 102.84 22 Dee 34.28 123.41 23 Forty Niner 68.56 411.36 24 Discovery 61.70 342.80 25 End Zone 47.99 411.36 30 Hinge 10.28 24.00 40 West Button 41.14 82.27 50 Central 10.28 40.14 60 Upper Dee 10.28 24.00
Missing assays and intervals with poor recovery that could not be sampled were excluded from
the compositing routine and estimation, as were selected drill holes identified by the onsite
team as having poor location, sampling, or drilling angle to mineralized structures.
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VARIOGRAPHY
Omnidirectional and directional variograms were developed for gold and silver and used to
establish search distances for the different estimation domains.
BLOCK MODEL CONSTRUCTION
Estimation of gold, silver, and accessory elements was performed in Maptek’s Vulcan software
by Barrick personnel. Initial indicator routines (to separate mineralized and unmineralized
material) were performed on a 9.1 m x 9.1 m x 6.1 m block model. Minimum sub-block size
was 3.0 m x 3.0 m x 3.0 m. All blocks within the mineralized domain were subsequently limited
to the minimum sub-block size. Final grade estimation was performed on a 12.2 m x 12.2 m x
6.1 m sub-blocked model limited to 3.0 m x 3.0 m x 3.0 m within the mineralized domains for
high grade indicator interpolation and grade estimation. Following grade estimation, the South
Arturo block model was re-blocked to 12.2 m x 12.2 m x 6.1 m for use in mine planning.
Contained tonnes and depleted block ounces were calculated for each mineralized block,
which were summed in the reblocked model. Grade variables of the reblocked model were
determined by dividing the summed block ounces by the summed tonnes. All other variables
were assigned based on majority.
GRADE INTERPOLATION
Gold and silver grades were interpolated using ID2, employing varying search criteria
(directions and distances) customized to each search domain and grade domain within the
model. Select composite weights were assigned manually by Barrick to allow limited influence
of composites across grade domain boundaries (Table 14-4). The unmineralized domain was
estimated using hard boundaries, but weighted at 0.5 in the low grade domain.
The interpolation approach at South Arturo, within the mineralized domains, included ten
nested estimation runs; the first and smallest being a box search equal to the block dimensions,
with a minimum of one and maximum of 99 composites, and only one composite per hole.
Search ellipse dimensions were set to the lag distance at 80% and 90% of the variogram sill
for each search domain for the second and fourth passes, respectively, which were each
followed by a pass using a half size search ellipse with fewer composite restrictions. The
second and fourth estimation runs required a minimum and a maximum of two and three
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composites, respectively. Minimum required composites was decreased to one in the third
and fifth pass. Pass 2 through pass 5 were run individually for the low and high grade domains
within the mineralized domain. A final estimation pass using a large search ellipse over each
search domain was performed ignoring grade domain restrictions. Blocks estimated in the
final pass were not classified. Grade interpolation was limited to below the upper Vinini
Formation contact. The unmineralized domain was estimated in a single pass for each search
domain.
Additional interpolation routines for cyanide leach gold/fire assay gold ratios, silica, arsenic,
CO3, mercury, redox, and several metallurgical variables were also completed for use in
material type definition. Nearest neighbour interpolation was run for gold in parallel to ID2 for
validation purposes.
TABLE 14-4 SUMMARY OF COMPOSITE WEIGHTS Premier Gold Mines Limited – South Arturo Mine
Subdomain Weight Subdomain Weight
Code Search Mineralization Low High Code Search Mineralization Low High
10 Arturo 30 Hinge Unmineralized 0.5 0 Unmineralized 0.5 0 Low 1 0.75 Low 1 0.25 High 0.5 1 High 0.5 1
22 Dee 40 West Button Unmineralized 0.5 0 Unmineralized 0.5 0 Low 1 0.25 Low 1 0.75 High 0.5 1 High 0.5 1
23 Forty Niner 50 Central Unmineralized 0.5 0 Unmineralized 0.5 0 Low 1 0.25 Low 1 0.75 High 0.5 1 High 0.5 1
24 Discovery 60 Upper Dee Unmineralized 0.5 0 Unmineralized 0.5 0 Low 1 0.5 Low 1 0.75 High 0.5 1 High 0.5 1
25 End Zone Unmineralized 0.5 0 Low 1 0.5
High 0.5 1
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DENSITY
Density values were determined by performing acrylic-seal volume displacement tests for the
various rock formations. Barrick adjusted the rock bulk density to reflect in-situ cavities that
do not yield core for bulk density determination. Density values were then assigned to each
block according to previously assigned rock type codes in the model as illustrated in Table 14-
5.
TABLE 14-5 DENSITY VALUES BY ROCK TYPE Barrick Gold Corporation – South Arturo Mine
Rock Type Density (t/m3) Number of Samples
Carlin Formation 2.00 Goldstrike Default Non-silicified Ov and Drc 2.34 22 Silicified Ov and Drc 2.53 40 Bootstrap Limestone 2.67 17 Fill 1.99 Rock density with 20% swell
Notes:
1. Ov = Ordovician Vinini Formation 2. Drc = Devonian Rodeo Creek Formation
CLASSIFICATION
Definitions for resource categories used in this report are consistent with those defined by CIM
(2014) and adopted by NI 43-101. In the CIM classification, a Mineral Resource is defined as
“a concentration or occurrence of solid material of economic interest in or on the Earth’s crust
in such form, grade or quality and quantity that there are reasonable prospects for eventual
economic extraction”. Mineral Resources are classified into Measured, Indicated, and Inferred
categories. A Mineral Reserve is defined as the “economically mineable part of a Measured
and/or Indicated Mineral Resource” demonstrated by studies at Pre-Feasibility or Feasibility
level as appropriate. Mineral Reserves are classified into Proven and Probable categories.
The Measured component of the Mineral Resource is assigned to blocks directly intersected
by drill holes used in the interpolation, and estimated during the initial box search. Indicated
Mineral Resources are those blocks estimated in the second or third pass, equal to a maximum
distance range of 80% of the variogram sill. Inferred Mineral Resources are those blocks
estimated in the fourth and fifth passes, where the search ellipse dimensions are equal to, or
smaller than, a distance range of 90% of the variogram sill for each area.
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POST PROCESSING
Underground mine workings were flagged and their density and grade adjusted. Following the
estimation of all variables, the block model was exported to QPit for optimization. Blocks were
divided into different material types by assigning a revenue based on geology, process route
costs, and mining costs for each option. Final routing and material code for each block was
assigned based on maximizing revenue.
MODEL VALIDATION
Checks and validation performed by Barrick included:
• Examination of the interpolation scripts and comparison to the interpolation plan
• Visual comparisons of interpolated gold and silver grades relative to drill hole composite values on sections and plans.
• Comparison of block model grades and gold and silver assays using histograms and
cumulative frequency plots
• Comparison of the ID2 estimation to the nearest neighbour (NN) estimation model, and the mid-year 2013 model.
RPA has reviewed various modelling aspects of the South Arturo mine, with focus on the South
Arturo, Forty Niner and West Button areas, which combined represent the majority of classified
material at South Arturo. RPA’s observations and comments from the model validation are
provided below. All comments are based on the mid-2014 model data.
Final reblocked dimensions and orientations were reviewed and are considered by RPA to be
appropriate to the drilling density, mineralization, and proposed mining methods. The initial
block size of 3.0 m x 3.0 m x 3.0 m within the mineralized domains appears to be small relative
to the drill density in some areas.
RPA verified the reported Mineral Resources, prepared using QPit software, using Vulcan
software. Reported Mineral Resources were limited by optimized pit shells and an end-of-year
2014 surface.
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RPA compared flagged formation codes to formation wireframes and expected stratigraphy
and density and found the block model to be appropriately flagged.
Compositing routines were checked to confirm appropriate flagging. RPA is satisfied with the
compositing routines. Composite lengths used in the grade estimation within the low, medium,
and high grade domains are equal to the relevant block height and are considered by RPA to
be appropriate.
High grade indicator thresholds were reviewed over the Forty Niner, Discovery Zone, and
Arturo search domains using basic statistics, histograms, and probability plots. RPA found
limited support for the grade thresholds used to divide the populations. As an additional check,
isotropic and anisotropic grade shells over the search domain areas were completed using
Aranz’s Leapfrog software. Grade shells at the indicator threshold for gold compared well to
the indicator grade shells and general grade trends were honoured. RPA is of the opinion that
improved continuity of grade may be achieved using traditional high grade wireframes in favour
of indicators, and that this approach should be investigated in future updates.
RPA compared gold grade continuity and mineralization trends to search ellipse orientations
within the Arturo and Forty Niner search domains and found moderate agreement in some
areas, and good agreement in others. RPA recommends reviewing the use of search domains
and investigating the incorporation of trend surfaces and traditional grade wireframes in future
updates.
The Arturo and Forty Niner search domains were reviewed using histograms, probability plots
and decile analysis to confirm appropriate gold grade caps. RPA is satisfied with the chosen
gold grade caps, however, recommends reviewing gold grade caps by grade domain in
addition to search domain in future updates.
RPA is of the opinion that density values are based on a low number of samples and that
additional samples should be acquired for use in future updates.
RPA reviewed block and database flagging, field calculation, block estimation, and block
calculation files and scripts provided by Barrick for errors and found them to be in good order.
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RPA conducted visual comparisons of assay, composite and block gold values in cross section
and plan and found good spatial correlation. Gold and silver grades were not observed to
extend into regions dominated by waste and did not appear to be overly smoothed in higher
grade areas. An example cross section of composite and block gold grades, restricted to the
mineralized domains within Arturo is shown in Figure 14-2. RPA notes that many blocks are
estimated using a single composite sample, however, these blocks are limited to within close
range of a drill hole.
RPA prepared a basic statistical comparison of declustered composites and blocks in a volume
(approximately 100 million m3) overlying the West Button open pit and encompassing
mineralized and unmineralized domains. Gold grades compared well, however, silver grades
in the block model reported lower than the declustered composites. Results are shown in
Table 14-6.
TABLE 14-6 COMPARISON OF COMPOSITE AND BLOCK GRADES Barrick Gold Corporation – South Arturo Mine
Statistic Gold (g/t) Silver (g/t)
Capped Composites
Sub-blocked Model
Reblocked Model
Capped Composites
Sub-blocked Model
Reblocked Model
Min 0.02 0.02 0.00 0.02 0.02 0.00 Max 41.14 41.14 33.61 82.27 82.27 70.67 Mean 0.71 1.67 Declustered Mean 0.38 0.31 0.31 1.30 0.79 0.76 No Samples 5,514 194,435 34,650 5,506 189,879 34,650
RPA reviewed the classification criteria at South Arturo as well as visually inspected classified
blocks in cross section and plan view. RPA considers restricting the Measured component of
the Mineral Resource to those blocks directly intersected by drill holes to be conservative, and
not practical for mine design purposes. Furthermore, the reblocking algorithm used for
classification, based on majority, removes almost all material classified as Measured from the
block model. RPA is of the opinion that, in general, classification of blocks is in line with
industry best practices, however, the use of a post processing classification script based on
drill hole spacing and geological confidence should be developed for the property. An example
cross section of classified blocks in the original and reblocked models is shown in Figure 14-
3.
Facing East: Section -2,500 E
Resource Shell
Surface
5500 L
4500 L
32000 N
5000 L
6000 L
31500 N
31000 N
30500 N
30000 N
29500 N
< 0.00
< 5.14
Gold (g/t)
< 1.37
< 17.14
< 0.14
< 6.86
< 2.74
< 68.56
< 3.43
< 205.68
0 100 200 300 400 50 Feet0
0 50 100 15 Metres0
July 2015Note: Grid Coordinate System is in Imperial Units
South MineArturo
Comparison of Block andComposite Gold Grades at Arturo
Premier Gold Mines Limited
State of Nevada, U.S.A.
Figure 14-2
14-1
3
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Original Subblocked Model
Reblocked Model
West ButtonForty Niner
West Button
Reserve Pit Design Resource Shell
Forty Niner
Reserve Pit Design Resource ShellResource Shell
Resource Shell
EOY 2014 Topo
EOY 2014 Topo
6000 L
5000 L
6000 L
5000 L
-6000 E
-5000 E
-4000 E
-3000 E
-2000 E
1000 E
0 E
1000 E
Upper Dee
Upper Dee-6
000 E
-5000 E
-4000 E
-3000 E
-2000 E
1000 E
0 E
1000 E
Facing North: Section 33,300 N
Measured
Classification
Inferred
Indicated
0 500 1000 1500 200 Feet0
0 100 400 50 Metres0300200
July 2015
Note: Grid Coordinate System is in Imperial Units
South MineArturo
Block Classification
Premier Gold Mines Limited
State of Nevada, U.S.A.
Figure 14-3
14-1
4
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15 MINERAL RESERVE ESTIMATE Mineral Reserves were estimated by Barrick and reviewed by RPA. Mineralization is
widespread throughout the South Arturo area. The mineralized areas include the South Arturo,
Dee Deep South, SW Dee, Hinge, and the West Button Hill. Based on current operating costs,
process recoveries, and metal prices, the only area that comprises Mineral Reserves, as of
December 31, 2014, is the West Button Hill.
Metal prices used for Mineral Reserves are based on consensus, long term forecasts from
banks, financial institutions, and other sources. For Mineral Resources, metal prices used are
slightly higher than those for Mineral Reserves.
RPA has reviewed the reported Mineral Resources, dilution factors, production schedules, and
economic analysis used for conversion of Indicated Mineral Resources to Probable Mineral
Reserves. In RPA’s opinion, the basis for the conversion is appropriate and the estimate of
Probable Mineral Reserves is acceptable.
Based on the contribution of silver to the cash flow, Barrick has elected to include the silver
content as Mineral Reserves. RPA concurs with this approach.
Table 15-1 summarizes Barrick’s December 31, 2014 Mineral Reserve estimate and
represents 100% of the Mineral Reserves for the deposit. Table 15-2 summarizes the 40%
attributable to Premier.
TABLE 15-1 MINERAL RESERVES (100%) - DECEMBER 31, 2014 Premier Gold Mines Limited – South Arturo Mine
Category/ Process Type
Tonnes Gold Grade
Contained Gold
Silver Grade
Contained Silver
(000 t) (g/t Au) (000 oz) (g/t Ag) (000 oz) Probable Reserves ROM Leach 773 0.74 18 3.39 84 Mill Oxide 461 2.48 37 11.23 151 TCM 321 10.09 104 11.83 111 Roaster 1,298 5.86 245 6.90 261 Total 2,852 4.41 404 6.62 607
Notes:
1. Mineral Reserves estimated according to CIM definitions.
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2. Stockpile reserves include open pit material. 3. Mineral Reserves estimated at $1,100/oz Au and $17/oz Ag. 4. Silver ounces are reported in the Barrick LOM cash flow, but only represent 3.8% of gross revenue. 5. Cut-off grades are incorporated into the net block value calculation, which was used to determine the
processing method for each block.
TABLE 15-2 MINERAL RESERVES (40% PREMIER) - DECEMBER 31, 2014 Premier Gold Mines Limited – South Arturo Mine
Category/ Process
Type
Tonnes Gold Grade
Contained Gold
Silver Grade
Contained Silver
(000 t) (g/t Au) (000 oz) (g/t Ag) (000 oz) Probable Reserves ROM Leach 309 0.74 7 3.39 34 Mill Oxide 184 2.48 15 11.23 60 TCM 128 10.09 42 11.83 44 Roaster 519 5.86 98 6.90 104 Total 1,141 4.40 161 6.62 243
Notes:
1. Mineral Reserves estimated according to CIM definitions. 2. Stockpile reserves include open pit material. 3. Mineral Reserves estimated at $1,100/oz Au and $17/oz Ag. 4. Silver ounces are reported in the Barrick LOM cash flow, but only represent 3.8% of gross revenue. 5. Cut-off grades are incorporated into the net block value calculation, which was used to determine the
processing method for each block.
It should be noted that the Mineral Reserves correspond to the Mine Plan of Operations that
was submitted to the BLM for approval. Approval to mine South Arturo has been formally
granted by the BLM for the West Button Hill area of the Mine. Mining of the West Button Hill
pit area started on March 26, 2015.
The South Arturo mine is an expansion of the historic Dee pit, which was profitably mined in
the 1980s and 1990s by previous owners of the property. The West Button Hill ultimate pit is
shown in Figure 15-1, and it lies approximately one kilometre east of the previously mined Dee
pit.
0E
34000 N
-2000 E
32000 N
-4000 E 1000 E-1000 E3000 E-5000 E
33000 N
31000 N
0E-2000 E-4000 E 1000 E-1000 E3000 E-5000 E
34000 N
32000 N
33000 N
31000 N
DEE PIT
(Existing)
WEST BUTTON HILL PIT
5520
5880
5640
5880
5820
5700
5760
5340
5520
5580
5760
5700
5640
5820
5940
5880
5820
5640
5700
5940
5760
5580
5580
5520
5640
5700
0 500 1000 1500 200 Feet0
0 100 400 50 Metres0300200
N
July 2015
Note: Grid Coordinate System is in Imperial Units
Premier Gold Mines Limited
South MineArturo
West Button Hill Ultimate Pit
State of Nevada, U.S.A.
Figure 15-1
15-3
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WHITTLE ANALYSIS AND BLOCK VALUE INPUTS
Whittle, a Lerchs-Grossmann algorithm commercial software package for analyzing the
profitability of open pit mining, was used to evaluate the South Arturo Mine. Table 15-3 defines
the Whittle parameters and block value inputs used to generate the ultimate pit shell. Costs
were generated by Barrick personnel from Goldstrike historical costs, and the slope inputs
were supplied by Piteau Associates Engineering Limited (Piteau) of North Vancouver, British
Columbia.
A net block value was generated for each 12 m x 12 m x 6 m block for each of the processing
methods available at the existing Barrick operations, which are the following:
• Run of Mine (ROM) Heap Leaching;
• Oxide Milling (CIL);
• TCM-Acid Autoclave;
• TCM-Alkaline Autoclave; and
• Roasting.
The processing method that returned the highest net value was selected as the processing
method for the block, and its net value was exported to Whittle for the pit optimization. If all
processing methods returned a negative net value, the block was classified as waste.
TABLE 15-3 WHITTLE AND BLOCK VALUE INPUT PARAMETER SUMMARY Premier Gold Mines Limited – South Arturo Project
Whittle and Block Value Inputs Input Value Units ROM Heap Leach Oxide Mill TCM-Acid TCM-Alkaline Roaster Gold Price US$/oz Au 1,100 1,100 1,100 1,100 1,100Silver Price US$/oz Ag 17 17 17 17 17 Selling Costs US$/st 0.583 0.583 0.583 0.583 0.583Net Proceeds Royalty % 4.0% 4.0% 4.0% 4.0% 4.0%Processing Cost US$/st - Processed 2.20 23.00 56.48 56.48 30.35Mining Cost US$/st - Mined 1.40 1.40 1.40 1.40 1.40REDOX Limits redox < 2.5 redox < 2.5
2014 & LOM Gold Recovery Equations
Gold Grade Limits Equations
ROM Heap Leach Recovery = ((0.801*Cyanide Solubility Ratio)+(-0.142*Silica)+0.204)*0.85 Crushed Heap Leach Recovery = ((0.801*Cyanide Solubility Ratio)+(-0.142*Silica)+0.204) Oxide Mill Recovery = (0.509*Cyanide Solubility Ratio)+(-0.030*Silica)+0.482 TCM-Acid If Au Grade > 1.3 Recovery = 95.0% + 1.23 – 1.5 +2.35 TCM-Acid If Au Grade >0.28 & < 1.3 Recovery = 6.4334(HG)3 – 23.02(HG)2 + 28.56(HG) + 82.247 + 1.23 – 1.5 + 2.35 TCM-Acid If Au Grade < 0.28 Recovery = 661.36(HG)3 – 628.91(HG)2 + 208.23(HG) + 65.114 + 1.23 – 1.5 + 2.35 TCM-Acid For Arturo Silica Encapsulation
(-0.026 * Silica) Roaster If Au Grade > 1.15 Recovery = 93.07% Roaster If Au Grade >0.250 & < 1.15 Recovery = 3.179LN(HG) + 92.612 Roaster If Au Grade >0.125 & < 0.250 Recovery = 71.836+40.456*HG-0.009*TPOH+0.151*TCM OXIDATION Roaster If Au Grade > 0.055 & < 0.125 Recovery = -1017.2(HG)2 +377.14(HG) + 51.909 Roaster Arsenic Effect (As > 1,200 ppm) Roaster If Au Grade > 1.15
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Pit Slope Angles (By Zone) Angles (deg.) Zone 0 28 Zone 1 35, 36, 35 Zone 2 36, 38, 38, 36 Zone 3 35, 36, 35 Zone 4 24, 27 Zone 5 35 Zone 6 36, 31, 31, 37, 37 Zone 7 36, 32, 31, 32, 36, 38 Zone 8 37, 32, 31, 32, 36, 37 Zone 9 33 Zone 10 27, 27, 27, 27, 27 Zone 11 38 Zone 12 38 Zone 13 38, 37, 38, 38, 38 Zone 14 20, 20, 21, 25, 25,
Revenue Formula for ROM Leach revrom = ((0.85*min(1,(-0.142*max(0.0,silica)+(0.801*max(0.0,Aurat))+0.204)))*max(0.0,auopt)*1055.44)+(1.1* max(0.0,agopt))-2.2 Revenue Formula for Oxide Mill revmill = (min(1,(-0.030*max(0.0,silica)+(0.509*max(0.0,aurat))+0.482))*max(0.0,auopt)*1055.44)+(min(1,(0.800*max(0.0,agrat)+0.298))*max(0.0,agopt)*15.76)-23 Revenue Formula For TCM-Acid evacid_hi=(95+1.23-1.5+2.35)/100
revacid_med = (6.4334*(auopt*auopt*auopt)-23.02*(auopt*auopt)+28.56*auopt+82.247+1.23-1.5+2.35)/100 revacid_lo=(661.36*(auopt*auopt*auopt)-628.91*(auopt*auopt)+208.23*auopt+65.114+1.23-1.5+2.35)/100 revacid=(((-0.026*max(0.0,silica))+revacid_hi+revacid_med+revacid_lo)*max(0.0,auopt)*1055.44)+(3.94*max(0.0,agopt))-56.48
Revenue Formula For TCM-Alkaline revalk_hi=(95-6.86-1.5+1.95)/100 evalk_med = (6.4334*(auopt*auopt*auopt)-23.02*(auopt*auopt)+28.56*auopt+82.247-6.86-1.5+1.95)/100 revalk_lo = (661.36*(auopt*auopt*auopt)-628.91*(auopt*auopt)+208.23*auopt+65.114-6.86-1.5+1.95)/100 revalk=(((-0.026*max(0.0,silica))+revalk_hi + revalk_med + revalk_lo)*max(0.0,auopt)*1055.44)+(3.94*max(0.0,agopt))-56.48
Revenue Formula For Roaster revrost_hmg = (3.179*LN(auopt)+92.612)/100 revrost_mg = (71.836+40.456*auopt-.009*730+.151*.85)/100 revrost_lmg = (-1017.2*(auopt*auopt)+377.14*auopt+51.909)/100 revrost_lg = (-1017.2*(auopt*auopt)+377.14*auopt+51.909)/100 revrost = (((-0.026*max(0.0,silica))+revrost_lg+revrost_lmg+revrost_mg+revrost_hmg+revrost_hg)*max(0.0,auopt)*1055.44)+(1.58*max(0.0,agopt))-30.35
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Effective recoveries utilized at the cut-off grade are shown in Table 15-4.
TABLE 15-4 EFFECTIVE RECOVERIES AT CUT-OFF GRADE Premier Gold Mines Limited – South Arturo Mine
Process Method Gold
(%) Silver
(%) Roaster 66.21 10.00 TCM Acid 78.70 25.00 Oxide Mill 76.79 33.07 ROM Leach 45.78 7.00
DILUTION
Barrick determined that the dilution was accounted for in the generation of the block model for
the Mineral Reserve tonnes and grade and incorporated into the mining schedule. In RPA’s
opinion, given the disseminated type of gold mineralization, the large selective mining unit
(SMU) dimensions, the historical reconciliations at the Dee mine, and the experience of the
adjacent mines on the Carlin Trend in addressing dilution factors, the appropriate measures
have been employed for the dilution in the Mineral Reserves. In addition, a whole-block
analysis was done for each block, which incorporated lower grade and lower recovery portions
for each block.
CUT-OFF GRADES
Typical South Arturo cut-off grades for different processing methods at an US$1,100 gold price
are shown in Table 15-4. It should be noted that the block value calculation incorporates more
variables than the cut-off grades shown in Table 15-5, however, the cut-off grades shown in
Table 15-4 are typical for the South Arturo ores.
TABLE 15-5 CUT-OFF GRADE SUMMARY Premier Gold Mines Limited - South Arturo Mine
Process Method
Cut-off Grade (g/t Au)
Autoclave 2.11 Roaster 1.43 Oxide Mill 0.99 Leach 0.17
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16 MINING METHODS MINE DESIGN, MINING METHOD
OPEN PIT DESIGN Ultimate design pit limits were determined by generating Whittle pit shells based on the net
cash block values generated in Vulcan general mine planning software, and the pit slopes
recommended by Piteau. Based on these results, Barrick designed the final pit with haul ramps
and appropriate catch benches. The system of units used at the mine is imperial.
Haul ramps are designed to be 42.7 m (140 ft) wide, including the safety berm for double lane
traffic accommodating the 263 t (290 st) class haul trucks. From approximately 171 m (560 ft)
above the final pit bottom, haulage ramps reduce down to single lane traffic at a width of 12.2
m to 16.8 m (40 ft to 55 ft) wide. For both double and single lane traffic, haulage ramps have
a maximum of a 10% grade. All pits are designed to be mined on 6.1 m (20 ft) high flitches in
ore, with 9.1 m to 12.2 m (30 ft to 40 ft) wide catch benches for every other production bench.
Table 16-1 summarizes the West Button Hill pit dimensions.
TABLE 16-1 PIT DESIGN PARAMETERS AND DIMENSIONS SUMMARY Premier Gold Mines Limited – South Arturo Mine
Open Pit Overall Slopes
(degrees) Length
(m) Width
(m) Depth
(m) Pit Bottom Elevation
(MASL) West Button Hill 31 - 34 853 701 171 1,524
OPEN PIT MINING
The South Arturo operation will be an open pit mine with production sourced from several
interconnected phased pits that are designed to optimize both mill feed and dewatering
campaigns. The average mining rate will be 130,000 tpd of ore plus waste over the mine life.
The current mine life is three years (2015-2017), however, if the price of gold increases, the
mine life will be re-evaluated. Mining of the West Button Hill pit began on March 26, 2015.
Mining is carried out with a Barrick owned fleet of mining equipment including 263 t (290 st)
class rear dump haul trucks, electric shovels, hydraulic excavators, a front end loader, and
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blast hole drills for 222 mm to 251 mm (83/4 in. to 97/8 in.) diameter blast holes. Pit benches
are 6.1 m (20 ft) in height in ore and 12.2 m (40 ft) in waste. Track dozers, graders, front end
loaders, and service vehicles support the mining operation.
Overburden is transported by off-highway, 263 t (290 st) trucks from the open pit to adjacent
overburden storage areas, which are approximately 0.9 km from the pit exit. Mined ore is
trucked over existing and proposed haul roads to appropriate stockpiles, depending on ore
type. Ore that requires milling is transported to a pre-determined stockpile location for
transportation to Barrick’s Goldstrike facilities for processing located approximately five
kilometres from the South Arturo Mine. Mill-grade ore is transported to Barrick’s Goldstrike
facilities. Approximately 1.62 million tonnes of refractory ore are planned to be transported
from South Arturo to Goldstrike. Sub-grade ore material may be placed in stockpiles, or on a
selected portion of the overburden storage areas for possible future processing. Oxide mill
ore is transported by truck to Barrick’s Cortez operation for processing, which is located
approximately 118 km from South Arturo.
Typical loading production statistics used for the hydraulic and electrical shovels, and trucks
are summarized below:
• P&H 4100: 4,375 short ton per hour (stph) at 1.5 min/truck load;
• P&H 2800: 2,362 stph at 2.3 min/load; and
• Hitachi 5500: 1,159 stph at 3.9 min/load.
Overall, a total fixed time of 5.6 minutes was used to calculate truck hours.
Diesel-powered and/or electric rotary drills will be used for drilling blast holes. Typical drilling
penetration rates will range from 29 m/hr to 46 m/hr. For 12.2 m (40 ft) high benches, the
typical subdrill will be 1.2 m (4 ft) and stemming lengths will average approximately 6.1 m to
6.7 m (20 ft to 22 ft). Average drill availability and utilization are 86% and 62%, respectively.
Vertical blast holes are loaded with ammonium nitrate and fuel oil (ANFO) or emulsion, which
subsequently is detonated. Powder factors vary due to the changing lithological units and
geological structures/conditions. Powder factors range from 0.09 kg of explosive per tonne to
0.31 kg/t (0.18 lb/st to 0.62 lb/st). Unconsolidated gravels and growth media that do not require
the use of blasting techniques prior to removal are ripped with a dozer, as needed. Blasting is
performed only during daylight hours and under strict safety procedures. Explosives and
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blasting agents are handled by licensed haulers and stored on site in compliance with the
required regulations of the Bureau of Alcohol, Tobacco, and Firearms, Mine Safety and Health
Administration, and the Department of Homeland Security. Federal, state, and county
roads/highways are used to transport explosives and other mining materials by licensed
trucking companies.
ORE CONTROL
Ore control procedures developed and currently in use at the Goldstrike open pit mine are
used at South Arturo. Cuttings from production drill holes are sampled and logged by the drill
operators following procedures outlined by the ore control department. Every morning these
samples are delivered to the laboratory for analysis and the results will be downloaded from
the Laboratory Information Management System (LIMS) repository to an acQuire database as
an ASCII file. The ore control geologist imports the assays into mine planning software and
model the blocks using predefined modelling parameters.
Interpolation of the blasthole assay and metallurgical data will be performed in MineSight
software using the ID2 process, which estimates into an existing ore control block model of 3
m x 3 m x 6 m (10 ft X 10 ft X 20 ft) blocks. These blocks and blasthole survey data are
displayed on the MineSight screen and delineated by the ore control geologist/engineer into
ore or waste by grouping blocks of similar characteristics utilizing the routing ore/waste routing
criteria.
Values for the ore polygons regarding their unique identifier number/letter combination, AuFA
and LECO values (metallurgical characteristics) are entered into the dispatch Virtual Network
Computing (VNC) file automatically after creation in MineSight, a general modelling package.
This dispatch file allows the ore composite to be displayed on the Dispatch and loading unit
screens for routing to the various stockpiles. Loads are tracked to their destination via
Dispatch.
Ore is routed by process type to the appropriate facility. Oxide ore will be treated on a leach
pad or at an oxide mill facility, dependent on grade cut-offs. Refractory ore will be treated at a
roaster facility via various stockpiles according to grade and metallurgical characteristics for
blending purposes.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 16-4
Waste is routed as inert or environmentally adverse. Environmentally adverse waste is to be
segregated to the interior of the waste rock disposal facilities.
OVERBURDEN/WASTE STORAGE DESIGN DISCUSSION
Barrick proposes to increase the area and height of the currently authorized Overburden
Storage Areas Nos. 1-4 and Phase C, as noted in the Arturo Plan of Operations dated August
2012. The Plan of Operations addresses the need to accommodate the overburden from the
mining of additional pits, if production is expanded beyond the West Button Hill pit in future
years. The majority of the overburden will be placed in the West Overburden Storage Area
(WOSA), with the remainder placed in the East Overburden Storage Area (EOSA). A buffer
zone around the waste/overburden storage areas is planned, which can be up to 30 m (98 ft)
to make accommodations for storm water controls and haul roads. The heights of the waste
rock disposal facilities (WRDF) are planned to be between approximately 75 m and 150 m
above the ground surface.
Condemnation drilling is planned for proposed overburden storage areas to verify the absence
of Mineral Resources, and to collect geotechnical data.
Possible economic mineralization is known to extend beneath the proposed pits. Pit backfilling
was not considered because of the possibility of resource sterilization. The overburden storage
expansions will be engineered, designed, and constructed in the same manner as existing
waste dumps and currently authorized overburden storage areas in order to:
• Safeguard long-term dump stability;
• Provide for effective reclamation;
• Reduce the overall visual impact; and
• Facilitate deer migration.
Overburden storage area capacities may vary within the proposed footprints. The WOSA can
contain an estimated 550 million tonnes of overburden at a height of approximately 160 m, and
the EOSA can contain approximately 50 million tonnes of overburden with a height of 80 m.
The Mine could expand to contain approximately 190 million tonnes of volcanic Carlin
Formation overburden, 320 million tonnes of rock overburden, and 25 million tonnes of
previously mined overburden and fill. The overburden (including both Carlin Formation and
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 16-5
rock overburden) is anticipated to be approximately 88% oxide material and 12%
environmentally adverse material, which may be potentially acid generating.
Mined overburden will be hauled to the authorized and proposed facilities and placed by off-
highway truck end dumping from the top of the active faces, resulting in working faces of
approximately 1.3H:1V, which is the natural angle of repose. The side slopes of the
overburden storage areas will be graded to 3H:1V, except in areas of steep underlying terrain
where the overall reclaimed slopes will be 2.5H:1V. The overburden storage areas will be
constructed in 15 m to 45 m lifts. Also, an undulating and varied topography will be sculpted
along the edges of the dumps to create a more natural-looking post-mining landform.
Storm water controls utilizing best accepted practices will be built for the erosion control and
long-term stability. Engineered storm water diversion ditches, constructed up gradient of the
Mine’s facilities, will be designed to handle water flow from a 24-hour, 100-year storm event,
which will be re-routed to flow down gradient of the South Arturo facilities.
Baseline studies and laboratory testing have been completed to determine overburden
characteristics. The South Arturo geochemical characterization database includes
approximately 225 acid-base accounting tests, 89 meteoric water mobility tests (MWMT), and
six humidity cell tests. Overburden samples tested are representative of the rock type and
oxidation state of the overburden to be mined. Since environmentally adverse overburden only
constitutes approximately 12% of the overburden, it will be intermixed with oxidized overburden
and not segregated. Environmentally adverse overburden will not be placed within 15 m of the
final reclaimed perimeter. At least 7.6 m will be maintained between environmentally adverse
overburden and the natural ground surface. At least 0.7 m of growth media (topsoil cover) will
be placed over areas that receive environmentally adverse overburden. In summary, the
material will be mixed with oxide overburden and encapsulated by oxide overburden within the
overburden storage facilities.
GEOMECHANICS
PIT SLOPES In 2007, Barrick contracted Piteau to perform a geotechnical study on the South Arturo Mine
area. Piteau was chosen due to its extensive experience in performing geotechnical work at
the nearby Goldstrike operation. For the study, Piteau was provided with preliminary pit
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 16-6
designs for North Deep and South Arturo based on a gold price of $575 per ounce. Piteau
performed a nine-hole geotechnical drilling campaign that incorporated geo-mechanical core
logging, oriented core logging, laboratory testing, and piezometer installations.
The Piteau report (Piteau, 2008) emphasizes that the formation of highest concern in dictating
the final pit design slopes is the Carlin Formation. Six additional geotechnical holes were
drilled in 2013-2014. The southern portion of the South Arturo pit is affected the most by this
formation. An upper and lower ash formation, the lower of which is at the base of the Carlin
Formation, is the problematic rock type. The ash can become altered into a weak clay-like
rock of high plasticity and exhibit a friction angle of nine degrees with cohesion of 720 lb/ft2.
Basic parameters used in the design of the Arturo West Button Hill (Phase II) are listed below:
• Catch benches will be designed every 18 m (60 ft) in ore and 12 m (40 ft) in waste and will be built in 6.1 m (20 ft) high lifts;
• Minimum effective catch benches will be 9.1 m (30 ft) wide for 18 m (60 ft) high triple benches, and 7.0 m to 7.6 m (23 ft to 25 ft) wide for 12.2 m (40 ft) high benches;
• A minimum of 32 m (105 ft) wide step out for ramp width;
• A minimum factor of safety (FOS) for the north pit wall overall slope of 1.30; a FOS for the southeast overall slope of 1.22; a FOS for the south wall overall slope of 1.46; and a FOS for the west and northwest overall slopes of 1.50.
• Table 16-2 shows the recommended slopes for the South Arturo open pit(s) from Piteau.
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Prem
ier Go
ld M
ines L
imited
– So
uth
Artu
ro P
roject, P
roject #2499
Tech
nical R
epo
rt NI 43-101 – Ju
ly 15, 2015 P
age 16-7
TABLE 16-2 BUTTON HILL PIT SLOPE RECOMMENDATIONS Premier Gold Mines Limited - South Arturo Mine
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 16-8
HYDROGEOLOGY The regional bedrock groundwater level has been lowered to below ultimate pit levels from
pumping that is occurring at the neighbouring underground mines: Meikle, Rodeo, and Leeville.
West Button Hill (Phase II) represents the current, life of mine plan for South Arturo, and it is
primarily composed of the Carlin Formation. The Carlin Formation’s primary hydrological
characteristics are listed below: • The Carlin Formation overlies bedrock in thickness up to 60 m - composed of fine
grained lakebed silts and sands, and coarse grained river sands and gravels. Variably altered volcanic ash fall tuffs form continuous and widespread tuff layers, which form boundaries to water flows that include both perched and confined zones of compartmentalized groundwater as identified via drilling and piezometer installation.
• Due to the poor conductivity of the Carlin Formation, passive drainage will occur prior to and during mining to help promote slope stability.
• The passive drainage plan will include installation of vertical drains for drainage into the bedrock prior to mining, and will include installation of horizontal drains during mining (pending approval from State of Nevada).
• Water flows will be managed via piping to sumps or tanks where fill stands will be installed for filling water trucks to use in dust control.
WASTE ROCK FACILITIES Design criteria for the Waste Rock Disposal Facilities (WRDF) are summarized below (Tierra
Group International, Ltd. (Tierra), May 2014):
• The waste rock stacking plan includes waste rock from the Bootstrap, Rodeo Creek and Vinini Formation and a small amount of the lower strength Carlin Formation (Carlin). In all, the stacking plan includes 5% Carlin Formation waste rock spread over a possible nine year operation. Higher Carlin content will be removed during the first quarter of mining with Carlin making up from 10% to 50% of monthly tonnages. The first lift of the WRDF southern section will contain as much as 50% Carlin according to the waste rock stacking plan. Carlin is known to exhibit low strength properties; though mixing it with waste rock would increase its strength depending on the Carlin percentage.
A summary of waste rock material properties is shown in Table 16-3.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 16-9
TABLE 16-3 WASTE ROCK DISPOSAL FACILITY MATERIAL PROPERTIES Premier Gold Mines Limited - South Arturo Mine
Material Strength Model Density, lb/ft3 Cohesion, lb/ft3 Slope Angle
Waste Rock Mohr-Coulomb 110 0 38
Tailings Dam 1 Mohr-Coulomb 110 0 34
Tailings S=f(overburden) 85 ζ/σ = 0.1
Carlin Mixed Mohr-Coulomb 110 550 12.3
Carlin Bedrock Mohr-Coulomb 115 250 30
• Static FOS 1.30;
• Pseudostatic (Earthquake) FOS 1.05;
• The peak ground acceleration (PGA) used was 0.35 g corresponding to the maximum credible earthquake (MCE) of 7.0 magnitude;
• The horizontal acceleration used in the analysis is one half of the PGA or 0.175 g;
• A phreatic surface within the tailings material was applied seven feet below the ground surface.
Tierra’s recommendations for WRDF construction are listed below:
• Waste rock can be stacked up to 43 m (140 ft) high on top of TD1 (Historical Dee Gold tailings dam), while maintaining FOS values that exceed minimum design criteria for both static and pseudostatic conditions provided the WRDF toe is maintained at least 34 m (110 ft) downstream from the existing TD1 buttress toe.
• Waste rock can be stacked up to 213 m (700 ft) on the northwest side of the facility and still meet minimum FOS for static and pseudostatic conditions.
• Typical slopes were designed at 3H:1V.
• The south side of the WRDF, and anywhere Carlin will be concentrated at a ratio of greater than 20% in the first lift, requires encapsulation within the WRDF.
• Carlin material should be spread throughout the WRDF, and not concentrated in specific areas within the WRDF, particularly on the toes and outer faces of lifts; and Carlin material should not be stacked more than one lift 15 m (50 ft) high. Successive lifts of Carlin material should be horizontally offset (separated by competent, non-Carlin waste rock) to prevent continuous zones of Carlin more than 15 m (50 ft) high within the WRDF.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 16-10
LIFE OF MINE PLAN
The January 2015 Life of Mine (LOM) plan for the South Arturo schedules the operation to run
from 2015 to 2017 producing an approximate total of 97 million tonnes of ore and waste.
Production is scheduled to start/peak at 220,000 tpd for the first year with the use of Goldstrike
mining equipment. The ore will be processed by four possible routes: heap leach, oxide mill,
roaster, and pressure oxidation (POX)/TCM leach. Of the planned 2.85 million tonnes of ore
to be produced; 0.77 million tonnes at a grade of 0.74 g/t Au will go to heap leach, 0.46 million
tonnes at a grade of 2.48 g/t Au will be processed in an oxide milling circuit, and the final 1.6
million tonnes at a grade of 6.70 g/t Au will be shipped to the Goldstrike roaster or POX/TCM
leach circuit. The heap leach ore will be stockpiled for processing in the future. Table 16-4
summarizes the expected LOM mining production schedule by year on a 100% basis, i.e.,
which includes the total amount of material mined and total ounces mined. Premier is a 40%
partner in the Mine and Premier will be responsible for approximately 40% of the costs and will
benefit from approximately 40% of the revenue.
TABLE 16-4 LIFE OF MINE – MINE PRODUCTION Premier Gold Mines Limited - South Arturo Mine
Year Ore
Tonnes (000)
Ore Grade (g/t Au)
Contained Gold (000 oz Au)
Waste Tonnes (000)
Total Tonnes
Mined (000)
Stripping Ratio
2015 240 0.92 7.1 54,804 55,044 228.4 2016 809 2.34 60.8 36,269 37,078 44.8 2017 1,803 5.79 335.9 3,367 5,171 1.9 Total 2,853 4.40 403.7 94,441 97,292 33.1
From Barrick, 2010a (adjusted for 2014 EOY reserves) Numbers may not add due to rounding
MINE EQUIPMENT
Though the South Arturo Mine is not yet in the full production phase, Barrick is using a
conventional rear dump 263 t (290 st) haul truck fleet loaded by 35 yd3 to 62 yd3 hydraulic and
electric shovels. A list of the main equipment to be utilized is shown in Table 16-5, with most
of the equipment provided by Barrick’s Goldstrike Mine.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 16-11
TABLE 16-5 MINING EQUIPMENT Premier Gold Mines Limited – South Arturo Mine
Type of Unit Number
Komatsu 930E Trucks 263-t (290-st) 16 P&H 4100 Electric Shovels 62 yd3 2 P&H 2800 Electric Shovel 46 yd3 1 EX5500 35 yd3 Shovels 1 LeTourneau Loader 1 Komatsu 685 Conv. Water truck 1 Komatsu 930E Conv. Water truck 1 Atlas Copco Drills 2 Dozers Track/Wheel 5 Caterpillar Graders 3 From 2014 LOM Equipment A43A
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 17-1
17 RECOVERY METHODS Ore from South Arturo will be processed via one of four routes: ROM heap leaching, milling
and CIL, roasting and CIL, or POX and TCM leaching (previously CaTS or calcium thiosulphate
leaching). Metallurgical testing and mineralogical study work was conducted on various
samples taken from South Arturo to support a Feasibility Study (Barrick, 2012). The
metallurgical testing is described in Section 13 Mineral Processing and Metallurgical Testing.
Based on information from the Life of Mine plan, approximately 95% of the contained gold in
South Arturo ore will be processed off-site at Barrick’s Cortez or Goldstrike operations in a CIL
circuit or the roaster, with the remainder processed via ROM heap leaching.
Ore from South Arturo will be routed based on the maximum net cash flow that can be
achieved. The majority of the precious metal production will come from ore that will be trucked
to existing Barrick’s processing circuits located approximately 12.9 km away over improved
gravel roads.
HEAP LEACHING
ROM ore will be placed on a permanent leach pad by haul trucks. Cyanide solution will be
distributed by drip emitters. The pregnant solution will then be collected and pumped to a
carbon adsorption circuit. The cyanide concentration and pH of the barren solution will be
adjusted and the solution will be re-circulated via pumping to the heap leach pads. Loaded
carbon will be trucked to the existing autoclave carbon processing circuit for stripping and
refining to recover the precious metals and the carbon will be regenerated prior to being
returned to the carbon adsorption columns at South Arturo for reuse. The process flowsheet
is shown in Figure 17-1.
OXIDE ORE MILLING/CIL
The grinding and CIL circuits in the existing circuit at Cortez will be utilized to process the
South Arturo ore on a campaign basis. The process flowsheet is shown in Figure 17-2. The
treatment plant currently includes crushing, semi-autogenous grinding (SAG), ball milling, grind
thickening, carbon-in-column (CIC) circuit for the grind thickener overflow solution, CIL circuit,
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 17-2
tailings countercurrent decantation (CCD) wash thickener circuit, carbon stripping and
reactivation circuits, and a refinery to produce gold doré.
ROASTER/CIL
Ore that is scheduled for roaster/CIL processing will be toll processed in the existing roaster
circuit at Goldstrike on a campaign basis. The roaster pre-oxidizes ore that contains refractory
carbonaceous and sulphidic material so it can be effectively processed in a traditional CIL
circuit. The Goldstrike roaster process flowsheet is shown in Figure 17-3.
POX/TCM LEACHING
Some of the South Arturo ore is characterized as low quality roaster feed with sulphide
concentrations above oxide cut-off grades. It is expected that this material would be amenable
to thiosulphate leaching via the Goldstrike TCM leach process shown in the simplified
flowsheet in Figure 17-4 (Choi et al., 2013). Calcium thiosulphate is used to leach the gold
after pressure oxidation rather than using cyanide. Resin is used to collect the dissolved gold
in a resin-in-leach (RIL) process rather than using activated carbon. Metallurgical recovery is
based on the existing TCM leach metallurgical testwork and recovery curves.
FROM PIT
LIME
ROMHEAP
LEACHPAD
MAKE-UPWATER
PREGNANT SOLUTIONCOLLECTION
CYANIDESTORAGE
TANK
BARRENTANK
STRIPPEDCARBON
FROMGOLDSTRIKE
CARBON COLUMNS
Barren Solution Flow
Preg. Solution FlowCarbon Flow
Ore Flow
LOADEDCARBON
TOGOLDSTRIKE
NaCN
Source: Barrick Gold Corporation, 2011.July 2015
South Arturo Mine
ROM Heap LeachProcess Flowsheet
Premier Gold Mines Limited
State of Nevada, U.S.A.
Figure 17-1
17-3
ww
w.rp
acan
.co
m
1 Belt
ROM Ore
3 Belt6 Belt
5 Belt
Lime
Sump
Hydro Cyclone x 1020" Dia
Trash Bin
NaCN
Surge Tank
TrashScreen
Floc
To CIL
To CIL
DewateringScreen
Kiln x 2
Fresh Carbon
Press
Flux
Oven
Gold
E/W CellsBarren Tank
26' x 28'
Preg. Tank26' Diax 28'
Boiler x 3
Air
Propane
CCD Thickener #165' Dia
CCD Thickener #265' Dia
ToProcessWater Reactor
HoldingTank
MixingTank
FeSO4
TailingsPond
Floc
Floc
Lime
HeatExchangers
Elution Column5' Dia x 28'
HCI
Acid Wash x 35' Dia x 28'
To CIC
To CIC
A-30/28 Truck
A-30/28 Truck
To Process Water
SafetyScreen
SafetyScreen
TrashScreen
SafetyScreen
SafetyScreen
CIC Circuit x 611' x 8' Dia x 15'
CIL Circuit x 856' Dia x 58'
AirBlowers
Crushing Circuit
Legend:
Grinding Circuit
Thickening CircuitCIL CircuitCIC Circuit
Carbon
Regen Carbon
From Kiln
Grind Thickener65' Thickener4 Belt
Ball Mill16' x 28.5' Dia4500 hp
SAG Mill26' Dia x 11'4500 hp VS
2 Belt
Jaw Crusher47' x 63'300 hp
Regen Carbon
From Kiln
Pregnant SolutionBarren Solution
AirElutionsRefinery
CCD Thickeners
TailsBarren Soln
NaCN
Source: Barrick Gold Corp., 2011.July 2015
South Arturo Mine
Oxide Ore Treatment - Cortez
Premier Gold Mines Limited
State of Nevada, U.S.A.
Figure 17-2
17-4
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� 2 stages� minus 3.75 cm
� 2 x Double Rotator� 7,353 kW/unit� Wi = 18 kWh/t� P80 = 74 MICRONS�
� Carbon in leach circuit� 16 hours retention time
Tailingspond
Carbonto/from
AA block
Neutralization
Hg removal
SO2 scrubbing
CO, NOx reduction
CALCINETHICKENER
CRUSHINGGRINDING
� 2 x Roasters� 2 stage fluid bed� Independence type� 1,100 TPD O2
GAS TRAIN
ROASTING
LEACHING
GAS CLEANING
Wet ESP
Dust Scrubberand Condenser
2 HOT TRAINS
1 COLD TRAIN
Source: Hatch-Powerpoint Presentation Slide.July 2015
South Arturo Mine
Barrick GoldstrikeRoaster Process Flowsheet
Premier Gold Mines Limited
State of Nevada, U.S.A.
Figure 17-3
17-5
ww
w.rp
acan
.co
m
oversize
loaded
barren
reagentrecycle
reagentrecycle
Milling FeedThickener
Autoclave
Lix Kill
Ore & WaterOxygen
Plant
Neutralization
TS Regen
RO
CaTSManufacture
EluentsPreparation
Elution
EW
Reagents
Doré
Grit Screen
RIL
TailsThickener
New TSF
Source: Choi et al., 2013.July 2015
South MineArturo
Treatment at Goldstrike
POX/TCM Leach Flowsheet
Premier Gold Mines Limited
State of Nevada, U.S.A.
Figure 417-
17-6
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w.rp
acan
.co
m
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 18-1
18 PROJECT INFRASTRUCTURE Project infrastructure includes:
• Expansion of the open pit that began on March 26, 2015
• New Waste Rock Disposal Facilities
• Upgrades and widening segments of Bootstrap Haul Road, including light vehicle access, that are nearly complete
• Support facilities, including a communication site that has been installed
• New power transmission lines that have been installed
The Mine will not require new operating facilities such as a maintenance shop for mine
equipment and administrative offices. Both water and electricity supplies still exist on site from
previous operations. Figure 18-1 shows the proposed Mine site layout and utilities.
Regional access from Elko, and Reno, Nevada, is via Interstate Highway 80. Local access to
the South Arturo Mine is by way of paved and improved gravel roads. The Barrick Goldstrike
Mine property, which is located 4.8 km to the southeast of South Arturo, and both are
connected by improved gravel roads. Access to the Mine is also available over gravel road
from the Dunphy exit on Interstate Highway 80, located approximately 40 km south.
Electrical power is provided by Nevada Energy through an existing 69 kV power line (right-of-
way N-38874) that terminates at a substation near the previous Dee mill. A new substation
and associated power lines have been constructed to supply power to the site facilities. The
existing substation and a portion of the existing power line will be removed after the cessation
of mining and processing.
Water will be supplied locally from deep wells installed with submersible pumps. The process
supply wells will provide process water and fire reserve water to a single head tank. Potable
water will be supplied to a separate water tank and the water will be treated.
The use of the Goldstrike mobile maintenance facility was determined to provide the best cost
savings and provide better flexibility to the Goldstrike and South Arturo operations. It is
currently proposed that any satellite offices will consist of a single building of modular
construction.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 18-2
In 2014, the Mine completed construction of a number of facilities and made improvements to
existing infrastructure (Barrick, 2015a). Infrastructure to be completed in 2015 includes
(Barrick, 2015b):
• Mine road construction;
• Fuel bay of an approximate size of 114 m3 (30,000 gal);
• Ore stockpile;
• Stormwater dam;
• Mine perimeter fencing; and
• Vertical dewatering wells as needed, and after approval is granted from the State Engineer’s Office.
Infrastructure installed on the site is listed below:
• 120 kV powerline;
• 115 kV to 13.8 kV substation;
• Approximately 7.3 km of 13.8 kV distribution electrical line around the West Button Hill pit area;
• Communication system was installed on April 6, 2015 that provides reliable wireless communication between South Arturo and Goldstrike;
• A water well capable of producing 28 L/s (450 gpm) supplies water to a 3,800 m3 (one million gallon) tank;
• 4.8 km of access road improved;
• Guard station and property gates that can be activated with security badges;
• Explosive Magazine with two, 91 t (100 st) capacity and perimeter security fencing.
• Eight passive vertical dewatering wells have been installed as needed for the West Button Hill mining;
In order to reduce capital for the project, the truckshop, truckwash, warehouse and associated
facilities have been eliminated. The facilities at Goldstrike will be used as an alternative. Items
being eliminated include:
• Truckshop
• Truckwash
• Tireshop
• Drill pad
• Warehouse
• Offices
• Dry
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 18-3
• Light vehicle fuel bay
• Sewage for area
• Roads and earthworks for area
• Firewater system for this area
• Fresh water system for this area
• Potable water piping to the area
SUBSTATION
BO
ULD
ER
CR
EE
K
BOOTSTRAPHAUL ROAD
LAYDOWN AREA
FUEL BAYARTURO PIT
HELIPAD
282000 N
264000 E
WELL
WELL
GUARD HOUSE ANDTRUCK WEIGH SCALE
PoO BOUNDARY& FENCELINE
MINE HAULROAD
WATERTANK PADTRUCK
LIME SILO
PAD ACCESS AND
COVER STORAGE
HEAP LEACHPAD
PROCESSPLANT
MINE HAULROAD
PRILLSILO
ORESTOCKPILE
AREA
284000 N
286000 N
288000 N
266000 E
268000 E
270000 E
272000 E
274000 E
Haul Road
Vehicle Road
Power Lines (120 kV)
Power Lines (13.8 kV)
Fire Water
Potable Water
Fresh Water
Gas Pipeline
Proposed Fence
Legend:
0 500 1000 1500 200 Feet0
0 100 400 50 Metres0300200
Source: Barrick Gold Corporation, 201 .2July 2015
South MineArturo
Site Layout and Utilities
Premier Gold Mines Limited
State of Nevada, U.S.A.
Figure 18-1
18-4
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m
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 19-1
19 MARKET STUDIES AND CONTRACTS The principal commodities of gold and silver at South Arturo are freely traded, at prices that
are widely known, so that prospects for sale of any production are virtually assured. RPA used
a gold price of $1,250 per ounce gold for the Base Case cash flow, except for 2015 a gold
price of US$1,200 per ounce gold was used.
CONTRACTS
Comment on terms of contracts, arrangements, rates, or charges for: • Mining – No contract mining contract is in place at South Arturo; Barrick performs all
mining functions, except for the loading of the blast holes.
• Concentrating – No contract concentrating contract needed for South Arturo; Barrick processes all.
• Smelting & Refining – Final, commercial smelting and refining is completed by Johnson and Mathey located in Salt Lake City, Utah.
• Sales, Hedging, Forward Sales – RPA is unaware of any Sales, Hedging, and Forward sales contracts in place for the South Arturo gold production.
All major contracts are within industry norms.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 20-1
20 ENVIRONMENTAL STUDIES, PERMITTING, AND SOCIAL OR COMMUNITY IMPACT ENVIRONMENTAL STUDIES
The Mine will develop an Environmental Management System (EMS) for operation. It is also
expected that an ISO 14001 standards system will be created and implemented for the Mine
and the system will be periodically certified.
Based on information presented in the 2012 Feasibility Study, baseline studies were
considered complete for the Mine area, but additional studies may be undertaken as needed.
The baseline conditions and project impacts have been formally and extensively evaluated.
Potential impacts on water quality will be mitigated in accordance with an approved plan.
Mitigating measures include water quality monitoring, treatment of unsuitable water quality
prior to discharge, and re-assessment of forecasted water quality conditions every five years.
To date, the most significant environmental impact is the pit lake water quality after the
cessation of mining.
TAILINGS STORAGE FACILITY
No storage of tailings on site is required since the mill grade ore will be processed off site. All
ore that requires mill processing will be treated at the Barrick Goldstrike or Cortez facilities.
Tailings facilities at Goldstrike and Cortez will be utilized for the storage of the South Arturo
tailings and are reported to have enough capacity for the storage of South Arturo tailings.
Tailings associated with the roaster circuit are permitted for disposal in the North Block Tailings
Disposal Facility (NBTDF) or for delivery to the Rodeo paste backfill plant.
PERMITTING
The primary responsibility for permitting is assigned to Barrick’s regional permitting team
(Barrick, 2012). The primary permitting action for the South Arturo Mine will be driven by the
National Environmental Policy Act (NEPA) because a majority of the site resides on public
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 20-2
lands. Permitting work was coordinated through the BLM district office located in Elko,
Nevada. Three past NEPA actions had been performed for the Dee mine, all of which were
Environmental Assessments (EA). For the South Arturo Mine, Barrick initiated the NEPA
process in June 2009 when the Plan of Operations, written by SRK Consulting (U.S.) Inc.
(SRK), was submitted to the BLM. It was determined by the BLM that an Environmental Impact
Statement (EIS) would be required for this Mine. The Record of Decision was issued on May
7, 2014.
Even though the South Arturo Mine is on the site of the previously operated Dee mine, there
are no known environmental liabilities. It is important to note that the Dee mine has been
substantially reclaimed.
To date, the most significant environmental impact is the pit lake water quality after the
cessation of mining.
Based on information received during the site visit and recent documentation from Barrick
(Barrick, 2015b), the status of federal, state, and local permits required for the South Arturo
Mine are listed in Table 20-1.
SOCIAL OR COMMUNITY REQUIREMENTS
Barrick has operated in the Elko area since 1987, therefore, the need to establish new plans
for community engagement, resettlement, indigenous peoples, community development
programs, local workforce development/education/training, local procurement/supplier
development or immigration management is not anticipated. The Mine will not significantly
affect the actual area of operations or the daily lives of the local community, however, it
sustains mining employment in the area.
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TABLE 20-1 MAJOR PERMITS AND APPROVALS Premier Gold Mines Limited - South Arturo Mine
Permit or Approval Stage Estimated Time Frame Date Received
Record of Decision NVN-087946 Completed May 7, 2014 Bootstrap Road ROW-NVN-092787
Completed
Reclamation Plan Permit/RCE Bond 0355
Completed August 4, 2014
Water Pollution Control Permit NEV2013101
Completed Aug 20, 2012 modified Mar 6, 2015
Explosives Permit - US Bureau of Alcohol, Tobacco, and Firearms
Completed March 11, 2015
Working in Waters Permits (Boulder-NVW-39774, Bell-NVW-39775)
Completed
Hazardous Materials Permit State of Nevada; Fire Marshall Division
Completed August 4, 2014
Water Rights Completed/In Progress
Various
Storm Water General Permit NVR300000 MSW-39602
Completed July 3, 2014
Nevada State Dam Permit (storm water ponds) NDWR J-710
Completed March 2, 2015
Permit to Appropriate Water - Change in Point of Use and Diversion
Completed
Industrial Artificial Pond Permit NDOW
Not Started 3 months
Class III Landfill Waiver SW1760 Completed October 24, 2014 County Building Permits As Needed Potable Water System NDEP-Bureau of Safe Drinking Water
Not Started 12 months
Septic System NDEP-Bureau of Water Pollution Control
Not Started 6 months
Note. NDWR - Nevada Division of Water Resources; NDOW - Nevada Department of Wildlife; NDEP – Nevada Division of Environmental Protection
MINE CLOSURE REQUIREMENTS
The 2012 Feasibility Study states that reclamation of disturbed areas resulting from land
disturbance incurred during the mining process will be completed in accordance with BLM and
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NDEP regulations. Reclamation and mining practices will occur under the direction of Nevada
Revised Statutes (NRS) 519A, which states:
Surface management is to prevent unnecessary or undue degradation of public lands by
operators authorized by the mining laws. Anyone intending to develop mineral resources
on public lands must prevent unnecessary or undue degradation of the land and reclaim
disturbed areas. This subpart established procedures and standards to ensure that
operators and mining claimants meet this responsibility and provide for the maximum
possible coordination with appropriate state agencies to avoid duplication and to ensure
that operators prevent unnecessary or undue degradation. In addition, the State of
Nevada requires that a reclamation plan be developed for new mining projects and for
expansions of existing operations. (SRK, 2009)
It has been estimated that the major closure liabilities to the fully permitted Mine area will be
the following:
• Approximately 283 ha of rock waste dump;
• A post-mining pit lake;
• Approximately 60 ha of detoxified heap leach pad; and
• A proposed waste dump that would cover existing reclaimed historical heap leach pads and tailings facilities.
The following measures will be implemented to prevent unnecessary and undue degradation
at the Mine site:
• Regulated components of the facility will be designed and constructed to meet or exceed BLM/Nevada Division of Environmental Protection (NDEP)/Nevada Department of Wildlife (NDOW)/Nevada Division of Water Resources (NDWR) design criteria. Overburden storage areas and stockpiles, which do not require engineered containment, will be evaluated for potential to release constituents and will be monitored routinely, or in accordance with an approved overburden management plan.
• Surface disturbance will be limited to areas that are reasonably incidental to
exploration.
• Mining, mineral processing, and reclamation operations.
• The heap leach facilities will be operated as zero discharge and in accordance with fluid management, emergency response, and monitoring plans established by the Barrick-Dee Mining Venture, NDEP permit conditions, International Cyanide Code, and the BLM Cyanide Management Plan.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 20-5
• Mineral exploration and development drill holes, monitoring and observation wells, and
production dewatering wells subject to Nevada regulations will be properly abandoned to prevent potential contamination of water resources.
• Regulated wastes will be managed according to relevant regulations.
• Surface disturbance will be minimized while optimizing the recovery of mineral
resources.
• Fugitive dust emissions from disturbed and exposed surfaces will be controlled in accordance with NDEP regulations and permits.
• Surface water drainage control will be accomplished by diverting stormwater, isolating
facility runoff, and minimizing erosion.
• Where suitable as growth media, surface soils and overburden material in the open pit may be managed as a growth media resource and removed, stockpiled, and used during reclamation.
• A reclamation plan will be implemented, which addresses earthwork and re-contouring,
re-vegetation and stabilization, detoxification and disposal, and monitoring operations necessary to satisfactorily reclaim the proposed disturbance, including: roads, process ponds, heaps, overburden storage areas, buildings, and equipment. Reclamation activities on previously disturbed areas have proven successful, with all previously reclaimed areas having achieved bond release, or are in later stages of reclamation.
In 2014, the mine closure costs were estimated to total approximately US$2.6 million for the
mine plan from 2015 to 2017. During mining, concurrent reclamation will take place on inactive
portions of the waste rock facility when it is safe and practical. Final reclamation is expected
to be completed during the three-year mine life, and one additional year following the end of
mining operations.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 21-1
21 CAPITAL AND OPERATING COSTS CAPITAL COST
Pre-stripping capital for the period of 2015 to 2017 is estimated to be US$153.4 million.
The sustaining capital costs for the South Arturo Mine are developed and revised on an annual
basis as part of the budget cycle. The total direct capital expenditure in the LOM plan including
pre-stripping is approximately $205 million. RPA has added approximately $5.1 million of
contingency on top of this to allow for unknown costs.
The 2015 LOM capital plan for sustaining capital to support the LOM as developed at the site
for approval by the Barrick/Premier Venture is shown below in Table 21-1.
TABLE 21-1 LOM SUSTAINING CAPITAL COSTS (2015-2017) Premier Gold Mines Limited – South Arturo Mine
Capital Cost Totals 2015 2016 2017
US$(000) US$(000) US$(000) US$(000) Mine Capital 24,875 20,945 1,812 2,118
Process Capital 13,418 - 550 12,868 Dewatering Capital 4,459 1,109 2,250 1,100
Condemnation Drilling 973 973 - - Infill Drilling 4,150 - 2,000 2,150 Dee Capital 3,137 1,637 1,000 500
Totals 51,012 24,664 7,612 18,736 Source: A43ABudgetActuals_0+12_ph.xlsx
OPERATING COSTS
The operating costs for South Arturo are developed annually as part of the Goldstrike site
budget process. The total direct operating costs estimated for the South Arturo Mine are
shown in Table 21-2 before inventory adjustments, deferred stripping, silver credits, and
adjustments.
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TABLE 21-2 LOM (2015-2022) OPERATING COSTS Premier Gold Mines Limited – South Arturo Mine
Operation Unit 2015 2016 2017 2020 2022
Mining Cost US$/tonne mined 1.69 1.69 3.25 Autoclave US$/tonne processed - 59.89 59.91 Roaster US$/tonne processed 36.76 32.52 29.15 Mill US$/tonne processed - 13.96 14.22 14.66 14.66 Leach US$/tonne processed 2.57 2.57 2.57 2.57 2.57 G&A Included in mining cost
Source: 43A Tier I 2015 100% Phase 2 _0+12+LOM_Final.xlsm
MANPOWER Manpower levels for the 2015 LOM plan (three year mine life case) are represented as a
percentage of the Barrick Goldstrike manpower as shown in Table 21-3. Manpower levels
remain relatively steady through the mine life until the cessation of mining in 2017.
TABLE 21-3 LOM (2015-2017) MANPOWER Premier Gold Mines Limited – South Arturo Mine
LOM
Average 2015 2016 2017 South Arturo Manpower as a Percentage of Goldstrike Manpower 48% 54% 35% 6%
Prorated, Attributable Arturo Manpower 176 302 194 33
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 22-1
22 ECONOMIC ANALYSIS A Cash Flow Projection has been generated from the Life of Mine production schedule and
capital and operating cost estimates, and is summarized in Table 22-1. This cash flow is based
on revenue and costs for the Mine on a 100% basis. A summary of the key criteria is provided
below.
ECONOMIC CRITERIA REVENUE
• 130,000 tonnes per day mining of ore and waste from the West Button Hill pit only.
• Mill recovery by zone, as indicated by testwork, averaging 86.1%.
• Reduction in ounces for gold entrained in mill circuit.
• Gold at refinery 99.965% payable.
• Silver revenue was not included, and it is assumed to be non-material to the cash flow.
• Metal price: US$1,250 per ounce gold, except for 2015 that used US$1,200 per ounce gold.
• Revenue from 353,000 tonnes of lower-grade, stockpiled oxide mill ore was assumed to be realized in 2020.
• Heap leach mineralization revenue was assumed to be realized in 2022; this material is being stockpiled for future processing.
• Net Smelter Return includes doré refining, transport, and insurance costs.
• Revenue is recognized at the time of production.
COSTS
• Pre-production period: none, mining was initiated on March 26, 2015.
• Mine life: less than three years (2015 to 2017).
• Life of Mine production plan as summarized in Table 22-1.
• Mine life capital totals US$213 million.
• Capital cost contingency estimated to be 10%, which excludes capitalized pre-stripping.
• Costs from 353,000 tonnes of lower-grade, stockpiled oxide mill ore was assumed to be realized in 2020.
• Heap leach ore will not be processed during the first three years of mining, however, it will be stockpiled. RPA assumed a processing date of 2022 in the cash flow.
• Average operating cost over the mine life is $29.87 per tonne milled.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 22-2
• All In Sustaining Cost (AISC) is US$950/oz.
TAXATION AND ROYALTIES
Nevada Net Proceeds tax was applied to the cash flow. An average royalty of 4.9% was
applied to the Gross Revenue. RPA relied on Premier for the taxes applied to the Mine.
CASH FLOW ANALYSIS Considering the Project on a stand-alone basis, the undiscounted pre-tax cash flow totals $84
million over the mine life, and simple payback occurs approximately 2.5 years from start of
production.
The World Gold Council Adjusted Operating Cost (AOC) is US$316 per ounce of gold. The
mine life capital cost, including both pre-production and sustaining unit cost, is US$634 per
ounce, for an AISC of US$950 per ounce of gold. Average annual gold production during mine
operation (2015-2017) is approximately 104,000 ounces on a 100% basis.
The after-tax Net Present Value (NPV) at a 5% discount rate is $25 million, and the Internal
Rate of Return (IRR) is 12.5%.
A summary of the cash flow analysis is presented in Table 22-1.
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INPUTS UNITS TOTAL 2015 2016 2017 2018 2019 2020 2021 2022 2023MININGOpen Pit
Mine Operating Days 365 days 746 281 365 100Stacking Operating Days days - - - -Leaching Operating Days days - - - -Tonnes moved per day tonnes / day 130,418 195,884 101,583 51,705
'000 tonnes 2,853 240 809 1,803g/t 4.40 0.92 2.34 5.79
'000 tonnes 3,367 - - 3,367'000 tonnes 91,072 54,804 36,269 -'000 tonnes 97,292 55,043 37,078 5,171
ProductionAu GradeWasteWaste - CapitalizedTotal MovedStripping Ratio 33.1 228.4 44.8 1.9
Total Production'000 tonnes 2,853 240 809 1,803Total Tonnes Mined
Average Grade Au g/t 4.40 0.92 2.34 5.79
PROCESSING
'000 tonnes 321 - 50 270oz 104,002 - 10,209 93,794oz 92,873 - 8,984 83,889
g/t Au 10.09 - 6.293 10.798% 89.3% 0.0% 88.0% 89.4%
10.21 93.80'000 tonnes 1,298 2 265 1,031
oz 244,656 829 34,616 209,211oz 209,357 740 28,221 180,396
g/t Au 5.86 12.137 4.066 6.312% 85.6% 89.3% 81.5% 86.2%
'000 tonnes 461 - 36 72 353oz 36,738 - 5,455 10,248 21,035oz 24,673 - 4,281 6,680 13,712
g/t Au 2.48 - 4.711 4.406 1.853% 67.2% 0.0% 78.5% 65.2% 65.2%
'000 tonnes 773 - - - 773oz 18,300 - - - 18,300oz 8,378 - - - 8,378
g/t Au 0.74 - - - 0.737% 45.8% 0.0% 0.0% 0.0% 45.8%
'000 tonnes 2,853 2 351 1,373 353 773oz 403,696 829 50,280 313,253 21,035 18,300oz 335,282 740 41,486 270,965 13,712 8,378
g/t Au 4.40 12.137 4.452 7.094 1.853 0.737
AutoclaveTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery RateRoasterTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery RateMillTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery RateLeachTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery RateTotalTonnes ProcessedContained OuncesOunces ProducedGrade ProcessedRecovery Rate % 83.1% 89.3% 82.5% 86.6% 65.0% 45.8%
REVENUEMetal Prices Input UnitsAu 1,250$ US$/oz Au $1,250 $1,200 $1,250 $1,250 $1,250 $1,250 $1,250 $1,250 $1,250 $1,250Total Contained Revenue US$ '000 $419,065 $888 $51,858 $338,707 $0 $0 $17,140 $0 $10,472 $0Total Payable Revenue 99.97% US$ '000 $418,918 $888 $51,840 $338,588 $0 $0 $17,134 $0 $10,469 $0
Transport $0.000 US$/oz Au US$ '000 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Refining cost $0.583 US$/oz Au US$ '000 $195 $0 $24 $158 $0 $0 $8 $0 $5 $0Treatment $0.000 US$/oz Au US$ '000 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Total Charges US$ '000 $195 $0 $24 $158 $0 $0 $8 $0 $5 $0Net Smelter Return US$ '000 $418,723 $887 $51,815 $338,430 $0 $0 $17,126 $0 $10,464 $0Nevada Net Proceeds US$ '000 $16,675 $20 $1,916 $13,718 $0 $0 $598 $0 $424 $0Royalty NSR Input Rate Into US$ '000 $20,515 $43 $2,539 $16,581 $0 $0 $839 $0 $513 $0Net Revenue US$ '000 $381,533 $824 $47,361 $308,132 $0 $0 $15,690 $0 $9,527 $0Unit NSR US$/t milled $1,190 $388 $135 $224 $0 $0 $44 $0 $12 $0
TABLE 22-1 CASH FLOW SUMMARYPremier Gold Mines Limited - South Arturo Mine
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INPUTS UNITS TOTAL 2015 2016 2017 2018 2019 2020 2021 2022 2023OPERATING COST
US$/t moved $ 2.99 $ 1.69 $ 1.69 $ 3.25 $ 3.25 $ 3.25 $ 3.25 $ 3.25 $ 3.253.25 $Mining CostProcessing 23.36$
59.91US$/t Autoclave $ $0.00 $59.89 $59.91 $59.91 $59.91 $59.91 $59.91 $59.91 $59.91US$/t Roaster 29.91$ $36.76 $32.52 $29.15 $29.15 $29.15 $29.15 $29.15 $29.15 $29.15US$/t milled 3.23$ $0.00 $13.96 $14.22 $14.22 $14.66 $14.66 $14.66 $14.22 $14.22
AutoclaveRoasterMillLeach US$/t Leach 2.57$ $2.57 $2.57 $2.57 $2.57 $2.57 $2.57 $2.57 $2.57 $2.57
US$/t milled -$ $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00G&ATotal Unit Operating Cost US$/t milled 29.87$ $227 $38 $47 $0 $0 $15 $0 $3 $0
Mining Cost US$ '000 $18,583 $405 $1,365 $16,814 $0 $0 $0 $0 $0 $0Processing US$ '000 $66,636 $78 $12,135 $47,263 $0 $0 $5,175 $0 $1,985 $0
Autoclave US$ '000 $19,209 $0 $3,022 $16,187 $0 $0 $0 $0 $0 $0Roaster US$ '000 $38,736 $78 $8,610 $30,047 $0 $0 $0 $0 $0 $0Mill US$ '000 $6,707 $0 $503 $1,029 $0 $0 $5,175 $0 $0 $0Leach US$ '000 $1,985 $0 $0 $0 $0 $0 $0 $0 $1,985 $0
G&A US$ '000 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Total Operating Cost US$ '000 $85,219 $483 $13,500 $64,076 $0 $0 $5,175 $0 $1,985 $0
Operating Cashflow US$ '000 $296,314 $341 $33,861 $244,055 $0 $0 $10,514 $0 $7,542 $0
CAPITAL COSTDirect Cost
US$ '000 $153,596 $ 92,428 $ -61,168 $US$ '000 $29,334 $22,054 $4,062 $3,218US$ '000 $13,727 $0 $550 $12,868 $309 $0US$ '000 $3,137 $1,637 $1,000 $500
Capitalized StrippingMiningProcessingInfrastructureInfill Drilling & Condemnation Drilling US$ '000 $5,123 $973 $2,000 $2,150
Total Direct Cost US$ '000 $204,917 $117,092 $68,780 $18,736 $0 $0 $0 $0 $309 $010% US$ '000 $5,132 $2,466 $761 $1,874 $0 $0 $0 $0 $30.91 $0.00Contingency (Stripping not included)
Initial Capital Cost US$ '000 $210,049 $119,558 $69,541 $20,610 $0 $0 $0 $0 $340 $0US$ '000 $0US$ '000 $2,602 $ 551 $ 569 $ 587 $ 289 606 $
SustainingReclamation and ClosureWorking Captial US$ '000 $0 $2,422 $4,897 $21,751 -$24,909 $17 $1,140 -$5,318 $4,952 -$4,952
Total Capital Cost US$ '000 $212,651 $122,531 $75,008 $42,948 -$24,303 $306 $1,140 -$5,318 $5,292 -$4,952
PRE-TAX CASH FLOWUS$ '000 $83,663 ($ 122,190) ($ 41,146) $ 201,107 $ 24,303 ($ 306) $ 9,374 $ 5,318 $ 2,250 $ 4,952US$ '000 ($ 122,190) ($ 163,337) $ 37,771 $ 62,074 $ 61,768 $ 71,142 $ 76,461 $ 78,711 $ 83,663US$ '000 $35,118 $ 0 $ 3,968 $ 29,813 $ 0 $ 0 $ 529 $ 0 $ 808 $ 0US$ '000 $48,545 ($ 122,190) ($ 45,114) $ 171,294 $ 24,303 ($ 306) $ 8,845 $ 5,318 $ 1,442 $ 4,952
Net Pre-Tax CashflowCumulative Pre-Tax Cashflow
TaxesAfter-Tax CashflowCumulative After-Tax Cashflow US$ '000 ($ 122,190) ($ 167,305) $ 3,990 $ 28,293 $ 27,987 $ 36,832 $ 42,150 $ 43,592 $ 48,545
Total Cash Cost US$/oz $316 $712 $387 $298 $0 $0 $439 $0 $299 $0Capital Cost US$/oz $634Total Production Cost US$/oz $950
PROJECT ECONOMICS% 21.7%
5.00% US$ '000 $55,2767.50% US$ '000 $43,722
Pre-Tax IRRPre-tax NPV at 5.0% discountingPre-tax NPV at 7.5% discountingPre-tax NPV at 10.0% discounting 10.00% US$ '000 $33,588
% 12.5%5.00% US$ '000 $24,9827.50% US$ '000 $15,494
After-Tax IRRAfter-Tax NPV at 5.0% discountingAfter-Tax NPV at 7.5% discountingAfter-tax NPV at 10.0% discounting 10.00% US$ '000 $7,234
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SENSITIVITY ANALYSIS Project risks can be identified in both economic and non-economic terms. Key economic risks
were examined by running cash flow sensitivities:
• Gold price
• Contained gold ounces
• Operating costs
• Capital costs
• Recovery
NPV sensitivity over the base case has been calculated for -20% to +20% variations. The
sensitivities are shown in Figure 22-1 and Table 22-2.
FIGURE 22-1 SENSITIVITY ANALYSIS
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TABLE 22-2 SENSITIVITY ANALYSES Premier Gold Mines Limited – South Arturo Mine
Parameter Variables Units -20% -10% Base 10% 20%
Gold Price US$/oz 1,000 1,125 1,250 1,375 1,500 Contained Au Ounces oz (000) 327 365 404 442 481
Operating Cost US$ millions 68.18 76.70 85.22 93.74 102.26 Capital Cost US$ millions 170 191 213 234 255
Recovery % 71% 76% 80% 85% 90%
Pre-tax NPV @ 5% Units -20% -10% Base 10% 20% Gold Price US$ millions (9.35) 22.96 55.28 87.59 119.91
Contained Au Ounces US$ millions (8.05) 23.61 55.28 86.94 118.61 Operating Cost US$ millions 69.20 62.24 55.28 48.32 41.36
Capital Cost US$ millions 95.18 75.23 55.28 35.32 15.37 Recovery US$ millions 18.00 36.64 55.28 73.91 92.55
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 23-1
23 ADJACENT PROPERTIES The South Arturo Mine is located on the north end of the Carlin gold trend. Barrick’s Goldstrike
Mine and processing operations lie 4.8 km to the southeast. Effective December 31, 2015,
Barrick reported Proven plus Probable Mineral Reserves at Goldstrike of 80.5 million tonnes,
grading 3.70 g/t Au, containing 9.6 million oz Au and Measured plus Indicated Mineral
Resources of 8.2 million tonnes, grading 6.30 g/t Au, containing 1.7 million oz Au.
Other projects that are near to the South Arturo Mine are Newmont Mining Corporation’s
Bootstrap/Capstone and Tara mines.
The access to the historically mined, underground Storm Project is located in the existing Dee
open pit mine, immediately west of the West Button Hill open pit.
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24 OTHER RELEVANT DATA AND INFORMATION No additional information or explanation is necessary to make this Technical Report
understandable and not misleading.
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25 INTERPRETATION AND CONCLUSIONS Based on the site visit and subsequent review, RPA offers the following conclusions:
GEOLOGY AND MINERAL RESOURCES
• The South Arturo deposits are Carlin-type deposits located in the north end of the Carlin Trend.
• The drilling, sampling, sample preparation, analyses, security, and data verification meet or exceed industry standards and are appropriate for Mineral Resource estimation.
• The parameters, assumptions, and methodology used for Mineral Resource estimation are appropriate for the style of mineralization.
• Mineral Resources, at December 31, 2014, for the South Arturo Mine, exclusive of Mineral Reserves and adjusted to reflect 40% ownership by Premier, include Measured and Indicated Resources of 19.1 million tonnes grading 1.35 g/t Au and 7.05 g/t Ag, containing 831,000 ounces of gold and 4,338,000 ounces of silver. Inferred Resources total 3.9 million tonnes grading0.68 g/t Au and 3.46 g/t Ag, containing 80,000 oz of gold and 430,000 oz of silver.
• The current drill hole database is reasonable for supporting a resource model for use in Mineral Resource and Mineral Reserve estimation.
• Mineral Resource estimates have been prepared using acceptable interpolation strategies. The classification of Measured, Indicated, and Inferred Resources conform to Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves dated May 10, 2014 (CIM definitions). Restricting the Measured component of the Mineral Resource to those blocks directly intersected by drill holes is considered by RPA to be conservative, and not practical for mine design purposes.
• Gold and silver grades are not overly smoothed in higher grade areas. MINERAL RESERVES AND MINING
• The South Arturo Mine is located less than five kilometres from Barrick’s Goldstrike operation.
• Mining is by open pit at 130,000 tpd ore and waste.
• All Barrick Goldstrike systems (safety, geological control, mining, processing, administration, environmental) have been implemented for mining at South Arturo and they are operating efficiently.
• Mineral Reserves are restricted to the West Button Hill area.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 25-2
• Probable Mineral Reserves for the South Arturo Mine, adjusted to reflect Premier’s 40% basis, as of December 31, 2014, total 1.14 million tonnes grading 4.40 g/t Au and 6.62 g/t Ag containing 161,000 oz of gold and 243,000 oz of silver, respectively.
• Mining of the West Button Hill area began on March 26, 2015, and the Mine’s current mine life is estimated to be less than three years (2015-2017).
MINERAL PROCESSING AND METALLURGICAL TESTING
• Ore will be processed via one of four routes: o CIL milling at Cortez for the oxide ores o Roasting and CIL at Goldstrike o POX and TCM leach at Goldstrike o Stockpiling and future ROM heap leaching at South Arturo
• Ore trucks hauling refractory ore from Barrick’s Cortez operation to Goldstrike will be
used to backhaul oxide mill material to Cortez.
• Historical operating data from the Dee mine and the recent metallurgical test work indicate that the ore is amenable to processing. Processing of siliceous, carbonaceous, and sulphidic materials that are extracted from new deposits and deeper areas of existing deposits may not result in metallurgical responses that are similar to historical operations.
• The metallurgical test results determined the following: o Sulphide ore and ore containing preg-robbing organic carbon above the target
cut-off gold grade would be roasted. o Oxide ore above the target cut-off gold grade would be processed via ROM
heap leach. o Ore containing preg-robbing organic carbon below the cut-off grade gold grade
for roasting will be considered waste.
• The mill recovery ranges from 48% to 79% depending on the process employed. Recovery may be higher than predicted if the ore is ground finer than 74 µm in size. A gold deportment study completed by AMTEL and metallurgical test results indicated that a large portion of the gold is most likely encapsulated in silica, therefore, finer grinding could assist with improved gold liberation.
• The heap leach recovery and relationships between particle sizes and recovery may be different from the estimates because the samples tested are not in the same area of the mineralization that will be processed on the heap leach pads.
• Additional sampling and column leach tests of material from the West Button Hill deposit would provide additional metallurgical data for analysis.
ENVIRONMENTAL CONSIDERATIONS
• During the mining operations the Mine will undertake concurrent reclamation on inactive portions of the waste rock facility.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 25-3
• Cultural sites were identified near the proposed mine area. The necessary mitigation was completed and approved prior to issuance of the Record of Decision.
• It is expected that the two major, long-term environmental liabilities that will impact on the Mine are the mitigation of damage to cultural sites within planned, disturbed areas and the presence of a pit lake that will be created from passive water inflow after the dewatering pumps are removed.
• Approximately 343 ha of disturbance will be created within the permit boundary for waste storage facilities and a heap leach pad.
• It is recognized that proper construction, operation, and closure techniques should minimize the long-term environmental liability.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 26-1
26 RECOMMENDATIONS RPA makes the following recommendations:
GEOLOGY AND MINERAL RESOURCES
• Investigate the use of traditional grade wireframes and mineralization trend surfaces in favour of indicator grade domains and search domains in future resource model updates.
• Grade capping at South Arturo has been performed appropriately, and could be further improved by considering grade caps by grade domain in addition to search domain.
• Collect additional density samples and incorporate into the Mineral Resource model.
• Develop a classification script based on drill hole spacing and geological confidence for the property to prevent the loss of Measured Resources during reblocking.
MINERAL RESERVES AND MINING
• Create an overall Mine development schedule for tracking all of the significant South Arturo milestones.
• Closely monitor the controlled blasting and begin implementing a highwall slope monitoring program in the Carlin Formation.
• Investigate the use of blast movement monitoring for accurately locating the post blast location of all ore and waste material types.
MINERAL PROCESSING AND METALLURGICAL TESTING
• Representative samples of each ore type should be collected and confirmatory test work conducted using these samples to ensure that the gold and silver recovery and anticipated operating costs are accurate. Particular emphasis should be placed on a range of gold and silver head grades for each of the ore types to be processed and test work at a range of particle sizes for both heap leaching and CIL processing.
• After additional metallurgical data is available, appropriate trade-off studies should be completed in order to determine the optimum processing alternatives under changes in gold and silver prices.
ENVIRONMENTAL CONSIDERATIONS
• Monitor sites to effectively manage potential environmental and geochemical issues.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 27-1
27 REFERENCES Barrick Gold Corporation (Barrick), 2009, Technical Reserve and Resource Report, Barrick-
Arturo Project, Internal Report, December 2009. Barrick, 2012, Barrick Goldcorp, Barrick-Dee Mining Venture, Arturo Project Feasibility Study,
Revision 0, internal report, (December, 2012). Barrick, 2014 Cut-Off Grade Report Arturo Open Pit, Internal Report, Barrick, December 2014. Barrick, 2014, Impact of 2014 Arturo met pull, internal Barrick presentation, Q1 2014. Barrick, 2014, Hydrogeology Summary - Arturo Project, Internal Summary. Barrick, 2015a, Barrick Gold Corporation, Annual Information Form for the year ended
December 31, 2014, (March 27, 2015). Barrick, 2015b, Barrick Dee Mining Venture Overview, internal Barrick presentation, (March
25, 2015). Barrick, 43A Tier I 2015 100% Phase 2 _0+12+LOM_Final.xlsm, Internal MS Excel Workbook,
Barrick, December 2014. Barrick, A43A_Truck_Study_V2.xlsm, Internal MS Excel Workbook, Barrick, December 2014. Barrick, 2499_ManPower_Costs_RPA_V2.xlsx, Internal MS Excel Workbook, Barrick,
December 2014. Barrick, A43A_0+12+LOM Drill and Blast.xlsx, Internal MS Excel Workbook, Barrick,
December 2014. Barrick, A43ABudgetActuals_0+12_ph.xlsx, Internal MS Excel Workbook – Capital Costs,
Barrick, December 2014. Barrick, Equipment Requirements_43A_V6.xlsx, Internal MS Excel Workbook, Barrick,
December 2014. Barrick, AR_COG_EY2014_Workbook_v3.xlsx, Internal MS Excel Workbook, Barrick,
December 2014. Bloom, L., 2005: Review of the Storm Resource Area Assay Quality Control Program, a
memorandum from Analytical Solution Ltd. to Barrick Gold Corporation. Canadian Institute of Mining, Metallurgy and Petroleum (CIM), 2014, CIM Definition Standards
for Mineral Resources and Mineral Reserves, adopted by CIM Council on May 10, 2014. Card N, Newfields, Estimated Runoff to South Pit, Technical Memorandum, Barrick, April 3,
2015.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 27-2
Carrera J., Tierra Group International, Ltd., WRDF Stability, Technical Memorandum, Barrick, May 9, 2014.
Choi, Y., Baron, J.Y., Wang, Q., Langhans, J., and Kondos, P., 2013, Thiosulfate Processing
– from Lab Curiosity to Commercial Application, World Gold Conference, September 26 – 29, 2013, pp. 45-49.
Lonergan J., Lightwood G., Nicholas D., Call and Nicholas, Inc., Pit Slope Review for the Dee
Pit, Report, June 1995. Piteau Associates, Review of 2008 Recommended Slope Designs – Arturo (Dee) A43AP18
Mine Plan, Barrick, PowerPoint Summary, November 21, 2014. Porter, J., 2013, Arturo metallurgical reassays, internal Barrick memorandum (August 14,
2013). Premier Gold Mines Limited website RPA, 2012, Barrick Gold Corporation, Technical Report on the Arturo Project, Elko County,
State of Nevada, U.S.A., Internal Report (January 31, 2012). Schafer Limited LLC, Arturo Mine Project, Adaptive Waste Rock Management Plan, Report,
Barrick, August 2013. Scholz M., Rose N., Piteau Associates, Arturo Project – Recommended Feasibility Open Pit
Slope Designs for the Arturo Project, Barrick, Memorandum, March 8, 2010. Scholz M., Rose N., Shalka M., Piteau Associates, Arturo Project – Recommended Feasibility
Open Pit Slope Design Criteria for the Hinge and West Button Hill Pits – 825 Mine Plan, Barrick, Memorandum, April 20, 2010.
Stieger J., Barrick, Arturo 2014 Year End Reserves and Resources Reporting, Internal
Memorandum, February 4, 2015.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 28-1
28 DATE AND SIGNATURE PAGE This report titled “Technical Report on the South Arturo Mine, Elko County, State of Nevada,
U.S.A.” and dated July 15, 2015 was prepared and signed by the following authors: (Signed & Sealed) “Wayne W. Valliant” Dated at Toronto, ON July 15, 2015 Wayne W. Valliant, P.Geo. Principal Geologist (Signed & Sealed) “Stuart E. Collins” Dated at Toronto, ON July 15, 2015 Stuart E. Collins, P.E. Principal Mining Engineer (Signed & Sealed) “Brenna J.Y. Scholey” Dated at Toronto, ON July 15, 2015 Brenna J.Y. Scholey, P.Eng. Principal Metallurgist
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 29-1
29 CERTIFICATE OF QUALIFIED PERSON WAYNE W. VALLIANT I, Wayne W. Valliant, P.Geo., as an author of this report entitled “Technical Report on the South Arturo Mine, Elko County, State of Nevada, U.S.A.” prepared for Premier Gold Mines Limited and dated July 15, 2015, do hereby certify that:
1. I am Principal Geologist with Roscoe Postle Associates Inc. of Suite 501, 55 University Ave Toronto, ON, M5J 2H7.
2. I am a graduate of Carleton University, Ottawa, Ontario, Canada in 1973 with a
Bachelor of Science degree in Geology.
3. I am registered as a Geologist in the Province of Ontario (Reg. #1175). I have worked as a geologist for a total of 40 years since my graduation. My relevant experience for the purpose of the Technical Report is: • Review and report as a consultant on more than fifty mining operations and
projects around the world for due diligence and resource/reserve estimation • General Manager of Technical Services for corporation with operations and mine
development projects in Canada and Latin America • Superintendent of Technical Services at three mines in Canada and Mexico • Chief Geologist at three Canadian mines, including two gold mines
4. I have read the definition of "qualified person" set out in National Instrument 43-101 (NI
43-101) and certify that by reason of my education, affiliation with a professional association (as defined in NI 43-101) and past relevant work experience, I fulfill the requirements to be a "qualified person" for the purposes of NI 43-101.
5. I visited the South Arturo Mine on June 24, 2015.
6. I am responsible Sections 2 to 12, 14, and 23 and contributed to Sections 1, 24, 25, 26, and 27 of the Technical Report.
7. I am independent of the Issuer applying the test set out in Section 1.5 of NI 43-101.
8. I have previously prepared an internat report on the property that is the subject of the Technical Report.
9. I have read NI 43-101, and the Technical Report has been prepared in compliance with NI 43-101 and Form 43-101F1.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 29-2
10. At the effective date of the Technical Report, to the best of my knowledge, information, and belief, the Technical Report contains all scientific and technical information that is required to be disclosed to make the Technical Report not misleading.
Dated this 15th day of July, 2015. (Signed & Sealed) “Wayne W. Valliant” Wayne W. Valliant, P. Geo.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 29-3
STUART E. COLLINS I, Stuart E. Collins, P.E., as an author of this report entitled “Technical Report on the South Arturo Mine, Elko County, State of Nevada, U.S.A.” prepared for Premier Gold Mines Limited and dated July 15, 2015, do hereby certify that: 1. I am Principal Mining Engineer with RPA (USA) Ltd. of 143 Union Boulevard, Suite 505,
Lakewood, Colorado, USA 80228.
2. I am a graduate of South Dakota School of Mines and Technology, Rapid City, South Dakota, U.S.A., in 1985 with a B.S. degree in Mining Engineering.
3. I am a Registered Professional Engineer in the state of Colorado (#29455). I have been a member of the Society for Mining, Metallurgy, and Exploration (SME) since 1975, and a Registered Member (#612514) since September 2006. I have worked as a mining engineer for a total of 28 years since my graduation. My relevant experience for the purpose of the Technical Report is: • Review and report as a consultant on numerous exploration, development and
production mining projects around the world for due diligence and regulatory requirements;
• Mine engineering, mine management, mine operations and mine financial analyses, involving copper, gold, silver, nickel, cobalt, uranium, coal, and base metals located in the United States, Canada, Mexico, Turkey, Bolivia, Chile, Brazil, Costa Rica, Peru, Argentina, and Colombia.
• Engineering Manager for a number of mining-related companies; • Business Development for a small, privately owned mining company in Colorado; • Operations supervisor at a large gold mine in Nevada, USA; • Involvement with the development and operation of a small underground gold mine in
Arizona, USA.
4. I have read the definition of "qualified person" set out in National Instrument 43-101 (NI 43-101) and certify that by reason of my education, affiliation with a professional association (as defined in NI 43-101) and past relevant work experience, I fulfill the requirements to be a "qualified person" for the purposes of NI 43-101.
5. I visited the South Arturo Mine on June 24, 2015.
6. I am responsible for the open pit portions of Sections 15, 16, 21, and 22 and share responsibility with my co-authors for Sections 1, 2, 3, 24, 25, 26, and 27 of the Technical Report.
7. I am independent of the Issuer applying the test set out in Section 1.5 of NI 43-101.
8. I have previously prepared an internat report on the property that is the subject of the Technical Report.
9. I have read NI 43-101, and the Technical Report has been prepared in compliance with NI 43-101 and Form 43-101F1.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 29-4
10. At the effective date of the Technical Report, to the best of my knowledge, information, and belief, the Technical Report contains all scientific and technical information that is required to be disclosed to make the Technical Report not misleading.
Dated this 15th day of July, 2015. (Signed & Sealed) “Stuart E. Collins” Stuart E. Collins, P.E.
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Premier Gold Mines Limited – South Arturo Mine, Project #2499 Technical Report NI 43-101 – July 15, 2015 Page 29-5
BRENNA J.Y. SCHOLEY I, Brenna J.Y. Scholey, P.Eng., as an author of this report entitled “Technical Report on the South Arturo Mine, Elko County, State of Nevada, U.S.A.” prepared for Premier Gold Mines Limited and dated July 15, 2015, do hereby certify that: 1. I am Principal Metallurgist with Roscoe Postle Associates Inc. of Suite 501, 55 University
Ave., Toronto, ON, M5J 2H7. 2. I am a graduate of The University of British Columbia in 1988 with a B.A.Sc. degree in
Metals and Materials Engineering. 3. I am registered as a Professional Engineer in the Province of Ontario (Reg. #90503137)
and British Columbia (Reg. #122080). I have worked as a metallurgist for a total of 25 years since my graduation. My relevant experience for the purpose of the Technical Report is: • Reviews and reports as a metallurgical consultant on a number of mining operations
and projects for due diligence and regulatory requirements. • Senior Metallurgist/Project Manager on numerous base metals and precious metals
studies for an international mining company. • Management and operational experience at several Canadian and U.S. milling,
smelting and refining operations treating various metals, including copper, nickel, and precious metals.
4. I have read the definition of "qualified person" set out in National Instrument 43-101 (NI 43-
101) and certify that by reason of my education, affiliation with a professional association (as defined in NI 43-101) and past relevant work experience, I fulfill the requirements to be a "qualified person" for the purposes of NI 43-101.
5. I have not visited the South Arturo Mine. 6. I am responsible for preparation of Sections 13, 17, and 20 and contributed to Sections 1,
24, 25, 26, and 27 of the Technical Report. 7. I am independent of the Issuer applying the test set out in Section 1.5 of NI 43-101. 8. I have had no prior involvement with the property that is the subject of the Technical Report. 9. I have read NI 43-101, and the Technical Report has been prepared in compliance with NI
43-101 and Form 43-101F1. 10. At the effective date of the Technical Report, to the best of my knowledge, information, and
belief, the Technical Report contains all scientific and technical information that is required to be disclosed to make the Technical Report not misleading.
Dated this 15th day of July, 2015. (Signed & Sealed) “Brenna J.Y. Scholey” Brenna J.Y. Scholey, P.Eng.