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Mount Milligan 2017 - Centerra Gold · 2019. 5. 21. · The Mount Milligan concentrator was...

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Win As a Team Be Responsible Miners Strive For Continuous Improvement Deliver Results Mount Milligan 2017
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  • Win As a Team Be Responsible MinersStrive For Continuous Improvement Deliver Results

    Mount Milligan 2017

  • Mount Milligan Location

    2

  • Mount Milligan Location

    3

  • Mount Milligan Minesite

    4

  • Mt. Milligan Claim Status

    5

  • Regional Geologic Setting

    6

  • Deposit Geology

    7

  • Main Deposit Cross Section

    8

  • Resource Expansion Potential

    9

  • Mt. Milligan Exploration Targets

    10

  • Mount Milligan Site Overview

    11

    Open Pit

    North Pond

    East Pond

    South Pond

    Cleaner Cell

    PAG Cell

    South Embankment

    SE Embankment

    North Embankment

    NE Embankment

    East Embankment

    Mill

    Primary Crusher

    South Seepage Collection Pond

    North #2 Seepage Collection Pond

    North #1 Seepage Collection Pond

    WSBOpen Pit

    North Pond

    East Pond

    South Pond

    Cleaner Cell

    PAG Cell

    South Embankment

    SE Embankment

    North Embankment

    NE Embankment

    Mill

    Primary Crusher

    WSB

    Alpine Lake

    Secondary Crusher

    TSF

  • Mine Summary

    12

    • Environmental Assessment Certificate granted in 2009• Construction began in 2010• Commercial production, February 18, 2014• 22 year projected mine life• Gold (average grade 0.36) & Copper (average grade 0.19%)

    • BC’s first major new metal mine in more than 15 years

    • Second largest gold reserve in Canada• Open-pit mine produces 120,000 TPD• Nominal 62,500 TPD processing plant

  • Current Pit – June 2017 (looking south)

    13

  • Mine Operations – Major Equipment

    14

    Major Mining Equipment:

    • 2 Caterpillar 7495HR2 Electric Mining Shovels• 2 Caterpillar 994F Wheel Loaders• 2 Caterpillar Electric Drill MD6640• 1 Caterpillar Diesel Drill MD6290• 13 Caterpillar 793F Haul Trucks• 2 Caterpillar 789C Haul Trucks

  • Mine Operations – Mining Strategy

    15

    A 15 m bench height is usedfor mining both ore and waste. The overall mining sequence was developed through a series of mining pushbacks specific to the MBX, 66 and WBX subzones (collectively, the Main Zone), and SS phases. The approach was designed to:

    • maintain higher grade mineralization in the MBX and 66 subzones;• maintain a smooth waste/ore ratio with required TSF construction

    materials;

    • develop an ore blending strategy while selectively mining from the Main Zone and SS pits to smooth delivery of copper and gold head grades to achieve the required concentrate grades;

    • provide potential waste rock storage in the mined out sections of the Main Zone pit for waste generated from the WBX and SS mining phases

  • Mine Operations – Waste Rock Strategy

    16

    • Mining and placement of overburden, non-acid generating (NAG) sulphide rock, weathered and oxide rock from the mine is integrated at the TSF with the construction of the south, southeast, northeast, and north embankments, Pipeline Corridor Causeway (PCC), Eskers Road and West Separator Berm (WSB).

    • Delivery of potentially acid generating (PAG) rock for sub-aqueous storage at the TSF will be integrated in the cleaner/scavenger tailing Separator Dyke and bulk storage area within the TSF.

    • Residual overburden will be stockpiled in the WSB laydown area and a temporary stockpile located west of the primary crusher (the South Stockpile).

    • Overburden will be reclaimed from the South Stockpile during the later years of the mine life for shortfalls of TSF material requirements, and for the completion of the last four construction stages (Stages 18–21) of the TSF embankment.

  • TSF Main Components

    17

    Open Pit

    North Pond

    East Pond

    South Pond

    Cleaner Cell

    PAG Cell

    South Embankment

    SE Embankment

    North Embankment

    NE Embankment

    East Embankment

    Mill

    Primary Crusher

    South Seepage Collection Pond

    North #2 Seepage Collection Pond

    North #1 Seepage Collection Pond

    WSBOpen Pit

    North Pond

    East Pond

    South Pond

    Cleaner Cell

    PAG Cell

    South Embankment

    SE Embankment

    North Embankment

    NE Embankment

    MillSouth Seepage Collection Pond

    North #1 Seepage Collection Pond

    WSB

    Alpine Lake

    Meadows Creek Pumping Stations

    North #2 Seepage Collection Pond

  • Tailings Storage Facility Design Concepts

    • Mine waste to be confined behind a zoned water retaining earth-rockfilldam approximately 7,300 meters long averaging 55 to 70 meters high with a maximum height of 90 meters;

    • Cleaner tailing will be stored within a separate cell within the larger scavenger tailing basin;

    • High PAG, low PAG, Low NAG, oxide and weathered rock waste storage areas (located within TSF)

    • Portion of low NAG, oxide and weathered materials used in construction of the upstream shell zones

    • Tailing distribution system,Reclaim water system;

    • PAG, low PAG and low NAG Waste Storage Area (located within TSF)

    18

  • TSF Design

    19

    Design follows a modified centerline construction

  • TSF Till Core Construction

    20

    Glacial till material is mined directly from deposits overlying bedrock throughout the Mine

    Till is placed in the Core zone and spread with tracked dozers

  • 21

    Placed till is compacted to specified density

    Downstream of till core has two filter zones (Filter (F) and Transition (T))

  • TSF Waste Embankment Construction

    22

    Upstream and downstream embankments are constructed from run of mine rock

    Rock is placed in 1-2 meter lifts

  • TSF Construction

    23

    Till Core Downstream filter zones

    Downstream Embankment

    Upstream Embankment

    TSF construction – typical completed lift

  • Seepage Collection Ponds

    24

    Seepage collection ponds at toe of dam collect all drainage which is pumped back into the facility

  • Milling

    25

    The Mount Milligan concentrator was originally designed to process ore at a nominal rate of 60,000 t/d, producing a marketable concentrate of copper, gold and silver. A secondary crushing circuit together with mill optimization projects will increase throughput to a nominal rate of 62,500 t/d.

    Key process equipment consists of:

    • primary crushing plant with a 1.525 m x 2.794 m gyratory crusher• secondary pre-crushing plant with two cone crushers, each powered by one 1,000 kW• motor prior to the grinding circuit• SAG/ball mill/crusher grinding circuit:

    • one 12.20 m diameter x 6.71 m EGL SAG mill with one 23.5 megawatt (MW) gearless motor drive• two 7.32 m diameter x 12.50 m EGL ball mills each driven by two 6.5 MW variable speed

    synchronous motors (26 MW total installed ball mill power)• two cone crushers, each powered by one 750 kW motor

    Flotation circuits:• rougher flotation: two parallel trains of five 200 m3 tank cells• first cleaner flotation: seven 100 m3 tank cells• second and third cleaner flotation: six 30 m3 tank cells

    Regrinding and gravity concentration circuits:• one 1,119 kW tower mill operated in closed circuit with six 380 mm cyclones• two 3,000 kW IsaMills operated in closed circuit with twenty-six 250 mm cyclones• one centrifugal gold concentrator

  • Simplified Process Plant Flowsheet

    26

  • New Secondary Crusher Facility

    27

    Primary Crusher

    Secondary Crusher

    Coarse Ore Stockpile Mill

  • Process Plant Improvement Opportunities

    28

    During 2016, the operation has spent approximately $51 M to increase tonnage beyond 60,000 t/d with the financial plan target being 62,500 tpd. However, data indicates that as throughput increases there will be a shift in the bottleneck from primary grinding downstream to two areas: the ball mills being able to achieve target grind and the flotation circuits to achieve recovery.

    In order to further enhance the processing plant to achieve targeted throughput and recovery, a number of capital improvement initiatives have been identified.

    Capital Projects Estimated Cost $ MAdditional Grinding Capacity $18.9Additional Cleaner Capacity $4.6Additional Rougher Capacity $9.1Water Quality Control Circuit $9.1Water Treatment Circuit $3SAG Discharge/Cyclone Feed Pump Box Modifications $1.5Total $46.2

    All of these projects require test work, engineering and execution before a proper cost and benefit analysis can be performed. At this time the capital costs associated with the above improvements are scoping quality in nature with an accuracy of -30% to +50%.

  • Reclaim Barge in South Pond

    29

  • 2017 Technical Report Reserves

    30

    MINERAL RESERVE ESTIMATE EFFECTIVE DECEMBER 31, 2016

    Mineral Reserve Category Tonnes (000) Cu (%)

    Au (g/t)

    In-Situ Cu Mlb

    In-Situ Au (000 oz)

    Proven 256,847 0.187 0.424 1,058.6 3,503 Probable 239,362 0.188 0.293 990.9 2,257 Total Proven + Probable 496,210 0.187 0.361 2,049.5 5,760

    Notes: (1) CIM definitions were followed for Mineral Reserves. (2) Mineral Reserves are estimated at a $6.25/t (C$8.12/t) cut-off value using metal prices of $2.95 per

    pound copper and $1,200 per ounce gold, and a US$/C$ exchange rate of US$1.00/C$1.30. (3) Figures may not total exactly due to rounding.

  • 2017 Technical Report Reserves

    31

  • 2017 Technical Report Resources

    32

  • 2017 Technical Report Reserves (by Phase)

    33

  • LOM Phases Plan and Section

    34

  • LOM – Pit and TSF at End of 2016

    35

  • LOM – Pit and TSF at End of 2017

    36

  • LOM – Pit and TSF at End of 2018

    37

  • LOM – Pit and TSF at End of 2021

    38

  • LOM – Pit and TSF at End of 2025

    39

  • LOM – Pit and TSF at End of 2032

    40

  • LOM – Pit and TSF at End of 2038

    41

  • Opportunities

    42

    Near-term

    • Continue to optimize comminution circuit

    • Mill throughput averaged 53,000 tpd for Q1, improving on monthly basis, should achieve about 60,000 tpd average for the year,

    • Focus on optimizing mine and mill to increase gold and copper recoveries

    Long-term

    • Geometallurgical drill program to build geomet model (18 months)

    • Expand throughput to 70,000 tpd

    • Add gold cyanidation circuit


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