BLASTHOLE DRILLING IN OPEN PIT MINING 109 USAK, TURKEY Powerful drilling, reliable production To accomplish this, Tuprag Metal Mandencilik San. Tic. A. (Tuprag) uses Secoroc COP Gold DTH hammers on two Atlas Copco DM45 rigs and a ROC L6 at the Kisladag gold mine. Designed for the production drilling market, Secoroc COP Gold hammers feature a specially designed piston for efficient energy transfer; control tube suspension with steel disc compression rings and lower buffer rings; steel grade hammer casing that provides greater impact strength and excellent wear resistance; and superb flushing capabilities. Secoroc COP Gold hammers have proven to be efficient, reliable and du- rable with a 10-15 percent longer service life than equivalent hammers. Further- more, with the COP Gold E-kit, they can be rebuilt and restored to their original performance levels up to three times at a fraction of the cost of a new hammer. These factors, along with intensive training of local operators and main- tenance personnel, have seen produc- tivity levels increase beyond expecta- tions since the mine opened in 2006. Secoroc hammers on the job At 157 km², the Kisladag gold mine in the Usak province of western Turkey is the largest gold mine in the country. It is owned by Tuprag Metal Madencilik San. Tic. A. (Tuprag), a wholly owned subsidiary of Eldorado Gold Corp. Kisladag Mine Manager Ahmet Raci Uslu in front of one of two Atlas Copco DM45 rigs that enables his team to surpass productivity expectations. Secoroc hammers go for gold Secoroc COP Gold hammers The number of meters drilled is directly tied to the productivity level of a mine. The type of rig, hammers and bits must be able to handle the geology of the site while achieving the desired per- formance levels – and do so cost- effectively.
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Blasthole Drilling in open pit mining 109
Usak, TUrkey
Powerful drilling, reliable productionTo accomplish this, Tuprag Metal Mandencilik San. Tic. A. (Tuprag) uses Secoroc COP Gold DTH hammers on two Atlas Copco DM45 rigs and a ROC L6 at the Kisladag gold mine. Designed for the production drilling market, Secoroc COP Gold hammers feature a specially designed piston for efficient energy transfer; control tube suspension with steel disc compression rings and lower buffer rings; steel grade hammer casing that provides greater impact strength and excellent wear resistance; and superb flushing capabilities.
Secoroc COP Gold hammers have proven to be efficient, reliable and du- rable with a 10-15 percent longer service life than equivalent hammers. Further- more, with the COP Gold E-kit, they can be rebuilt and restored to their original performance levels up to three times at a fraction of the cost of a new hammer.
These factors, along with intensive training of local operators and main-tenance personnel, have seen produc- tivity levels increase beyond expecta-tions since the mine opened in 2006.
secoroc hammers on the job
At 157 km², the Kisladag gold mine in the Usak province of western Turkey is the largest gold mine in the country. It is owned by Tuprag Metal Madencilik San. Tic. A. (Tuprag), a wholly owned subsidiary of Eldorado Gold Corp.
Kisladag Mine Manager Ahmet Raci Uslu in front of one of two Atlas Copco DM45 rigs that enables his team to surpass productivity expectations.
secoroc hammers go for goldsecoroc COP Gold hammersThe number of meters drilled is directly tied to the productivity level of a mine. The type of rig, hammers and bits must be able to handle the geology of the site while achieving the desired per-formance levels – and do so cost-effectively.
seCOrOC hammers GO fOr GOld
110 Blasthole Drilling in open pit mining
Tuprag uses two Atlas Copco DM45 rigs equipped with Secoroc COP 64 Gold DTH hammers for bits with a QL60 shank. In addition, there is an Atlas Copco ROC L6 equipped with a Secoroc COP 34 DTH hammer for bits with COP 34 shanks for presplitting, or a COP 54 Gold DTH hammer for bits with a QL 50 shank for production.
The result is reliable performance on the site that has continuously increased production from 70,895 ounces in 2006 to 109,177 ounces in just the first six months of 2009. The grade is 1.41 gram per ton.
maintaining productivity
Kisladag started commercial produc-tion in 2006 with a local mine contrac-tor and has been developed as a low grade, bulk tonnage open pit operation using heap leaching for gold recovery.
In May 2008, the mine began the tran- sition to being a fully owner-operated pit. The transition, which included technical and practical training of ope- rators and maintenance crews, was completed in four months, and the mine began using its own fleet exclusively in October 2008.
Kisladag has been using Atlas Copco rigs with Secoroc hammers and bits since the transition began. Penetration rates are good through the volcanic rock and Ahmet Raci Uslu, mine manager, says the rigs and rock drilling tools were selected to maintain the high pro-ductivity rates required at the mine.
“The amount of meters we drill is really important for us to keep up mine production,” says Uslu. “In June 2009 we drilled nearly 48,000 meters and we aim to maintain this level of production. High productivity is one of the reasons we chose Atlas Copco.”
The anticipated production capa-city at Kisladag is 1.73 million tons a month, but the current rate of mining is more than two million tons per month. To achieve this, drilling operations are run for 20 hours a day; mining ope-rations are 10 hours per shift and there are 14 shifts per week.
A ROC L6 equipped with its Secoroc COP 34 DTH hammer averages 45 m per hour drilling pre-split holes. Hole diameters are 95 millimeters and the
10 m
A = 22 m Pre-split holesB = 11 m Buffer holesC = 11 m Production holes
Berm
Pre-splitholes
Bufferholes
Production holes
5.5 m
5.5 m
1 m
2.5 m
4.2 m
4.2 m
4.8 m
10 m
A B C C C ……
10 m
5.5 m
The drilling pattern at the Tuprag open pit with 152–165 mm production holes, 152 mm buffer holes and 95 mm pre-split holes. The purpose of the pre-split holes and the row of buffer holes is to ensure thestability of the final walls of the pit.
The ROC L6 with a Secoroc COP 34 DTH hammer drills the pre-split holes. Each hole is 95 mm in diameter with an average depth of 45 m. Hole spacing is 1 m. (Inset) the blasting sequence of the pre-split holes.
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Blasthole Drilling in open pit mining 111
spacing between the holes is 1 meter. The holes are 22 meters deep and have an inclination of 65-77 degrees.
For production drilling, the ROC L6 with the Secoroc COP 54 Gold hammer averages 400 meters per shift. Each DM45, equipped with a Secoroc COP 64 Gold hammer, averages 31-35 meters per hour. The hole diameters are 152-165 millimeters and the drilling pattern is 5.5 meters x 5.5 meters with vertical holes. The production drilling benches are 10 meters high with 0.5-0.8 meters of sub-drilling.
The total drilling capacity for all rigs is 58,000 m/month. This is inclu-ding 2 x DM45 and one ROC L6. The availability of the rigs is 92%.
Hole quality is checked by measur-ing tape before each blast. Kisladag uses cord, downhole delays and surface delays for detonators and ANFO and emulsion ANFO explosives.
While high speed drilling increases the number of holes completed per day, air consumption, fuel costs, penetration rates and bit and hammer life have a major impact on profitability. The operating life for the Secoroc DTH hammers with E-kits is: COP 34-9,900 meters; COP 54 Gold-12,853 meters; and COP 64 Gold-27,332 meters.
maximizing, extending bit lifeKisladag uses Secoroc drill bits to achieve high production rates for extended intervals. To utilize the full power of the drill rigs, regular bit grinding is essential. The bit on the COP 34 averages 1,540 meters; the bit on the COP 54 hammer, 2,257 meters; and the bit on the COP 64 Gold, 3,099 meters.
However, the economics of drill-ing often comes down to balancing penetration against bit life. A rule of thumb is that a 10-percent increase in penetration rate results in a reduction of 20 percent in bit life.
To extend the life of its bits and maximize the number of drilled meters per bit, Kisladag uses a Secoroc Grind Matic grinder, and each bit is reground two or three times. The efficient grind-ers extend the service life of the bits, which also results in less wear and tear
on each rig’s drillstring. The availability of consumables and parts, as well as the durability of the equipment, also played a role in Ahmet Raci’s Uslu’s decision to use Atlas Copco at Kisladag. “We have our own maintenance shop and crew. We get good maintenance sup-port from Atlas Copco Turkey and a good supply of parts and consumables – that makes life easy for us,” he says.
exceeding productivity expectationsSince the first year of commercial production (July 2006), Kisladag has surpassed productivity expectations. Initially, plans were to increase produc-tion in year four, but Tuprag was able to move forward with expansion in year two. And the trend continues. Tuprag’s parent company, Eldorado Gold, re-cently completed a review of the
Kisladag mine. The study identified opportunities to effectively increase annual production by 30-40 percent, while decreasing unit operating costs by approximately 15 percent – all of which is expected to be achieved using Tuprag’s existing fleet.
For Ahmet Raci Uslu, the relation-ship with Atlas Copco and the reliabil-ity of the equipment will continue to contribute to the production capability of Kisladag. And with Secoroc equip-ment offering the lowest cost per meter in the industry, taking all costs into consideration, his fleet will also make a major contribution to the mine’s prof-itability.
acknowledgements
This article first appeared in Mining & Construction, No. 3 2009, and was updated June, 2010.
Bahadir Ergener, RDT/GDE product manager, Atlas Copco-Turkey, demonstrates how to use a gauge to determine when a tungsten carbide bit needs regrinding. Kişladağ uses a Secoroc Grind Matic BQ2-DTH.
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112 Blasthole Drilling in open pit mining
Secoroc hammers are purpose-matched for all rock types and applications. Where high performance is the main criterion, Secoroc COP Gold hammers arerecommended in blast hole drilling.
