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SURFACE MINING The mine's Hitachi EX-3600 hydraulic excavators are matched with Caterpillar 785C haulers. When new haulers arrive on site, they will be equipped for trolley assist. (Photo: Simon Walker) mt, while total rock mined reached 24 mil- lion mt. Eldorado completed an expansion of the leach pads, installed larger carbon columns in the ADR (adsorption-desorp- tion-recovery) plant and undertook design work on increasing crushing capacity to more than 12 million mt/y. Gold produc- tion rose to 237,200 oz at a cash cost of US$280/oz. Design work on the capacity expansion continued during 2010, while mine output rose again, to 274,600 oz at a cash cost of US$329/oz. Permitting for the expansion was granted in June 2011, allowing the company both to increase its leaching capacity for Kişladağ ore and construct a new processing plant to handle flotation concentrates from its Efemçukuru under- ground mine in Izmir province, which came on stream during the year (See E&MJ;, February 2012, p.20). The new plant is designed to recover around 70% of the recoverable gold from Efemçukuru, with the remainder being recovered at a gravity- concentration unit at the mine. Capex at the mine totaled US$55 million in 2010 and a further US$53 million during 2011, most of which was invested in completing the expansion project. Phased Pit Development Since mining began, the pit floor at Kişladağ has reached an elevation of 874 m above sea level, from an 1,100 m start- ing point. A six-phase operation is being studied, with the final pit bottom engi- neered for an elevation of 400 m, giving ultimate pit dimensions of 1,700 by 30 E&MJ; • MAY 2012 1,500 m (5,600 by 5,000 ft), by 650 m (2,100 ft) deep. Since taking over the mining operation from its initial contractor, Tüprag has been relying on two Atlas Copco DM45 drill rigs for the bulk of its production blasthole drilling, together with an Atlas Copco FlexiROC D50 that is used mainly for pre- split drilling around the pit perimeter, plus some production work as well. In August 2011, the mine took delivery of an Atlas Copco Pit Viper PV-235 blasthole rig, which will add capacity once drilling demands increase as the next stage of expansion gets under way. Loading and hauling involves two Hitachi EX3600 face- shovel hydraulic excavators, a Caterpillar 993 wheel-loader and a fleet of 14, Caterpillar 785C 150-mt-capacity rear- dump trucks. Designed as a mid-range blasthole drill capable of either rotary or down-the-hole drilling, the Kişladağ PV-235 is powered by a 597-kW (800-hp) Caterpillar C27 engine. Crawler-mounted, and with an all-up weight of some 58 mt, the rig can exert 267 kN (60,000 lbf) of hydraulic pull-down and 29.5 mt (65,000 lb) of weight on the bit. The mine uses 152- or 165-mm bits on 114-mm-diameter drill pipe, with the rig drilling 12-m-deep holes in one pass. Mine Manager Serkan Yüksel described to E&MJthe; contribution that the Pit Viper had made since it had arrived on site, with the two DM45s and the PV-235 having completed a total of 650,000 drill meters during the first 11 months of the year. "During the four months that it's been here, the Pit Viper has contributed around 70,000 m to that total," he said. "We are using the Pit Viper in the hard- er rock in the pit, so we're not really in a position yet to make direct comparisons between it and the DM45s. What it has done for us, though, is to give us drilling capacity ahead of our production needs, so we can chose to be selective about where we use it at the moment," Yüksel said. Not only that, but the mine operates with a 'cushion' of broken ore sufficient for between 20 and 25 days' production which, he added, has been helped by the extra drilling capacity now available. Both ore and waste is drilled on a dia- mond pattern, with a 4.5-5.25 m burden and slightly greater spacing. Blastholes cover the depth of a 10-m mining bench, with typically 800-mm (31.5-in.) sub- drilling. The mine uses both ANFO and Emulite emulsion explosives, depending on whether holes are wet or dry. A blast every day meets the mine's current production needs, with some 1.5 million mt of broken ore 'in stock' at the end of November 2011. Dig and Dump Equipped with 21-m3 buckets, the two Hitachi EX-3600 hydraulic shovels bear the brunt of the rock-loading duties, with a high-lift Caterpillar 993K wheel loader on hand to add capacity when needed. The mine's initial fleet of 10 Cat 785C haulers was augmented with a further four machines during 2011, in preparation for future increases in tonnage handling. Other equipment on site includes two Cat D9 doz- ers, a Cat 834 wheel dozer, and two Cat 16M graders and three water trucks for haul road maintenance and dust suppression. As Yüksel explained, there is good rea- son for high-quality haul-road care. This is an arid part of Turkey where annual rainfall averages 425 mm, mainly in winter when temperatures are 5-10°C (40-50°F) during the day and down to -10°C (15°F) at night. In summer, by contrast, typical daytime temperatures are up to 33°C (90°F). With the rock density varying from 2.1 to 2.5 mt/m3, haul-truck loads can range between 120 and 150 mt, he pointed out. Average haul runs are currently around 2 km to the waste-rock dumps and 1.4 km to the primary ore crusher. Given its relatively compact footprint, maintaining pit-wall stability will become increasingly important as the pit gets deep- er, which is where the mine's Atlas Copco FlexiROC D50 comes into play. The rig is www.e-mj.com