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16 E&MJ; • MARCH 2016 www.e-mj.com Golpu Studies Support Two-stage Block Cave Development REGIONAL NEWS - AUSTRALIA/OCEANIA Harmony Gold has reported the results of feasibility and prefeasibility studies for Stages 1 and 2, respectively, of its joint- venture Golpu gold-copper project in Papua New Guinea. Harmony and Newcrest Mining each currently own 50% of Golpu through their Wafi-Golpu joint venture. The Papua New Guinea govern- ment retains the right to purchase for its pro-rata share of historical costs up to a 30% equity interest at any time before the commencement of mining. If the govern- ment chooses to take up its full 30% inter- est, the interests of Harmony and Newcrest will become 35% each. The Golpu deposit is located approxi- mately 65 km southwest of the port city of Lae on Papua New Guinea's east coast. Stage 1 of Golpu development focuses on the mining of two block caves, along with all associated infrastructure. Stage 2 con- templates a third, deeper block cave. Stage 1 project capital is estimated at $2.6 billion. Plant throughput capacity is planned at 7 million metric tons per year (mt/y), with potential for a doubling to 14 million mt/y during Stage 2. Stage 1 mine life is estimated at 28 years, producing a total of 3.6 million oz of gold and 2.2 million mt of copper in con- centrates. At peak production, the mine would produce 297,000 oz/y of gold and 135,000 mt/y of copper in concentrates. Golpu mineral resources, as of Decem- ber 31, totaled 820 million mt, containing 18.6 million oz of gold at a grade of 0.70 g/mt, 8.6 million mt of copper at a grade of 1.0% copper, 33.1 million oz of silver at a grade of 1.3 g/mt, and 74,000 mt of molybdenum at a grade of 90 ppm. Harmony is undertaking additional work to optimize the Golpu Stage 1 feasibility study, including the driving of two access declines toward the orebody to create drilling platforms required to verify geot- echnical and hydrological interpretations of the orebody at depth. Further investigation and modeling of water will focus on increasing the confi- dence in the geohydrology model by obtain- ing additional data from drilling cam- paigns, modeling the effectiveness of a dewatering bore field around the block cave subsidence zone, and streamflow and sur- face hydrology modeling and management. The Golpu project can only progress to execution upon the granting of a special mining lease, which will include all neces- sary permits, approvals, and consents required by the Papua New Guinea govern- ment, landowners, and other relevant stake- holders. Assuming all such approvals are obtained, the feasibility study estimates that project development will require five years from the start of earthworks to first ore milled and that another 2.5 years will be required to reach steady-state production. Saracen Restarting Thunderbox Operations Saracen Mineral Holdings began commis- sioning its refurbished Thunderbox gold processing plant in Western Australia in early February. The company acquired the idle open-pit mine and plant from Norilsk Nickel in a transaction that was completed in May 2014. Norilsk had held the opera- tion on care and maintenance since 2007. Thunderbox is located 45 km south of the town of Leinster in central Western Australia, about 940 km northeast of Perth. Saracen completed a Thunderbox redevel- opment feasibility study and initiated an A$65 million redevelopment program in March 2015. Refurbishing of the gold pro- cessing plant was the key to bringing the project back into production. Throughput capacity is 2.5 million mt/y. The flowsheet includes a single-stage crusher, SAG and ball mill grinding, and conventional carbon- in-leach and elution circuits. Stage 1 of Thunderbox redevelopment is based on open-pit mining and is scheduled to produce 597,000 oz of gold over an initial 4.5- year mine life. Saracen is studying the poten- tial for extending the project's life through development of a Stage 2 underground mine and mining of Stage 3 satellite open pits. Saracen currently produces gold from its Carosue Dam operations in the South Laverton gold field 120 km northeast of Kalgoorlie, Western Australia. Production totaled 167,531 oz during the company's fiscal year to June 30. Drilling activity at the Golpu project in Papua New Guinea. The gold-copper property is jointly owned by Harmony Gold and Newcrest Mining. (Photo: Newcrest Mining)