Engineering & Mining Journal

NOV 2012

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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REGIONAL NEWS - U.S. & CANADA Stillwater Mining reports progress on its $180-million Blitz and $8-million Graham Creek underground mine development projects on the J-M Reef near its existing under- ground platinum group metals mines in south-central Montana. (Illustration courtesy Stillwater Mining Co.) 2012 was about 5,700 ft (1,740 m). The TBM development is scheduled to wrap up late in the first quarter of 2013, after which two new vertical ventilation raises to surface will be added. Total cost of Graham Creek develop- ment work is projected at around $8 mil- lion, of which about $4 million had been spent through September. In view of the technical complexity of the ventilation raises, the company anticipates it may need to bring in an outside contractor to develop the raises, which could increase the total estimated cost of the Graham Creek project by about $3 million. Stillwater Mining could realize some early Graham Creek PGM production dur- ing 2014, although full development, including all definitional drilling, is target- ed for completion in early 2015. The com- pany does not yet know if the project will facilitate any increase in production rates at East Boulder, which like the Stillwater mine has excess permitted mill capacity. In other developmental news, at Stillwater Mining's processing operations in Columbus, Montana, the company is nearing completion of a project to con- nect an older, previously idled smelting furnace to its current primary furnace, which was commissioned in 2009. The idled furnace has been reconfigured as to serve as a slag-cleaning furnace, support- ing improved metal recoveries and addi- tional recycling growth, as well as provid- ing backup smelting capacity. The newly structured slag cleaning operation will be functional at the beginning of December 2012, and both furnaces should be oper- ating in tandem by the end of the year to increase PGM recoveries. Stillwater Mining anticipates the slag cleaning operation will yield more than 2,500 oz/y of PGMs from both mined and recycled materials that would otherwise remain bound up in smelter slags. 10 E&MJ; • NOVEMBER 2012 At the Marathon PGM-copper project in Ontario, Canada, owned 75% by Stillwater Mining and 25% by Mitsubishi, a definitive engineering study is currently being conducted by Nordmin Engineering Ltd. The study will yield a final project design and firm cost estimates, as well as information required to obtain the final Marathon operating permits. An environmental impact statement for the Marathon project, submitted in July 2012, is currently under public review and open to public comment, with hearings by a joint federal-provin- cial environmental review panel expect- ed to begin sometime in the second quarter of 2013. Yukon-Nevada Changes its Name to Veris Gold Yukon-Nevada Gold Corp. changed its name to Veris Gold Corp. in early October 2012. The company's primary asset is its Jerritt Canyon gold mine located 50 mi north of Elko, Nevada. Veris also holds a diverse portfolio of precious metals prop- erties in British Columbia and Yukon Territory, Canada, including the former producing Ketza River mine. The Jerritt Canyon mine is operated by Queenstake Resources USA, a wholly- owned subsidiary of Veris Gold. During the third quarter of 2012, the mine produced and shipped 35,523 oz of gold. The com- pany is targeting a run rate of 16,000 oz/m by the end of December 2012. On October 18, 2012, Veris received approval to operate the Jerritt Canyon roaster circuit at 250 st/h, an increase of 13.6% from the 220 st/h previously allowed. The increase allows the roasting facility to operate at its ultimate engi- neered capacity of 6,000 st/d. At this operating rate, Veris expects to be able to produce 200,000 oz of gold in 2013 from 3,000 st/d of Jerritt Canyon ore. Comstock Mining Pours First Gold and Silver Doré Comstock Mining brought production back to the historic Comstock mining district south of Virginia City, Nevada, at the end of September 2012 when it began smelt- ing Merrill Crowe precipitate from its heap leaching operations. The first pour pro- duced six doré bars containing 3,414 oz of silver and 329 oz of gold. Five doré bars were sold for more than $700,000, repre- senting a gold price of $1,777.25/oz and a silver price of $34.61/oz, with one bar held in reserve to produce 1-oz commem- orative bars celebrating the event. The Nevada Territorial Mint in Lyon county Nevada produced 250 of the commemorative bars, and the bars sold out within days of their introduction to the market. Comstock Mining has constructed an operation that includes surface mining, hauling, crushing, stacking, leaching, processing, filtering, drying, smelting and pouring. Further refining to produce final gold and silver bullion is completed at a contracted refinery. Resources on the company's proper- ties are estimated at 20.4 million oz of silver and 2.4 million oz of gold. Comstock Mining President and CEO Corrado De Gasperis said, "We are cur- rently operating at a rate of approximate- ly 1 million dry tons per year. This should result in an annualized production rate of approximately 20,000 gold equivalent ounces per year and stabilized cash flow. Once stable, we intend to further increase production levels during 2013." Comstock Mining began acquiring properties in the Comstock district in 2003 and as of August 2012 had consol- idated 5,869 acres. The company contin- ues acquiring properties in the district, expanding its footprint and creating oppor- tunities for further exploration and mining. www.e-mj.com

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