Engineering & Mining Journal

FEB 2019

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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Page 45 of 75

GREAT BASIN DEVELOPMENT 44 E&MJ • FEBRUARY 2019 management from Gold Resource, con- tractor Ledcor, and local community lead- ers, Jason Reid reminded everyone of the magnitude of the situation, saying "It's not every day you get to open a mine." Gold Resource purchased its own crusher and conveyor systems, which are currently in operation today. Ledcor will move waste and ore at a pace of 20,000 t/d for the first two years in the Isabella pit. Then mining operations will be reduced to 4,000-5,000 t/d of all high-grade ore once they access the Pearl deposit. "We are certainly looking forward to those days where we are moving fewer tons, but pro- ducing more gold," Devlin said. A processing facility is currently being built that includes an absorption/desorp- tion recovery (ADR) plant for making doré on-site. The barren and pregnant ponds have been built and lined. Leach-pad construction is complete, and placement of the overliner of crushed material on the pad is nearly complete. Mining on the first ore bench at Isabella is under way and the company is also stripping the overburden at the Pearl deposit. This summer Isabella Pearl will emerge as the flagship operation for Gold Resource's fu- ture Nevada operations and the company believes it can increase its reserves in this district substantially beyond the current four-year mine plan. Pumpkin Hollow Progress In 2015, Nevada Copper had to put their Pumpkin Hollow project on hold due to market conditions. "We eventually made the decision to finish construction and today we're fully financed and moving for- ward," said Greg French, vice president of exploration and project development, Ne- vada Copper. Pumpkin Hollow is a prime example of a Walker Lane project moving from survival mode to growth. Nevada Copper plans to build two mines and two mills in the district. They are starting with an underground copper mine and they are anticipating near-term production. "We plan on achieving pro- duction in Q4 2019," French said. "A new 5,000-t/d mill will start processing ore. We're fully permitted for the mill and another open-pit mine. Our land package is all on private lands, which reduces the company's exposure to the federal permit- ting process. We also have a large area for exploration potential. Nevada Copper is building the mill that will process the ore from the under- ground mine now and it believes the tim- ing is good. The Pumpkin Hollow mine is located about 8 miles from Yerington, Nevada. It has access to power and infrastructure and, because it's a former copper produc- er, they have good support locally. Not only is the timing good, but French believes they are also in the right location with respect to mineral deposits. Showing a map of the Yerington district, he out- lined others working in the region. HudBay Minerals, for example, recently purchased the Mason Resources properties. "When you look at the Yerington batholith in its entirety, it's a mineral endowment north of 33 billion lb of copper," French said. In his presentation titled, "The Pump- kin Hollow Project: 1960 to 2018," French gave a detailed history of the deposit and its discovery. During the 1960s, U.S. Steel was looking for mag- netite deposits in the western U.S. when they discovered a huge magnetic anom- aly, French explained. "Their first drill hole was 800 ft of 50% iron," French said. "Then iron prices softened, and the steel mill in Provo, Utah, closed, so they eventually leased the property to Anacon- da. Copper prices steadily declined, they closed it and the property reverted back to U.S. Steel. Cyprus Minerals picked it up in the late 1980s and invested more work in it through the early 1990s." In 2006, Nevada Copper acquired the property and introduced it as a maiden resource with a 6,000-ft in-fill drilling program. The property already had an existing 500,000 ft of drill data, French explained. "All the cores and pulp were at Nevada Copper has started construction on a 5,000-t/d mill (foreground) at Pumpkin Hollow. The headframe for the main shaft serving the underground operations can be seen in the background. GREAT BASIN DEVELOPMENT

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