General Moly has announced the results of an updated pre-feasibility study (PFS) for its 100% owned Liberty molybdenum-copper project 20 miles north of Tonopah, Nevada.

The project is based on redevelopment of a property operated first by Anaconda and then by Cyprus Minerals as the Hall-Tonopah open-pit mine during the 1980s. Idaho General Mines (now General Moly) gained control of the property in 2007 and renamed the project the Liberty project.

The updated Liberty project PFS estimates total production of 402 million lb of molybdenum and 308 million lb of copper in concentrates over a 32-year, open-pit mine life. General Moly CEO Bruce D. Hansen said, “This PFS confirms the economically robust nature of the Liberty project. In addition, there are many significant attributes, including its secure Nevada jurisdiction, substantial existing infrastructure and long life. This analysis also details our plan to build the Liberty project at a low initial capital cost of $366 million, with 26,500 st/d mill throughput.”

The Liberty project is expected to produce an annual average of 14 million lb of molybdenum and 7.5 million lb of copper over the first five years of operations, and is estimated to average 12.6 million lb of molybdenum and 9.6 million lb of copper annually over the life of the mine. Average on-site cash costs are estimated at $6.32/lb of molybdenum, using copper as a byproduct credit. Total cash costs are estimated at $7.79 lb, which would include off-site roasting, smelting and shipping costs.

“Depending on market conditions and financing options, Liberty could be advanced through a feasibility study as early as end of year 2015, with the potential to initiate construction as early as late 2017 under Nevada state permits, with production to follow in late 2019,” Hansen said. 

“Full realization of the economics of this PFS are partly dependent on the ultimate receipt of a federal Environmental Impact Statement record of decision (ROD) at the start of production, as a portion of the project is located on federal land, but a less favorable economic plan could be executed solely on private land for a few years, should there be a delay in receiving the ROD.

“We expect the feasibility study would focus on improving the project economics based on further drilling, sampling, and metallurgical testing to drive the potential for higher mill throughput, process recovery, and more optimal mine plan options.”