Canadian microcap Lion Copper and Gold Corp, which this week posted its preliminary economic assessment on a proposed US$413 million copper project in Nevada, USA, says the use of Rio Tinto’s Nuton sulphide leaching technology could significantly improve its permitting speed and project economics.
Lion hopes to produce 117 million pounds of copper a year at an average $2.87/lb all in sustaining cost over at least 12 years at MacArthur, in the Mason Valley southeast of Reno, where it wants dual-processing circuits to include a Nuton leaching facility handling up to 17 million short tons per annum of sulphide ore feed from the former Yerington mine, and a standard 25Mtpa oxide leaching stream.
“Given the multitude of advantages offered by Nuton compared to conventional sulphide processing, it serves as the project’s preferred and foundational approach, forming the cornerstone of this PEA,” Lion said.
The PEA outlines low-strip openpit operations extracting 450Mt grading 0.21% copper at Yerington and MacArthur, including 148.5Mt at 0.29% of sulphide material (including chalcopyrite) to be crushed and agglomerated before placement on the heap leach pad for Nuton processing and projected circa-74% recoveries.
Lion says hydrometallurgical testing examined both Yerington and MacArthur materials while its studies also examined production data from Arimetco’s legacy heap leach operations.
“Further testing of Nuton technologies is slated to confirm metallurgical performance through replicate trials, with completion anticipated in 2024,” the company said.
“Utilisation of cutting-edge Nuton technologies for recovering cathode copper from primary sulphide materials [negates] the need for a concentrator, tailings impoundment and smelter operations.”
Lion said synergistic co-location of processing facilities within a single legacy-affected site, servicing both the Yerington and MacArthur mines, reduced regional environmental impacts.
Dewatering of the existing Yerington pit lake, involving the pumping of about 43,000 acre-feet of water at a cost of $50 million, would facilitate pit expansion and produce water for alternative uses in the Mason Valley area.
“The projected economics showcase the tremendous value that can be unlocked by adopting an innovative and sustainable approach centred around Nuton technologies for primary sulphide processing,” Lion CEO Travis Naugle said.
“We are dedicated to advancing the Yerington copper project in a positive manner that prioritises environmental stewardship, water conservation, and benefits for tribal and local communities.
“The minimal footprint of our optimised strategy, with its consolidated infrastructure sited within the brownfield Yerington area, exemplifies our commitment to sustainable development that benefits all stakeholders.”
