Nevada-focused junior Lion Copper and Gold (TSXV: LEO) has announced positive results of a preliminary economic assessment (PEA) on its Yerington copper project, which it is advancing along with its other projects through an option to earn-in agreement with Nuton LLC, a Rio Tinto technology venture.
The PEA envisions an open pit copper mining strategy followed by a heap-leach operation, enhanced by the application of Nuton’s technologies to process primary sulfide materials. According to Lion Copper, the leaching process using Nuton’s methods can deliver recovery rates of 74% and eliminate the need for a concentrator, tailings impoundment and resource-intense smelter operations.
Given advantages offered by Nuton compared to conventional sulfide processing, it serves as the project’s preferred and foundational approach, forming the cornerstone of this PEA, the company said.
Copper production over an estimated 12-year life is expected to reach 1.4 billion pounds, or 117 million pounds annually, encompassing operations at Yerington and, at a later phase, the MacArthur project, a large oxide copper deposit that was previously active in the 1990s.
The development strategy begins with the reprocessing of legacy rock stockpiles and tailings at the Yerington mine, followed by mining activities within the base of the legacy Yerington pit once the pit has been dewatered.
To facilitate the processing, the oxide and sulfide materials will be mined and transported to separate lined heap leach pads to be located at the legacy Yerington mine. Material from the MacArthur mine will also be transported to this site, using existing infrastructure set up during the initial Yerington phase.
According to the company, by merging the two projects with co-location of processing facilities and a single legacy-affected site, the environmental impacts of the operation would effectively be minimized. Unlike Yerington, the MacArthur project is situated exclusively on federal lands, so it will be subjected to certain permitting requirements.
As detailed in the PEA, the integrated Yerington project has a post-tax net present value (at a 7% discount) of $356 million and an internal rate of return of 17.4%, calculated at a copper price of $3.85/lb. Initial capital expenditure is estimated at $413 million, with a payback period of five years.
“We are very pleased with the results of this preliminary economic assessment, which outlines a compelling path forward for advancing the integrated Yerington copper project. The projected economics showcase the tremendous value that can be unlocked by adopting an innovative and sustainable approach centered around Nuton technologies for primary sulfide processing,” Lion Copper CEO Travis Naugle said in a news release.
“The minimal footprint of our optimized strategy, with its consolidated infrastructure sited within the brownfield Yerington area, exemplifies our commitment to sustainable development that benefits all stakeholders,” Naugle added.
In late 2023, Rio Tinto formally opted into Stage 2b of the option to earn-in agreement, which provides for full funding of $10 million for completion of a pre-feasibility study on the Yerington project, anticipated to be completed later this year. The Australian miner also provided a further $1.5 million advance on Stage 3 funding for exploration on certain portions of the Bear deposit.
