Excelsior to test Rio Tinto’s Nuton copper tech in Arizona

Excelsior Mining (TSX: MIN; US-OTC: EXMGF) has entered into a collaboration with Nuton LLC, a Rio Tinto venture, to evaluate the use of its Nuton copper heap leaching technologies at Excelsior’s Johnson Camp mine in Cochise Cty, Ariz.

Rio Tinto’s extensive portfolio of advanced copper heap leaching technologies is targeted at primary sulphide minerals (including lower grade minerals), which could not otherwise be processed using traditional leaching or sulphide processing technologies. The Nuton technologies are a product of almost 30 years of research and development.

Excelsior believes Nuton’s proprietary technologies offer the potential to produce more copper in a cost-effective manner while producing less waste from new and ongoing operations.

The first stage of the collaboration involves Nuton completing certain test work on materials collected from the company’s Johnson Camp mine project to confirm that suitable conditions exist to deploy the heap leaching technologies.

Assuming this test work is successful, the parties would work toward negotiating commercial terms for a full-scale deployment of the technologies at the Johnson Camp mine.

The test work is expected to begin during the first quarter of 2023. If all goes well negotiations on commercial terms could start during the third quarter, Excelsior says.

The Johnson Camp mine has historically been a heap leach operation since the 1970s. It includes two open pits, a two-stage crushing-agglomerating circuit, a fully functioning solvent extraction-electrowinning (SX-EW) plant capable of producing 25 million lb. of copper cathode per year.

Excelsior is currently exploring re-opening the Burro and Copper Chief pits — previously mined in 2010 by Nord Resources — to produce run-of-mine material that can be placed on a new leach pad as a means of extracting copper from the remaining mineral resources within the two pits.

The company also owns and operates the Gunnison copper project in Arizona, a low-cost, environmentally friendly in-situ recovery copper extraction project that is permitted to produce 125 million lb. of copper cathode per year.