Metallurgical Improvements At The Cactus Mine Project

CASA GRANDE, AZ - Arizona Sonoran Copper Company Inc. reported interim results from its ongoing metallurgical testing programs, in the form of sequential assaying, bottle roll testing and column testing for the mineral resources at the Cactus Mine, that demonstrates improved overall recoveries of ~1% total soluble copper (CuSol) and a decreased net acid consumption of ~2 lb per ton of material. The Cactus Mine project envisages a heap leach oxide and enriched sulfide (chalcocite/covellite dominant) recoveries and a solvent extraction/electrowinning (SX/EW) plant for producing LME Grade A Copper Cathodes.

Ian McMullan, COO, said, “Within mineral resource, and from the PEA, we have identified an initial 1 billion pound copper soluble leachable material. These results, now track over 2 years of metallurgical observations and provide us with additional clarity and confidence towards future copper oxide and enriched leaching opportunities. The results further de-risk the technical assumptions used in the Cactus PEA as we move towards increasing levels of confidence for inputs into the PFS due later this year.”

A copper heap leach column testing program to delineate the metallurgical performance characteristics of the existing stockpile and remaining unmined copper resources at the Cactus mine has been ongoing since 2020. Results have been progressively reported in PEA, commensurate with Canadian National Instrument NI 43-101 reporting requirements.

Copper recovery is estimated for acid soluble copper (CuAS) and cyanide soluble copper (CuCN) content as determined by a standard sequential copper assaying methodology developed at the Skyline Laboratory facility in Tucson, Arizona. The CuCN assay fraction is classified as enriched secondary copper sulfide mineralization. The combined CuAS + CuCN content of the materials represents potentially soluble copper that is recoverable using heap leaching techniques (“CuSol”). Projected copper recovery estimates previously reported have been derived based on this leachable copper content and continues to be validated in the ongoing Prefeasibility Study (PFS) testing program.

Primary copper in mineralization that is not readily acid or cyanide copper soluble per the assay methods (e.g. native copper, chalcopyrite, bornite) reports in the total copper assay (“CuT”). Copper assayed that does not report in the soluble copper assay methodologies is not expected to provide meaningful recoverable copper contributions with the commercial methodologies anticipated.

Drilling completed on the project in 2020 and 2021 was supervised by on-site ASCU personnel who prepared core samples for assay and implemented a full QA/QC program using blanks, standards and duplicates to monitor analytical accuracy and precision. The samples were sealed on site and shipped to Skyline Laboratories in Tucson AZ for analysis.