Excelsior Mining has started solvent extraction-electrowinning (SX-EW) operations at its Gunnison Copper Project in Arizona and expects copper cathode production to begin "within 30 days," the company said Nov. 10.
"After only three-months of acid injection, we have collected enough copper to start initial production," Excelsior CEO Stephen Twyerould said in a statement. "This will allow us to commission and evaluate SX-EW capabilities."
Excelsior said it has optimized Gunnison's wellfield since announcing plans to restart operations in August, allowing the company to recover sufficient copper-in-solution through acid injection from a limited number of wells to move forward with the project.
"The issue of copper precipitates and other precipitates blocking wells has been solved, and the upgrades to the wellfield implemented earlier in the year have proven effective," Excelsior said. "Copper grades in the wells that have been consistently operated are in-line with expectations."
Work at the site was temporarily suspended in March in response to the coronavirus pandemic.
Staffing levels at Gunnison were still reduced and restricted due to the pandemic, so operations have been conducted at a smaller scale in line with safety measures, Excelsior said.
Twyerould said Excelsior will continue to upgrade additional wells at the site and resolve potential challenges in order to expand production to full capacity through 2021.
"A variety of issues still need to be worked through, such as how to minimize the impact of carbon dioxide on fluid flows and how best to maximize flow rates in general," he said. "However, we believe that all of these challenges are temporary and will not impact long-term copper production."
Gunnison will have an initial copper production capacity of 25 million lb/year once operations are ramped up, but the project is permitted to allow expansion to 125 million lb/year.
Source: Platts |
