Snapshot: Capstone Mining's plan to produce battery-grade cobalt in Chile

Vancouver-based Capstone Mining is considering to produce 22,600t/y of battery-grade cobalt sulfate from a Chilean copper, iron and gold mine.

Construction at Santo Domingo, 50km southwest of state miner Codelco’s El Salvador mine, is expected to start this year, but the company recently updated its technical report to include an opportunity involving cobalt.

Santo Domingo is controlled by Capstone (70%) and Korea Resources Corporation (30%).

Originally, investment was set at US$1.51bn, but the cobalt complex would raise capex to US$2.18bn. Mine life is 18 years, with cobalt production starting in the third year.

During the first five years of full production, Santo Domingo’s average annual contained copper production is set to be 159Mlb/y, and 263Mlb/y with cobalt. 

Capstone aims to produce 10.4Mlb/y of cobalt in the form of 22,600t/y of battery-grade cobalt sulfate over the mine life. 

The project includes the development of two open pit mines and a copper-iron concentrator with a maximum processing capacity of 65,000t/d. A desalination plant will also be included as the project is 100km from the Pacific coast, providing access to deepwater port facilities. 

“If Santo Domingo was in operation today, refined production of 4,700t/y of cobalt would make Capstone the fourth largest battery-grade cobalt producer outside China, and the largest in the Americas,” Capstone CEO Darren Pylot said in a release.  

In 2019, Capstone received all critical construction permits and the approval of the mine closure plan. Santo Domingo has the potential to improve project economics with infrastructure sharing. 

Chile was a cobalt producer until 1944 and, according to copper commission Cochilco, the country currently has seven active projects with cobalt potential besides Santo Domingo. Six of them are in Atacama region and one in Valparaíso region.