South32 (ASX, LSE, JSE: S32) announced Tuesday updated ore reserve and mineral resource estimate (MRE) for the Sierra Gorda copper mine in Chile.
The updates, the company said, reflect enhanced orebody definition following successful infill drilling programs, with approximately 85,000 metres from 200 drillholes completed between 2023 and 2025.
The updated estimates as of July 31 2026 reflect a 61% increase in the ore reserve estimate to 1,100 million tonnes, averaging 0.39% total copper, 0.016% total molybdenum and 0.06 g/t gold, at a total copper equivalent grade of 0.46%.
An extension of the initial reserve life by approximately five years to 2045; and an MRE of 1,870 million tonnes, averaging 0.37% total copper, 0.016% total molybdenum and 0.06 g/t gold, at a total copper equivalent grade of 0.44%.
Sierra Gorda is a large, conventional, open pit copper mine located in the Antofagasta region of northern Chile with modern processing equipment onsite. The copper concentrate produced at the operation is transported by truck and rail to the ports of Antofagasta and Angamos for international export to end markets.
“This update highlights the scale, quality and long-life orebody at Sierra Gorda, which we expect will be a significant source of copper for decades to come,” South32 CEO Matt Daley said in a news release.
“It follows the approval in July to proceed with execution of the fourth grinding line project at Sierra Gorda, which is expected to increase copper production by approximately 30% from 2031,” Daly said.
“With the current orebody remaining open at depth, the mine offers potential for further growth beyond today’s increase to ore reserve and reserve life. We continue to work with our joint venture partner to drive further growth and value at Sierra Gorda.
Sierra Gorda includes the Catabela Northeast exploration project, where exploration holes have intersected significant copper mineralisation, highlighting the potential for future mine life extension, the company said.
South32 acquired a 45% interest in Sierra Gorda in February 2022 and has joint control alongside 55% joint venture partner KGHM Polska Miedź.
