South32 Boosts Ore Reserve Estimate for Sierra Gorda Copper Mine in Chile

04:06 AM EDT, 08/25/2026 (MT Newswires) -- South32 (S32.L, S32.JO) said Tuesday the ore reserve estimate at its Sierra Gorda copper mine in Chile jumped 61% to 1.1 billion tonnes. The ore reserve estimate averages 0.39% total copper, 0.016% total molybdenum, and 0.06 grams per tonne of gold, at a total copper equivalent grade of 0.46%. The mine's initial reserve life was extended by five years to 2045. Sierra Gorda's mineral resource estimate stands at 1.87 billion tonnes at an average grade of 0.37% total copper, 0.016% total molybdenum, and 0.06 g/t of gold, at a total copper equivalent grade of 0.44%. The mining company said the update follows the approval to boost processing capacity at the project to increase copper production by 30% from 2031. South32 holds a 45% stake in Sierra Gorda alongside joint venture partner KGHM Polska Miedź, which owns 55%.