Valterra Platinum is closing in on a decision to take Mogalakwena, the world’s largest open pit platinum mine, underground. The Sandsloot underground project has been under evaluation for years. The company now plans trial mining later this year and a final investment decision in 2027, with the feasibility study due to complete in the first half of that year.
Mogalakwena, midway between Pretoria and the Zimbabwe border, holds more than eight decades of reserves and produces roughly 900,000 to 1,000,000 ounces a year at the bottom of the global cost curve. The problem is geometry: as the open pits deepen, grades decline, waste ratios rise toward 6 to 1 or 10 to 1, and costs follow. Sandsloot’s underground waste to ore ratio is about 2 to 1, which cuts tonnage moved and diesel burned per ounce.
Finance director Sayurie Naidoo told Bloomberg Television that going underground is the most cost effective option for the company, framing it inside a value over volume strategy. Chief executive Craig Miller said the portfolio holds many decades of platinum group metals, so supply is not the constraint.
A go ahead would be Valterra’s most significant move since its separation from Anglo American in 2025, and it would unlock millions of ounces of higher grade ore just as global PGM production is expected to dwindle. The demand side remains the open question: catalytic converters for petrol and diesel cars are still the largest PGM use, and Valterra’s leadership argues battery electric vehicle uptake forecasts have consistently run ahead of reality, a view South Africa’s August production slump, covered here on October 14, does not settle either way.