Valterra Platinum is nearing a decision that’s likely to take the world’s largest platinum mine underground.

Mogalakwena — half way along the road from South Africa’s capital Pretoria to the Zimbabwe border — is the company’s flagship asset, with more than eight decades of reserves remaining. But as ore grades decline in its open pits and mining the material becomes more expensive, Valterra is exploring deep beneath the surface.

That underground project, known as Sandsloot, has been under evaluation for years but finally appears on the cusp of becoming a reality. Valterra plans to begin trial mining later this year and to reach a final investment decision in 2027.

“We believe that going underground is the most cost-effective option for us,” CFO Sayurie Naidoo said in an interview with Bloomberg Television’s Chief Future Officer.

The green light for an underground mine at Mogalakwena would be the firm’s most significant step forward since being spun off from Anglo American in June 2025. It would unlock millions of ounces of high-grade ore at a time when global production of platinum-group metals is expected to dwindle in the years to come.

“We have many, many decades of PGMs available just within our portfolio, so the supply is not a concern,” CEO Craig Miller said on the same show.

Valterra owns three operations in South Africa, which holds nearly 80% of global reserves of the metals, but the evolution of Mogalakwena would be pivotal for the future of the country’s biggest PGM miner by value.

That’s partly because the project comes as the biggest source of demand for PGMs — devices that curb harmful emissions from gasoline and diesel cars — is under pressure from the rise of electric vehicles.

Valterra’s leadership remains bullish, saying that forecasts on the uptake of battery EVs have consistently proved to be overoptimistic.

“We still feel that PGMs will have a role to play in future mobility,” Miller said. He points to the staying power of internal combustion engines, the role played by hybrid cars and – in the longer term – the potential for transport powered by hydrogen.

In addition, the artificial intelligence build-out, involving massive investments in data centers and advanced chips, “is an area where we see a lot more potential,” Naidoo said.