Precious metals miner Sibanye-Stillwater is in talks to buy nickel and copper assets in Brazil, as it looks to step up supplies of raw materials that are key to the transition to low-carbon energy sources.

The South Africa-based miner on Monday confirmed that it was in negotiations with affiliates of funds advised by London-based private equity fund Appian Capital Advisory, regarding the acquisition of the producing Santa Rita nickel/copper/cobalt mine and Serrote copper/gold project, in Brazil.

Sibanye-Stillwater did not disclose the valuation under discussion, but The Wall Street Journal, which first reported the story earlier on Monday, said that the transactions could be valued at about $1-billion, including debt.

Sibanye-Stillwater has been stepping up its presence in the battery materials supply chain in recent months. The miner has invested $490-million in a lithium/boron mining project in Nevada, US. It has also previously struck deals to acquire a stake in the owner of a lithium project, in Finland, and to buy a nickel hydrometallurgical processing facility, in France.

Globally, mining majors are racing to increase their exposure to metals key to a low-carbon future. BHP Billiton and Australian billionaire Andrew Forrest are both trying to secure an undeveloped nickel, copper and chrome asset in northern Ontario, Canada.

Appian took the Santa Rita mine out of bankruptcy and brought it back into production in late 2019. The previous owner, Australia’s Mirabela Nickel, spent about $1-billion on the mine, which has a processing capacity of 6.5-million tons of ore a year. Appian last year delivered a preliminary economic assessment to extend Santa Rita’s life from eight to 34 years.

Serrote, meanwhile, is a greenfield project that was completed in mid-2021 with the first shipment of high-grade copper/gold/silver concentrate scheduled for November. Serrote will produce an average of about 22 000 t/y of copper equivalent over an initial 14-year mine life from a low-strip, openpit mine supplying a 4.1-million-ton-a-year processing plant.  The Serrote project was delivered for about $200-million.