Rio Tinto producing battery-grade lithium from waste rock at California mine site

by Michael Green
Using waste material at Boron site is 'valuable next step', said Rio Tinto CEO Sinead Kaufman. Photo: Rio Tinto
Rio Tinto said today it had started producing battery-grade lithium from waste rock at a lithium demonstration plant at the Boron mine site it controls in California.

The plant, which has a design capacity of 10 tonnes per year of battery-grade lithium, will run throughout this year, as part of Rio’s feasibility assessment for considering a production-scale facility.

The company said a full-scale plant would likely have an initial production capacity "of at least 5,000 tonnes per year – or enough to make batteries for approximately 70,000 electric vehicles”.

'Innovative thinking'

Mining at Boron, about 100 miles northeast of Los Angeles, began in 1927. Borates – a group of minerals used to make soaps, cosmetics and other consumer goods – have been produced at the site.

Rio has said previously that it discovered lithium while testing the site’s tailings for gold.

CEO Sinead Kaufman said: "This is a valuable next step in scaling up our production of lithium at the Boron site, all from using waste material without the need for further mining.”

"It shows the innovative thinking we are applying across our business to find new ways to meet the demand for emerging commodities like lithium, which are part of the transition to a low-carbon future.”