Rio Tinto Group is starting pilot production of lithium in California, sifting through old mining waste instead of excavating new areas, as the electric car battery revolution fuels demand for the material.
Work to reprocess waste piles from a 90-year-old mining site in the Kern County community of Boron has produced lithium carbonate — needed in rechargeable batteries for electric vehicles and consumer technology, Rio said this week. Efforts are now focused on improving quality and lifting volumes, the company said.
A pilot plant being assembled at Boron under a $10-million first phase is expected to produce about 10 metric tons a year of lithium carbonate equivalent by chemically processing material from the pile of mining waste.
The company will consider expanding to become the top domestic supplier in the United States.
Boron is part of a unit in California’s Death Valley that has produced borates — materials used in such items as laundry soap and nuclear reactor components — since 1872. There are at least 80 minerals to be found in material from the site, and staffers had initially been combing the waste for gold and other elements when they discovered lithium, according to Rio.
Rio, the world’s No. 2 miner, will next consider a $50-million investment to build an industrial-scale lithium plant with capacity for 5,000 tons a year that could be sold to battery makers. That volume would be enough to make batteries for about 15,000 of electric automaker Tesla Inc.'s Model S cars, the company said.
“If the trials continue to prove successful, this has the potential to become America’s largest domestic producer of battery-grade lithium — all without the need for further mining,” Bold Baatar, chief executive of Rio’s energy and minerals division, said in a statement. Currently the only supplier in the United States is Albemarle Corp.’s Silver Peak operation in Nevada, according to the U.S. Geological Survey.