
SYDNEY -- Anglo-Australian miner Rio Tinto has found high-grade lithium in the waste rock at an existing American mine, potentially paving the way to become the largest producer in the U.S.
Rio will build a $10 million pilot plant in the next few months to process lithium from waste rock at its borates operation in California. If feasibility tests identify an extraction method that will secure profitability, the miner will look at constructing facilities capable of producing 5,000 tons of lithium carbonate annually. This would potentially make it the largest high-grade lithium producer in the U.S., the company told Nikkei.