Rio Tinto produces battery-grade lithium from waste rock at US mine

7th April 2021 By: Mariaan Webb - Creamer Media Deputy Editor Online

Rio Tinto produces battery-grade lithium from waste rock at US mine

Diversified major Rio Tinto has started production of battery-grade lithium from waste rock at a lithium demonstration plant at the Boron mine in California.

The demonstration plant is the next step in scaling up what the company states is a breakthrough lithium production process developed at Boron – to recover the critical mineral and extract additional value out of waste piles from more than 90 years of mining at the operation.

“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,” Rio Tinto Minerals CE Sinead Kaufman says in a statement.

An initial small-scale trial in 2019 successfully proved the process of roasting and leaching waste rock to recover high grades of lithium.

The demonstration plant has a design capacity of 10 t/y of battery grade lithium. The plant will be run throughout 2021 to optimise the process and to inform the miner’s feasibility assessment for progressing to a production scale plant of at least 5 000 t/y.

Best known for its iron-ore, aluminium and copper offerings, Rio Tinto is keen to expand more into battery metals. The company’s lithium pipeline also includes the Jadar lithium/borate project, in Serbia, for which a feasibility study is expected to be complete by the end of the year.