Rio Tinto announced on April 7 that it has kicked off the production of battery-grade lithium from waste rock at a lithium demonstration plant at the Boron mine site in California, United States. Lithium is a vital component in the production of batteries that power electric vehicles (EVs) and most high-tech electronics.
Next step in scaling up lithium production
The company said that the demonstration plant is the next step in scaling up a new lithium production process developed at Boron mine site, to recover the critical mineral and extract additional value out of waste piles from over 90 years of mining at the operation.
Successful small-scale trial in 2019
Rio Tinto’s initial small-scale trial in 2019 had successfully proved the process of roasting and leaching waste rock to recover high grades of the metal. The lithium was successfully extracted from tailings at the 90-year-old open pit mine, which produces borates.
Following this, the company had earmarked a $10 million investment to build a pilot plant that will be able to produce lithium-carbonate – the California demonstration plant.
10 tonnes per year design capacity
The company said that the California demonstration plant has a design capacity of 10 tonnes per year of battery-grade lithium. Rio said that the plant will be run throughout 2021 to optimize the process.
The company said that the plant will also inform Rio a feasibility assessment for progressing to a production scale plant with an initial capacity of at least 5,000 mt per year. This is enough to make batteries for approximately 70,000 electric vehicles.
Rio Tinto Minerals chief executive 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.”
Feasibility study at Jadar
Rio’s lithium pipeline also includes the 100%-owned lithium and borates mineral project in Jadar, Serbia. The company said that the project’s feasibility study is expected to be completed by the end of 2021.