Scientists from Australia’s Nuclear Science and Technology Organisation (ANSTO) have developed a world-first innovation that sees lithium extracted from mining waste.
Together with researchers from Lithium Australia Limited (LIT), the scientists developed a way of treating lithium mining waste to optimise the lithium that can be recovered from hard rock deposits.
Australia supplies 60% of the world’s lithium consumption, with a natural abundance of ‘hard rock’ lithium and one of the largest lithium deposits globally. But demand for the metal has increased with a boom in the lithium-ion battery market as technology for portable electronics has grown over the last three decades.
ANTSO’s Dr Chris Griffiths said the new technology would increase the sustainability of lithium operations worldwide.
“Until now, it has been quite accepted by industry that a large amount of lithium is ‘lost’ during processing. We’re the first in the world to achieve such an efficient level of extraction,” Griffiths said.
The conventional way of extracting the metal from the mineral concentrate spodumene is limited because the process (which involves a rotary kiln and temperatures reaching up to 1000 degrees Celsius) only worked on batches of a certain type and size.
The traditional process results in a large proportion of the lithium in these hard rock deposits to be wasted. ANSTO and LIT researchers wanted to address the problem with current techniques only recovering between about 50%-70% lithium from the original ore.
“This technology really has huge potential for an industry which is integral to our transition to the electrification of transport, and ultimately to a cleaner and greener future,” Griffiths said.
The new patented extraction process, dubbed LieNA®, does not require high-temperature conditions. Scientists believe it can also utilise more than 95% of lithium value from Australia’s hard rock deposits with significantly less energy than conventional methods.
Its development has been supported by a $1.3 million federal government award in 2020 from the Department of Industry, Science and Technology with the aim of completing a feasibility study and progressing the LieNA technology to commercialisation.
“The technology involves an initial treatment of the waste spodumene with caustic under autoclave conditions to form a synthetic lithium sodalite which can be easily recovered,” ANTSO said.
“Lithium is then easily extracted and purified in relatively straightforward, hydrometallurgical processing steps and finally isolated as lithium phosphate, which can be directly used in the manufacture of lithium ferro-phosphate batteries.”