Research to revolutionise lithium extraction technique

An international research team has pioneered a filtration technique that could substantially change the way lithium-from-brine is extracted.

The technique has the potential to slash lithium extraction times from months and years to hours and to facilitate lithium recovery rates of about 90 per cent.

This is compared with the 30 per cent recovery rate achieved through the conventional solar evaporation process.

The study, completed by Monash University, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), the University of Melbourne and The University of Texas at Austin researchers, was published in the Nature Materials international journal.

The findings demonstrate how metal-organic framework (MOF) channels can mimic the filtering function, or ion selectivity, of biological ion channels embedded within a cell membrane.

Inspired by the filtering capabilities of a living cell, the researchers have developed a synthetic MOF-based ion channel membrane that is precisely tuned to filter lithium ions.

This technology is the subject of a worldwide patent application filed in 2019. Energy Exploration Technologies (EnergyX) has since executed a worldwide exclusive licence to commercialise the technology.

Benny Freeman from the McKetta department of chemical engineering at The University of Texas said the strategy could provide a road map for resource recovery and low energy water purification of many different molecular species.

“Thanks to the international, interdisciplinary and collaborative team involved in this research, we are discovering new routes to very selective separation membranes,” Freeman said.

Zhe Liu from the University of Melbourne said the MOF-based membrane systems had multiple filtration applications, including for use in lithium-from-brine extraction.

“The working mechanism of the new MOF-based filtration membrane is particularly interesting, and is a delicate competition between ion partial dehydration and ion affinitive interaction with the functional groups distributed along the MOF nanochannels,” he said.

Lithium-from-brine extraction is most common in the Lithium Triangle – a region of the Andes bordering Argentina, Bolivia and Chile, which holds roughly half of the world’s lithium reserves.

With the majority of Australia’s lithium produced from the mineral spodumene, the new technique could spur on the investigation of Australia’s salt lakes for potential lithium production options.

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