New method for extracting lithium from solid salt requires minimal fresh water

A team of scientists at Monash University in Australia has developed a novel method for recovering lithium, crucial for battery manufacturing. The process extracts lithium from solid, lithium-containing salt mixtures rather than from liquid brines. This new approach requires substantially less fresh water and energy, offering a more environmentally friendly alternative for lithium extraction.

Currently, lithium is primarily obtained through two main methods: mining solid rock and subsequent refining, or evaporating lithium-rich brines in large ponds. Evaporation processes can take months to years to yield a usable concentrated lithium chloride solution. While faster direct lithium extraction (DLE) methods exist, they consume vast amounts of fresh water, which is scarce in the arid regions where these brines are found, impacting local ecosystems and communities. Furthermore, these traditional methods are inefficient, recovering less than half of the available lithium.

The technique developed by Monash University scientists utilizes the solid salt crust left after evaporation, where lithium is bound. Researchers wash the salt using industrial solvents such as ethanol and acetone. These organic liquids dissolve the lithium while simultaneously separating it from impurities like boron and sulfate. These impurities typically adhere to the lithium matrix and require separate chemical treatments in conventional methods. This minimizes the need for large volumes of fresh water.

The recovered lithium achieves high purity directly after extraction, facilitating its use in batteries. The method is reported to extract up to 95 percent of the lithium, nearly double the yield of conventional processes. The university has filed for a patent for this technology, representing a significant advancement in more sustainable and efficient lithium production.