New method of mining lithium in saltwater lakes

The new method allows up to 90% of lithium to be extracted from high-altitude salt lakes without depleting freshwater resources.

A team of researchers from Monash University and the University of Queensland, Australia, has developed a method that allows for the direct extraction of lithium from harsh environments, Interesting Engineering reported on October 23. The new method, called EDTA-assisted liquid nanofiltration (EALNF) , is faster and more sustainable than traditional methods. The study was published in the journal Nature Sustainability.

New method exploits magnesium and lithium at the same time. (Photo: Monash Suzhou Research Institute).

Lithium is a key resource in energy storage solutions, but its extraction is water-intensive, damaging ecosystems and communities. These methods are also ineffective for lithium from saltwater sources. As a result, about 75% of the world's lithium reserves are currently untapped.

China and Bolivia have huge reserves of lithium. However, due to harsh conditions, the high-altitude brine lakes in these two countries have not been exploited. Traditional lithium mining involves separating magnesium from lithium, which is energy-intensive and time-consuming. Magnesium concentrations in high-altitude brine lakes are very high, making lithium extraction even more difficult.

"The huge amounts of water, chemicals and infrastructure required for traditional mining are not readily available, highlighting the need for innovative technologies ," said Zikhao Li, a researcher at Monash University.

EALNF solves the problem by mining magnesium along with lithium instead of separating it as waste. Nanofiltration then uses a colloidal agent to separate the magnesium from the lithium. The resulting magnesium is of high quality and can be sold as a valuable by-product along with the lithium.

"The new technology achieves a lithium recovery efficiency of 90%, nearly double that of traditional methods, while significantly reducing the extraction time from several years to just a few weeks ," Li added.

Another advantage is that while traditional methods use freshwater, which depletes water resources, EALNF produces freshwater as a by-product. The new method is also flexible and can be scaled up quickly, meaning that it will not take many years to go from testing to industrial deployment.

'With Monash University's EALNF technology, high-altitude salt lakes can now become a viable commercial source of lithium and contribute to the global supply chain. This breakthrough is critical to avoiding future lithium shortages, providing access to lithium from hard-to-reach sources, and accelerating the transition to clean energy ,' Li said.