Engineers unlock lithium from extreme environments

October 24, 2024

An innovative approach developed by researchers at Monash University and Queensland University in Australia enables direct lithium extraction from extreme environments such as deserts. 
 
Called EDTA-aided loose nanofiltration (EALNF), the approach is faster and more sustainable than conventional methods, according to a university press release. 

As countries work to transition their economies to be powered by cleaner energy sources, the demand for lithium has shot up. A critical resource in energy storage solutions, lithium is abundantly available on Earth, but its extraction processes are water-intensive and have been reported to damage ecosystems and communities in areas where it is mined. 

Moreover, the methods are ineffective in extracting lithium from saltwater sources. This effectively means that 75 percent of the world’s lithium reserves are not being tapped currently.  
 
With surging demand, experts warn that global lithium supply could fall short as early as 2025, slowing down the transition to clean energy. Researchers Zikhao Li at Monash and Xiwang Zhang at the University of Queensland have developed the EDTA-aided loose nanofiltration (EALNF) approach, which could help solve the problem.

How does it work?
  
The global supply of lithium is sourced from China and Bolivia, which have large deposits of the element. However, due to tougher brine conditions, high-altitude salt brine flats in these countries are not being tapped.  
 
Conventional lithium extraction involves the separation of magnesium from lithium during the extraction process, which is energy-consuming and time-consuming. Magnesium concentrations in high-altitude salt brine flats are very high, making lithium extraction even more difficult.  
 
“The vast amounts of water, chemicals and infrastructure required for conventional extraction just aren’t available either, underscoring the need for innovative technologies,” said Li in a press release.  
 
EALNF solves the problem by extracting magnesium alongside lithium instead of separating it as waste. Later, nanofiltration uses a selective chelating agent to separate magnesium from lithium, which has previously proven to be a difficult and time-consuming step.  
 
Magnesium, thus separated, is of high quality and can be sold as a valuable by-product alongside lithium. 

Advantages of EALNF
 
The technology achieves 90% lithium recovery, nearly doubling traditional methods’ performance. “Our technology achieves 90 percent lithium recovery, nearly double the performance of traditional methods, while dramatically reducing the time required for extraction from years to mere weeks,” added Li.  
 
But the advantage of this approach isn’t limited to its efficiency alone. While traditional methods rely on fresh water in the extraction process and have been responsible for depleting water resources, EALNF creates freshwater as another by-product. 

The approach is highly flexible and can be scaled up rapidly. This means testing to industrial-scale deployment of the technology will not take years.  
 
“With Monash University’s EALNF technology, these (high altitude salt brine flats) can now be commercially viable sources of lithium and valuable contributors to the global supply chain,” added Li in the press release.

“This breakthrough is crucial for avoiding a future lithium shortage, making it possible to access lithium from hard-to-reach sources and helping power the shift to clean energy.”