
As manufacturers worldwide seek more cost-effective and environmentally sustainable methods to produce lithium, direct lithium extraction (DLE) has gained renewed attention.
Edith Cowan University’s (ECU) Associate Professor Amir Razmjou was recently invited by the International Lithium Association to provide an independent expert report on DLE technology.
The report emphasises the significance of membrane technology for DLE, alongside adsorption, ion exchange, and solvent extraction methods.
“DLE technology for lithium production has the potential to be a game-changer, enabling sustainable ramp-up of lithium in the rapidly expanding multi-billion-dollar industry,” stated Associate Professor Razmjou.
He highlighted the controversy surrounding DLE’s merits within the lithium sector, which has puzzled investors, technology providers, and researchers.
The report underscores the importance of membrane DLE, which eliminates the need for water or acid stripping, crucial for production.
Membrane DLE enables modular design, reducing water and carbon footprints while minimising water loss and brine contamination.
This facilitates the reinjection of lithium-depleted brine back into aquifers and underground reservoirs.
DLE offers significant environmental advantages over traditional extraction methods, including lower environmental risks, reduced land use, carbon footprint, and water usage.
It also significantly reduces the time required for lithium production. While solar evaporation can take over 18 months and hard rock mining several months, DLE processes can accomplish extraction in hours or days.
This rapid production scaling allows stakeholders to adapt to market demands more effectively.
DLE involves the selective extraction of lithium ions directly from lithium-rich solutions, bypassing the need for evaporation ponds. The report analysed various DLE methods:
- Adsorption-based DLE: Lithium molecules are physically adsorbed onto the surface of a sorbent material.
- Ion Exchange-based DLE: Involves trading lithium ions for cations within the structure of a sorbent material, requiring an acid solution for stripping and recovering the lithium.
- Solvent Extraction-based DLE: Selectively extracts lithium from complex brines while maintaining high purity levels.
Lithium is critical in the transition to clean energy, particularly for lithium-ion batteries used in home appliances and electric vehicles (EVs).
The International Energy Agency (IEA) estimates that global lithium demand could increase by 40 times by 2040.
The report suggests that membrane technology will continue to play a significant role in DLE, using less water, producing less waste and greenhouse gases, and increasing efficiency.
Another DLE approach is electrochemical or battery-based DLE, which relies on selectively capturing lithium on or inside electrodes in AC or DC power mode systems.
While this technology is still in its early stages and requires further trials, it represents a promising area for future research and development.
In conclusion, DLE technology presents a sustainable and efficient solution for lithium extraction, addressing the environmental and economic challenges of traditional methods.
As the demand for lithium continues to rise, advancements in DLE will be crucial for meeting these demands sustainably and efficiently.