Ekos Research and the University of Melbourne have developed new, environmentally conscious technology to produce high-purity lithium. One company has already committed to adopt the Direct Lithium Extraction solvent exchange process and two are currently reviewing contracts, putting Ekosolve on the path to playing a key role in providing a more efficient, greener process to produce lithium carbonate, a critical element for battery power.
Lithium is an important material in the transition to a cleaner energy economy. Over the next decade, demand is expected to quadruple. Electric vehicle battery demand and Gigafactories are leading this rapid increase, while other environmentally sensitive technologies and solutions such as grid storage, and e-scooters are contributing to a fast-growing lithium battery market.
But conventional production methods – including fractional crystallisation, membrane filtering, MOF’s, adsorption, reverse osmosis, and ion exchange – are inefficient and expensive. They result in low recoveries of lithium from brines and can have significant environmental and social impacts.
Currently, lithium extraction from salt brines involves building large ponds, using large amounts of lithium brines, which destabilises groundwater levels, and takes years to construct and put into operation. At best, these methods recover only 55 to 70 per cent of the lithium contained in the brines resulting in significant losses of a valuable resource.
Ekosolve Direct Solvent Extraction provides an alternative to these inefficient methods. It produces a high-purity product quickly, with much lower environmental impact and greener footprint. And it doesn’t negatively impact the people living in the isolated regions where these brines occur.
AN ENVIRONMENTALLY CONSCIOUS SOLUTION
Developed by researchers from the Department of Chemical Engineering led by Laureate Professor Dr Geoff Stevens AO and Associate Professor Dr Kathryn Mumford in collaboration with the research company Ekos Research, Ekosolve™ returns a 99 per cent purity lithium product and is over in just 10 to 12 hours. It reclaims 95 per cent of the solvent and uses very little fresh water.
Dr Mumford, project director and lead for the University’s Advanced Separations Technologies Group, says providing an environmentally safe, efficient solution was a key driver.
“Batteries are seen as a way to combat global warming by storing energy from green low carbon sources such as solar, wind and wave power. But you can’t have all these successes without having an impact somewhere else. In the take-up of battery power, there is a real risk of having a massive impact and causing future problems for places we don’t see every day, like the salares in the mountains of Argentina and Chile.
“Those salt lakes are beautiful, and they are ecologically very fragile. So, we wanted to find a way to protect what we have while also getting what we need to support the transition to clean energy. I don't want to see one area destroyed to save something else.”
GIVING A PROVEN TECHNOLOGY NEW LIFE
Based on established solvent exchange principles, the process crucially involves a designed solution that directly targets and extracts lithium, after which it can be separated and purified.
“We draw salt water out of the salares, mix it with the developed solvents to form one phase, then – thanks to the solvent design – the lithium moves from the brine to the solvent. After a short time, the two liquids separate (like oil and water do) and the solvent, which now hosts the lithium, is separated from the brine via density differences.
“We then strip the lithium from the solvent and crystalise it. What’s left is solid lithium chloride or, with the addition of sodium carbonate, lithium carbonate that can be used for batteries. Ekosolve™ is that entire process,” Dr Mumford says.
The efficiency of the process equates to a very low impact solution to lithium production. It also benefits lithium producers since it requires significantly lower capital and operating costs, and results in a quality product that affords higher returns. There is no front-end scrubbing to remove magnesium and calcium to prepare the brine for treatment which is the major drawback with most other technologies.
Dr Carlos Sorentino, Chief Technical Officer at Ekos Research and Ekosolve™, the company established to commercialise the technology, says:
“Lithium has been extracted from brines since around 1970. But conventional methods are wasteful. Our process improves yields by about 50 per cent and doesn’t affect the water supply.
“One thing that excites me is its capacity to produce from very low lithium concentration salares. Ekosolve™ is making them viable. So, from an economic point of view, it’s much more efficient. But also, from an environmental point of view it’s very conservative.”
BRINGING EXPERTISE TOGETHER
Developing Ekosolve™ – which the University and Ekos Research hold the IP and rights for respectively – began when Ekos Research approached the Advanced Separations Technologies Group. After seeing some of their publications and recognising Dr Mumford and Dr Stevens as world experts in solvent extraction and ion exchange, they asked whether the Group's solvent exchange methods could work for the salares they had experience with. These were Rincon, Pocitos, Rio Grande, Incahuasi and Pozuelos in Argentina.
“They wanted to see whether we could develop a solvent that could purify lithium from their salares, considering their unique ionic compositions,” says Dr Mumford.
After around 18 months of testing brines sent from the salares in South America, and making minor modifications, the process looked very promising and the partnership was formed.
From there, it has been a collaborative process anchored by a shared vision to create a genuinely first-rate solution. Over the next four years, Dr Sorentino, Phillip Thomas, CEO at Ekosolve Limited, and the University conducted further research and development to design the specific Ekosolve™ technology. In 2022, they licenced it.
“They came to us acknowledging we have the expertise in solvent extraction and would provide a critical evaluation of the potential of the technology for their salares, rather than trying to sell them something,” Dr Mumford says.
“They are experts in their respective fields too. And they didn’t have an agenda other than trying to develop a state of the art, efficient direct extraction technology. So, there was equal trust. It's a very respectful collaboration between experts who share a vision.”
NEXT STEPS AND TRAINING THE WORKFORCE
Ekosolve, the company, is now in the process of bringing other companies on board to eventually use the Ekosolve™ Solvent Extraction process in purpose-built plants. Refining the technology and progressing through the development pipeline continues in Melbourne.
“There are three or four phases,” Mr Thomas says. “We’re completing testing for the larger pilot plant now. Then we’ll build it, followed by a mini plant, then a much larger one to put directly in the salares in South America for our first client at Incahuasi or Pocitos salar.”
“In a few years, we hope to be building these plants for many companies, which can then produce high-purity lithium with a very green footprint. We have contracts for the first 10,000 tonne plant and two others reviewing the documentation.”
Plans to begin training the workforce needed to operate the technology are also in development, with the team dedicated to upskilling locals, Dr Sorentino says. “So far, five people know about this technology. So, we'll need more people trained. Our intention is to use the local Argentinean workforce.”
An environmentally low impact, responsible way to produce lithium to meet demand is certainly closer. And that holistic solution is what excites Dr Mumford.
“We have a potential way to get the lithium we need safely and help the communities in which the facilities are located. People in those places want industry to come to create jobs and develop other businesses in their towns. Maybe this is a solution to provide that without hurting the environment and causing other detrimental issues.”
First published on 12 August 2022.
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