Reducing the environmental footprint of lithium production
Helping companies achieve more sustainable and cost-effective lithium production
Through CYANEX® 936, a reagent dedicated to the fast-growing lithium industry, Solvay’s mining solutions business, part of its global Technology Solutions unit, is helping companies achieve more sustainable and cost-effective lithium production.
CYANEX® 936 allows mining operations to extract lithium from brines (i.e., saltwater from salars, which are also known as salt flats) and supports a new approach to lithium recovery.
A new process based on solvent extraction
In collaboration with Tenova Advanced Technologies, a mining engineering firm that developed a new process to extract lithium based on solvent extraction, Solvay’s mining solutions team came up with an optimized extractant formulation for the Tenova process. CYANEX® 936 enables the production of high-purity lithium salts in a matter of hours, rather than 12 to 18 months under conventional evaporation methods, irrespective of weather conditions. Under this new process, the lithium-free saltwater can be re-injected into the salar following solvent extraction, saving billions of liters of water. For the same output capacity, the product also helps reduce the environmental footprint by three orders of magnitude by eliminating the need for evaporation ponds, which occupy significant space.
The rise in demand of lithium batteries and the rapid growth of electric vehicles worldwide have boosted lithium demand. The market is expected to grow three-fold to 125 million electric vehicles by 2030 according to the International Energy Agency forecast.
Cheaper, faster, and more sustainable
According to Laurent Cohen, Global Marketing Manager, Metal Extraction Products, Solvay, “When it comes to critical metals that are used for battery applications and electric vehicles, these make up more than 50% of the global supply essential to lithium. The underground water beneath salt flats in Argentina, Chile and Bolivia naturally contains lithium in very small concentrations, among other minerals. We at Solvay, in collaboration with our engineering partner, have developed a new method to selectively extract and concentrate the lithium, and then return the water to its original environment. Overall, leveraging solvent extraction for lithium recovery is cheaper, faster and, most importantly, more sustainable than the existing methods.”
The traditional method of extracting lithium from salars is carried out through evaporation and precipitation methods. This entails a long process estimated to take 18 months to execute and which requires a large, costly infrastructure of evaporation ponds (artificial ponds designed to evaporate water by sunlight). The process is often deemed inefficient, weather-dependent and environmentally unfriendly as a result of its large footprint and water requirements.
Overall, leveraging solvent extraction for lithium recovery is cheaper, faster and, most importantly, more sustainable than the existing methods.
Laurent continues: “The way we extract the lithium is by contacting the brine with an organic solvent containing our CYANEX® 936 extractant. This is a closed-loop, liquid-liquid process that allows, after the lithium has been extracted, to return the brine to the salar, exempt of any organic solvent of course. In terms of sustainability, time and cost benefits, there’s no other existing process in the market which competes at our level. With this product, Solvay is pushing the boundaries of solvent extraction technology.”