Is it possible to recover lithium compounds from complex brines employing electromembrane processes exclusively?

Abstract

Research to develop direct lithium extraction technologies from aqueous sources is fundamental due to the environmental and techno-economic shortcomings of the evaporitic technology currently in use. Electromembrane processes are an attractive alternative since they could be much faster, more readily adaptable to brines of different compositions, sustainable since they use electrons as reactants, avoiding waste production, the use of chemicals, and decreasing the water footprint. Valuable Li+ ions are only a very minor component in a complex matrix of very high ionic strength with co-existing cations, most importantly Mg2+ and Na+, displaying similar chemical properties. A review from the recent literature shows that adaptation from the simple electrodialysis configuration will be needed to selectively recover pure lithium products. Testing of the proposed methodologies at meaningful concentrations, representative of real brines is key to bring these closer to industrial scale applications.