Novel approaches for lithium extraction from salt-lake brines: A review

Due to the abundant reserves and increasing demand, the extraction and separation of lithium from salt-lake brines have attracted great interest worldwide. This review aims to summarize the major developments in lithium recovery from brines, starting from an overview of lithium demand and consumption, available resources and processing methods, and challenges of processing brines, followed with the advancements in solvent extraction, ion-sieve adsorption, electrochemical approaches, and membrane technology, successively. The paper focuses on the principles, mechanisms, operations, and comparison of the various approaches. Other promising techniques, such as the modification of ion-sieves, rocking-chair batteries, and liquid-membrane electrodialysis, also are discussed in the depth of mechanisms. These processes present excellent performance in the separation of Li+/Mg2+ or Li+/Na+. Finally, insights into the directions and prospects of lithium extraction from brines are presented. It can be concluded that only by integrating the advantages of various recent technologies will it be possible to develop an efficient, low cost, environmentally sustainable, and scalable process for lithium extraction from brines.