Environmentally benign techniques of lithium extraction from salt lakes: a review

To address the increasing demand for lithium, the recovery of lithium from salt lake brines has garnered significant attention. Techniques have been developed; however, these approaches exhibit drawbacks such as high energy consumption, excessive freshwater usage, and substantial dissolution losses, presenting environmental concerns. This review discusses the application and characteristics of four extractant systems used in solvent extraction: organophosphates, ionic liquids, crown ethers, and β-diketones. Furthermore, we present the optimization of organophosphate systems to make them more environmentally friendly. Optimization encompasses four key aspects: synergistic extractants, coextractants, diluents, and main extractants. Solvent extraction is a simple, cost-effective, and environmentally benign technique for lithium extraction from brine. Modifying the structure of these extractants can reduce dissolution rates and improve extraction efficiencies.