Research progress and prospect of membrane method in seawater/brine extraction of lithium

With the widespread promotion of new energy electric vehicles for lithium batteries worldwide, the demand for lithium is surging. And the industry chain of lithium is in the process of technological transformation and upgrading, the extraction of lithium from salt lake brine is becoming the main source. Comprehensively compare the precipitation method, adsorption method, calcining leaching method, extraction method, and other processes used in the extraction of lithium from brine, membrane separation is a high-efficiency and energy-saving separation and purification technology without phase change at room temperature, and it has become the most promising energy-saving and environmentally-friendly new technology in the lithium extraction industry. At present, the research on membrane processes with lithium separation effect mainly includes membrane-adsorption, membrane-solvent extraction and membrane-electrodialysis, etc. And membrane-electrodialysis technology has been successfully applied to extract lithium from salt lake brine in industry. However, the existing shortcomings of organic membranes, such as membrane blockage, organic matter dissolution loss, and environmental pollution, limit the promotion of membrane-electrodialysis in the lithium extraction industry. Inorganic ceramic membranes are divided into microfiltration, ultrafiltration and nanofiltration according to the pore size. The separation process is mainly based on the “physical screening” theory, and the inorganic ceramic membrane material has stable chemical structure, good mechanical properties, simple preparation process, high temperature resistance, uniform pore size, It has many advantages such as narrow pore size distribution range and long life. Therefore, the development of new inorganic membrane materials has attracted widespread attention from the academic community and has become a hot issue in the study of lithium extraction by membrane methods.