Lithium extraction from salt lake brines with high magnesium/lithium ratio: a review

The demand for lithium is growing rapidly with the increase in electric vehicles, batteries and electronic equipments. Lithium can be extracted from brines, yet the separation of lithium ions Li+ from magnesium ions Mg2+ is challenging at high Mg/Li ratios. Here, we review methods to extract lithium from brines, such as extraction, adsorption, nanofiltration, selective electrodialysis and electrochemical intercalation/de-intercalation, with focus on the selective separation of lithium at high Mg/Li ratios. Extraction can be done with organic solvents and ionic liquids. Adsorption is performed with aluminum-, manganese- and titanate-based adsorbents.