Recovery of lithium from salt‐lake brine by liquid–liquid extraction using TBP‐FeCl3 based mixture solvent

Abstract

AbstractIn this study, a complete cyclic process was developed for the lithium extraction from high‐concentration salt‐lake brine by using a high flash point, low water solubility, and low toxicity diluent mixed with the TBP‐FeCl3‐based organic solvent. The process was composed of four sections, including extraction, scrubbing, stripping, and regeneration. The optimal conditions for each section were determined first. Then, a 13‐stage cyclic extraction process was designed and validated experimentally for the high lithium concentration brine, which reached 8.612 g/L. By using the diluent at the optimized conditions, the overall recovery of lithium was higher than 96%. The stripping liquid contained 38.87 g/L Li+, while all the ratios of impurities of sodium, potassium, and magnesium to lithium were less than 0.1. The aims of enrichment and purification of Li+ from the complicated brine system were achieved by the developed extraction process with little Fe loss, which provided the technical support for the development of the salt‐lake lithium resource.