Study on the enrichment of Li, Rb and Cs in Salt Lake Brine and the mechanism of Li at the mineral interface

Trace elements (Li, Rb, Cs) enrichment and extraction from weakly carbonate salt lake brines are considerably influenced by other ions in the brine. In the early stages of evaporation, when sodium salts, potassium salts, and magnesium salts in the brine become saturated, Li+, Rb+, and Cs+ have not reached saturation, yet significant losses occur during this stage. To address the above problems, this paper combines experimental studies and simulation calculations to investigate the enrichment patterns of trace elements in the aqueous salt systems of Mg2+, Na+, K+//SO42−, and Cl−-H2O as well as the interfacial properties of Li in magnesium carbonate salt crystals. The results of the study show that, in addition to entrainment by the mother liquor, the relatively high potential and rough surface of magnesium salts cause Li+ to be adsorbed and doped on the surface of magnesium carbonate crystals during the brine's evaporation process. The study clarifies the mechanisms of Li adsorption and doping on the surface of crystals of magnesium carbonate. These findings offer a foundation of reference for the economical and ecologically responsible use of lithium resources in salt lake brines.