Hydrometallurgical processing of lithium, potassium, and boron for the comprehensive utilization of Da Qaidam lake brine via natural evaporation and freezing

A strategy for the hydrometallurgical processing of potassium, boron, and lithium for the comprehensive utilization of Da Qaidam lake brine based on freezing and natural evaporation was developed. This process involves five major crystallization steps: remove sulfate by crystallizing mirabilite at low temperature, deposit carnallite through natural evaporation, enrich boron and lithium by eliminating magnesium through the addition of mirabilite and further evaporation, crystallize borate by brine dilution, and crystallize lithium sulfate monohydrate through further evaporation. In this study, potassium, boron, and lithium salt deposits with relatively high grades and yields were obtained through the controlled crystallization processes. This process provides a feasible and environmentally-friendly alternative for the comprehensive utilization of the Da Qaidam lake brine.