Extraction of lithium from brine with neutral organophosphorous solvents

Extraction of lithium from simulated brine in the presence of ferric chloride having a high magnesium to lithium ratio was investigated with neutral organophosphous solvents. The influences of contact time, extractant concentration, concentrations of some salts (Mg 2+ , Na +, K +) in the solution, hydrochloric acid acidity and extraction temperature on the lithium extraction were studied using the TBP kerosene system. The results show that tri n butyl phosphate (TBP) dissolved in kerosene is a good extractant for lithium against DBBP and TOPO. The suitable extraction conditions are found to be: contact time not any less than 20min; 20~25℃; [Fe 3+ ]/[Li +] about 1.5~2.0; TBP volume fraction 50%~70%; MgCl 2 exceeding 3mol/L; pH about 2; with most sodium and potassium salts in the aqueous phase removed before extraction.