Abstract:Process Study of Calcium, Magnesium, and Lithium Deep Separation for high calcium, high lithium, and Low Magnesium Lithium Ratio (Mg/Li:0.02) Foreign Argentine Salt Lake Brine. A two-step method was used to remove Ca2+ and Mg2+ from the solution: first, sodium sulfate was added to generate calcium sulfate precipitation to remove a large amount of Ca2+, and then sodium hydroxide was added to form magnesium hydroxide and calcium hydroxide to remove a small amount of Ca2+ and Mg2+. The influences of the material ratio, reaction temperature, feeding time, feeding rate, and pH value on the impurity removal effect of brine were investigated respectively. The experimental results showed that at the reaction temperature of 60 ℃, the amount of sodium sulfate was 1.3, the feeding rate was 6 mL/min, and the reaction time was 70 min, the removal rate of Ca2+ in the solution was 96.22%, and the loss rate of Li+ was 1.44%; at pH 14, 10 mol/L NaOH, reaction time of 50 min, reaction temperature of 50 ℃, and feeding rate of 8 mL/min, the final removal rates of Ca2+ and Mg2+ in the solution were 99.75% and 100%, respectively, and the loss rate of Li+ was 0.04%. The deep removal of calcium and magnesium ions was achieved, which created favorable conditions for the preparation of lithium carbonate in subsequent processes.