从吸附法盐湖卤水提锂溶液中去除钙、镁试验研究

Removal of Calcium and Magnesium Ions From High Lithium Solution

利用碳酸钙、碳酸镁、碳酸锂在溶液中的溶度积的差异,研究了用碳酸钠从吸附法盐湖卤水提锂所得高锂溶液中去除钙、镁离子,考察了反应时间、碳酸钠用量、体系pH及晶种循环方式对钙、镁去除率的影响。试验结果表明:用质量浓度为50g/L的碳酸钠溶液,在反应时间30min、碳酸钠用量为沉淀钙、镁所需理论量、溶液pH为11.5,采用晶种循环方式改善过滤性能条件下,钙、镁去除率分别为98.8%和99.98%,所得溶液中,Ca2+质量浓度为9mg/L,Mg2+质量浓度为0.7mg/L,整个除杂过程锂损失仅为3%左右。

By the solubility differences of calcium carbonate ,magnesium carbonate and lithium carbonate ,removing calcium and magnesium ions from high lithium solution was studied .The effects of reaction time ,sodium carbonate dosage ,solution ,pH and seed circulation style on the removal of impurities w ere investigated . The results show that at the conditions of sodium carbonate concentrations of 50 g/L ,reaction time of 30 min ,sodium carbonate dosage as much as the theoretical amount for precipitation of calcium and magnesium ,adjusting the pH to 11 .5 ,the crystal cycle ways , removal rates of calcium and magnesium are 98 .8% and 99 .98% ,respectively .The high lithium solution with Ca^2＋ concentration of 10 mg/L and Mg^2＋ concentration of 0 .7 mg/L can be obtained . The lithium loss in the process is only about 3% .