盐湖高锂卤水中硫酸根的分离与锂的迁移

以盐湖高锂卤水为原料,采用化学沉淀法,以无水氯化钙作为沉淀剂,脱除卤水中的硫酸根。详细考察了原料配比（钙离子与硫酸根物质量的比）、加料方式、加料时间、反应时间、搅拌转速和反应温度等条件对除硫率的影响,同时重点研究了反应过程中锂的夹带损失率和生成锂的复盐形式。得到除硫的适宜条件：原料配比为1.2,加料方式为正向加料即氯化钙溶液加入卤水中,反应温度为25 ℃,加料时间为24 min,搅拌转速为150 r/min,反应时间为60 min。在该实验条件下卤水中硫酸根的脱除率达到99.02%,锂的夹带损失率达到27.71%;通过扫描电镜可以得到沉淀产物的形貌,通过XRD表征结果可以说明在分离硫酸根的过程中锂离子主要是以Li₂SO₄·H₂O和LiAl₂（OH）₇（H₂O）₂的形式夹带损失。

Separation of sulfate and migration of lithium in high lithium brine of salt lake

The salt-lake brine with high lithium concentration was used as raw material,and SO₄^2- in this brine was removed by chemical precipitation method by adding calcium chloride as precipitant.The effects of raw material ratio（ratio of substance amount of Ca²⁺/SO₄^2-),feeding mode,feeding time,reaction time,stirring speed and reaction temperature on the desulfuriza-tion rate were investigated in detail.Meanwhile,the entrainment loss rate of lithium under different operating conditions and the form of lithium complex salt formation were emphatically studied.The research results showed that the optimum conditions for desulfurization were below：the ratio of raw materials was 1.2,the react temperature was 25 ℃,the feeding time was 24 min,the stirring speed was 150 r/min and the reaction time was 60 min.In this experiment condition,the removal rate of SO₄^2- in brine could reach 99.02%,the entrainment loss rate of lithium was 27.71%.The morphology of the precipitation products could be obtained by SEM.The results of XRD showed that the loss of lithium was mainly in the form of Li₂SO₄·H₂O and LiAl₂（OH）₇（H₂O）₂ in the process of separating SO₄^2-.