硫酸钴溶液深度净化工艺研究

Advanced Purification Process for Cobalt Sulphate Solution

以氧化酸浸和化学沉淀除铁砷后得到的硫酸钴溶液为原料,制备杂质含量低的硫酸钴溶液。研究结果表明:当氟化铵用量为1.8倍理论用量,反应温度为60℃,Ca、Mg去除率分别为98.51%和96.62%。P204萃取除Zn,当萃原液pH值为3.5,P204体积分数为20%,有机相与水相的体积比为1∶1,Zn去除率达到99.39%,Mn去除率为49.02%,Co直收率为99.19%。P204萃取除Mn,当萃原液pH值为2.5,P204体积分数为10%,采用3级逆流萃取,Co直收率达到96.23%,Mn去除率为96.5%,溶液中Mn浓度仅为0.023 g/L。P507萃取Co,当萃原液pH值为4.0,P507体积分数为10%,有机相与水相的体积比为1∶1,采取5级逆流萃取,Co萃取率达到99.72%,Ni去除率98.7%,萃取余液中Co浓度仅为0.041 g/L。钴总回收率达到94.7%。

High-purity cobalt sulphate solution was prepared with the cobalt sulphate solution as raw material attained after removing Fe and As by oxidation acid leaching and chemical precipitation. The results showed that the removal rates of Ca and Mg were 98.51% and 96.62% respectively when the dosage of NH4F was 1.8 times of its theoretical content, and the reaction temperature was 60 °C. When P204 was used to extract Zn, the removal rates of Zn and Mn were up to 99.39% and 49.02% respectively, and the recovery rate of Co was 99.19% under the condition of initial pH of 3.5, P204 volume fraction of 20% and organic-aqueous phases volume ratio of 1 ： 1. When P204 was used to extract Mn through 3-stage counter-current extraction, the recovery rate of Co was 96.23%, and the removal rate of Mn was 96.5% with a content of 0. 023 g/L in the solution under the condition of initial pH of 2.5 and P204 volume fraction of 10%. When P507 was used to extract Co through 5-stage counter-current extraction, under the condition of initial pH of 4, P507 volume fraction of 10% and organic-aqueous phases volume ratio of 1： 1, the extraction rate of Co was 99.72%, the removal rate of Ni was 98.7% and the concentration of Co in the solution was only 0. 041 g/L. The overall recovery rate of Co was up to 94.7%.