硫酸锌溶液四氢硼酸钠还原法除钴的实验研究

Experimental Study on Cobalt Removal by Sodium Borohydride Reduction with Zinc Sulfate Solution

采用四氢硼酸钠作为还原剂处理含钴硫酸锌液,研究了四氢硼酸钠加入量、温度、反应时间及pH对除钴效果的影响。四氢硼酸钠是硫酸锌溶液良好的除钴剂,常温下除钴速度快,四氢硼酸钠用量少,最优除钴条件:NaBH4用量为0.16 g/g Co,反应温度为40℃,pH为4.5,反应时间14 min,此条件下除钴率为96.4%,钴离子含量从25 mg/L降低到0.89 mg/L。在除钴过程中,生成的单质钴存在轻微的“返溶”现象,因此达到合理的除钴时间后应尽快过滤分离。

Sodium borohydride was used as reducing agent to treat zinc sulfate solution containing cobalt ions,the effects of sodium borohydride addition,temperature,reaction time and pH on the removal of cobalt ions were studied.Sodium borohydride was a good cobalt remover for zinc sulfate solution,it had the advantages of fast cobalt removal at room temperature and less sodium borohydride consumption,optimal cobalt removal conditions:NaBH 4 dosage was 0.16 g/g Co,the reaction temperature was 40℃,pH=4.5,the reaction time was 14 min.Under this condition,the cobalt removal rate was 96.4%and cobalt ion content decreased from 25 mg/L to 0.89 mg/L.In the process of cobalt removal,the generated elemental cobalt had a slight“return to dissolution”phenomenon,so it should be filtered and separated as soon as possible after reaching a reasonable cobalt removal time.