响应面法优化酒石酸还原浸出电解锰阳极渣工艺

Reductive leaching technology of manganese anode slag using tartaric acid as reducing agent optimized by RSM

以湘西某电解锰厂的电解锰阳极渣为原料、酒石酸为还原剂、硫酸为助浸剂湿法还原浸出阳极渣中的锰并富集铅。通过单因素实验并基于响应曲面法BBD模型对浸出工艺进行了优化。设定浸出温度、液固比、硫酸浓度、酒石酸用量4个影响因子,锰浸出率为响应值,考察优化得到最佳浸出条件及独立因素对锰浸出率的影响程度。结果表明:最佳浸出工艺条件为浸出温度为80℃、硫酸浓度为3.7mol/L、液固体积质量比(mL/g)为3.5、酒石酸用量为1.5g(理论用量的1.1倍)、浸出时间为1h,该条件下锰浸出率为98.27%,铅浸出率为0.16%。对阳极渣中锰浸出率的影响效果由大到小依次为:硫酸浓度、液固比、浸出温度、酒石酸用量、浸出时间。对浸出液和浸出渣进行表征分析,探讨了其反应机理。用酒石酸还原浸出富集阳极渣中的锰、铅,具有无二次污染、反应时间短、浸出率较高、锰铅分离效果较好等特点。该研究能够为电解锰阳极渣的资源化利用提供理论依据。

Electrolytic anode slag from an electrolytic mill in Xiangxi was used as raw material,tartaric acid was used as re-ducing agent,sulfuric acid was used as leaching aid to leach anode slag and enrich lead simultaneously.Through the single factor experiment,the leaching engineering was optimized based on Box-Behnken Design(BBD)response surface method-ology.Four factors were set,including leaching temperature,liquid-solid ratio,sulfuric acid concentration,amount of tartaric acid,and manganese leaching rate was taken as the response value.The optimal leaching conditions and the influence of in-dependent factors on manganese leaching rate were investigated and optimized.The experimental results indicated that the optimal leaching conditions were:leaching temperature of 80℃,sulfuric acid concentration of 3.7 mol/L,liquid-solid ratio(mL/g)of 3.5,tartaric acid dosage of 1.5 g(1.1 times of theoretical dosage),leaching time of 1 h.Under these conditions,the leaching efficiency of manganese and lead was 98.27%and 0.16%respectively.At the same time,the effects on the leaching rate of anode slag from big to small were:sulfuric acid concentration,liquid-solid ratio,leaching temperature,amount of tartaric acid,leaching time.The leachate and leaching residue were characterized and analyzed,and the reaction mechanism was discussed.It had the characteristics of non secondary pollution,short reaction time,high leaching rate,and great separation effect between manganese and lead by using tartaric acid as reducing agent to leach manganese and enrich lead.This study could provide a theoretical basis for the resource utilization of electrolytic manganese anode slag.