烟道灰中铜锌锰的分离与回收

摘要

采用碱浸—沉淀法回收锌,酸浸—置换法回收铜及酸浸—沉淀法回收锰使烟道灰中的铜、锌、锰得到分离回收.通过正交实验得到最优化工艺.碱浸法最优化工艺∶固液比为1∶4,NaOH浓度为10％,反应温度为65℃,反应时间2h,锌浸出率达到97.6％,所得ZnCO3渣含锌量达50.0％,回收率达96.0％;酸浸法最优化工艺:固液比为1∶5,硫酸浓度为7.5％,反应温度为60℃,反应时间2h,其铜、锰浸出率分别达到96.0％,95.0％;铁置换法最优化工艺:初始pH值为2.0,铁过量系数为1.15,反应温度为65℃,反应时间2h,铜回收率达98.0％,铜含量达90.5％以上;利用沉淀法回收锰得MnO2,锰回收率达99.0％以上,锰含量达55.0％以上.%The Cu,Zn and Mn in the flue dust were separated and recovered by using the alkali-immersionprecipitation method to recover the Zn,using the acid leaching-replacement method to recover the Cu,and using the acid leaching-precipitation method to recover the Mn.The optimal scheme was obtained by orthogonal experiments.Optimization process of alkali leaching:by adjusting the ratio of solid-liquid was 1 ∶ 4 and the concentration of NaOH was 10％,the leaching rate of Zn reached 97.6％ and the Zn content of the ZnCO3 slag was up to 50.0％ and the recovery rate is up to 96.0％,when the reaction temperature was 65℃ and the reaction time was 2 h.Optimization process of acid leaching:by adjusting the ratio of solid-liquid was 1 ∶ 5 and the concentration of sulfuric acid was 7.5％,the leaching rate of Cu was up to 96.0％ and the leaching rate of Mn was up to 95.0％,when the reaction temperature was 60℃ and the reaction time was 2 h.Iron displacement method optimization process:by adjusting the initial pH value was 2 and the iron excess coefficient was 1.15,the recovery rate of Cu was up to 98.0％,and the content of Cu was more than 90.5％ when the reaction temperature was 65 ℃ and the reaction time was 2 h.The recovery of manganese was up to 99.0％ and the content of Mn was more than 55.0％ by precipitation to obtain MnO2.