烟道灰中铜锌锰的分离与回收

Separation and Recovery of Cu,Zn and Mn in Flue Dust

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2 h,锌浸出率达到97.6%,所得ZnCO_3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2 h,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2 h,铜回收率达98.0%,铜含量达90.5%以上;利用沉淀法回收锰得MnO_2,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 usingthe 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 Na OH was 10%,the leaching rate of Zn reached 97. 6% and the Zn content of the ZnCO_3 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 to95. 0%,when the reaction temperature was 60℃ and the reaction time was 2 h. Iron displacement method optimization process： by adjusting the initial p H 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 than55. 0% by precipitation to obtain MnO_2.