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研究了一种简单的从电解锌流程中产生的Cd-Cu-Zn滤饼中选择性回收镉的湿法工艺。镉的浸出、过滤和再浸出常规流程需多个阶段,成本较高。此研究的目的是寻找一种更简单的方法从电解锌流程锌净化阶段的Cu-Cd滤饼中回收镉。所研究的流程包括从Cu-Cd滤饼中除去锌,选择性浸出镉和通过去除Fe、Tl和Co,净化之后再进行电解和熔铸。Cu-Cd滤饼中的锌通过两个阶段转移至液相中,铜和镉在滤饼中富集。在较高的固液质量体积比条件下从滤饼中选择性浸出镉,溶液中镉的浓度较高。在特殊条件下选择性浸出镉可使富镉溶液中共同沉淀的杂质最少。浸出反应在铜的溶解开始时停止。用KMnO_4和NaOH氧化和沉淀杂质,如Fe、Tl和部分Co。净化后的硫酸镉溶液通过电积得到阴极镉,然后熔铸得到99.95%的金属镉。整个流程中,镉总回收率为70%～72%。
A simple wet process for the selective recovery of cadmium from Cd-Cu-Zn filter cake produced in the electrolytic zinc process was studied. Cadmium leaching, filtration and re-leaching of conventional processes require multiple stages, the cost is higher. The purpose of this study was to find an easier way to recover cadmium from the Cu-Cd filter cake in the zinc purification stage of the electrolytic zinc process. The procedure studied included the removal of zinc from the Cu-Cd filter cake, the selective leaching of cadmium and the removal of Fe, Tl and Co, followed by electrolysis and casting. Zinc in the Cu-Cd filter cake is transferred to the liquid phase in two stages, with copper and cadmium being enriched in the filter cake. Under high solid-liquid mass-to-volume ratio conditions, cadmium was selectively leached from the filter cake and the concentration of cadmium in the solution was high. Selective leaching of cadmium under special conditions minimizes the co-precipitation of impurities in cadmium-rich solutions. The leaching reaction stops when the dissolution of copper begins. Oxidation and precipitation of impurities such as Fe, Tl and some of Co with KMnO 4 and NaOH. Purified cadmium sulfate solution by cathodic electrodeposited cadmium, and then cast to obtain 99.95% of the metal cadmium. Throughout the process, the total cadmium recovery rate of 70% to 72%.