METHOD FOR PRODUCING INDIUM METAL

PROBLEM TO BE SOLVED: To provide a highly efficient and high yield method for producing indium metal by solving the problem that, when indium substitution precipitates generated in a cementation step using zinc powder are used as they are to produce indium metal, the content of zinc in the indium metal is made high thus reducing the content of zinc in the indium metal.SOLUTION: Provided is a method for producing indium metal comprising: a leachate production step where an indium-containing leachate is obtained from an indium-containing raw material; a cementation step where zinc is added to the leachate, and, by substitution reaction, indium substitution precipitates are obtained; a dissolving step where the indium substitution precipitates are dissolved to obtain crude indium; and an electrolytic refining step where indium metal is obtained from the crude indium, in which the indium substitution precipitates are separated into low zinc indium precipitates and high zinc indium precipitates, and, in the dissolving step, the low zinc indium precipitates in the indium substitution precipitates are dissolved.SELECTED DRAWING: Figure 1 【課題】亜鉛粉末を用いたセメンテーション工程で発生するインジウム置換析出物をそのまま用いて、インジウムメタルを製造すると、インジウムメタル中の亜鉛の含有量が多くなる。よってインジウムメタル中の亜鉛の含有量を少なくし、高効率で、高収率なインジウムメタルの製造方法を提供する。【解決手段】インジウム含有原料から、インジウム含有の浸出液を得る浸出液製造工程と、該浸出液に亜鉛を添加して置換反応によりインジウム置換析出物を得るセメンテーション工程と、該インジウム置換析出物を熔解して粗インジウムを得る熔解工程と、該粗インジウムからインジウムメタルを得る電解精製工程と、が含まれ、インジウム置換析出物を低亜鉛インジウム析出物と高亜鉛インジウム析出物とに分別し、熔解工程で、インジウム置換析出物の低亜鉛インジウム析出物を熔解する。【選択図】図１