What is the function of indium?

Indium is mainly used as a raw material for manufacturing low melting point alloys, bearing alloys, semiconductors, electric light sources, etc. 1863, Reich and Li Xite studied sphalerite by spectrometry and found a new element indium. Indium is a metallic element with symbol In and atomic number 49. Indium is a silvery white metal, slightly blue, very soft and can be scratched with nails.

The distribution of indium in the earth's crust is small and scattered. Its rich minerals have not been discovered, but exist as impurities in metal minerals such as zinc, so it is listed as a rare metal. Known indium minerals include copper indium sulfide ore, iron indium sulfide ore and indium water ore.

Indium is a rare metal and a scarce resource. The global indium reserves are estimated to be only 50,000 tons, of which 50% can be mined. Since no independent indium ore has been found, the recovery rate of indium is about 50-60% by purifying waste zinc and tin. Only 1.5- 1.6 million tons of indium can be really obtained in this way.

The extraction process of indium is mainly extraction-electrolysis, which is also the mainstream technology of indium production in the world today. Its principle process flow is: indium-containing raw materials → enrichment → chemical dissolution → purification → extraction → back extraction → zinc (aluminum) replacement → sponge indium → electrolytic refining → refined indium.