Indium and Indium Compounds

AbstractIndium is a very soft, silvery metal and its abundance is about 0.05 ppm in the earth's crust. It is widely distributed, but never in concentrations high enough to justify mining for its own intrinsic value. Indium is considered a minor metal and is a by‐product of other mining and refining operations. Important mines producing indium are in South America, Canada, China, and the Republic of Korea. Indium is recovered from fumes, dusts, slags, residues, and alloys from zinc or lead‐zinc smelting. Indium metal itself poses little or no environmental risks, however sometimes the form that indium takes or other metal associated with it may pose dangers to the environment. A large portion of secondary indium is produced from indium tin oxide (ITO) recycling. Indium's major use is in the production of ITO. ITO thin film coatings are primarily used for electrically conductive purposes in a variety of flat‐panel devices. Other uses include solders and alloys, electrical components, and semiconductors.