Brief Introduction

Indium has a wide range of applications. It is widely used in aerospace, radio and electronic industries, medical, national defense, high-tech, energy and other fields. The production of ITO targets (for the production of liquid crystal displays and flat screens) is the main consumption area of indium ingots, accounting for 70% of global indium consumption, followed by electronic semiconductors, accounting for 12% of global consumption, solders and alloys accounting for 12%, and the research industry accounting for 6%^[20].

Coating ^[20]

Indium is easy to form a firm coating on the metal surface and has good corrosion resistance, especially to prevent the corrosion of alkaline solution. The indium coating not only has a bright color, but also is easy to polish. The bronze wire mesh coated with indium can be used to remove mercury vapor from vacuum instruments.

ITO target ^[17-18]

Because indium ingots have good optical permeability and conductivity, the glassy composite (ITO) of high purity indium oxide and tin oxide is used to make transparent and conductive electrodes in plasma TV and LCD TV screen industry, as well as sensitive elements for some gas measurements. ITO is the largest market of indium. In recent years, it rapidly grows.

Semiconductor ^[17]

Indium is widely used in electronic semiconductors and radio industries because of its high boiling point, low resistance and corrosion resistance. In the radio and electronics industry, indium is used to make special contact devices, that is, the oxides of indium and silver are mixed and pressed.

Solder ^[20]

Many fusible alloys of indium are used as brazing filler metal. Even the pure indium metal itself is easily wetted with the surface of glass, quartz and mica, and adheres very well. Indium can be used to weld the parts made of piezoelectric materials firmly to each other. In the fabrication of multi-layer integrated circuits, the selection of indium-containing solder is a very important step.

Aerospace equipment gaskets^[19]

Because of its excellent ductility (plasticity), low vapor pressure and ability to adhere to a variety of materials, it is widely used as a gasket or lining material in high-altitude instruments and aerospace equipment.

Atomic energy industry^[19]

Indium is used as an indicator for the manufacture of neutrons. Many indium alloys are often used in the manufacture of control rods in atomic nuclear reactors. Indium is also an excellent material for making neutron detectors and is comparable to gallium metal.

Reference

[17] The Electroluminescent Light Sabre. Nanotechnology News Archive. Azonano. June 2, 2005. Accessed 5 Mar. 2020

[18] Bachmann, K. (1981). Properties, Preparation, and Device Applications of Indium Phosphide. Annual Review of Materials Science, 11(1), pp.441-484. Accessed 5 Mar. 2020

[19] Scoullos, M. (2001). Mercury, cadmium, lead. Dordrecht: Kluwer Academic Publishers, p.222. Accessed 5 Mar. 2020

[20] Sciencesruck. Available at https://sciencestruck.com/indium-uses. Accessed 29 May. 2020

This chart covers the complete industrial chain, market prospects and recovery process of indium. After indium is extracted from raw materials, it can be divided into ITO powder, high purity indium, ultra-pure indium, indium chloride and so on according to the morphology, element and purity after processing. Different indium and indium compounds have different applications and markets. Among them, the most promising markets for future development are ITO and information electronics industry. Mercury-free battery is also a good development direction. Almost all indium products can be recycled through waste targets recovery. The whole industrial chain forms a closed loop and saves energy effectively.