Japan Urgently Needs to Increase Recovery of Rare Metal 'Indium'

As thin-film display screens such as liquid-crystal displays (LCDs) and plasmatic display panels become larger in size, and gain popularity in the market, there has been a rapid rise in demand for indium-tin-oxide (ITO) target materials, which is used in transparent conducting film. The Japanese demand for indium is the highest in the world, with more than 80 percent of its production geared to ITO for transparent electrodes. However, due to its rarity, indium is associated with high costs and supply problems.

Indium is a byproduct obtained in small amounts during the refining of zinc. In March 2006, the Toyoha Mine in Hokkaido, the only zinc and lead mine in Japan, closed down, which also ended domestic indium production, and signaled the increased importance of indium recycling from scrap metals.

Indium is usually recovered by first pulverizing LCD panels in glass cullets and smelting them with hydrochloric acid. Impurities are then eliminated by the alignment extract method, during which other elements are removed from the deflection plates and alignment films used in LCD panels. After electrolysis and refining, highly pure indium is recovered.

In December 2005, Akita Rare Metal Corp., a member of the Dowa Mining Co. Group, the world's leading indium recycling enterprise, has increased its annual capacity to recover indium from used ITO target materials to 150 tons, making it the largest scale operation of its kind in the world.

http://www.dowa.co.jp/english/index.htm

Posted: 2006/05/17 03:49:28 PM
Japanese version