2. Recovery of non-ferrous materials from home electrical appliances recycling
Various rare metals are used for home electrical appliances; however, only three rare metals are being collected by home appliance recycling plants: platinum and palladium from printed circuit boards and nickel from shadow masks. Base metals such as gold, silver and copper are predominantly being collected. Recent concern for resource nationalism has focused attention on and heightened the expectation of increasing the recovery of rare metals from digital home appliances. The economic profitability, however, is low because of the very small amount of rare metal usage and the short cycle of the use of digital appliances. Consequently, it has not yet led to business-based expansion.
Mitsubishi Materials recovers valuable metals such as gold, silver, copper, platinum, palladium, lead, antimony and bismuth from printed circuit boards collected at each home appliance recycling plant in partnership with copper, noble metal, and lead smelting plants.
The Home Appliance Recycling Law describes the melting process for printed circuit boards in built-in televisions that is required by the Ministry of Health, Labour and Welfare Ordinance. In home appliance recycling plants, printed circuit boards are taken apart by hand as shown in Fig. 2-1. Many of the collected printed circuit boards are disposed of at non-ferrous materials smelting plants. It is reported that these components contain gold (12-54g/ton), silver (340-470g/ton), palladium (9-12g/ton) and copper (8-13%).
Thin-screen televisions were added as subject to control in April, 2009. It is known that silver is used in the panel part of a plasma television and that a thin-screen television has a glass panel coated by 250-300 ppm of indium. When a surface treatment is applied by sandblasting, sandblast dust enriches indium to about 0.5%. It is thought that as far as the current price goes, around 10% of indium is economically profitable.