Novel Technology for Low Cost Detoxification of Waste Liquid and Recovery of trace amount of Precious Metal
Tanaka Kikinzoku has developed a technology capable of recovery of precious metal such as gold, platinum and palladium contained in trace amounts in waste liquid through detoxification of cyanogen plating waste liquid. The cyanogen plating waste liquid is produced during processing plating such as semiconductor components contain cyanogen compounds and inorganic carbonates in addition to precious metals.
Typically in 1 cubic meter of cyanogen plating waste liquid there is 0-3 grams of gold, 0-3 grams of platinum and 0-5 grams of palladium, in addition to a variety of trace amounts of valuable metals such as rare earths. The new technology will make it possible to recover precious metals from the residue obtained by decomposing concentrated cyanogen plating waste liquid (sludge) in a lower temperature range than conventional methods and separating cyanogen compounds from sludge as cyanogen gas. The new technology provides a low cost and simple solution for processing waste liquid and at the same time stops the corrosion of furnace due to presence of inorganic carbonate that are fusible salts which do not melt in the furnace.