Metals Recycling from Wastewaters in Surface Finishing Industries

Abstract

Various examples of the metals recycling on the commercial scale and the R&D stage from the wastewaters discharged from surface finishing industries have been described. Although the amount of the recycled metals from these wastewaters is limited as a whole, many processes are in operation or under development. Precious metals in the plating effluent, copper in the spent etching solutions, chromium in the effluents of plating and chromate treatment, nickel in the spent electroless nickel baths, and zinc and tin in the plating effluents can be recovered by using various methods such as precipitation, cementation, solvent extraction, resin ion exchange, and adsorption.