Chromate-based Solutions Are Not Dumped Any More: Industrial Experience in Russia, USA Germany

摘要

Chromate-based solutions used for the passivation of Zn, Cd or Cu, for etching, stripping, etc., are usually dumped when the concentrations of metal ions exceed certain critical value. All types of such solutions can be regenerated directly in a process tank or in a separate regeneration unit. Plating shops in the USA and Germany that are regenerating black zinc chromate solutions (silver-containing) have never dumped them for many years. A number of plating shops in Russia stopped dumping different chromate-based solutions used for the treatment of Zn, Cd and Cu.