SLUDGE-FREE TREATMENT OF COPPER CMP WASTES

摘要

Waste slurry containing dissolved metal from CMP (11), e.g., is subjected to sludge-free processing. Embodiments include separating the waste slurry with a solids filter (13) into a solid-free dissolved metal-containing liquid filtrate portion (18) and a concentrated solids-containing portion (16), removing the dissolved metal from the filtrate by means of an ion exchanger (20), back-washing the concentrated solids-containing portion with metal-free effluent (25) from the ion exchanger (20) to further reduce its dissolved metal content, discharging the washed concentrated solids-containing portion to a waste drain (23), removing the metal from the ion exchanger in solution form, and optionally extracting solid metal from the solution by electrowinning (32).