TREATMENT OF PREFORMS CONTAINING COPPER WITH A MIXTURE CONTAINING CHLORINE-FREE AND CARBOXYL-FREE ACIDS AND OXIDANTS

摘要

A method for treating preforms containing copper, wherein an aqueous mixture (M), containing (a.) chlorine-free acids without carboxyl groups, (b.) oxidants, (c.) aqueous solvent and optionally further additives is brought into contact with the preform. The method is inter alia characterized in that the aqueous mixture (M) additionally (e.) contains dissolved copper after etching or pickling and is separated from the preform. The invention also relates to a method for processing the separated aqueous mixture (M), which additionally contains dissolved copper, by electrolysis. The invention further relates to mixtures (MI) containing (a.) from 10 to 40% w/w methane sulphonic acid, (b.) from 10 to 20% w/w hydrogen peroxide and (c.) from 40 to 80% w/w water and to the use thereof for etching or pickling preforms containing copper.