Process for the maintenance of metallization baths

摘要

To regenerate the electrolyte of a metal plating bath, which does not use a current, at least a part-flow (5) of electrolyte is taken from the bath by a pump (8) to be regenerated and returned. The electrolyte is passed through a dialysis and/or electro-dialysis unit (11), where released anions are exchanged for hydroxide ions through an ion-selective membrane (19). A counter solution (9) to the dialysis and/or electro-dialysis contains an alkali and/or alkaline earth hydroxides. Before return to the bath, the electrolyte is enriched with a copper sulfate feed (1) and formaldehyde (2).