A close-looped process based on the membrane separation and electrolysis is proposed to regenerate the copper etchant in-situ, recover copper on-site and reuse it. It is characterized by selective separation of copper from the spent etchant, which is accomplished by the ion exchange membrane-electrowinning, and at the same time the other components useful for etching are reclaimed. The experiments show that at least 90% of electricity efficiency for copper removal can be maintained and the optimum condition for membrane-electrowinning is: cell voltage 2-2.5 V, operating temperature 40 - 50 deg...
