Apparatus and a process for regenerating a CUCl.sub.2 etchant

A process for regenerating a solution of used etchant in a sump, said used etchant solution containing a concentration of a metal in divalent form, said process comprising the steps of:

• supplying a quantity of said etchant solution containing said metal in divalent form to a control tank;
• forcing an overflow of solution from said control tank to said sump;
• supplying solution from said control tank to a first electrolytic cell;
• electrolytically converting said solution with said divalent form of said metal in said first electrolytic cell to a solution containing a high fraction of a monovalent form of said metal;
• returning said solution containing a high fraction of said monovalent form of said metal to said control tank;
• supplying said solution containing a high fraction of said monovalent form of said metal from said control tank to a second electrolytic cell;
• and
• electrolytically converting said monovalent form of said metal in said solution to said metal in said second electrolytic cell.