The technology involves reclamation of copper using electrolytic recovery of a PVC-based membrane. Finishing Services Ltd manufactures printed circuit boards. In making printed circuits unwanted copper foil is etched away by an acid solution of cupric chloride.
Dissolved copper reduces the effectiveness of the solution.
The solution is typically regenerated by oxidizing the cuprous ion with acidified hydrogen peroxide. The volume of solution, however, increases steadily and the surplus liquor must be stored. The copper in the surplus liquor is precipitated as copper oxide and landfilled. The new technology uses electrolytic recovery with a PVC-based membrane which allows the passage of hydrogen and chloride ions but not the copper. The copper is transferred to the cathode and recovered as pure flakes.