| 摘要 |
PURPOSE:To easily separate and recover metallic copper from the surface of a cathode, when a waste copper chloride etching soln. is regenerated by an electrolytic method and metallic copper is deposited on the cathode, by adjusting the area and current density of the cathode to a specified range. CONSTITUTION:The etching power of a CuCl2 etching soln. used in a process of etching copper of a printed substrate or the like is reduced owing to an increase in the CuCl content as the soln. is used. So, the soln. is electrolyzed to deposit metallic copper on a cathode as well as chlorinate CuCl to CuCl2. At this time, the current density of the cathode is adjuted to 20-150A/cm<2>, and the area of the cathode is reduced to a half or less of that of an anode. By controlling the increase of the anode current density to a half or less of that of the cathode current density, polarization is inhibited to prevent the CuCl2 regeneration efficiency from lowering, and metallic copper is deposited on the cathode in the form of fine grains to easily separate and recover metallic copper from the cathode surface. |
