As the metal bearing stream enters the system cell, it is channeled in a serpentine path through a series of electrolytic chambers, each containing two anodes sandwiching a cathode. The turbulence created at the cathode interface is said to provide high plating efficiency, translating into fast plate-out to very low concentrations. The metal deposits on and within the cathode. Any non-adherent solids that tend to accumulate during the electrowinning process are swept to the cell bottom and contained for draining (the electrodes are raised 3-in. above the cell floor to eliminate the possibility of the solids causing a short circuit). Each system cathode can hold up to 30-lb of metal (150-lb for the whole cell).
The system can be used to remove and recycle metals on a batch basis from a spent plating bath or other metal-bearing solution, as well as on a continuous basis from a primary drag-out rinse to ameliorate or preclude precipitation or ion exchange. The system may also be used on a batch basis to recycle ion exchange regenerant.
The manufacturer states that depending upon variables such as the solution, treatment time, solution volume, and current, concentrations below 0.5-ppm are attainable with this system.
Precious Metals Processing Consultants Inc., 430 Bergen Boulevard, Palisades Park, NJ 07650. Tel: 201-944-8053. Fax: 201-944-8003.