Electrolytic recovery of metal from solution

摘要

Recovery of silver from a photographic fixer solution in an electrolytic cell is controlled so as to maintain a high current efficiency whilst minimising unwanted side effects. The difference between plating voltages when operating at two different current levels is monitored, and the plating current adjusted in response to detection of a maximum of said differences. Such control allows the cell to be operated continually at high current efficiency in response to changing chemical conditions within the cell.