Electrochemical sensors for the HydroCopper™ process solution

Platinum, a DSA (dimensionally stable anode) mesh and gold electrodes were investigated for use as redox potential sensors for the Outokumpu HydroCopper™ process. The redox potential was measured in a standard HydroCopper™ solution with constant pH, temperature and sodium chloride concentration. The concentration of cupric ions was varied in the range 0–40 g/dm3. dox potential was observed to increase logarithmically with increasing cupric ion concentration and to decrease linearly with time. Platinum and DSA-type electrodes were found to be electrochemically inert and allowed the measurement of the redox potential. With the gold the corrosion potential of the electrode was measured.