Electrochemical and physical characterisation of lead-based anodes in comparison to Ti–(70%) IrO2/(30%) Ta2O5 dimensionally stable anodes for use in copper electrowinning

The suitability of various dimensionally stable anodes (DSAs®) was investigated in comparison to the conventional lead alloy anodes in the electrowinning of copper. DSA® plate and mesh specimens of composition Ti–(70%) IrO2/(30%) Ta2O5 and lead–(6%) antimony were evaluated. The electrochemical behaviour of these anodes was studied by carrying out open circuit potential measurements, galvanostatic chronopotentiometry, cyclic voltammetry and chronoamperometry. Physical characterisation was done using a scanning electron microscope. It was observed that the DSA® plate anode exhibited the highest corrosion resistance followed by the DSA® mesh and lead anodes, respectively. The results also showed that during copper electrowinning using lead anodes, dissolution of the anode occurs while for both DSAs® marginal loss of coating was observed. The lead anode had the highest anode potential followed by the DSA® plate and mesh anodes, respectively. Overall, it was demonstrated that the DSA® plate anode is the most suitable anode for copper electrowinning.