Effect of Halide Ions on the Dissolution of Copper Single Crystal Planes in Dilute Sulphuric Acid

The rates of dissolution of copper single crystal planes in dilute sulphuric acid containing various concentrations (10−8 to 10−2M) of Cl−, Br− and I− are determined at 30°C. The dissolution rates, which are controlled by transport process in solution, are a function of the temperature, stirring rate, oxygen solubility, crystallographic orientation and the concentration of halide ions. Halide ions acted as anodic inhibitor at low concentrations and cathodic inhibitor at high concentrations. The changes in the dissolution rates have been attributed to specific adsorption of halide ions or precipitation of cuprous halides on the surface of the crystal planes