Fluidised-bed anodic dissolution of covellite

The anodic dissolution of synthetic covellite (CuS) has been investigated using a fluidisedbed anode technique. In sulphuric acid electrolyte the dissolution of CuS is accompanied by excessive oxygen evolution at the Pt feeder electrode unless the applied current is maintained at unrealistically low values. In mixed electrolytes, such as sulphuric acid-sodium chloride or sulphuric acid-potassium bromide, the anodic dissolution of CuS proceeds at acceptable values of applied current via a charge transfer mechanism provided by the $\text{Cl}{}^{\mathrm{?}}\text{-}\text{1}\text{2}\text{Cl}{}_2\text{or Br}{}^{\mathrm{?}}\text{-}\text{1}\text{2}\text{Br}{}_2$ redox couple. The results of the present study are compared with previous work on the fluidised-bed anodic dissolution of chalcocite (Cu₂S).