ELECTROCHEMICAL OXIDATION OF ARSENOPYRITE IN CHLORIDE SOLUTIONS

Cyclic voltammetry, potential step, and AC impedance techniques were a pplied to study the electrochemical reaction of arsenopyrite in chlori de solutions, The relationship between anodic current density and time in potential step measurements indicates that the oxidation of arseno pyrite is irreversible. The results of the constant potential coulomet ry show that the stoichiometric factor of electron involves in the ove rall reaction is 14. It is proposed that the dissolution of arsenopyri te is retarded by the coverage of sulfur produced in the reaction as a n intermediate product. The measured results of AC impedance strongly support this proposition, The proposed reaction mechanism also explain s satisfactorily the charging current density and slopes of polarizati on plot measured in potential step measurements.