INVESTIGATION OF THE KINETICS OF CHALCOPYRITE OXIDATION BY POTASSIUM DICHROMATE

The kinetics of chalcopyrite oxidation by potassium dichromate in sulphuric acid were investigated. The effects of stirring rate, temperature, dichromate concentration, sulphuric acid concentration and particle size on the rate of chalcopyrite oxidation were examined. The activation energy is 48-54 kJ/mol, indicating that the rate of chalcopyrite oxidation is chemically controlled. The dichromate ion concentration had no effect on rate of chalcopyrite dissolution and, relative to sulphuric acid, an order of 0.80-0.92 was established. In addition, the effects of chloride, copper(II) and iron(III) concentrations on the rate of chalcopyrite oxidation were investigated.