INVESTIGATION OF PYRITE OXIDATION BY POTASSIUM DICHROMATE

The results obtained in the investigation of the kinetics of pyrite oxidation by potassium dichromate in sulphuric acid are presented. The effects of temperature, dichromate and sulphuric acid concentrations, particle size and stirring speed were examined. The results obtained showed that the reaction is chemically controlled and that the activation energy is 50 kJ/mol. The concentration of dichromate ions had no effect on the rate of pyrite oxidation (zero order), whereas for sulphuric acid concentration a first order dependence was established. The rate of pyrite oxidation was also found to be independent of stirring speed. On the addition of chloride ions the rate of pyrite oxidation remained unchanged.