THE MECHANISM OF THE BACTERIAL OXIDATION OF ARSENOPYRITE-PYRITE MIXTURES - THE IDENTIFICATION OF PLANT CONTROL PARAMETERS

Previous conclusions concerning the mechanisms of the bacterially catalysed oxidation of pyrite and arsenopyrite are reviewed. Further available experimental evidence is described and interpreted to give a more detailed mechanism for the reactions. The mechanistic conclusions are used to identify the parameters which are important in the control of the plant operation of the processing of gold-bearing refractory pyrite/arsenopyrite minerals. These parameters are the concentrations of iron(II) and (III), arsenic(III) and (V), and the values of pH, electrode potential, pulp density and the bacterial population.