RATE-LIMITING FACTORS IN DUMP LEACHING OF PYRITIC ORES

A model describing the oxidation of mining heaps containing pyrite was presented in an earlier paper and applied to cylindrical heaps. Special attention was given to the interaction of macroscopic transport with the microscopic particle kinetics. We reexamine the model using the more realistic truncated cone geometries. It is seen that while macroscopic transport is still the major rate-limiting factor, the overall behavior of the heap oxidation is significantly different from that shown in previous studies using the simple cylindrical heap geometry. Water infiltration, which was omitted in the earlier model, is included, and the impact of the irrigation rate on the oxidation rate of the heap is examined.