MODELING THE ROLE OF BACTERIA IN LEACHING OF LOW-GRADE ORES

A robustious structural model is developed to describe the role of bacteria in the leaching process of low-grade ores under conditions controlled by intraparticle diffusion. The main impetus behind developing this model is to provide an insight into such systems, together with a suitable framework for interpreting experimental data. The model is derived in detail with respect to reaction chemistry and the role of bacteria in catalyzing these reactions, specifically the synergism of chemistry, physics and biology in determining the overall behavior of the system. The model is used to simulate the atmospheric oxidation of iron disulfide contained in porous solids in the presence of Thiobacillus ferrooxidans (T. ferrooxidans). The experimental data are predicted well by the model which demonstrates its applicability and supports the view that the rate of intraparticle diffusion is the controlling mechanism for this system.