Abstract:
An analytical dynamic mathematical model representing the adsorption anddesorption mechanisms of the microorganisms in the batch leaching system wasdeveloped. The model was used to determine adsorption-desorption parameters usedin the model of the bacterial leaching process.A one-dimensional dynamic mathematical model, which is a set of partialdifferential equations, for the bacterial leaching of a low grade copper ore containingChalcopyrite and Pyrite was developed and solved numerically by orthogonalcollocation method. The rate of mineral oxidation was related to the oxygenconsumption rate of bacteria of both attached and unattached to the ore surface by aMonod type equation. Therefore, the dissolved oxygen in the leaching solution wasthe limiting substrate in the overall leaching process. The model was used tocalculate the copper and the bacterial concentrations in the solution reservoir and alsoto calculate the profiles of oxygen concentrations in both liquid and gas phases,bacterial concentrations in both attached and unattached to the ore surface, copperconcentrations and temperatures along the ore bed. The parameters used in the modelwere determined by fitting the model results to the obtained experimental data. Themodel was then used to study the effects of bed height and irrigation flow rate to theleaching rate of a column system. This model provided a usefkl tool for designingand optimizing both pilot-scale column leaching and in heap leaching processes.