Bioleaching of a cobaltiferous pyrite at 20% solids: a continuous laboratory-scale study

The continuous bioleaching of a cobaltiferous pyrite was carried out at 20% solids in laboratory-scale stirred reactors. Various potentially limiting factors, such as agitation, aeration, dissolved oxygen concentration and na ture of the nitrogen source were investigated. Direct measurement of O-2 an d CO2 consumptions was performed using on-line gas analysers in order to st udy the physiological behaviour of the micro-organisms during oxidation and to improve the evaluation of oxygen requirements for pyrite oxidation. The study was also used to propose a mathematical model of the bioleaching process, which was calibrated with experimental data.