A model of conditioning in the flotation of a mixture of pyrite and chalcopyrite ores

Collector control in flotation plants is an important factor, which affects recovery and grade. The performance of a control system can be improved by calculating the collector requirement using a kinetic model of conditioning, which is capable of predicting the adsorption density of the collector on the surfaces of ores. In this paper, a semi-empirical model for the kinetics of conditioning of pyrite-chalcopyrite ore was suggested and tested. The suggested model for conditioning fits well the experimental data. The model is based on an electrochemical mechanism, and it also takes into account the effect of the degree of conditioning. Experiments with batch conditioning of a mixture of high-content chalcopyrite and pyrite ores sieved to a certain particle size class were carried out at pH 9. The dissolved oxygen concentration and the pulp potential were varied in the conditioning, which resulted in different rates of xanthate adsorption. The flotation was started immediately after the conditioning. The flotation model based on first order kinetics gave an excellent fit to the experimental data. The effects of the degree of conditioning on the kinetics and efficiency of flotation were also shown. It was noted that the higher the degree of conditioning with moderate conditioning times, the better the recovery of chalcopyrite and the greater the rate of chalcopyrite flotation. Long conditioning times were found to deteriorate the grade, although the high level of chalcopyrite recovery was maintained. (C) 2000 Elsevier Science B.V. All rights reserved.