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 conditionin g, which is capable of predicting the adsorption density of the collector o n the surfaces of ores. In this paper, a semi-empirical model for the kinet ics of conditioning of pyrite-chalcopyrite ore was suggested and tested. Th e suggested model for conditioning fits well the experimental data. The mod el is based on an electrochemical mechanism, and it also takes into account the effect of the degree of conditioning. Experiments with batch condition ing of a mixture of high-content chalcopyrite and pyrite ores sieved to a c ertain particle size class were carried out at pH 9. The dissolved oxygen c oncentration and the pulp potential were varied in the conditioning, which resulted in different rates of xanthate adsorption. The flotation was start ed immediately after the conditioning. The flotation model based on first o rder kinetics gave an excellent fit to the experimental data. The effects o f the degree of conditioning on the kinetics and efficiency of flotation we re also shown. It was noted that the higher the degree of conditioning with moderate conditioning times, the better the recovery of chalcopyrite and t he greater the rate of chalcopyrite flotation. Long conditioning times were found to deteriorate the grade, although the high level of chalcopyrite re covery was maintained. (C) 2000 Elsevier Science B.V. All rights reserved.