The effect of different clay minerals on the flotation kinetics of chalcopyrite

This study investigated the effects of clay minerals (montmorillonite, illite, and kaolinite) on chalcopyrite recovery and flotation kinetic parameters. Classical first-order flotation kinetic model was applied as a function of froth height and amount of clay minerals to fit overall flotation results on chalcopyrite recovery against flotation time. Clay minerals enhanced chalcopyrite recovery by mechanical entrainment and slime coating of valuable chalcopyrite particles. Flotation tests have shown that the deleterious impact of clay minerals on the chalcopyrite flotation is enhanced as follows: montmorillonite>kaolinite>illite. Montmorillonite significantly raised viscosity and also considerably diminished chalcopyrite grade. Recovery and selectivity were lower for montmorillonite than kaolinite and illite. The adjunct of illite was of little effect on chalcopyrite flotation kinetics. The obtained flotation rate constants indicate that clay minerals are carried to the concentrate together with the chalcopyrite. The flotation rate constants increased with increasing the amount of all clay minerals. Slime minerals easily entered to concentrate by mechanical entrainment, and the inhibition effect of clay particles on chalcopyrite became more obvious with increasing flotation time. However, the negative effect of clay minerals is reduced with high froth height.