Investigations of the collision process between particles and gas bubbles in flotation — A theoretical analysis

Abstract

The collision between a mineral particle and a gas bubble in froth flotations is studied theoretically. Special attention is paid to the bubble interface deformation resulting from the impact with the particle. Analytical formulas are obtained for the deformation depth and the frequency of oscillation as dependent on the kinetic energy of impact, particle size, surface tension, viscosity, etc. Theoretical calculations are compared with experimental data. A conclusion is drawn that collisions causing a pronounced deformation of the bubble surface are ineffective for the formation of a three-phase contact since the oscillation period is relatively short and there is no sufficient time left for the thinning and rupture of the film between the particle and the bubble and the establishment of strong contact between them. From this point of view one can assume that collisions occurring without considerable deformation, i.e. the slidings, are more favourable for the efficiency of flotation.