Hydrodynamics of Bubble-Mineral Particle Collisions

Abstract This chapter surveys the hydrodynamic interactions between particles and bubbles in flotation. Some new approximate equations are given for collision efficiency. It is shown that collision processes of particles with bubbles are less effective than sliding processes because of their short duration and the strong deformation of the bubble at the collision point. Methods are suggested to estimate collision and sliding times. During contact between a particle and a bubble, the just forming thin liquid film must drain off and rupture. Therefore, possible ways of calculating film drainage time are discussed. Furthermore, possible experimental methods to determine these quantities are briefly described and recent experimental results presented.