Analysis of particle trajectories of small particles in flotation when the particles and bubbles are both charged

Abstract

AbstractThe trajectory of a small particle moving to a bubble surface was analyzed by taking into account the effects of surface charges of the bubble and particle and the short range hydrodynamic interaction near the bubble surface, in a flotation process. The particle trajectories obtained theoretically were in good agreement with those obtained by direct observation. Even if the signs of the surface charges of the bubble and particle were the same, the particle adhered to the bubble surface when the net surface force, that is, the sum of the electrostatic force and the van der Waals force, was attractive. Particle capture efficiency, ηS, per bubble was estimated by trajectory analysis and the flotation efficiency, ηT, was calculated. The values of ηT calculated by the particle trajectory analysis were in reasonable agreement with those obtained experimentally. The dependence of particle diameter on ηT was also examined by the particle trajectory analysis.