Flotation of Fine Particles: A Review

Literature shows that flotation is highly size dependent and processing both coarse and fine size fractions is problematic. The latter is the subject of the current paper. Fine particles have a relatively high surface area, and therefore more reagents are needed for their processing. In addition, the problem of fine particle flotation is mainly due to their low collision and attachment efficiencies with bubbles. Several strategies are proposed in the literature to overcome the problems of fine particle flotation. They mainly rely on increasing particle size by selective aggregation and decreasing the bubble size by using nano or microbubbles, but also on using reactor-separator type flotation cells which promote a much stronger particle–bubble interaction. The pros and cons of these strategies are discussed in this paper.