ROLE OF HYDROPHOBIC INTERACTION IN FLOTATION AND FLOCCULATION

A good correlation between aggregation of the hydrophobicity of mineral particles has been observed experimentally. A comparative characterization is presented for all components of the interaction energies in adhesion processes, and it has been determined that the energy of hydropbobic interaction is one or two orders of magnitude greater than the energy of electrostatic or molecular interaction. Thereby, the decisive role of hydrophobic interaction has been defined in flotation and also in hydrophobic flocculation. Attachment of hydrophobic particles to a bubble is accompanied by rupture of the boundary layer of water, entry of the hydrocarbon chains of the adsorbed layer of surfactant into the air of the bubble, and the formation of a three-phase contact; hydrophobic particles can be fixed on the bubble only through a hydrate film, and without direct contact. Fixation without contact always destroys the selectivity of flotation.