Modeling Flotation from First Principles

Abstract

Many investigators developed flotation models in the past, most of which were empirical and incorporated only physi-cal parameters such as particle size, bubble size and energy dissipation. As a result, these models could not be used to predict flotation from some of the key chemistry parameters such as particle hydrophobicity (or contact angle) and surface charges (or c-potentials) of bubbles and particles. Yoon and Mao (1996, 1997) derived a first-order flotation rate equation by using both surface chem-istry and hydrodynamic parameters. Furthermore, this model was derived from first principles and therefore it had diagnostic and predictive capabilities. The model was developed based on the premise that bubble-particle adhe-sion is induced by the hydrophobic force, a strong attra-ctive force between two hydrophobic surfaces in water, measured for the first time by Israelachvili and Pashley (1982). This model, however, was applicable only for flotation under laminar flow conditions, and did not consider the events taking place in froth phase.