6 - Summary of the Theoretical Aspects of Flotation

Abstract

This chapter summarizes the theoretical aspects of flotation. Flotation is a combination of chemical, physiochemical, and physical phenomena that govern the three-phase flotation system. The mineral–water, mineral–air and water–air interfaces are considered to possess a surface energy that plays a decisive role in most of the aspects of the flotation phenomenon. Because the atoms and ions, which are part of the mineral surface, are subjected to different transformations due to the changes in the environment, the same can apply to the water and gaseous phases. The mineral particle phase is a multi-mineral system, which is composed of a variety of different minerals with different crystallographic chemical and surface properties. The liquid (i.e., water) is the phase in which the separation of minerals by flotation takes place. The air phase has always been associated with aeration of flotation pulp and dissolved gases. The flotation process is governed by a complex phenomenon occurring on the surface of mineral particles and air bubbles formed in the water phase. From the practical point of view, the hydrophobicity and bubble mineralization are perhaps the two most important factors in flotation and govern the system kinetics and selectivity of flotation.