The behaviour of particles in flotation froths

Abstract

This paper covers some developments over the past 10 years in research into the behaviour of floating and entrained mineral particles in the froth phase of the flotation process. It focuses on the current understanding of the pulp-froth transfer of solid particles and water, and the separation and transfer processes occurring in the froth phase, in both mechanical cells and flotation columns. An analysis is also made of three methods that may be used to distinguish between the contributions made by true flotation and the entrainment of mineral particles during flotation. The observations that have been made from experimental investigations and a review of the published literature suggest that, in many cases, the froth phase is limiting the rate at which floating particles are recovered in the concentrate. Furthermore, because the region at the pulp-froth interface is instrumental in the rejection of weakly floatable valuables, gangue and water, and therefore the initial upgrading in the froth, it is suggested that future floation research should focus largely on the development of techniques to study and quantify pulp-froth transfer processes. This will enable relationships between the froth transfer parameters and operating conditions to be established more accurately, and so assist in the simulation of flotation networks. Importantly, emphasis should also be placed on the refinement of simulation models and their reconciliation with operating data.