Review of froth modelling in steady state flotation systems

Froth models proposed in the literature are reviewed with the aim of identifying their significance and usefulness in the modelling and scale-up of the froth phase in steady state flotation systems. Literature indicates that froth phase performance is better understood in terms of froth recovery, the fraction of material presented at the pulp-froth interface that reports to the concentrate. This review suggests that froth recovery is a strong function of drainage rate of particles from the froth phase to the slurry phase. Drainage rate, in turn, is determined by physical factors, such as froth removal technique, geometry of the rotation cell, flux and distribution of air at the pulp-froth interface the water content, particle size and solids content, and chemical factors, such as froth stability and froth loading. These factors influence the froth residence time, which has been identified as a key froth parameter. Finally, it is proposed that future work should focus largely on the development of a methodology to investigate froth performance based on the froth recovery in different flotation systems. This will enable generic relationships between the froth recovery and froth sub-processes and key froth parameters to be established, and make it possible to relate froth performance in different flotation systems. (C) 1998 Elsevier Science Ltd. All rights reserved.