Aerosol Collector Addition in Coarse Particle Flotation - A Review

The ability to successfully recover coarse particles by flotation has long been seen as the area where significant step-change improvements to energy efficiency of mineral processing operations could be made. Recent developments in the field of fluidized bed flotation have introduced exciting new possibilities for coarse particle flotation. The hydrodynamic aspects of fluidized bed flotation have been a subject of many studies over the years, with many more currently underway. However, the impact of pulp chemistry within such a radically different hydrodynamic environment has not received similar attention. In flotation systems, chemistry and hydrodynamics are intricately linked, so a radical change in one, necessitates a similar change in the other. One such possibility is the use of aerosol collector addition, whereby collector reagents are introduced to a flotation system via the surfaces of bubbles rather than through the aqueous solution to the mineral particles. The concept of aerosol collector addition is not novel, but relatively poorly studied. The few studies that have focused on it have demonstrated that thermodynamically such methods result in a significant improvement in collector adsorption. However, how such a method would perform in the context of fluidized bed flotation is not known. This paper reviews the available literature on the underlying mechanisms of aerosol collector addition in flotation and how it impacts the collector coverage and resulting hydrophobicity of mineral particles. The review is performed in the context of the unique hydrodynamic environment of fluidized bed flotation of coarse particles. The goal of the work is to determine the potential of utilizing aerosol collector addition to further boost the efficacy of coarse particle recovery.