Influence of bentonite on flotation of minerals with different densities

Abstract

This short communication investigates the impact of bentonite on the flotation performance of minerals with varying densities, specifically galena and sphalerite. Despite existing research on bentonite influence on flotation, its effects on minerals with different densities have not been analyzed so far. The results from this study demonstrated that bentonite adversely affected the flotation recoveries of both galena and sphalerite due to the high pulp viscosity. The addition of Ca²⁺ ions mitigated this detrimental effect by reducing the pulp viscosities around 8 times. As a result, the flotation performance of galena was markedly enhanced, showing a 33 % increase in recovery and a 37 % improvement in settling rates. However, in the absence of Ca²⁺ ions, the flotation recovery of galena decreased more than that of sphalerite, considering that the density of galena is 1.9 times higher than that of sphalerite. This study shows that in the presence of Ca²⁺ ions, the flotation recoveries of galena and sphalerite became similar, as Ca²⁺ reduced the consistency index and prevented galena particles from detaching from bubbles.