Bio-flotation of Egyptian Phosphate Using Desulfvibrio Desulfuricans Bacteria

摘要

The bio-flotation and bio-flocculation processes concern the mineral response to the bacterium presence, which is essentially considered as interplay between microorganism and the physicochemical properties of the mineral surface. The adhesion of microorganisms to minerals results in alteration of surface chemistry of minerals relevant to beneficiation process due to a consequence of the formation of a biofilm on the surface or bio-catalyzed surface oxidation or reduction products. In this paper, the amenability of utilization of Desulfvibrio desulfuricans isolated and adapted on surfaces of phosphate ore, as flotation reagents for separating silica from apatite in the bio-flotation of quartz-apatite minerals system has been studied. The effect of this bacterial isolates on the surface properties of the two single minerals has been studied through zeta potential and adhesion measurements as well as micro-flotation tests. The effect of pH of the medium on the surface properties and flotation behaviour of each single mineral is determined. Flotation of binary mixtures of quartz-apatite as well as natural phosphate ore has also been performed at different operating parameters. Different characterization techniques for both single minerals and bacteria isolated from their surfaces have been done using XRD, SEM, and contact angle as well as morphological and biochemical identification of bacterial isolates.