Microbially enhanced removal of pyrite and chalcopyrite from oxide gangue minerals with reference to desulfurization of tailings

Abstract

The selective removal of sulfide minerals, such as pyrite and chalcopyrite, from oxide gangue minerals, quartz and calcite was achieved in the presence of bacterial cells and metabolic byproducts of Bacillus polymyxa. A selective affinity of the bacterial cells towards the mineral surface was obsd. through adsorption studies. Changes in the surface chem. behavior of bacterial cells, as well as minerals, after mutual interaction were established though zeta-potential measurements with respect to time and pH. Flocculation and flotation of the minerals after interaction with bacterial cells and bacterial biomass led to an effective sepn. of pyrite and chalcopyrite from quartz and calcite from the viewpoint of desulfurization of mine tailings with respect to environmental control.