Microbially-induced flocculation and flotation for pyrite separation from oxide gangue minerals

Selective separation of pyrite from quartz and calcite was achieved through microbiologically induced flotation and flocculation in presence of Bacillus polymyxa. Adsorption behavior of bacterial cells onto pyrite, calcite and quartz was established. Surface chemical changes on various minerals brought about by bacterial interaction were established through zeta-potential measurements as a function of pH. It has been shown that pyrite can be separated from quartz and calcite through either selective flocculation or flotation after interaction with cells of B. polymyxa or bioproteins separated from the bacterial metabolite. The results of this study are significant from the viewpoint of desulphurisation of flotation tailings with respect to environmental control.