Role of a heterotrophic Paenibacillus polymyxa bacteria in the bioflotation of some sulfide minerals

A pure strain of Paenibacillus polymyxa and mineral-adapted strains are use d to bring about surface chemical changes oil pyrite and chalcopyrite and, thus, their flotation. Paenibacillus polymyxa was adapted by repeated subcu lturing in the presence of pyrite and chalcopyrite. The surface chemical ch anges of bacteria doe to adaptation and of minerals after their interaction with bacterial cultures are evaluated by electrokinetic and infrared spect roscopy and are discussed with reference to their flotation responses. Inte raction of bacterial cells, bacterial metabolites and whole bacterial cultu res affected the Hallimond flotation behavior of the sulfide minerals. The Xanthate flotation results show that pyrite, but not chalcopyrite, is depre ssed when the rests are carried out after interaction with chalcopyrite-ada pted Paenibacillus polymyxa. This investigation demonstrated that the surfa ce chemical properties of bacteria can be manipulated successfully to achie ve the desired effects in the flotation process.