Role of bacterial interaction and bioreagents in iron ore flotation

Abstract

Interaction between Paenibacillus polymyxa and iron ore minerals such as hematite, corundum, calcite, quartz and kaolinite brought about significant surface chemical changes on all the minerals. Quartz and kaolinite were rendered more hydrophobic, while the other three minerals became more hydrophilic after bacterial interaction. Predominance of bacterial polysaccharides on interacted hematite, corundum and calcite and of proteins on quartz and kaolinite was responsible for the surface chemical changes. The bacterial strains could be preadapted to different mineral substrates. Corundum-adapted strains were seen to secrete mineral-specific proteins which could be used to separate alumina from iron ores. The utility of bioprocessing in the beneficiation of iron ores for removal of silica and alumina is demonstrated.