CHARACTERIZATION OF BACILLUS POLYMYXA FROM JAMNAGAR MINE WATER AND BIOBENEFICIATION OF BAUXITE ORE FOR IRON THROUGH SURFACE MODIFICATION

2 Abstract: Preliminary screening of the mine water sample from bauxite ore deposits in Jamnagar, India showed the presence of heterotrophic bacteria B.polymyxa. Growth conditions for the bacteria to bring about maximum beneficiation were standardized by using the enriched Bromfield medium. B. polymyxa brought significant changes in the surface modifications of the mineral calcite. The interaction resulted in surface chemical changes both on the cell and on the mineral surface by studying their electrophoretic mobilities using Zeta meter 3.0. Flocculation and settling studies in the presence of microorganisms establish the foundation in which these processes could be used for the utility of beneficiation in the efficient separation of the impurities from the ore, thus confirmed that B.polymyxa has greater affinity towards calcite and could be efficiently used to remove calcium from calcite. Experiments with respect to the bauxite ore was initiated after confirming the above result. Calcium removal from bauxite ore by B.polymyxa has been demonstrated under 2% sucrose concentration brought about 40% removals in four days and under similar conditions the control in absence of B. polymyxa only 20% calcium removal was seen. Thus, B. polymyxa plays a significant role in biobenficiation of bauxite mineral. These observations clearly indicated that a direct mechanism through bacterial attachment to the ore and an indirect mechanism through leaching with metabolites are involved in the biobeneficiation process.