Impact of the Adsorption of Bacteria on Enhancing the Separation Selectivity of Dolomite and Apatite

Abstract

The surface modification of minerals by bacteria has recently been examined in an attempt to improve their separation selectivities. In this paper, a study of the effect of Corynebacterium diphtheriae intermedius (CDI) bacteria on the dolomite/apatite separation process is reported. Bacterial interaction with both minerals was investigated employing Fourier-transform infrared (FT-IR) spectroscopy together with measurements of the adsorption isotherm and the zeta potential. FT-IR methods were used to identify the functional groups on the surface of each mineral before and after the adsorption of bacteria, while the adsorption isotherm and the zeta potential were used to illustrate the type of adsorption process involved, i.e. physical versus chemical adsorption. The application of bioflotation processes to natural ores using CDI bacteria can lower the MgO content of the ores to less than 1%.