Abstract: Civil and Environmental Engineering Institute，University of Science and Technology Beijing The Serratia spp strain USTB-1 is obtained from the soil of Sijiaying Iron Mine in Luanxian, Hebei Province. Possibility and effect of the strain as flotation collector for hematite was investigated in the flotation tests on pure hematite by means of microscopy observation and the infrared spectroscopy analysis, and Zeta potential analyzer. The results showed that the bacterium was nearly spherical brevibacterium. Both non-polar and polar groups were detected on the cell surface, showing as negative charge, so it can be acted as collector for hematite. Under the conditions of solution pH 6 and cell concentration of 60 mg/L USTB-1, -30 μm hematite forms as large hydrophobic flocculation group so that the recovery of 80.48% for pure hematite was obtained.

Key words: Fine hematite, Serratia spp strain USTB-1, Floatation, Flocculation