Adsorption-collecting function of Rhodococcus erythropolis on hematite and quartz

The possibility and effect of Rhodococcus erythropolis(R.erythropolis) as a flotation collector for hematite were investigated.The surface morphology and cell wall constituent of R.erythropolis were analyzed.The surface potentials of the strain,hematite and quartz before and after adsorption with R.erythropolis were measured.Flotation tests for the collection of pure hematite and pure quartz respectively and the separation of hematite-quartz mixture(1:1,mass ratio) were carried out.The adsorption characteristics and mechanisms were also discussed.The results show that the rod-shaped bacterium is detected with hydrophobic and hydrophilic groups on the cell wall,showing highly negative charged and strongly hydrophobic characteristics.The adsorption is significantly more selective onto hematite than onto quartz.The hematite recovery of 89.68% and quartz recovery of only 26.25% are obtained under solution pH value of 6 and cell concentration of 75 mg/L.Iron concentrate with the grade of 50.08% and recovery rate of 76.41% is recovered from the mixture after one-stag flotation.The chemical adsorption of the strain onto hematite makes hematite form hydrobolic agglomerate.It is confirmed that R.erythropolis can be acted as the collector for hematite.