Microbially induced selective flocculation of hematite from kaolinite

Biological beneficiation of kaolin: A review on iron removal

“…As an alternative approach to bioleaching, microbially induced separation of kaolin and iron oxides can be achieved via selective bioflocculation or bioflotation which mainly depend on the surface chemistry of microorganisms and minerals (Poorni and Natarajan, 2013). Therefore, any changes in the surface chemistry brought about by adsorption and adhesion of bacterial cells and their metabolic products would be important (Deo and Natarajan, 1998).…”

“…EPS adsorb on mineral surfaces through hydrophobic, electrostatic, covalent, and polymer-polymer interactions (Whitfield, 1988;Cao et al, 2011). Adsorption of bacterially generated proteins on mineral surface renders them more hydrophobic; whereas, polysaccharides make them hydrophilic (Poorni and Natarajan, 2013). Table 3 puts together the use of these mechanisms for separation of iron minerals from clays which are published in some recent literatures.…”

“…Similarly, iron ores such as hematite may contain clays like kaolin as contamination which cause problems in the operation of blast furnaces. Therefore, the first beneficiation step to make these raw materials commercially valuable is to effectively eliminate iron oxides from kaolinite clays and vice versa (Poorni and Natarajan, 2013).…”

“…Iron oxide existence in kaolin is biologically induced, so it is better to apply a biological process for removing it from clays by exploiting microorganisms (Poorni and Natarajan, 2013). Interaction of microbes with clay minerals conserves the clay structure, fertility, and chemistry of the soil through the cation exchange and pH buffering (Kostka et al, 1999a).…”

Improving the separation efficiency of Southern African haematite from slimes through selective flocculation coupled with magnetic separation

“…Selective flocculation of haematite from gangue can be achieved through various methods using microorganisms (Poorni and Natarajan, 2013;Pradhan et al, 2006); polymers (Abro, 2009;Abro et al, 2013;Ahmed and Mahran, 2013;Arol and Aydogan, 2004;Drzymala and Fuerstenau, 2014;Hanumantha Rao and Narasimhan, 1985;Kumar and Mandre, 2017;Ma, 2012;Weissenborn, 1996;Weissenborn, Warren, and Dunn, 1994), and collectors such as sodium oleate (Pascoe and Doherty, 1997;Roy, 2012;Song, Lopez-Valdivieso, and Ding, 1999;Song, Lu, and Lopez-Valdivieso, 2002;Yin et al, 2011).…”