Beneficiation of Ferruginous Bauxite

Abstract

A Sample of Ferruginous bauxite from Amarkantak assaying 39% Al2O3,28.1% Fe2O3, 7.1% TiO2, 3.0% SiO2 18.5% L.O.I. was received in the National Metallurgical Laboratory to improve its Al2O3 content by suitable ore dressing techniques. Ferruginous minerals, quartz and rutile constituted the gangue, and bauxite was free from these at about 100 mesh size. Tabling, magnetic separation and flotation tests were performed for elimination of gangue from bauxite. Tabling at 28 mesh produced a bauxite concentrate assaying 42.78% Al2O3, 23.52% Fe2O3 with a recovery of only 62.9% Al2O3.Reduction roast followed by wet magnetic separation at 100 mesh/size produced a bauxite concentrate assaying 68.14% Al2O3 with a recovery of 55.3% Al2O3 in the product. Rougher flotation followed by three cleanings using a reagent combination of sodium metaphosphate, dextrin, sodium silicate and oleic acid emulsion produced a refloat concentrate assaying 57.0% Al2O3,9.8% Fe2O3 with a recovery of 66.4% Al2O3.The concentrate is of a grade suitable for alumina production.