Beneficiation of low grade Magnetite from Salem, Madras: Part I

Abstract

The results of studies on beneficiation of a magnetite ore assaying 36.5% Fe and 44.2% SiO2 and containing principal magnetite, quartz, hematite, goethite, Kyanite and sillimanite are presented. Dry magnetic separation of the sample did not produce satisfactory results. Wet magnetic separation at -40 and -65 mesh sizes yielded magnetic assaying 62.5% Fe, 11.1% SiO2 and 64.3% Fe, 9.6% SiO2 with a recovery of about 68% iron in both cases. Dry magnetic separation at -10 mesh followed by wet magnetic separation of the rougher concentrate at -40 mesh produced a final concentrate assaying 65.21% Fe and 8.0%SiO2 with an overall recovery of 82.8% Fe, but higher recovery could be obtained at the expense of grade of the concentrates . Tabling at -40 mesh and magnetic separation at -65 mesh can, therefore, yield nearly the same results, because the slime and tailing loss during tabling almost balanced the loss of hematite in the non-magnetite product. Results obtained by pilot plant trails employing tabling as well as magnetic separation are also presented.