Beneficiation of Indian High Alumina Iron Ore Fines – a Case Study

Beneficiation of high alumina iron ore fines from Noamundi, India is studied for producing sinter/ pellet grade concentrate. The iron ore fine sample has a feed grade of 59.77%Fe, %4.71SiO₂, and % 5.89Al₂O₃ with % 5.53 of LOI (Loss on Ignition). From the characterisation studies, it is revealed that the sample contains huge quantity of goethite which is partially weathered, interlocked with hematite and gangue minerals like gibbsite, kaolinite and quartz at different proportions. Two conceptual flow sheets have considered for the beneficiation of Indian high alumina iron ore fines. The first option, consisting of hindered settling classifier followed by two stage gravity concentration results in a product quality with 66.82%Fe and 2.1%Al₂O₃ content ensuring 25.15% iron recovery. In the second option, the iron ore fines treating in the similar approach but the second stage gravity concentration replaced by magnetic separation results in a product quality with 67.77% Fe, 1.53% Al₂O₃ with 28.95% of iron recovery. Mineralogical studies revealed that the concentrate product quality depends on presence of the goethite in the product.