Improvement in Cr:Fe Ratio of Indian Chromite Ore for Ferro Chrome Production

About 40% of the Indian chromite ore reserves are suitable for metallurgical purpose due to higher Cr:Fe ratio. The present investigation emphasized on the liberation and beneficiation characteristics of Indian chromite oreto improve the Cr: Fe ratio. The off grade chromite sample ofSukinda region, India analysed 40.8% of Cr2O3 with Cr:Fe ratio of 1.7 and 5.8% of SiO2 which was not suitable for metallurgical industry. Detailed characterisation studies were carried out to predict the theoretical limits to improve the Cr/Fe ratio. Mineralogical investigation by using QEMSCAN studies revealed that chromite, hematite, goethite, Fe Silicates and kaolinite are dominating phases in the ore.Half of the Fe was present in the chromite spinel, whereas other 30% and 20% werereported from silicates and iron minerals, respectively. It was predicted from characterisation that, product can be enriched to 2.48 Cr:Fe ratio by discarding the silicate/locked silicate, Fe silicate gangue minerals whereas product quality can be upgraded maximum to 3.58 of Cr:Fe ratio by separating all iron bearing minerals. The beneficiation studies revealed that, the product can be enriched to having Cr:Fe ratio of 2.31 and 3.35 by gravity concentration (wet shaking table) and high intensity magnetic separation (Induced Roll Magnetic Separator) respectively. So the high intensity magnetic separator (Induced Roll Magnetic Separator) was suggested for the quality improvement of the off grade chromite ore ofSukinda region, India.