Processing of Banded Hematite Quartzite Ore for Recovery of Iron Values

  • Veeranjaneyulu Rayapudi
  • Nikhil DhawanEmail author


This study investigates upgrading of low-grade banded hematite quartzite iron ore (Fe ~31%). Conventional beneficiation was found to be futile. The susceptibility of iron phases to microwave exposure and their selective absorption assists in the liberation of iron values. Microwave exposure of coarse particles at 540 W for 10 min yielded a concentrate with Fe 56.30% and recovery of 50.68%. Conventional carbothermic reduction at 500 °C, 60 min and 9% charcoal yielded a concentrate with Fe 57.6% and iron recovery of 68%. The presence of sufficiently bonded silica leads to an easy formation of a fayalite phase. The microwave reduction design yielded FeG of 57.6%, FeR of 47% and a yield of 24% at an optimal condition of 540 W, 8 min and 6% charcoal. It was found that a small fraction of microwave-irradiated ore-charcoal mixture melted rapidly, and pure ferrite balls were observed within 8 min. An optical micrograph of a ferrite ball reveals the retained austenite and martensite phase.


Low-grade iron ore Microwave Carbothermic reduction Magnetic separation Ferrite 



The authors would like to thank and acknowledge the funding agency of the Science Engineering Research Board for providing Early Career Research funds. The authors also wish to thank Ms. Kay Argyle for proofreading of the manuscript.

Compliance with Ethical Standards

Conflict of Interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.


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© Society for Mining, Metallurgy & Exploration Inc. 2020

Authors and Affiliations

  1. 1.Department of Metallurgical & Materials EngineeringIndian Institute of TechnologyRoorkeeIndia

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