Investigation on beneficiation of goethite-rich iron ores using reduction roasting followed by magnetic separation

ABSTRACT

In this study, reductive roasting followed by low-intensity magnetic separation were used to upgrade iron ore from Gua mines in Jharkhand. The work aimed to maximise the recovery of iron values by upgrading to a high-grade product suitable for pelletisation and sintering. The received ore contains 58% Fe, 7.82% silica, 4.26% alumina and 4.97% loss on ignition. Reductive roasting experiments were conducted at times of 10, 20 and 30 min at 600°C, 700°C and 900°C using coal as a reducing agent. Roasted samples were processed using a low-intensity magnetic separator. Best results were obtained at 800°C for 30 min using 10% coal in the charge. Using these conditions a product containing 66.6% Fe was produced at 90.4% recovery. The roasted samples were characterised by XRD which confirms the hematite to magnetite transformation and by SEM which highlighted the porous nature of the upgraded ore.

GRAPHICAL ABSTRACT

KEYWORDS:

• Iron ore
• reduction roasting
• magnetic separation
• goethite
• Recovery
• Upgradation
• Coal
• Magnetite

Acknowledgements

The authors are thankful to the Department of Fuel and Mineral Engineering, ISM Dhanbad. The authors would like to acknowledge the support by Dr M. Ravi, Senior Principal Scientist, Materials Science Division and the research staff assistants in Mineral processing division of CSIR-NIIST, Trivandrum. The authors extended their acknowledgment to Dr Selvakannan for XRD analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.