Implication of process mineralogy for beneficiation of low grade iron ore resources containing high alumina from eastern part of India

Kumar, Vinod and Jadhav, G N and Khosla, N K and Mehrotra, S P (2010) Implication of process mineralogy for beneficiation of low grade iron ore resources containing high alumina from eastern part of India. Proceedings of the XI International Seminar on Mineral Processing Technology, I . pp. 82-91.

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Total estimated reserve of iron ore in India is around 23 billion tonnes with annual consumption of about 100 million tonnes, while the anticipated demand by next two years is likely to increase by 150 million tonnes/annum. It is estimated that proven metallurgical grade ore is going to sustain the production of iron for another 30–35 years only. Depletion of high grade reserves coupled with increasing market pressure and the threat of environmental pollution has made to realize the need to exploit large tonnage of low grade iron ores for sustainable development. High alumina content in the low grade iron ore has been a major concern to the iron ore industries in their large scale utilization as it increases fuel consumption, slag volume, forms a viscous slag, decreases the furnace productivity and has adverse effect on sinter strength. Additionally, iron ore contains a host of other deleterious elements such as silica, phosphorous and sulfur and their removal are essential before feeding to the blast furnace. Selection of beneficiation methods depends on the level and nature of the gangue and the form of its dissemination, as well as the gangue and the impurities encapsulated in the structure of ore assemblages. The present paper deals with the characterization and beneficiation of high alumina iron ores from Noamundi Mines of Jharkhand, where environmental friendly methods will be studied for their sustainable exploitation. Low grade iron ores (hard laminated ore, lateritic ore, limonitic and shaly ore) from the selected deposit was investigated following physical beneficiation processes. The microscopy, petrography and ore mineralogical characterization will be investigated of various mineral beneficiated ores. Investigations suggest that iron ore samples were composed of hematite (two generations), goethite (two generations) and limonitic material (younger generation) in association with major gangue minerals such as clay minerals (kaolinite, gibbsite), cryptocrystalline silica (jasper, chert) and crystalline quartz as well as apatite. The ores were subjected to comminution to smaller size followed by Enhanced Gravity Separation (EGS), and magnetic separation (WHIMS). Hard laminated ore, inspite of the complex nature, shows good separation by both MGS (Multi Gravity Separator) and WHIMS (Wet High Intensity Magnetic Separator), especially for smaller size, where as in case of shaly ore and limonitic ore, iron bearing minerals report to tailing in the form of fine locked particles even in finer size ranges. Use of advanced gravity and magnetic separation techniques of beneficiation resulted in cleaner concentrate containing around 66% Fe at 60% recovery by weight for hard grade ores. However, in reference to shaly ore and limonitic ore, desired grade of concentrate was not obtained which was attributed to their complex nature and intricate ore-gangue association. This research work reiterates that the role of ore-gangue mineralogy is very useful in evaluating the separation efficacy of beneficiation processes.

Item Type:Article
Official URL/DOI:
Uncontrolled Keywords:High alumina iron ore, Process mineralogy, Beneficiation, EGS, MGS and WHIMS.
Divisions:Mineral Processing
ID Code:2289
Deposited On:30 Dec 2010 15:59
Last Modified:13 Oct 2011 12:47
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