Effect of process variables on sintering indices in relation to high LOI hematite ore fines of Gua mines

Chakraborty, Debarun and Goswami, M C and Bhagat, R P (2010) Effect of process variables on sintering indices in relation to high LOI hematite ore fines of Gua mines. In: Proceedings of the XI International Seminar on Mineral Processing Technology (MPT-2010), Dec 2010, NML Jamshedpur, India.

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Abstract

The strength parameters of sinter namely, Tumbler Indexes (TI), Reduction-Degradation Index (RDI) and Reducibility Index (RI) are key properties of sinter that influence the performance of blast furnace when used as burden. The contributing factor to the sinter quality could be the mineralogical composition of the sinter which is decided by the sinter chemistry and other process parameters. Besides the quality parameters of sinter, the effectiveness of the sintering process is determined by the productivity of the sintering machines. The process variables and the characteristics of ore fines do have significant influence on the sinter quality and its productivity .The present paper reports the effect of certain process variables on the sintering indices in relation to high LOI content beneficiated ore fines from Gua mines of SAIL. Pot sintering studies were carried out at NML using the beneficiated goethitic hematite ore from Gua mines of Jharkhand, India. The ore contains Fe -61.26, Silica-2.56%, Alumina-2.74%, LOI-6.27%. Raw materials namely limestone, dolomite, coke breeze were collected from Bokaro Steel Plant of SAIL and prepared according to the existing practice of the sinter plant of SAIL. The sinter basicity (CaO/SiO₂) was kept as variable having the values ranges from 1.6 to 2.6%. The MgO content of the sinter was also varied from 0.8% to 1.6%. The sinter quality parameters were evaluated according to the Indian standards. The effect of process variables namely basicity, bed height, MgO content of sinter, on the Vertical Speed of Sintering (VSS)[productivity], and quality parameters of sinter was investigated. The study shows that the amount of solid fuel and the moisture content, had inter-influencing effect on the sintering indices. Coke breeze at 5% of the raw mix and moisture content in between 5.5% to 5.8% seems to be optimum for an acceptable strength (TI) of sinter and in relation to RDI of sinter. More of desired mineral phases, calcium ferrites etc. do occur in the sinter when the process sinter was not over fused or under fused. The speed of sintering decreases, while the yield and strength of sinter increases with increase in bed height from 400 mm to 500 mm.The reduction parameters also improve which signifies a change in sinter mineralogy. More of calcium ferrites and magnetite phase is observed as the bed height increases.

Item Type:Conference or Workshop Item (Paper)
Official URL/DOI:http://www.nmlindia.org
Uncontrolled Keywords:Sintering, Iron ore, Sinter basicity, Bed height, Vertical speed of sintering (VSS), Tumbler index (TI), Reduction - degradation index (RDI), Reducibility index (RI).
Divisions:Metal Extraction and Forming
ID Code:2487
Deposited By:Dr. A K Sahu
Deposited On:10 Feb 2011 12:30
Last Modified:15 Nov 2011 16:07
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