ժҪ The vanadium titano-magnetite (VTM) iron ore fines of 110-150 ��m in diameter were reduced in a transparent quartz fluidized bed by 70%CO-30%H2 (volume fraction) mixtures. MgO powders served as coating agent to solve sticking problem. Two coating methods were introduced in this experiment: high temperature injection method and briquetting��oxidizing roast��crushing method. According to the experimental results, the minimum effective coating amount of MgO was 0. 1 mass%. The metallization ratio (MR) of the product rose from around 58% to above 90% with the above treatments. To investigate the sticking mechanism of fine ore, the morphology evolution was investigated. Instead of iron whiskers, an interlaced fibrous porous surface formed. The ulvospinel (2FeO��TiO2) in VTM is more difficult to be reduced than FeO according to thermodynamic calculation. XRD results showed that MgO diffused into Fe2O3 lattice before forming pleonaste (MgO��Fe2O3) during oxidizing roast at 1273 K. The melting point of the pleonaste is 1986 K and that made contribution to prevent the sticking problem.
Abstract��The vanadium titano-magnetite (VTM) iron ore fines of 110-150 ��m in diameter were reduced in a transparent quartz fluidized bed by 70%CO-30%H2 (volume fraction) mixtures. MgO powders served as coating agent to solve sticking problem. Two coating methods were introduced in this experiment: high temperature injection method and briquetting��oxidizing roast��crushing method. According to the experimental results, the minimum effective coating amount of MgO was 0. 1 mass%. The metallization ratio (MR) of the product rose from around 58% to above 90% with the above treatments. To investigate the sticking mechanism of fine ore, the morphology evolution was investigated. Instead of iron whiskers, an interlaced fibrous porous surface formed. The ulvospinel (2FeO��TiO2) in VTM is more difficult to be reduced than FeO according to thermodynamic calculation. XRD results showed that MgO diffused into Fe2O3 lattice before forming pleonaste (MgO��Fe2O3) during oxidizing roast at 1273 K. The melting point of the pleonaste is 1986 K and that made contribution to prevent the sticking problem.
��������:National Natural Science Foundation of China;National Basic Research Program of China 973 Program
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E-mail: guolei755246488@163.com
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Lei GUO,Jin-tao YU,Jing-kun TANG,Yin-he LIN,Zhan-cheng GUO,Hui-qing TANG. Influence of Coating MgO on Sticking and Functional Mechanism during Fluidized Bed Reduction of Vanadium Titano-magnetite[J]. �й������ڿ���, 2015, 22(6): 464-472.
Lei GUO,Jin-tao YU,Jing-kun TANG,Yin-he LIN,Zhan-cheng GUO,Hui-qing TANG. Influence of Coating MgO on Sticking and Functional Mechanism during Fluidized Bed Reduction of Vanadium Titano-magnetite. Chinese Journal of Iron and Steel, 2015, 22(6): 464-472.
2015, Vol. 22 
