Abstract
Reduction of chromium-bearing vanadium–titanium sinter (CVTS) was studied under simulated conditions of a blast furnace, and thermodynamics and kinetics were theoretically analyzed. Reduction kinetics of CVTS at different temperatures was evaluated using a shrinking unreacted core model. The microstructure, mineral phase, and variation of the sinter during reduction were observed by X-ray diffraction, scanning electron microscopy, and metallographic microscopy. Results indicate that porosity of CVTS increased with temperature. Meanwhile, the reduction degree of the sinter improved with the reduction rate. Reduction of the sinter was controlled by a chemical reaction at the initial stage and inner diffusion at the final stage. Activation energies measured 29.22–99.69 kJ/mol. Phase transformations in CVTS reduction are as follows: Fe2O3→Fe3O4→FeO→Fe; Fe2TiO5→Fe2TiO4→FeTiO3; FeO·V2O3→V2O3; FeO·Cr2O3→Cr2O3.
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References
H.G. Du, Principle of Smelting Vanadium–Titanium Magnetite in the Blast Furnace, Science Press, Beijing, 1996, p. 1.
J.X. Liu, G.J. Cheng, Z.G. Liu, M.S Chu and X.X. Xue, Reduction process of pellet containing high chromic vanadium–titanium magnetite in cohesive zone, Steel Res. Int., 86(2015), No. 7, p. 808.
M. Zhou, T. Jiang, S.T. Yang, K. Ma, X.X. Xue, and W.J. Zhang, Optimization utilization of vanadium–titanium iron ore in sintering based on orthogonal method, Metalurgija, 55(2016), No. 4, p. 581.
S.T. Yang, M. Zhou, T. Jiang, S.F. Guan, W.J. Zhang, and X.X. Xue, Application of a water cooling treatment and its effect on coal-based reduction of high-chromium vanadium and titanium iron ore, Int. J. Miner. Metall. Mater., 23(2016), No. 12, p. 1353.
M. Zhou, S.T. Yang, T. Jiang, and X.X. Xue, Influence of MgO in form of magnesite on properties and mineralogy of high chromium, vanadium, titanium magnetite sinters, Ironmaking Steelmaking, 42(2015), No. 3, p. 217.
M. Zhou, S.T. Yang, T. Jiang, and X.X. Xue, Influence of basicity on high-chromium vanadium–titanium magnetite sinter properties, productivity, and mineralogy, JOM, 67(2015), No. 5, p. 1203.
M. Zhou, T. Jiang, S.T. Yang, and X.X. Xue, Sintering behaviors and consolidation mechanism of high-chromium vanadium and titanium magnetite fines, Int. J. Miner. Metall. Mater., 22(2015), No. 9, p. 917.
Y.M. Wang, Z.F. Yuan, H. Matsuura, and F. Tsukihashi, Reduction extraction kinetics of titania and iron from an ilmenite by H2–Ar gas mixtures, ISIJ Int., 49(2009), No. 2, p. 164.
K. Sun, R. Takahashi, and J. Yagi, Reduction kinetics of cement-bonded natural ilmenite pellets with hydrogen, ISIJ Int., 32(1992), No. 4, p. 496.
M.L.D. Vries and I.E. Grey, Influence of pressure on the kinetics of synthetic ilmenite reduction in hydrogen, Metall. Mater. Trans. B, 37(2006), No. 2, p. 199.
Y. Zhao and F. Shadman, Reduction of ilmenite with hydrogen, Ind. Eng. Chem. Res., 30(1991), No. 9, p. 2080.
P.L. Vijay, R. Venugopalan, and D.S. Amoorthy, Preoxidation and hydrogen reduction of ilmenite in a fluidized bed reactor, Metall. Mater. Trans. B, 27(1996), No. 5, p. 731.
D.G. Jones, Kinetics of gaseous reduction of ilmenite, J. Chem. Technol. Biotechnol., 25(1975), No. 8, p. 561.
S. Itoh and A. Kikichi, Reduction kinetics of natural ilmenite ore with carbon monoxide, Mater. Trans., 42(2001), No. 7, p. 1364.
Y. Zhao and F. Shadman, Kinetics and mechanism of ilmenite reduction with carbon monoxide, AIChE J., 36(1990), No. 9, p. 1433.
G.Q. Zhang and O. Ostrovski, Reduction of ilmenite concentrates by methane-containing gas: Part I. Effects of ilmenite composition, temperature and gas composition, Can. Metall. Q., 40(2001), No. 3, p. 317.
S.T. Yang, M. Zhou, T. Jiang, Y.J. Wang, and X.X. Xue, Effect of basicity on sintering behavior of low-titanium vanadium–titanium magnetite, Trans. Nonferrous Met. Soc. China, 25(2015), No. 6, p. 2087.
M. Zhou, S.T. Yang, T. Jiang, L.H. Zhang, J.T. Xiao, X. Xue, and W.J. Zhang, Effects of carbon content on the sintering behavior of low-titanium vanadium–titanium magnetite, Metall. Res. Technol., 113(2016), No. 6, p. 612.
Y. Zhao, K. Wu, W. Pan, and Q.H. Liu, Investigation of the reduction kinetics process of sinter ore by sectional stepwise method, J. Northeast. Univ. Nat. Sci., 34(2013), No. 9, p. 1282.
W. Pan, K. Wu, X. Zhao, D.J. Min, H.Y. Wang, and Z.C. Zhang, Reduction kinetics of Shougang iron ore sinter, J. Univ. Sci. Technol. Beijing, 35(2013), No. 1, p. 35.
A.A. El-Geassy, Influence of doping with CaO and/or MgO on stepwise reduction of pure hematite compacts, Ironmaking Steelmaking, 26(1999), No. 1, p. 41.
A.A. El-Geassy, Reduction of CaO and/or MgO-doped Fe2O3 compacts with carbon-monoxide at 1173–1473 K, ISIJ Int., 36(1996), No. 11, p. 1344.
M.I. Nasr, A.A. Omar, M.H. Khedr, and A.A. El-Geassy, Effect of nickel oxide doping on the kinetics and mechanism of iron oxide reduction, ISIJ Int., 35(1995), No. 9, p. 1043.
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This work was financially supported by the National Natural Science Foundation of China (Nos. 51604065 and 51674084), the Fundamental Funds for the Central Universities (Nos. 150203003 and 150202001), the Natural Science Foundation of Liaoning Province (20170540316), the China Postdoctoral Science Foundation (2017M611246), and the NEU Postdoctoral Science Foundation (No. 20160304).
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Yang, St., Zhou, M., Jiang, T. et al. Isothermal reduction kinetics and mineral phase of chromium-bearing vanadium–titanium sinter reduced with CO gas at 873–1273 K. Int J Miner Metall Mater 25, 145–152 (2018). https://doi.org/10.1007/s12613-018-1557-z
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DOI: https://doi.org/10.1007/s12613-018-1557-z