Abstract
The reduction of vanadium titano-magnetite pellets by H2–CO at temperatures from 850 to 1050°C was investigated in this paper. The influences of pre-oxidation treatment, reduction temperature, and \({{{V_{{H_2}}}} \mathord{\left/ {\vphantom {{{V_{{H_2}}}} {\left( {{V_{{H_2}}} + {V_{CO}}} \right)}}} \right. \kern-\nulldelimiterspace} {\left( {{V_{{H_2}}} + {V_{CO}}} \right)}}\) on the metallization degree were studied. The results showed that pre-oxidation played a substantial role in the reduction of vanadium titano-magnetite pellets. During the reduction process, the metallization degree increased with increasing temperature and increasing \({{{V_{{H_2}}}} \mathord{\left/ {\vphantom {{{V_{{H_2}}}} {\left( {{V_{{H_2}}} + {V_{CO}}} \right)}}} \right. \kern-\nulldelimiterspace} {\left( {{V_{{H_2}}} + {V_{CO}}} \right)}}\). The phase transformation of pre-oxidized vanadium titano-magnetite pellets during the reduction process under an H2 atmosphere and a CO atmosphere was discussed, and the reduced samples were analyzed by scanning electron microscopy (SEM) in conjunction with back scatter electron (BSE) imaging. The results show that the difference in thermodynamic reducing ability between H2 and CO is not the only factor that leads to differences in the reduction results obtained using different atmospheres. Some of Fe3−x Ti x O4 cannot be reduced under a CO atmosphere because of the densification of particles’ structure and because of the enrichment of Mg in unreacted cores. By contrast, a loose structure of particles was obtained when the pellets were reduced under an H2 atmosphere and this structure decreased the resistance to gas diffusion. Moreover, the phenomenon of Mg enrichment in unreacted cores disappeared during H2 reduction. Both the lower resistance to gas diffusion and the lack of Mg enrichment facilitated the reduction of vanadium titano-magnetite.
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References
K.C. Sole, Recovery of titanium from the leach liquors of titaniferous magnetites by solvent extraction: Part 1. Review of the literature and aqueous thermodynamics, Hydrometallurgy, 51(1999), No. 2, p. 239.
P. Tan, H.P. Hu, and L. Zhang, Effects of mechanical activation and oxidation−reduction on hydrochloric acid leaching of Panxi ilmenite concentration, Trans. Nonferrous Met. Soc. China, 21(2011), No. 6, p. 1414.
G.H. Han, T. Jiang, Y.B. Zhang, Y.F. Huang, and G.H. Li, High-temperature oxidation behavior of vanadium, titanium-bearing magnetite pellet, J. Iron Steel Res. Int., 18(2011), No. 8, p. 14.
Y.L. Sui, Y.F. Guo, A.Y. Travyanov, T. Jiang, F. Chen, and G.Z. Qiu, Reduction roasting–magnetic separation of vanadium tailings in presence of sodium sulfate and its mechanisms, Rare Met., 35(2016), No. 12, p. 954.
B.C. Jena, W. Dresler, and I.G. Reilly, Extraction of titanium, vanadium and iron from titanomagnetite deposits at pipestone lake, Manitoba, Canada, Miner. Eng., 8(1995), No. 1-2, p. 159.
K.C. Sole, Recovery of titanium from the leach liquors of titaniferous magnetites by solvent extraction: Part 2. Laboratory-scale studies, Hydrometallurgy, 51(1999), No. 3, p. 263.
L.L. Sui and Y.C. Zhai, Reaction kinetics of roasting high-titanium slag with concentrated sulfuric acid, Trans. Nonferrous Met. Soc. China, 24(2014), No. 3, p. 848.
D.S. Chen, L.S. Zhao, Y.H. Liu, T. Qi, J.C. Wang, and L.N. Wang, A novel process for recovery of iron, titanium, and vanadium from titanomagnetite concentrates: NaOH molten salt roasting and water leaching processes, J. Hazard. Mater., 244-245(2013), p. 588.
S.P. Yang, J. Wang, X. Du, and J. Liu, Study on melting separation for metalized pellet of vanadium−titanium magnetite and TiO2 enrichment, Min. Metall. Eng., 34(2014), No. 1, p. 87.
Y.F. Guo, M.J. Tang, T. Jiang, L.J. Qing, and J.F. Zhou, Research on the slag phase type of vanadium-titanium magnetite in pre-reduction-electric furnace smelting processing, [in] 4th International Symposium on High-temperature Metallurgical Processing, TMS Annual Meeting, San Antonio, 2013, p. 87.
M.S. Jena, H.K. Tripathy, J.K. Mohanty, J.N. Mohanty, S.K. Das, and P.S.R. Reddy, Roasting followed by magnetic separation: a process for beneficiation of titano-magnetite ore, Sep. Sci. Technol., 50(2015), No. 8, p. 1221.
S.Y. Chen and M.S. Chu, Metalizing reduction and magnetic separation of vanadium titano-magnetite based on hot briquetting, Int. J. Miner. Metall. Mater., 21(2014), No. 3, p. 225.
D.S. Chen, B. Song, L.N. Wang, T. Qi, Y. Wang, and W.J. Wang, Solid state reduction of Panzhihua titanomagetite concentrates with pulverized coal, Miner. Eng., 24(2011), No. 8, p. 864.
S.S. Liu, Y.F. Guo, G.Z. Qiu, T. Jiang, and F. Chen, Solid-state reduction kinetics and mechanism of pre-oxidized vanadium–titanium magnetite concentrate, Trans. Nonferrous Met. Soc. China, 24(2014), No. 10, p. 3372.
L.S. Li and Z.T. Sui, Physical Chemistry Behavior of Enrichment Selectivity of TiO2 in Perovskite, Acta Phys. Chem. Sin., 17(2001), No. 9, p. 845.
A.A. Barde, J.F. Klausner, and R.W. Mei, Solid state reaction kinetics of iron oxide reduction using hydrogen as a reducing agent, Int. J. Hydrogen Energy, 41(2016), No. 24, p. 10103.
W.K. Jozwiak, E. Kaczmarek, T.P. Maniecki, W. Ignaczak, and W. Maniukiewicz, Reduction behavior of iron oxides in hydrogen and carbon monoxide atmospheres, Appl. Catal. A, 326(2007), No. 1, p. 17.
M.Z. Su, J.C. Ma, X. Tian, and H.B. Zhao, Reduction kinetics of hematite as oxygen carrier in chemical looping combustion, Fuel Process. Technol., 155(2017), p. 160.
D.B. Guo, M. Hu, C.X. Pu, B. Xiao, Z.Q. Hu, S.M. Liu, X. Wang, and X.L. Zhu, Kinetics and mechanisms of direct reduction of iron ore-biomass composite pellets with hydrogen gas, Int. J. Hydrogen Energy, 40(2015), No. 14, p. 4733.
E. Park and O. Ostrovski, Reduction of titania-ferrous ore by carbon monoxide, ISIJ Int., 43(2003), No. 9, p. 1316.
H.Y. Sun, J.S. Wang, Y.H. Han, X.F. She, and Q.G. Xue, Reduction mechanism of titanomanetite concentrate by hydrogen, Int. J. Miner. Process., 125(2013), p. 122.
J. Tang, M.S. Chu, F. Li, Y.T. Tang, Z.G. Liu, and X.X. Xue, Reduction mechanism of high-chromium vanadium-titanium magnetite pellets by H2–CO–CO2 gas mixtures, Int. J. Miner. Metall. Mater., 22(2015), No. 6, p. 562.
Y.L. Wang, Ferrous Metallurgy (Ironmaking), Metallurgical Industry Press, Beijing, 2005, p. 87.
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This study was financially supported by the Fundamental Research Funds for the Central Universities (2014zzts273).
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Sui, Yl., Guo, Yf., Jiang, T. et al. Gas-based reduction of vanadium titano-magnetite concentrate: behavior and mechanisms. Int J Miner Metall Mater 24, 10–17 (2017). https://doi.org/10.1007/s12613-017-1373-x
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DOI: https://doi.org/10.1007/s12613-017-1373-x