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Influence of Reduction Atmosphere and Temperature on the Separability and Distribution Behavior of Fe from FeTiO3 via Sulfurization

고온 황화반응에 의한 FeTiO3로부터 Fe의 분리성과 분배거동에 미치는 환원/황화 분위기 및 온도의 영향

  • Shin, Seung-Hwan (Dep. of Advanced Materials Engineering, Chosun University) ;
  • Kim, Sun-Joong (Dep. of Materials Engineering & Science, Chosun University)
  • 신승환 (조선대학교 첨단소재공학과) ;
  • 김선중 (조선대학교 재료공학과)
  • Received : 2019.04.11
  • Accepted : 2019.06.18
  • Published : 2019.06.30

Abstract

$TiO_2$ as a raw material for producing titanium can be produced by carbon reduction of natural ilmenite ores over 1823 K and acid leaching of the obtained titanium-rich slag. However, the conventional process can cause very high energy consumption and a large amount of leaching residues. In the present study, we proposed the sulfurization of $FeTiO_3$ with $Na_2SO_4$ at temperatures below 1573 K, which can separate Fe in $FeTiO_3$ as the FeS based sulfide phase and Ti as the $TiO_2-Na_2O$ based oxide phase. This study is a fundamental study for sulfurization of $FeTiO_3$ to investigate the influence of reducing atmosphere, reaction temperature and the sulfur/Fe ratio on the separability and distribution behaviors of of Fe, Ti, and Na between the oxide phase and the sulfurized phase. At 1573 K and carbon saturation condition, the Fe can be separated from $FeTiO_3$ as Fe-C-S metal and a part of FeS, and the concentration of Fe in oxide decreased to 4 mass% after sulfurization.

티타늄 생산 원료로서 $TiO_2$는 천연 일메나이트 광석을 1823 K 이상에서 탄소와 함께 환원 및 산 침출을 통해 티타늄이 풍부한 슬래그로부터 생산할 수 있으나, 공정상 매우 높은 에너지 소비 및 다량의 침출 잔류물을 발생한다. 본 연구에서는 1573 K 이하 온도에서 $Na_2SO_4$에 의해 $FeTiO_3$의 황화 처리를 통해서 철 자원은 FeS 황화물 상으로써 티타늄 자원은 $TiO_2-Na_2O$계 산화물 상으로 분리할 수 있는 반응을 제안한다. 본 연구는 $FeTiO_3$의 황화 처리의 기초 연구로서, FeS 황화물 상과 $TiO_2$계 슬래그 상의 분리성에 미치는 환원 분위기의 영향과 대기 분위기 속에서 반응온도와 Sulfur 비에 따른 Fe, Ti, Na 등의 거동을 조사하였다. 1573 K 및 탄소 포화 조건에서 $FeTiO_3$의 Fe는 Fe-C-S 금속과 일부 FeS로 분리 가능하며, 산화물 내 농도는 4 mass% 정도로 감소하였다. 또한, Sulfur/Fe 비가 높아질수록 자성 분리 후 회수된 산화물의 Fe 농도가 증가하며, 회수된 금속상 내 Fe 농도는 감소하였다.

Keywords

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Fig. 1. Schematic diagram of the experimental setup.

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Fig. 2. X-ray diffraction patterns of synthesized FeTiO3 (A) and sample obtained from Exp. A (B).

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Fig. 3. Standard free energy of the reactions of experiment as a function of temperature.

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Fig. 4. Mineralogical microstructure of Exp. B by FE-SEM.

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Fig. 5. X-ray diffraction patterns of the sample (Exp. B) in the Ar gas atmosphere: (1) Metal phase separated from the sample, (2) Oxide phase separated from the sample.

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Fig. 6. X-ray diffraction patterns of the sample (Exp. C-1,3) in the Ar gas atmosphere: (1) Separated sample at 1473 K, (2) Separated sample at 1273 K.

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Fig. 7. Contents of Ti, Fe and Na in oxide and Fe in metal as a function of temperature at 0.5 of S/Fe ratio.

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Fig. 8. Contents of Ti, Fe and Na in oxide and Fe in metal as a function of sulfur/Fe ratio at 1573 K.

Table 1. Initial composition of the sample and the used crucible for the Exp. A ~ C

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Table 2. SEM/EDS point analysis results obtained by Exp. B in the Ar gas atmosphere (mass%)

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References

  1. F. H. Froes, 1988 : The production of low-cost titanium powders. JOM, 50(9), pp.41-43. https://doi.org/10.1007/s11837-998-0413-4
  2. W. Kroll, 1940 : The production of ductile titanium. Transactions of the Electrochemical Society, 78(1), pp.35-47. https://doi.org/10.1149/1.3071290
  3. G. Z. Chen, D. J. Fray, and T. W. Farthing, 2000 : Direct electrochemical reduction of titanium dioxide to titanium in molten calcium chloride. Nature, 407(6802), pp.361. https://doi.org/10.1038/35030069
  4. K. Ono and R. O. Suzuki, 2002 : A new concept for producing Ti sponge: calciothermic reduction. JOM, 54(2), pp.59-61. https://doi.org/10.1007/BF02701078
  5. R. O. Suzuki, 2005 : Calciothermic reduction of $TiO_{2}$ and in situ electrolysis of CaO in the molten $CaCl_2$, Journal of Physics and Chemistry of Solids, 66(2-4), pp.461-465. https://doi.org/10.1016/j.jpcs.2004.06.041
  6. D. R. Sadoway, 1991 : The eelectrochemical processing of refractory metals. JOM, 43(7), pp.15-19. https://doi.org/10.1007/BF03220614
  7. T. H. Okabe, T. Oda, and Y. Mistuda, 2004 : Jounal of Alloys and Compounds. 364(1-2), pp.156-163. https://doi.org/10.1016/S0925-8388(03)00610-8
  8. T. H. Okabe, M. Nakamura, T. Oishi, and K. Ono, 1993 : Electrochemical deoxidation of titanium, Metallurgical and Materials Transactions B, 24(3), pp.449-455. https://doi.org/10.1007/BF02666427
  9. S. Jiao and H. Zhu, 2006 : Novel metallurgical process for titanium production, Journal of materials research, 21(9), pp.2172-2175. https://doi.org/10.1557/jmr.2006.0268
  10. Z. Yuan, X. Wang, C. Xu, W. Li, and M. Kwauk, 2006 : A new process for comprehensive utilization of complex titania ore, Minerals Engineering, 19(9), pp.975-978. https://doi.org/10.1016/j.mineng.2005.10.002
  11. C. S. Kucullaragoz and R. H. Eric, 2006 : Solid state reduction of a natural ilmenite, Minerals Engineering, 19(3), pp.334-337. https://doi.org/10.1016/j.mineng.2005.09.015
  12. S. Z. Eltawil, I. M. Morsi, and A. A. Francis, 2013 : Kientics of solid-state reduction of ilmenite ore, Canadaian Metallurgical Quarterly, 32(4), pp.281-288.
  13. R. Merk and C. A. Pickles, 1988 : Reduction of ilmenite by carbon monoxide. Canadian Metallurgical Quarterly, 27(3), pp.179-185. https://doi.org/10.1179/cmq.1988.27.3.179
  14. T. S. Mackey, 1974 : Acid leaching of ilmenite into synthetic rutile, Industrial & Engineering Chemistry Product Research and Development, 13(1), pp.9-18. https://doi.org/10.1021/i360049a003
  15. T. O. Kang and J. K. Yoon, 1978 : Reduction kinetics of synthetic ilmenite by graphite, J. Kor. Inst. Metals, 16(2), pp.80-89.
  16. E. Park and O. Ostrovski, 2003 : Reduction of Titania-Ferrous Ore by Carbon Monoxide, ISIJ International, 43(9), pp.1316-1325. https://doi.org/10.2355/isijinternational.43.1316
  17. E. Park and O. Ostrovski, 2004 : Reduction of Titania-Ferrous Ore by Hydrogen, ISIJ International, 44(6), pp.999-1005. https://doi.org/10.2355/isijinternational.44.999
  18. J. H. Chen and C. Christi, 1974 : Beneficiation of Titaniferous Ores, United States Patent 3,825,419.
  19. Schlechten, W. Albert et al., 1972 : Appendix D Letter Requesting Process Information, Companies Querite, and Replies, Processes for rutile substitutes, pp.130-132, NMAB-293, Washington, D.C., US.
  20. H. Walter, 1994 : Process for the Production of Synthetic Rutile, United States Patent 5,601,630.
  21. H. N. Sinha, 1973 : MURSO process for producing rutile substitute, R.I. Jaffe, H.M. Burte (Eds.), Titanium science and technology, pp.233-244, Cambridge, MA; A Publication of the Metallurgical Society of AIME 1973, Plenum Press, New York, London.
  22. Y. I. Son, H. S. Sohn, and J. Y. Jung, 2018 : The effects of reductants on the behaviors of Fe selective chlorination using an ilmenite ore, Journal of Korean Institute of Resources Recycling, 27(3), pp.30-38. https://doi.org/10.7844/KIRR.2018.27.3.30
  23. H. S. Sohn and J. Y. Jung, 2016 : Current status ilmenite beneficiation technology for production of $TiO_2$, Journal of Korean Institute of Resources Recycling, 25(5), pp.64-74. https://doi.org/10.7844/KIRR.2016.25.5.64
  24. M. Liu, X. Lv, E. Guo, P. Chen, and Q. Yuan, 2014 : Novel process of ferronickel nugget production from nickel laterite by semi-molten state reduction, ISIJ International, 54(8), pp.1749-1754. https://doi.org/10.2355/isijinternational.54.1749
  25. Q. Cheng, X. Zhang, Z. F. Huang, Z. Wang, and H. Zhou, 2013 : The DRESOR method for radiative heat transfer in semitransparent graded index cylindrical medium, Journal of Quantitative Spectroscopy and Radiative Transfer, 143(1), pp.16-24.
  26. N. Ma and N. A. Warner, 1999 : Smelting reduction of ilmenite by carbon in molten pig iron, Canadian metallurgical quarterly, 38(3), pp.165-173. https://doi.org/10.1179/cmq.1999.38.3.165
  27. C. Geng, T. Sun, H. Yang, Y. Ma, E. Gao, and C. Xu, 2015 : Effect of $Na_2SO_4$ on the Embedding Direct Reduction of Beach Titanomagnetite and the Separation of Titanium and Iron by Magnetic Separation, ISIJ International, 55(12), pp.2543-2549. https://doi.org/10.2355/isijinternational.ISIJINT-2015-420
  28. W. Lv, X. Lv, J. Xiang, Y. Zhang, S. Li, C. Bai, and K. Han, 2017 : A novel process to prepare high-titanium slag by carbothermic reduction of pre-oxidized ilmenite concentrate with the addition of $Na_2SO_4$, International Journal of Mineral Processing, 167, pp.68-78. https://doi.org/10.1016/j.minpro.2017.08.004
  29. G. Li, T. Shi, M. Rao, T. Jiang, and Y. Zhang, 2012 : Beneficiation of nickeliferous laterite by reduction roasting in the presence of sodium sulfate, Minerals Engineering, 32, pp.19-26. https://doi.org/10.1016/j.mineng.2012.03.012
  30. F. D. Richardson and J. H. E. Jeffes, 1952 : The thermodynamics of substances of interest in iron and steel making. Journal of Iron Steel Institute, 171, pp.165-175.
  31. J. P. Coughlin, 1954 : Bureau of Mines-Bulletin 542, Unitei-StatekS-Government Printing Office-Washington D. C, pp.23.
  32. G. M. Kale and K. T. Jacob, 1992 : Chemical potential of oxygen for iron-rutile-ilmenite and iron-ilmenite-ulvospinel equilibria, Metallurgical Transactions B, 23(1), pp.57-64. https://doi.org/10.1007/BF02654037
  33. E. Maxwell and D. Kelland, 1978 : High gradient magnetic separation in coal desulfurization. IEEE Transactions on Magnetics, 14(5), pp.482-487. https://doi.org/10.1109/TMAG.1978.1059826