Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
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Characteristics of Carbidization for Iron Ore Fines with a Wide Size Range

입도분포가 넓은 분철광석의 탄화특성

  • 황호순 (대원특수강(주) 기술연구소) ;
  • 정우창 (부산대학교 신뢰성연구센터) ;
  • 정원섭 (부산대학교 재료공학부) ;
  • 정원배 (부산대학교 재료공학부)
  • Published : 2003.10.01
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Abstract

Characteristics of reduction and carbidization for hematite ore with a wide size range have been investigated at high temperature(590∼64$0^{\circ}C$) under $H_2$ and $H_2$-CO gas mixtures. The apparent activation energy for reduction of hematite ore with H2 gas was found to be 20 kJ/mol. The weight loss by reduction was about 28% md the weight gain by carbidization was about 5%. The measured values of weight change were compared with those calculated from equation (3) & (5) and fairly good agreement was obtained. The rate of carbidization was increased with an decrease in temperature, particle diameter and gas ratio($H_2$/ CO). The free carbon was increased with decrease in gas ratio($H_2$/ CO). The rate of carbidization was increased with mixing of $H_2$ gas but this effect was not proportional to fraction of $H_2$ gas. It was also found that the rate of carbidization was the maximum in the $H_2$ gas fraction of 0.5. It is considered that $H_2$ plays a part as a catalyst for formation of iron carbide($Fe_3$C).

넓은 입도분포를 가지는 헤마타이트 철광석을 사용하여 $H_2$ 및 $H_2$-CO 혼합가스 분위기에서 환원 및 탄회특성에 대하여 고찰하였다. 환원에 의한 활성화에너지 값은 약 20kJ/mol 였다. 환원 및 탄화단계에서 무게변화는 환원단계에서는 약 28% 감소하였고, 탄화단계에서는 약 5%증가하였다. 이는 이론 계산식에 의한 값과 거의 일치하였다. 온도, 입도 및 가스비($_H2$/CO=1～5 범위)에 따른 탄화속도는 온도가 낮을수록 입자가 작을수록 그리고 가스비가 작을수록 탄화속도가 증가하였다. 또한 $H_2$의 가스비($H_2$/CO=1)가 낮을 때는 유리카본(C, free carbon)이 발생하였다. 수소가스를 혼합하였을 경우가 탄화속도는 증가하였으나, 수소분율에 비례하여 증가하지는 않았다. 혼합가스 중 수소분율($X_{H2}$ )이 0.5일 때 ($H_2$/CO=1) 탄화속도가 최대였다. 이때 수소가 탄화철 생성과정에 있어서 촉매역할을 한 것으로 추정된다.

Keywords

References

  1. Gradke, H. J., Muller-Lorenz, E. M., and Schneider. A., 2001: Carburization and Metal Dusting on Iron, ISIJ Int., 41, p. S1-S8 https://doi.org/10.2355/isijinternational.41.Suppl_S1
  2. Geiger, G. H., and Stephens. F. A., 1993: Ironmaking Conf. Proc., pp. 333-340
  3. Pollock. B. A., 1993: Iron Steelmaker 20, pp. 25-28
  4. Garraway., 1996: Nucor's Startup of the World's First Commercial Iron Carbide Plant, Iron Steelmaker, 23, pp. 27-31
  5. Steeling. O., 1985: J0M, 10, pp. 290-299
  6. Gray, P. R., and Leroy. B. J., 1975: U.S.A Patent 3 885 023
  7. Hager, J. P., Stephens, F. A. and Stephens. F. M., 1994: Method for Controlling the Conversion of Iron-Containing Reactor Feed into Iron Carbide, U.S.A Patent 5 366 897, Nov. 22
  8. Osdoit. B., 1960: Mem, Sc. Rev. Met., 57, pp. 194-199
  9. Nakagawa, H., Murayama, T., and Ono. Y., 1996: Tetsu-tohagane 82, pp. 1-8 https://doi.org/10.2355/tetsutohagane1955.82.1_1
  10. Conejo, A. N., and Martins. G. R, 1997: Conversion of Hematite to Iron Carbides by Gas Phase Carbidization, ISIJ Int., 37, pp. 967-976 https://doi.org/10.2355/isijinternational.37.967
  11. Hayashi, S., and Iguchi. Y, 1997: Synthesis of Iron Carbide by Reaction of Iron Ores with $H_2$-C0 Gas Mixtures Bearing Traces of Sulfur, ISIJ Int., 37, pp. 16-20 https://doi.org/10.2355/isijinternational.37.16
  12. Hayashi, S. and Iguchi. Y., 1997: Iron Carbide Synthesis by Reaction of Iron Ore with $H_2$-$CH_4$ GasMixtures Containing Traces of Sulfur, ISIJ Int., 37, pp. 345-349 https://doi.org/10.2355/isijinternational.37.345
  13. Hayashi, S. and Iguchi. Y., 1998: Production of Iron Carbide from Iron Ores in a Fluidized Bed, ISIJ Int., 38, pp. 1053-1061 https://doi.org/10.2355/isijinternational.38.1053
  14. Linoy, K., Gotoh, K., and Higashitani. K., 1991: Power Technology Handbook, Marcel Dekker, New York, PP. 13
  15. Edstr$\"o$m. J. 0., 1953: J. Iron Steel Inst., pp. 289
  16. Turkogan. E. T., 1980: Physical Chemistry of High Temperature Technology, Academic Press, New York, pp. 412
  17. Olmer. F, 1942: J. Phys. Chem., 46, pp. 405 https://doi.org/10.1021/j150417a012
  18. Kolesnik, N. F., and St. Pierre. G. R., 1980: Metall. Trans., 11B, pp. 28
  19. Manning, M. P., and Reid. R. C., 1977: Ind. Eng. Chem. Process Des. Dev., 16, pp. 358 https://doi.org/10.1021/i260063a020
  20. Stephenson, R. L., and Smailer. R. M., 1980: Direct Reduction Iron Technology and Economics of Production and Use, Iron & Steel Society of AIME, USA, pp. 24
  21. Chung, U. C., Lee, I. O., Kim, H. G., Sahajwalla, V., and Chung. W. B., 1998: Degradation Characteristics of Iron ore Fines of a Wide Size Distribution in the Fluidized-bed Reduction, ISIJ Int. 38, pp. 943-952 https://doi.org/10.2355/isijinternational.38.943