Metallurgical Transactions

, Volume 3, Issue 6, pp 1561–1574 | Cite as

Gaseous reduction of iron oxides: Part III. Reduction-oxidation of porous and dense iron oxides and iron

  • E. T. Turkdogan
  • J. V. Vinters
Process Metallurgy

Abstract

The internal reduction of high-grade granular hematite ore in hydrogen and carbon monoxide, and also the internal oxidation of porous iron granules in CO2-CO mixtures have been investigated. To assist the interpretation of the rate data for porous iron and iron oxides, rate measurements have been made also with dense wustite, previously grown on iron by oxidation. The iron formed by reduction of dense wustite is porous, similar to that observed when porous hematite is reduced. It is found that the rate of dissociation or formation of water vapor or carbon dioxide on the iron surface is about an order of magnitude greater than that on the surface of wustite. The results of the previous investigations using dense iron and wustite are in general accord with the present findings. The rate of reduction of hematite increases with increasing pore surface area of the reduced oxide. The results indicate that the rate of reduction of granules is controlled primarily by the formation of H2O or CO2 on the pore walls of wustite. The specific rate constants evaluated from internal reduction, using the total pore surface area, are about 1/50 to 1/100 of those for dense wustite. These findings indicate that with porous wustite or iron, the effective pore surface area utilized is about 1 to 2 pct of the total pore surface area. The rate of reduction in H2-CO mixtures is in accord with that derived from the rate constants for reduction in H2 and CO.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    E. T. Turkdogan and J. V. Vinters:Met. Trans., 1971, vol. 2, pp. 3175–88.Google Scholar
  2. 2.
    E. T. Turkdogan, R. G. Olsson, and J. V. Vinters:Met. Trans., 1971, vol. 2, pp. 3189–96.Google Scholar
  3. 3.
    W. M. McKewan and B. B. Rice: private communication, Fundamental Res. Lab. U. S. Steel Corporation, Monroeville, Pa.Google Scholar
  4. 4.
    L. Himmel, R. F. Mehl, and C. E. Birchenall:AIME Trans., 1953, vol. 197, pp. 827–43.Google Scholar
  5. 5.
    P. Hembree and J. B. Wagner:Trans. TMS-AIME, 1969, vol. 245, pp. 1547–52.Google Scholar
  6. 6.
    O. H. Gellner and F. D. Richardson:Nature, 1951, vol. 168, pp. 23–24.CrossRefGoogle Scholar
  7. 7.
    K. Hauffe and H. Z. Pfeiffer:Z. Metallic., 1953, vol. 44, pp. 27–36.Google Scholar
  8. 8.
    F. S. Pettit and J. B. Wagner:Acta Met., 1964, vol. 12, pp. 35–40.CrossRefGoogle Scholar
  9. 9.
    W. W. Smeltzer, L. A. Morris, and R. C. Logani:Can. Met. Quart., 1970, vol. 9, pp. 513–19.Google Scholar
  10. 10.
    H.-J. Grabke:Z. Elektrochem., 1965, vol. 69, pp. 48–57.Google Scholar
  11. 11.
    H.-J. Grabke:Ber. Bunsenges. Phys. Chem., 1967, vol. 71, pp. 1067–73.Google Scholar
  12. 12.
    L. S. Darken and E. T. Turkdogan:Heterogeneous Kinetics at Elevated Temperatures, pp. 25–92, Plenum Press, 1970.Google Scholar
  13. 13.
    H.-J. Grabke: Proc. 3rd Inter. Congress on Catalysis, pp. 928–38, North-Holland Pub. Co., Amsterdam, 1965.Google Scholar
  14. 14.
    R. J. Fruehan and L. J. Martonik:High Temp. Sci., 1971, vol. 3, no. 3, pp. 244–56.Google Scholar
  15. 15.
    E. T. Turkdogan and P. Grieveson:J. Electrochem. Soc., 1967, vol. 114, pp. 59–64.CrossRefGoogle Scholar
  16. 16.
    E. T. Turkdogan, W. M. McKewan, and L. Zwell:J. Phys. Chem., 1965, vol. 69, pp. 327–34.CrossRefGoogle Scholar
  17. 17.
    W. A. Edminston and R. E. Grace:Trans. TMS-AIME, 1966, vol. 236, pp. 1547–50.Google Scholar
  18. 18.
    J. H. Swisher and E. T. Turkdogan:Trans. TMS-AIME, 1967, vol. 239, pp. 426–31.Google Scholar
  19. 19.
    E. T. Turkdogan, R. G. Olsson, and J. V. Vinters:Carbon, 1970, vol. 8, pp. 545–64.CrossRefGoogle Scholar

Copyright information

© The Metallurgical of Society of AIME 1972

Authors and Affiliations

  • E. T. Turkdogan
    • 1
  • J. V. Vinters
    • 1
  1. 1.Chemical Metallurgy Division, Fundamental Research LaboratoryU. S. Steel CorporationMonroeville

Personalised recommendations