Metallurgical and Materials Transactions B

, Volume 41, Issue 2, pp 359–366 | Cite as

Transformation of Alumina Inclusions by Calcium Treatment

  • Minna Lind
  • Lauri Holappa


The objectives of this study were to investigate reactions of calcium with Al2O3 by different model experiments both on the laboratory and on the industrial scale. Experiments with solid Al2O3 and CaO were performed between 1350 °C and 1600 °C. Reaction rate constants were determined based on scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) observations of reaction products and weight measurements of the Al2O3 reacted via dissolution of the CaO bearing phases from the specimens after the annealing period. The results showed that the formation of calcium aluminate phases proceeded rapidly at temperatures greater than 1405 °C when a liquid calcium aluminate was formed. In the lowest temperature range (1350 °C–1405 °C), when the formation of liquid phase ceased, the reaction rate was several orders of magnitude lower. Industrial trials including Ca-alloy injection into steel, sampling and SEM/EDS analyses, as well as an inclusion rating in the samples show the concept of rapid transformation of the alumina inclusions with Ca treatment.


Al2O3 Reaction Layer Calcium Aluminate Manganese Sulfide Calcium Treatment 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    D.-Z. Lu, G.A. Irons, and W.-K. Lu: Scaninject VI, Luleå, Sweden, 1992, pp. 239-63.Google Scholar
  2. 2.
    K. Tähtinen, R. Väinölä, and R. Sandholm: Scaninject II, Int. Conf. Injection Metallurgy, Luleå, Sweden, 1980, pp.1-24.Google Scholar
  3. 3.
    I. Kohatsu and G.W. Brindley: Zeitschrift für Physikalische Chemie Neue Folge, 1968, vol. 60, pp. 79-89.Google Scholar
  4. 4.
    C.W. Bale, A.d. Pelton, W.T. Thompson, G. Erikson, K. Hack, P. Chartrand, S. Decterov, J. Melancon, and S. Petersen: FactSage 5.4.1,
  5. 5.
    G. Eriksson, and A.D. Pelton: Metall. Trans. B, 1993, vol. 24B, pp. 807-15.CrossRefADSGoogle Scholar
  6. 6.
    D.A. Jerebtsov and G.G. Mikhailov: Ceram. Int., 2001, vol. 27, no. 1, pp. 25-28.CrossRefGoogle Scholar
  7. 7.
    D.-Z. Lu, G.A. Irons, and W.-K. Lu: Ironmaking Steelmaking, 1994, vol. 21, no. 5, pp. 362-71.Google Scholar
  8. 8.
    G.M. Faulring, J.W. Farrell, and D.C. Hilty: Iron Steelmaker, 1980, vol. 7, no.2, pp.14-20.Google Scholar
  9. 9.
    Y. Higuchi, M. Numata, S. Fukagawa, and K. Shinme: ISIJ Int., 1996, vol. 36, pp. S151-54.CrossRefGoogle Scholar
  10. 10.
    L. Holappa, M. Hämäläinen, M. Liukkonen, and M. Lind: Ironmaking Steelmaking, 2003, vol. 30, no. 2, pp. 111-15.CrossRefGoogle Scholar
  11. 11.
    Z. Han, M. Lind, and L. Holappa: Int. Conf. on Non-metallic Inclusions Control and Continuous Improvement of Processes based on Objective Measurement, STÅL 2004, Borlänge, Sweden, 2004, p. 13.Google Scholar
  12. 12.
    M. Lind: PhD Dissertation, Helsinki University of Technology, Espoo, Finland, 2006.Google Scholar
  13. 13.
    O. Levenspiel: Chemical Reaction Engineering, 3rd ed., p. 586, Wiley, New York, NY, 1999.Google Scholar

Copyright information


Authors and Affiliations

  1. 1.Laboratory of MetallurgyHelsinki University of TechnologyEspooFinland

Personalised recommendations