Skip to main content
Log in

Investigation of the Thermodynamic Stability of C(A, F)3 Solid Solution in the FeO-Fe2O3-CaO-Al2O3 System and SFCA Phase in the FeO-Fe2O3-CaO-SiO2-Al2O3 System

  • Original Research Article
  • Published:
Metallurgical and Materials Transactions B Aims and scope Submit manuscript

Abstract

Silico-ferrite of calcium and aluminum (SFCA) is the major bonding phase in iron ore sintering process and is critical to enhancing the sinter properties, such as reducibility and mechanical strength in subsequent blast furnace operations. The phase relations foundations of the alumina-free silico-ferrite of calcium (SFC) have been previously experimentally investigated in air by the authors (Chen et al. ISIJ Int 59:795–804, 2019, Cheng et al. Metall Mater Trans B 51:1587–1602, 2020) and in 1 atm CO2 (Chen et al. ISIJ Int, 59:805–809, 2019). Present investigation using equilibration and quenching followed by electron probe X-ray microanalysis (EPMA) technique, follows those previous works on the SFC, with the focus on the effects of: (i) Al2O3 (in the “Fe2O3”-CaO-Al2O3 and the “Fe2O3”-CaO-SiO2-Al2O3 system in air), and (ii) the effect of \( p_{{{\text{O}}_{2} }} \) (the “Fe2O3”-CaO-Al2O3 in 1 atm CO2 atmosphere), to investigate the thermodynamic stability of the C(A, F)3 [Ca(Al, Fe)6O10] solid solution in the “Fe2O3”-CaO-Al2O3 system in both air and pure CO2 atmospheres between 1150 °C and 1250 °C; and the silico-ferrite of calcium and aluminum (SFCA) solid solution with 1, 2 and 4 wt pct of Al2O3 in bulk compositions in the “Fe2O3”-CaO-SiO2-Al2O3 system at temperatures in the range between 1255 °C and 1340 °C. Present study shows that C(A, F)3 is stable over a wide range of Al2O3 concentration (8.8 to 26.7 wt pct Al2O3, or 12.5 to 34.8 mol pct AlO1.5). It also becomes less stable in terms of both the temperature and the compositional stability range as the oxygen partial pressure is reduced. The SFCA phase in the “Fe2O3”-CaO-SiO2-Al2O3 system is found to be present in the range of 1 to 4 wt pct Al2O3 bulk compositions selected in air. The relative stability of this phase increases with increased Al2O3 in the bulk material. Tie-lines joining the SFCA and the corresponding liquid and hematite phases are constructed over the range of composition investigated at sub-liquidus temperatures. The new experimental measurements show that the CaO/SiO2 ratio in the SFCA phase is almost identical to that in the liquid. The distribution ratio of Al2O3 between SFCA and liquid is in the range 2/1 to 3/1.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  1. J. Chen, M. Shevchenko, P. C. Hayes and E. Jak, ISIJ Int., 2019, vol. 59, pp. 795-804.

    Article  CAS  Google Scholar 

  2. S. Cheng, M. Shevchenko, P. C. Hayes and E. Jak, Metall. Mater. Trans. B, 2020, vol. 51, pp. 1587-1602.

    Article  Google Scholar 

  3. J. Chen, M. Shevchenko, P.C. Hayes and E. Jak, ISIJ Int., 2019, vol. 59, pp. 805-809.

    Article  CAS  Google Scholar 

  4. T. Van den Berg, J. de Villiers and R. Cromarty, Int. J. Miner. Process., 2016, vol. 150, pp. 47-53.

    Article  Google Scholar 

  5. S. Nicol, J. Chen, W. Qi, X. Mao, E. Jak and P.C. Hayes, Minerals, 2019, vol. 9, p. 74.

    Article  Google Scholar 

  6. Pownceby MI, Clout JMF (2003) Trans Inst Min Metall C 112:C44-C51

    CAS  Google Scholar 

  7. T. R. C. Patrick and M. I. Pownceby, Metall. Mater. Trans. B, 2002, vol. 33B, pp. 79-89.

    Article  CAS  Google Scholar 

  8. E. Jak: 9th Int. Conf. Molten Slags Fluxes Salts (MOLTEN12), The Chinese Society for Metals: Beijing, China, 2012, p. W077.

  9. S. Nikolic, P. C. Hayes and E. Jak, Metall. Mater. Trans. B, 2009, vol. 40B, pp. 892-899.

    Article  CAS  Google Scholar 

  10. M. Shevchenko, J. Chen, and E. Jak: AMAS 2017 14th Bienn. Aust. Microbeam Anal. Symp., QUT, Brisbane, Australia, 2017, pp. 94–95.

  11. M. Shevchenko and E. Jak, Metall. Mater. Trans. B, 2018, vol. 49, pp. 159-180.

    Article  Google Scholar 

  12. M. Shevchenko and E. Jak, J. Phase Equilib. Diff., 2019, vol. 40, pp. 319-355.

    Article  CAS  Google Scholar 

  13. S. Cheng, M. Shevchenko, P.C. Hayes, and E. Jak: Experimental Phase Equilibria Studies in the FeO–Fe2O3–CaO–Al2O3 System in Air, Private communication, PYROSEARCH, The University of Queensland, 2020.

  14. C. W. Bale, E. Belisle, P. Chartrand, S. A. Decterov, G. Eriksson, A. E. Gheribi, K. Hack, I. H. Jung, Y. B. Kang, J. Melancon, A. D. Pelton, S. Petersen, C. Robelin, J. Sangster, P. Spencer and M. A. Van Ende, CALPHAD, 2016, vol. 54, pp. 35-53.

    Article  CAS  Google Scholar 

  15. S.A. Decterov, I.-H. Jung, E. Jak, Y.-B. Kang, P.C. Hayes, and A.D. Pelton: in SAIMM Symposium Series S36 (VII International Conference on Molten Slags, Fluxes and Salts), C. Pistorius, ed., The South African Institute of Mining and Metallurgy, Johannesburg, Republic of South Africa, 2004, pp 839–50.

  16. R.R. Dayal and F.P. Glasser: Sci of Cer-cs, vol. 3, G.H. Stewart, ed., Academic, London, 1967, pp. 199, 203, 205–07.

  17. K. Inoue and T. Ikeda, Tetsu-to-Hagane, 1982, vol. 68, pp. 2190-2199.

    Article  CAS  Google Scholar 

  18. Hamilton JDG, Hoskins BF, Mumme WG, Borbidge WE, Montague MA (1989) Neues Jahrb Mineral Abh 161:1-26

    CAS  Google Scholar 

  19. Mumme WG, Clout JMF, Gable RW (1998) Neues Jahrb Mineral Abh 173:93-117

    CAS  Google Scholar 

  20. Mumme WG (2003) Neues Jahrb Mineral Abh 178:307-335

    CAS  Google Scholar 

  21. P. Dawson, J. Ostwald and K. Hayes, Trans. Instn. Min. Metall. Sect. C, 1985, vol. 94, pp. C71-C78.

    Google Scholar 

Download references

Acknowledgments

This research was supported financially by the Baosteel Australia Joint Research Centre (BAJC). The authors wish to thank the members of the Baosteel Ironmaking Institute for their collaboration; in particular Director, Xiaoming Mao and Mr. Qi Wei. The authors would also like to acknowledge the Australian Research Council Linkage Program and Altonorte Glencore, Atlantic Copper, Aurubis, Olympic Dam Operation BHP Billiton, Kazzinc Glencore, PASAR Glencore, Outotec Oy (Espoo), Anglo American Platinum, Umicore, and Kennecott Rio Tinto for financial support to enable this research to be carried out, and the Centre for Microscopy and Microanalysis, at the University of Queensland for providing electron microscope facilities and the scientific and technical assistance.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Siyu Cheng.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Manuscript submitted April 23, 2020; accepted November 6, 2020.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chen, J., Cheng, S., Shevchenko, M. et al. Investigation of the Thermodynamic Stability of C(A, F)3 Solid Solution in the FeO-Fe2O3-CaO-Al2O3 System and SFCA Phase in the FeO-Fe2O3-CaO-SiO2-Al2O3 System. Metall Mater Trans B 52, 517–527 (2021). https://doi.org/10.1007/s11663-020-02035-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11663-020-02035-z

Navigation