Controlled Solidification of Liquids Within the SFC Primary Phase Field of the “Fe2O3”-CaO-SiO2 System in Air


To provide fundamental information on the phases and microstructures formed during sintering, a liquid with a bulk composition within the silico ferrite of calcium (SFC) primary phase field in the ternary “Fe2O3”-CaO-SiO2 system in air was solidified at a controlled rate. Samples of a bulk composition with a CaO/SiO2 ratio of 4.00 and 69.24 wt pct Fe2O3, were cooled from 1623 K (1350 °C) at 2 K/s, with samples quenched at temperatures between 1513 K (1240 °C) to 1453 K (1180 °C). The silico ferrite of calcium and aluminium I (SFCA-I) and Ca7.2Fe 2+0.8 Fe303+O53 phases were observed to form an intergrowth (‘SFC-I’) rather than the anticipated SFC phase. Solidification was found to occur in three stages, Liquid + ‘SFC-I’, Liquid + ‘SFC-I’ + C2S + CF2, and C2S + CF2 + CF, where C2S denotes dicalcium silicate, CF denotes calcium ferrite and CF2 denotes calcium diferrite. The phases formed and the solidification sequence differ from those predicted under equilibrium and Scheil–Gulliver Cooling. Although not directly applicable to industrial operations, this research clearly shows that the formation of both the SFCA and SFCA-I phase in iron ore sinters is controlled by kinetic processes rather than equilibrium conditions.

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

Fig. 1

Adapted from Ref. [16]

Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Adapted from Ref. [16]

Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15


  1. 1.

    J. Ostwald, BHP Tech. Bull. 1981, vol. 25, pp. 13-20.

    CAS  Google Scholar 

  2. 2.

    W. Mumme, J. Clout and R. Gable, Neues Jahrb. Mineral. Abh. 1998, vol. 173, pp. 93-117.

    CAS  Google Scholar 

  3. 3.

    W.G. Mumme, Neues Jahrb. Miner. Abh., 1988, vol. 8, pp. 359–366.

    Google Scholar 

  4. 4.

    W.G. Mumme, Neues Jahrb. Mineral. Abh. 2003, vol. 178, pp. 307-335.

    CAS  Google Scholar 

  5. 5.

    E. Grew, U. Halenius, M. Pasero, and J. Barbier, Miner. Mag., 2008, vol. 74, pp. 839–876.

    Article  Google Scholar 

  6. 6.

    G. Ferraris, E. Makovicky and S. Merlino: Crystallography of Modular Materials. Oxford : Oxford University Press, 2004.

    Google Scholar 

  7. 7.

    J. Hamilton, B. Hoskins, W. Mumme, W. Borbidge and M. Montague, Neues Jahrb. Miner. Abh. 1989, vol. 161, pp. 1-26.

    CAS  Google Scholar 

  8. 8.

    K. Sugiyama, A. Monkawa and T. Sugiyama, ISIJ Int. 2005, vol. 45, pp. 560-568.

    CAS  Article  Google Scholar 

  9. 9.

    D. Liles, J. de Villiers and V. Kahlenberg, Mineral. Petrol. 2016, vol. 110, pp. 141-147.

    CAS  Article  Google Scholar 

  10. 10.

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

    CAS  Article  Google Scholar 

  11. 11.

    K. Zöll, T. Manninger, V. Kahlenberg, H. Krüger and P. Tropper, Metall. Mater. Trans. B 2017, vol. 48, pp. 2207-2221.

    Article  Google Scholar 

  12. 12.

    A. Koryttseva, N. Webster, M. Pownceby and A. Navrotsky, J Am Ceram Soc 2017, vol. 100, pp. 3646-3651.

    CAS  Article  Google Scholar 

  13. 13.

    Toru Takayama, Reiko Murao and Masao Kimura, ISIJ International 2018, vol. 58, pp. 1069-1078.

    CAS  Article  Google Scholar 

  14. 14.

    S. Nicol, E. Jak, and P.C. Hayes, Metall. Mater. Trans. B, 2019.

  15. 15.

    S. Nicol, E. Jak, J. Chen, W. Qi, X. Mao, and P. Hayes: in The 6th Baosteel Australia Joint Centre Conference 2018, (Wollongong, 2018).

  16. 16.

    J. Chen, M. Shevchenko, P. Hayes and E. Jak: ISIJ Int., 2019, vol. 59, pp. 795–804.

    CAS  Article  Google Scholar 

  17. 17.

    H.I. Saleh: J. Mater. Sci. Technol., 2004, vol. 20, pp. 530–534.

    CAS  Google Scholar 

  18. 18.

    H. Hughes, P. Roos and D. Goldring, Mineral. Mag. J. Mineral. Soc. 1967, vol. 36, pp. 280-291.

    CAS  Article  Google Scholar 

Download references


The authors would like to thank the Australian Research Council Linkage Program and BHP for financial support to enable this research to be carried out, and the Centre of Microstructure and Microanalysis (CMM), the University of Queensland for providing electron microscope facilities that enabled the microanalytical measurements to be undertaken. This research was supported by an Education Endowment Fund (EEF) scholarship from the Australasian Institute of Mining and Metallurgy (AusIMM) and an Australian Government Research Training Program (RTP) Scholarship.

Author information



Corresponding author

Correspondence to S. Nicol.

Additional information

Publisher's Note

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

Manuscript submitted May 24, 2019.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Nicol, S., Jak, E. & Hayes, P.C. Controlled Solidification of Liquids Within the SFC Primary Phase Field of the “Fe2O3”-CaO-SiO2 System in Air. Metall Mater Trans B 50, 3027–3038 (2019).

Download citation