Viscosity of the CaO-MgO-Al2O3-SiO2 System

The CaO-MgO-Al2O3-SiO2 system, often abbreviated as CMAS, is one of the major systems for blast furnace slags and steelmaking and ironmaking slags.

This example using the TCS Metal Oxide Solutions Database (TCOX) demonstrates the comparison between the present calculation and the literature data regarding the viscosity of a blast furnace slag. The calculation is performed by using the components of CaO, MgO, Al2O3, SiO2 and O. After giving the temperature, pressure, size of the system and compositions, one more condition is needed to make the degree of freedom of the system as zero, so oxygen activity is used as a condition in this example. The CMAS system contains only single valent elements, so the absolute value of the activity has no effect on the final calculation.

Comparison between the literature data and the present calculation for the slag composition of 35.6 wt.%SiO2, 15wt.%Al2O3, 46.3 wt.% CaO and 3 wt.%MgO.

Figure 1: Comparison between the literature data and the present calculation for the slag composition of 35.6 wt.%SiO2, 15wt.%Al2O3, 46.3 wt.% CaO, and 3 wt.%MgO.

References

[1987Urb] G. Urbain, Viscosity estimation of slags, Steel Res. 58, 111–116 (1987).

[2013Suz] M. Suzuki, E. Jak, Quasi-Chemical Viscosity Model for Fully Liquid Slag in the Al2O3-CaO-MgO-SiO2 System. Part II: Evaluation of Slag Viscosities, Metall. Mater. Trans. B. 44, 1451–1465 (2013).

[2013Zha] G.-H. Zhang, K.-C. Chou, K. Mills, A Structurally Based Viscosity Model for Oxide Melts, Metall. Mater. Trans. B. 45, 698–706 (2014).

[2016Han] C. Han, M. Chen, W. Zhang, Z. Zhao, T. Evans, B. Zhao, Evaluation of Existing Viscosity Data and Models and Developments of New Viscosity Model for Fully Liquid Slag in the SiO2-Al2O3-CaO-MgO System, Metall. Mater. Trans. B. 47, 2861–2874 (2016).