Viscosity of SiO2

SiO2 is one of the most fundamental components for metallurgical oxide slags, which is why there are many studies conducted about the viscosity of SiO2. This example is an outline of the steps to calculate the viscosity of SiO2 using Thermo‑Calc and the TCS Metal Oxide Solutions Database (TCOX).

You can either define the elements of Si and O or the oxides of SiO2 and O. Since in most industrial applications, the component SiO2 is preferred in practice, SiO2 and O are used as the input components.

After entering the conditions of temperature, pressure, size of the system and composition, for example, T=2000K, P=1E5, X(SiO2)=1, you can perform the equilibrium calculation and plot the property of viscosity of SiO2 by using the parameter of dvis(ion), which in Thermo‑Calc is the viscosity of ionic liquid.

Considering the sharp change of viscosity of SiO2 as temperature changes, an option is to plot ln(viscosity) (natural log) as ln(dvis(ionic)).

The calculation below the melting point of SiO2 is the extrapolation from the viscosity of SiO2 melt.

Calculated viscosity of SiO2 compared to the literature data listed in the references.

Figure 1: Calculated viscosity of SiO2 compared to the literature data.