Structural and viscosity properties of CaO-SiO2-Al2O3-FeO slags based on molecular dynamic simulation

• The structural properties and viscosity of CaO-SiO2-Al2O3-FeO slags were carried out by molecular dynamics simulation.
• The effects of basicity on the structural properties of SiO2 rich samples and Al2O3 rich samples were studied.
• A correlation between structure properties and viscosities of CaO-SiO2-Al2O3-FeO slags has been established.

Since CaO-SiO2-Al2O3-FeO is one of the most important slag systems in metallurgic processes, it is important to explore its microstructural characteristics and viscosity. Molecular dynamics (MD) simulation was carried out to investigate the effect of basicity (R = CaO/SiO2 mole ratio) on both the structural and viscosity properties of CaO-SiO2-Al2O3-FeO slags. The viscosities were estimated based on the atomic self-diffusion coefficients obtained from MD simulations, and were compared with mathematical models and experimental data. The results showed that both Si-O and Al-O network depolymerized into simple structure with increasing basicity, while atomic self-diffusion coefficients increased and viscosities decreased. The increase in basicity has a lower influence on the structure of Al2O3 rich samples. In addition to the basicity effect, the CaO-SiO2-Al2O3-FeO slag with high Al2O3 content trended to form more complex structures. Finally, a correlation between structural properties and viscosity of CaO-SiO2-Al2O3-FeO slags was established.