Influence of the MgO Content and the CaO/Al2O3 Ratio on the Structure and Transport Properties of Molten CaO-Al2O3-MgO Slag Systems: A Molecular Dynamics Study

WW Ma and CZ Wang and JF Xu and R Yin, METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE, 56, 5821-5834 (2025).

DOI: 10.1007/s11663-025-03736-z

Liquid calcium aluminate containing magnesia serves as the foundational slag for ladle slag, which is of considerable industrial importance. The effects of the MgO content and the CaO/Al2O3 ratio on the microstructure and transport properties of molten CaO-Al2O3-MgO slag were investigated using molecular dynamic simulations. In addition, the quantitative relationship between the microstructure and the transport properties of molten slag was also discussed. The results showed that Al3+ combines with free O2- to form stable AlO45- tetrahedral structural units. Ca2+ and Mg2+ act as network modifiers, providing charge compensation to balance the structure's charge. While stabilizing the tetrahedra, these ions also bond with O2-, weakening the connections between network bodies. Increasing MgO content from 0 to 8 wt pct and CaO/Al2O3 ratio (R) from 0.6 to 1.2 both depolymerize the slag structure, leading to a decrease in shear viscosity and an increase in electrical conductivity. The calculated viscosity using different methods such as Einstein and Green-Kubo is consistent with the trend of experimental results. The logarithm of the electrical conductivity and the logarithm of the viscosity have a linear relationship, with a slope that aligns with previous studies.

Return to Publications page