The effects of CaO and FeO on the structure and properties of aluminosilicate system: A molecular dynamics study.

Using molecular dynamics simulations, the effects of different levels of calcium oxide and ferrous oxide on the local structural order, bonding network, transport characteristics, and other microstructures and viscosity of the aluminosilicate slag system were analyzed. It was found that CaO and FeO have almost no effect on the short-term ordering of aluminosilicates in the studied composition range. However, as the metal oxide content increases, the degree of depolymerization of CaO on the aluminosilicate network structure is greater than that of FeO. It shows that the degree of polymerization of calcium aluminosilicate system is lower than that of iron aluminosilicate, and the corresponding viscosity of this system decreases with the increase of metal oxide contents. When the mass fractions of CaO and FeO increase, the diffusion ability of each atom in the SiO 2 -Al 2 O 3 -CaO system is larger than that in the SiO 2 -Al 2 O 3 -FeO system. This indicates that the polymerization structure of SiO 2 -Al 2 O 3 -CaO slag system tends to be more simplified compared with SiO 2 -Al 2 O 3 -FeO system. • The similarities and differences between FeO-containg and CaO-containg slag. • Fe2+ and Ca2+ reduce the degree of polymerization as network modifiers. • 10 wt% is the turning point in which FeO or CaO plays a leading role. • Ca2+ is easier to destroy the slag structure than Fe2+ when FeO (or CaO) > 10 wt%. • A good relationship between viscosity and polymerization degree was found. [ABSTRACT FROM AUTHOR]