Effect of Ce 2 O 3 on microscopic structure of CaF 2 -CaO-Al 2 O 3 slag with molecular dynamics simulation

Molecular dynamics simulations were used to investigate the structural evolution of Ce 2 O 3 -CaF 2 -CaO-Al 2 O 3 slag with Ce 2 O 3 content ranging from 0 wt% to 16 wt% at 1873 K. The results show that increasing Ce 2 O 3 content leads to a shift in the role of F − from network former to modifier, as Ce 3+ ions replace F − with O 2− in AlO 3 F 4− units. Slag polymerisation increases up to 12 wt% Ce 2 O 3 , as evidenced by an increase in bridging oxygen from 30·8% to 39·2% and a rise in complex Q 3 +Q 4 units from 18·1% to 43·4%. However, at 16 wt%, excess O 2− ions disrupt the network, leading to depolymerisation. Consequently, the viscosity was calculated from diffusion coefficients derived from mean square displacement analysis. It exhibits a non-monotonic trend, increasing with Ce 2 O 3 content up to 12 wt% and decreasing at 16 wt%. This study highlights the effect of Ce 2 O 3 on slag structure and diffusion, providing insights for optimising Electroslag Remelting slag design. The simulation framework can be extended to other rare earth-modified slags and combined with experiments to further validate the polymerisation-depolymerisation mechanism.