(Invited review paper)
The MnO–Al2O3 system is very important for the non-metallic inclusion controls in steelmaking and the slag chemistry for high Mn alloy production. Farina and Neto presented their recent thermodynamic assessment on the MnO–Al2O3 system using a two-sublattice ionic liquid model for liquid oxide phase and the Compound Energy Formalism for solid phases. However, we found several doubts and mistakes in their assessment in particular related to the Gibbs energy of MnAl2O4 spinel phase.