Thermodynamic simulation models for predicting Al2O3-MgO castable chemical corrosion

The chemical corrosion of two Al₂O₃-MgO castables (containing distinct binder sources: hydratable alumina or calcium aluminate cement) were evaluated in this work via thermodynamic calculations. Two simulation models were proposed according to the following procedures: (1) firstly the matrix and later the aggregates of the castables were placed, separately, in contact with an industrial basic slag, and (2) the overall chemical composition of the design castables was directly reacted with the molten slag. The theoretical results were further compared with experimental data collected after corrosion cup tests. Although the thermodynamic evaluation of the overall castable compositions was able to identify the phase transformations correctly, a two-step analysis of the matrix components and aggregates particles seems to be the best alternative to evaluate the binder source effect on the corrosion performance of the two Al₂O₃-MgO refractory materials.