Effects of MgO micropowder on microstructure and resistance coefficient of Al2O3–MgO castable matrix

Development of lightweight refractories has been in high demand and the matrix of these materials is crucial for its slag resistance. This paper focuses on the relationship between the microstructure and the resistance coefficient of the Al2O3–MgO castables matrix. The permeability experiments were carried out, and the porous media model was adopted to describe both the viscous and inertial resistance. In addition, the effect of the MgO micropowder content is also discussed. Results indicate an improvement in the properties influenced by sintering such as bulk density and apparent porosity. Further, the pore size distribution range becomes narrower and the average pore size decreases when MgO micropowder content is fixed in the range 3–4.5 wt%. Moreover, the pore size is more crucial than the apparent porosity for the penetration resistance of the matrix. The relationship between the viscous resistance coefficient of the matrix and the microstructure parameters, fluid properties, and flow has been established to gain a better understanding of the slag penetration process.