New aspects on the corrosion resistance of dense refractory castables containing a novel calcium-magnesia-alumina binder

This paper presents a detailed analysis and evaluation of corroded samples of Al2O3-pre-formed spinel and Al2O3-MgO castables, thus representing pre-formed spinel castables as well as in-situ castables. Comparisons were made between systems based upon a calcium aluminate binder and a recently developed novel calcium magnesium aluminate cement CMA 72 ® . A model is presented which gives an explanation for the higher corrosion resistance of the castables based upon the CMA 72 ® cement. The respective model is based on optical and SEM image analysis. A correlation between the thermo-mechanical properties from phase and particle distributions, microstructural features, amorphous phase of the castables and the corrosion mechanism is established. Moreover, new routes for the optimization of castable corrosion resistance via formulation control are highlighted.