Slag Corrosion Behavior of Novel Lightweight Magnesia Castable in a High-Basicity Slag: Role of Micropores and Nanosized Zirconia

Abstract

This study examined the effects of micropores and nanosized zirconia (ZrO2) addition in a novel lightweight magnesia castable on the slag resistance. To this end, static and rotating finger tests were conducted to investigate the degradation of the novel lightweight and convectional fused magnesia castables in a high-basicity slag. A 3D transient numerical model was also established to assess wall shear stress distribution in the rotating finger tests. The corrosion process of the lightweight magnesia castable could be subdivided into the following three stages. In Stage 1, the slag penetrated into the castable through cracks and dissolved components, destroying the castable’s structure and reducing its strength. In Stage 2, wear and peeling occurred, and the weight of the castable decrease a nearly constant rate. In Stage 3, the shear stress dropped with the castable diameter reduction, and corrosion rate decreased, and the penetration and dissolution in Stage 1 become restrictive link again. The analysis revealed the effects of micropores and nanosized ZrO2 on the slag penetration and microstructure evolution: micropores alleviated cracks and absorbed slag, and the formed CaZrO3-ZrO2 provided stronger bonding.