Corundum-spinel castable is widely used in ladles. The type of spinel impacts the slag resistance of castables. Spinel formedin situ enhances penetration resistance but pre-synthesized spinel enhances corrosion resistance of castable. A light-burnedalumina-spinel composite (LBC) was used as spinel source in this study for a balance between the penetration and corrosionresistance. The effects of the LBC content on the penetration and corrosion resistance of the castables were studied by meansof crucible test. The phase compositions and lattice distortions of the spinels in alumina-spinel composites were studied by Xraydiffractometry (XRD) and the microstructures of the samples eroded were studied by scanning electron microscopy(SEM). The results indicated that the penetration resistance increased and corrosion resistance of slag decreased withincreasing in LBC content because of its smaller crystallite size and higher lattice distortion, as well as smaller particle size. The optimized LBC content is 17.6 wt%.

Keywords: Corundum-spinel castables, Light-burned alumina-spinel composite, Penetration resistance, Corrosion resistance