Three refractory castables containing corundum aggregates with different porosities, average pore size and strength and the same matrices were fabricated. The effects of the properties of corundum aggregates on the strength and slag resistance of refractory castables were investigated through an X-ray diffractometer (XRD), scanning electron microscopy (SEM), mercury porosimetry measurements, etc. It was found that the properties of corundum aggregates have an important effect on the bulk density, porosity, compressive strength and slag resistance of refractory castables, but have little effect on the flexural strength of refractory castables. Compared with a castable containing white fused corundum aggregate (with a porosity of 4.2% and a bulk density of 3.62 g/cm3), the castable containing a porous corundum aggregate (with a porosity of 42.0% and a bulk density of 2.29 g/cm3) has a higher porosity of 35.7%, a lower bulk density of 2.44 g/cm3, a lower but sufficient compressive strength (80.4 MPa) and a lower slag resistance, but has a similar flexural strength (20.3 MPa), and then has a potential application for a non-slag working lining of a ladle to decrease the consumption of energy and Al2O3 material.

Keywords: Corundum aggregate, Properties, Refractory castables, Strength, Slag resistance