Cast alumina (corundum) product is produced by melting and casting high purity alumina in electric furnace at 2000. Alpha-Beta corundum goods is formed when a-alumina and b-alumina inter-combine during their crystallization stage. A very compact structure is then formed; it has excellent endurance to strong alkali. Under 1350, the corrosion resistance to glass melt is the same as AZS products. Because it does not contain impurities such as Fe2O3 and TiO2, when comes into contact with liquefied glass, air bubbles are rarely found. Therefore, this product has the special characteristic of minimizing contamination to glass liquor. So it is very suitable for sidewalls, pond bottoms, fore-hearth feeders of slap-up glass kiln.