Zirconia Corundum Bricks Introduction AZS bricks, also known as fused zirconia corundum bricks, are made by carefully selected zircon sand and industrial aluminum oxide powder in a 1:1 ratio, with a small amount of flux added, mixed evenly, melted at 1800~1900 ℃, and then cast into shape. Generally, zirconium corundum bricks can be divided into several grades according to the content of ZrO2, such as three grades of 33%, 36% and 41%. They have high melting point, good chemical stability, and strong corrosion resistance to acid and alkaline media, especially molten glass.