Fused zirconium corundum brick is commonly known as white iron brick, also known as corundum - diagonal zircon brick. The main chemical composition Al2O3 50% ~ 70%, ZrO2 20% ~ 40%, the rest is SiO2.

The main mineral composition is plagiozircon (ZrO2), corundum ( -Al2O3) and glass phase. ZrO2 has a high melting point (2715 degree ), good chemical stability, and strong corrosion resistance to acidic and alkaline media, especially liquid glass.