Properties and characteristics of zirconium corundum brick
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 (α-Al2O3) and glass phase. ZrO2 has a high melting point (2715℃), good chemical stability, and strong corrosion resistance to acidic and alkaline media, especially liquid glass.
Irregular changes in thermal expansion. The expansion curve of fused zirconium corundum brick has an anomaly near 1000℃, and the internal Zr02 crystal has a reversible crystal transformation, and there is a large volume change. Therefore, the brick containing ZrO2 should not be used in the part where the temperature often fluctuates rapidly around 1000℃. When baking the kiln, the temperature change can not be too large when 900 ~ 1150 ° C, generally can not exceed 15 ° C /h, requiring stable temperature rise. Some parts should be prevented from blowing cold air, and other bricks should be used to protect them from cracking.
