Difference Between Corundum Castable and Corundum Mullite Castable

Both corundum castables and corundum mullite castables are a type of refractory castables, both of which have high-temperature resistance and corrosion resistance, and are often used in the lining construction of high-temperature industrial kilns. Although they all contain corundum, there are great differences in the refractory temperature and physical and chemical indicators used.

First of all, let’s first understand the “corundum” component contained in the two. Corundum is an oxide mineral whose main component is Al2O3. It has the characteristics of high hardness, high melting point, and corrosion resistance, so it is widely used in metallurgy and machinery. , chemical industry, electronics, aviation and national defense, and other industrial fields. As a refractory material, it has the characteristics of high-temperature resistance, corrosion resistance, and high strength, and is widely used in the lining of high-temperature kilns.

The second is the “mullite” component in the corundum mullite castable. Mullite is a mineral formed by aluminosilicate at high temperatures. Mullite will be formed when aluminosilicate is artificially heated. Generally, mullite is Artificially synthesized, it has the characteristics of high melting point, creep resistance, low expansion coefficient, thermal shock resistance, and corrosion resistance. It is a high-quality refractory material, so it is widely used in petroleum-cracking furnaces and metallurgical hot blast stoves, ceramic roller kilns, tunnel kilns, electric porcelain drawer kilns, glass crucible kilns, and lining pouring of various electric furnaces.

The difference between corundum castables and corundum mullite castables is mainly in the aluminum content of the two. The Al2O3 content of corundum castables is generally around 85%-95%, while the Al2O3 content of corundum mullite castables is generally 75%. %, although the corundum castable has high mechanical strength and wear resistance, the thermal shock resistance is slightly worse, so the corundum mullite castable just makes up for this shortcoming. The price of corundum castables is generally lower than that of corundum mullite castables. When we choose high-temperature kiln lining refractory materials, we must choose refractory materials according to the operating environment and temperature of the kiln.