Industry Knowledge of Corundum Refractory Brick

Corundum refractory brick is a high-quality refractory material made of corundum as the main raw material. It has a high temperature resistance, good thermal shock resistance, and excellent chemical stability. Due to its outstanding characteristics, corundum refractory bricks are widely used in high-temperature industrial furnaces such as steel making, cement kilns, glass melting furnaces and others.

Corundum refractory bricks are classified based on their composition and manufacturing process. There are two primary types, namely fired and unfired types. The fired corundum refractory bricks are grouped in magnesia-alumina and chrome types while unfired types are categorized as silicon carbide and zirconia-corundum.

The magnesia-alumina corundum bricks have a high refractoriness, high-temperature strength, and good thermal shock resistance. It is mainly used in the lining of steel refining furnaces, electric arc furnaces, and continuous casting tundish.

Chrome corundum refractory brick has excellent heat-resistant stability under extreme temperature conditions. It is used in the lining of high-temperature furnaces and kilns in various industries.

The silicon carbide corundum bricks have a high thermal conductivity, high elastic modulus, and good abrasion resistance. They are used in the lining of blast furnaces, reverberatory furnaces, and furnaces for roasting cement.

Zirconia-corundum bricks have excellent thermal shock resistance and good corrosion resistance to slag and molten metal. They are widely used in steel-making furnaces, chemical industry kilns and glass melting furnaces.

Corundum refractory bricks have high-density, low porosity, and low thermal conductivity. The bulk density of corundum refractory bricks ranges from 3.08 to 3.10 g/cm3. The apparent porosity is less than 3.5%, and the compressive strength is usually over 100Mpa. Operating temperature of corundum refractory brick can reach up to 1800°C, and thermal expansion is negligible.

The production process of corundum refractory brick is complex, consisting of a mixing process, mulling process, molding process, drying process, firing process, and cold compression test. The raw materials such as corundum, alumina, and other additives are mixed in a particular proportion. The mixture is then milled, molded under high pressure and dried in an oven. After drying, the brick is fired at a high temperature in a tunnel kiln or an electric furnace.

Corundum refractory bricks are widely used in various high-temperature industrial furnaces due to their superior characteristics. They come in various grades which offer different levels of heat resistance, chemical stability, and thermal shock resistance. With advancements in technology, the use of corundum refractory bricks is expected to increase in the future, and techniques in production are continuously being improved to optimize their properties and reduce production costs.