Refractory bricks are shaped refractory materials used in industrial kilns. The term originates from refractory materials with specific geometric shapes that often resemble bricks. Since nearly all industrial furnaces operate at high temperatures, refractory bricks must be able to withstand the corrosive effects of heat. That’s why they are also referred to as refractory bricks. Refractory bricks are produced through special methods, and manufacturers can create them in any required geometric shape. The bonding between bricks and mortar is crucial, as it determines the type of end result. The production method and mortar type are also used to determine the application area of refractory bricks. Based on this information, if we classify them: Composite Refractory Bricks: They are composed of Al2O3 – SiC, Al2O3, MgO, and ZrO2.
They can withstand extremely high temperatures. Therefore, they are commonly used in the steel industry and electric arc furnaces. AZS (ZrO2-Al2O3-SiO2) and CAS (CaO-SiO2-Al2O3) are used to make them. They are primarily used in glass melting furnaces due to their ability to withstand the corrosive effects of molten liquids. This is one of the widely used types of refractory bricks. They are made from a mixture of quartz and pure calcium oxide. During the production stage, quartz transforms into calcium silicate. Refractory brick manufacturers primarily use them in the construction of metallurgical furnaces. They have high resistance to acid-base erosion. Made from magnesite, they belong to the category of basic refractory materials. Magnesite binds iron oxide, quartz, and silicates together, similar to mortar. They exhibit high resistance to alkaline corrosion. However, their high-temperature resistance is relatively low. They are used in all types of basic furnaces. As the name suggests, they are made from a mixture of dolomite and chromite (with a typical mix ratio of 70/30). They are manufactured using dry pressing. Common applications include furnace roofs and gas outlets.
Refractory bricks made from dolomite, which is a very common material. Dolomite bricks are used in the furnace and inner walls of basic and electric arc furnaces.