Difference between Fireclay Brick and High Alumina Brick

Fireclay Brick Vs High Alumina Brick

Fireclay bricks and high alumina bricks are both aluminum silicate refractory materials. They have some similarities and differences. Both of them are high-temperature resistant shaped refractory bricks, but their alumina content is different.

Fireclay bricks refer to Al2O3 clay products containing 30% to 40% aluminum silicate materials. The materials are generally clay. Clay bricks are made of 50% soft clay and 50% hard clay clinker. They are batched according to certain particle size requirements. After molding and drying It is fired at a high temperature of 1300-1400℃.

High alumina brick refers to a type of inorganic non-metallic material with an alumina (Al2O3) content exceeding 48% and refractory temperature exceeding 1580°C. High alumina bricks are usually made of high-alumina bauxite clinker and a small amount of clay, which are ground and then cast and formed in the form of slurry using the gas generation method or foam method, and then fired at 1300 to 1500°C. In addition to the main component of alumina, it also mainly contains silicon oxide (SiO2), which is a type of aluminum-silicon refractory material and the most common type of refractory brick.

The differences between clay bricks and high alumina bricks as follows

Products properties are different

Clay bricks are weakly acidic refractory products, which can resist corrosion from acidic slag and acidic gases, but have slightly less resistance to alkaline substances. Clay bricks have good thermal properties and are resistant to rapid cooling and heat, but have a low load softening temperature.

The fire resistance and load softening temperature of high alumina bricks are higher than those of clay bricks, and they have good slag corrosion resistance (especially acidic slag). These functions increase with the increase of Al2O3 content, but the thermal stability is not as good as clay bricks. High alumina bricks have high density, low porosity, high mechanical strength and wear resistance.

Products applications are different

Fireclay bricks are mainly used for heat preservation and insulation, and are often used as insulation layers in high-temperature kilns. Also used for non-essential parts of coke ovens, such as regenerator wall sealing, small flue lining bricks, regenerator checker bricks, furnace door lining bricks, furnace roof and riser pipe lining bricks, etc.

High-alumina bricks are often used as lining materials for various high-temperature kilns. The burner of the coke oven combustion chamber and the burner of the bottom brick of the carbonization chamber are built with high alumina bricks, with good results; they are used for the lining and heat insulation of the kiln. layers, and areas without strong erosion and erosion from high-temperature molten materials. When in direct contact with flame, the surface contact temperature shall not be higher than 1350℃.