When high temperatures are involved in industrial processes and equipment, the use of refractory bricks becomes essential. Refractory bricks like high alumina fire bricks and other specialized compositions can withstand the extreme heat while maintaining structural integrity. They form a crucial part of furnaces, kilns and other applications that experience temperatures over 1,000°C.
What is Refractory Brick?
Refractory bricks are also commonly known as fire resistant bricks or refractories. Refractory materials are materials that are able to maintain their strength and shape at high temperatures. And also they are as used in applications where high heat resistance is required. Meanwhile, such as in furnaces, kilns, and other high-temperature industrial processes. Refractory bricks are made of materials such as alumina, silica, and magnesia, which have high melting points. In addition, they are able to withstand extreme temperatures without degrading or breaking down.
Common Types of Refractory Bricks
There are many types of refractory brick based on their chemical composition, insulation properties and temperature ratings. Some of the main types are:
• High alumina fire bricks – Contains up to 90% alumina and are used where temperatures exceed 1550°C. They have good thermal shock resistance and strength.
• Silica fire bricks – Contains up to 85% silica and are common in medium temperature ranges up to 1250°C. They are more economical.
• Chrome bricks – Made with chromite and magnesite and suitable for temperatures beyond 1600°C. Used in special very high temperature applications.
• Clay fire bricks – Contain multiple metal oxides and clay as binders. Used for temperatures up to 1200°C. More common and economical option.
• Insulating fire bricks – Have high porosity to provide thermal insulation at high temperatures. Used to line furnace walls.
Properties And Uses Of Refractory Brick
The key properties of refractory bricks that enable their use at high temperatures are:
Low thermal expansion
They expand very little with increase in temperature. This prevents cracks from forming.
Good thermal conductivity
Transfer heat efficiently while maintaining insulation properties.
High resistance to chemical attack and corrosion
Resist reaction with flue gases and material being processed.
Adequate mechanical strength
Retain strength even after prolonged exposure to heat.
Refractory fire bricks line the hot face walls, floors, ceilings and load-bearing structures in industrial furnaces, boilers, cupolas, incinerators and kilns. They protect the outer shell and enable efficient heat transfer and insulation.