Lightweight Insulating Fire Brick is a kind of shaped refractory brick with porous structure, which has high apparent porosity and thermal insulation property. It is featured with low thermal conductivity, low bulk density, energy saving, lightweight and easy construction. Lightweight Insulating Fire Brick can service in the temperature about 900~2000℃. According to different raw materials structure, there are many types of insulating fire bricks, such as Lightweight Fireclay Brick, Lightweight Silica Bricks, Lightweight High Alumina Brick and so on. Now, I will introduce the manufacturing method, refractoriness and properties of Lightweight Insulating Fire Bricks.
Manufacturing Method of Lightweight Insulating Fire Brick
- Directly cut into block from natural porous lightweight protolith.
- Use natural or manmade porous lightweight materials as the raw materials to make bricks.
- Add combustible materials with burnability into pug, such as saw powder, carburizing rice husk, polystyrene light ball, or add into sublimating material, such as naphthaline, forming porous structure after burning up and volatilizing.
- Add foaming agent into pug, such as rosin soap, getting porous structure after firing.
- Add carbonate into pug, aluminite powder and hydrochloric acid, forming porous structure in virtue of liberation of gas from chemical reaction. Generally, adopt the second, third and fourth point.
Refractoriness and Properties of All Kinds of Lightweight Insulating Fire Brick
- Diatomite Brick is manufactured with natural porous raw materials, its refractoriness is less than 1100℃. It has good thermal insulation property and low thermal conductivity.
- Lightweight Fireclay Brick is manufactured with firing method, its refractoriness is about 1200~1400℃ that can be used widely.
- Lightweight High Alumina Brick is manufactured with foam method, its refractoriness is about 1350~1500 ℃, it has good resistance to heat and is widely used for thermal insulation.
- Lightweight Corundum Brick is made of corundum as the main crystal phase and contains high Al2O3 content, its refractoriness is about 1600~1800℃.
- Lightweight Silica Bricks have high refractoriness under load and good thermal stability property, its refractoriness is about 1220~1550℃.
- Calciclase Lightweight Brick is made of CaO, Al2O3, Si02 as the main components, its refractoriness is about 1200~1300℃, it has low bulk density and good chipping resistance, it is stable in the reducing atmosphere.
- Magnesian Lightweight Insulating Fire Brick has good heat resistant property and high service temperature, its refractoriness is 1600~1800℃.
- Mullite Cordierite Lightweight Insulating Fire Brick has low thermal expansion and good spalling resistant properties, its refractoriness is 1300~1500℃.
- Silicon Carbide Lightweight Insulating Fire Brick has excellent features of good erosion resistance, good cracking resistance and high temperature strength. Its refractoriness is 1300℃.
- Alumina Lightweight Insulating Fire Brick is made by foam method, has good thermal stability, low reheating linear change rate and longer service life features. Its refractoriness is lower than 2000 ℃. It can be used in super high temperature furnace for thermal insulation.
- Zircon Lightweight Insulating Fire Brick is manufactured with foam method with good features of low thermal conductivity and good thermal shock resistance, which can be used in super high temperature furnace for thermal insulation.
- Zirconia Lightweight Insulating Fire Brick is produced with foam method. It has excellent properties of high melting point, high specific resistance, high index of refraction and low thermal expansion coefficient. It can be used in super high temperature furnace for thermal insulation.
Classification of Lightweight Insulating Fire Brick
- Lightweight Insulating Fire Brick generally is classified into three types as following:
- High Strength Lightweight Insulating Fire Brick, its service temperature is lower than 1000℃, mainly includes Diatomite Brick, Expanded Perlite Brick and so on, which is mainly used for the thermal insulation layer of heating equipment.
- Lightweight Insulating Fire Brick, its service temperature is between 1000 and 1500℃, mainly includes Lightweight Fireclay Bricks, Lightweight Silica Bricks, Lightweight High Alumina Brick, Mullite Insulation Brick, Poly Light High Aluminum Insulation Firebrick and so on.
- High Temperature Insulating Fire Brick, its service temperature is higher than 1500℃ and can directly contact fire, mainly includes Lightweight Corundum Brick, Alumina Bubble Brick and Zirconia Bubble Brick and etc.