Thermal insulation refractory can also be called lightweight refractory, and is also often called thermal insulation material. It is widely used in the insulation layer of industrial kiln. There are many varieties and classifications of heat insulation and refractory materials.
There are light clay bricks, light silica bricks, light high alumina bricks, mullite poly light bricks, alumina hollow ball bricks, high alumina poly light bricks, etc. Light brick has stable performance and convenient use, transportation and storage.
According to the temperature classification, the insulation refractory materials are divided into low temperature insulation materials (< 600 Celsius), medium temperature insulation materials (600 ~ 1200 Celsius) and high temperature insulation materials (> 1200 Celsius).
In terms of bulk density, the bulk density of commonly used lightweight insulation refractory materials is 1.0 ~ 1.2 g/cm3, and 0.3 ~ 0.6 g/cm3 is called ultra-lightweight insulation materials.
According to the shape of materials, powder thermal insulation materials, shaped thermal insulation materials, fibrous thermal insulation materials and composite thermal insulation materials are classified.
Granular thermal insulation material is composed of refractory powder or granular material and binder, which is a lightweight amorphous thermal insulation refractory material, that is, lightweight castable, and its bulk density is usually 1.0-1.2 g/cm3. Light castable is convenient and quick to construct, and has good integrity and airtightness. Fiber thermal insulation material has light weight, good thermal insulation performance, sound absorption and shockproof performance.
There are aluminum silicate fiber board, fiber felt, fiber cotton, ceramic fiber, fiber brick and so on. Composite thermal insulation materials are thermal insulation materials such as thermal insulation plates and thermal insulation coatings. Whether it is light castable, light insulation brick, fiber insulation material or composite insulation material, it is selected according to the design requirements of users or the temperature of furnace lining. Generally, the density of light brick is 1.0-1.2g/cm3, and that of light castable is also 1.0-1.2g/cm3. In the case of fiber products, the density is 0.18-0.22g/cm3. Of course, there are lighter or higher-grade ones, but not many. High-grade heat insulation lightweight materials are used for special furnaces or furnaces with too high temperature.