Insulating refractory bricks refer to refractory materials with high porosity, low volume density and low thermal conductivity. Insulating refractory materials are also called lightweight refractory materials. It includes the following categories.

1. High-aluminum insulating lightweight refractory bricks is an insulating lightweight refractory brick with bauxite as the main content and an AL2O3 content of not less than 48%. The production process adopts the foam method or the burnout additive method. High-aluminum insulating lightweight refractory bricks can be used to build thermal insulation layers and areas that are not subject to strong erosion and erosion by high-temperature molten materials. When in direct contact with flames, the surface contact temperature of general high-aluminum insulating refractory bricks shall not be higher than 1350°C. Mullite insulating refractory bricks can be directly exposed to flames and have the characteristics of high temperature resistance, high strength and significant energy saving effect. Suitable for lining of pyrolysis furnaces, hot blast furnaces, ceramic roller kilns, electric porcelain drawer kilns and various resistance furnaces.

2. Clay-based insulating lightweight refractory bricks are insulating refractory bricks with an AL2O3 content of 30% to 48% made of refractory clay as the main raw material. Its production process adopts burning and adding method and foam method. Using refractory clay, floating beads and refractory clay clinker as raw materials, adding binder and sawdust, through batching, mixing, shaping, drying and firing, a product with a bulk density of 0. 3 to 1. 5 g/cm3 is produced. . The output of clay insulation bricks accounts for more than half of the total output of insulating refractory bricks.

Chinese standards (GB 3994-1983) classify clay insulation bricks into NG-1.5, NG-1.3a, NG-1.3b, NG-1.0, NG-0.9, NG-0.8, NG-0.7, NG according to volume density. -0.6, NG-0.5, NG-0.4 10 grades.

3. Diatomite insulating lightweight refractory bricks are insulating refractory products made of diatomite as the main raw material. It is mainly used in heat insulation layers below 900°C. Chinese standards (GB 3996-1983) divide diatomite insulation products into GG-0.7a, GG-0.7b, GG-0.6, GG-0.5a, GG-0.5b and GG-0.46 according to volume density. Kind of brand.

4. Floated beads bricks are heat-insulating and refractory products made of bleached beads as the main raw material. Floating beads are hollow aluminum silicate glass beads floated from fly ash in thermal power plants. It is light, thin-walled, hollow, smooth in surface, resistant to high temperatures and has good thermal insulation properties. By utilizing these excellent properties of floating beads, lightweight heat-insulating refractory materials with excellent thermal insulation properties can be produced. Semi-dry molding can be used to produce floating bead bricks.

There are many types of insulating refractory bricks, which play a vital role in the heat insulation and insulation aspects of kiln construction.