Light refractory materials refer to refractories with high apparent porosity, low bulk density, low thermal conductivity and good thermal insulation properties. It includes heat-insulating refractory products, refractory fibers and refractory fiber products.
Light refractory material is a multi-phase combination of solid and gas phases such as crystalline phase and amorphous phase. Most of the solid phases are non-metallic oxides. Relatively speaking, these non-metallic oxides have high thermal conductivity, but they have high refractoriness and do not have heat insulation. Because the gas exists in the pores in the solid phase, the thermal conductivity of the gas is very low. The thermal conductivity of air at 0℃ is 0.023W/m·℃, and the thermal conductivity of air at room temperature is less than 0.03W/m·℃, 500℃ is 0.06 W/m·℃.
Therefore, the light refractory material with high porosity composed of solid phase and gas phase has good heat insulation effect, and the gas-filled bulk material or fibrous material has good heat insulation effect.
Next issue we will continue to introduce lightweight refractories, so stay tuned.