Insulating high alumina refractory bricks to keep warm

Insulating high alumina refractory bricks to keep warm

Insulating high alumina refractory bricks mainly refer to refractory products with an aluminum content of more than 48%. They are also called lightweight high-alumina bricks or heat-insulating high-alumina bricks due to their advantages of low bulk density, light weight, and good heat insulation effect. . It is a kind of thermal insulation refractory brick commonly used in high temperature industrial kilns and thermal equipment.

Due to different parts of use, the service temperature of high-alumina heat-insulating refractory bricks is different from that of heavy-duty high-alumina refractory bricks. Heavy refractory bricks can directly contact the solution or slag, with low porosity and strong penetration resistance; lightweight high-alumina refractory bricks cannot contact slag, and the porosity is high (66%-73%), and the slag penetrates through the pores. Damage inside the brick body.

What is the service temperature of Insulating high alumina refractory bricks? According to the characteristics of the production industry, different materials are used and different temperatures are used. For example, those made of light-weight high-alumina bauxite clinker are called ordinary light-weight high-alumina bricks; those made of fused or sintered alumina are used as the main material. The refractory bricks are called light corundum bricks. The different operating temperatures and characteristics of the two types of refractory bricks are as follows:

Ordinary lightweight high-alumina bricks are produced by the foam method. Using high-alumina clinker and gangue clay as raw materials, ash clay as sintering aid, plus 3%~5% sawdust as drying aid, and rosin soap as foaming agent, a foam with a density greater than 1.05g/cm3 was prepared The slurry is injected into the metal mold, and then dried together with the mold, and then fired at 1300~1350 ℃ in the inverted flame kiln, and the temperature is kept for 4~6 hours. After leaving the kiln, it can be used after grinding with a grinding wheel. The bulk density is 0.4-1.35g/cm3, the porosity is 66%-73%, the compressive strength is 1.3-8.1MPa, and the thermal conductivity is 0.291~-0.582W/(m·K). Lightweight high-alumina bricks have high refractoriness and good thermal shock resistance, and are often used as high-temperature insulation layers for kilns. Due to the good chemical stability of lightweight high-alumina bricks in a reducing atmosphere, kilns with hydrogen, carbon monoxide and other masonry as protective atmosphere generally use lightweight high-alumina bricks as thermal insulation linings. The maximum operating temperature is generally 1350~1500℃.

Insulating high alumina refractory bricks have the following characteristics:

high temperature strength

Corrosion resistant to various atmospheres

Excellent thermal shock stability

Good thermal insulation performance

The energy-saving effect is remarkable and so on.