mullite insulation brick

Mullite bricks refer to high-alumina refractory materials with mullite as the main crystal phase. Generally, the alumina content is between 65% and 75%. In addition to mullite, the mineral composition contains a small amount of glass phase and cristobalite in those with lower alumina content; a small amount of corundum in those with higher alumina content. Mainly used in hot blast furnace tops, blast furnace shafts and bottoms, glass melting furnace regenerators, ceramic sintering kilns, dead-end furnace linings in petroleum cracking systems, etc.

It is made of high bauxite, industrial alumina and refractory clay, with charcoal or coke fine particles as reducing agent, and is made by reduction fusion after molding. Its Al2O3 content is about 72-74%, the apparent porosity is about 17%, the volume density is 2.58g/cm3, the compressive strength at room temperature is about 39.2Mpa, and the softening temperature under load of 0.2Mpa is 1620-1660℃. Compared with sintered mullite bricks, it has better thermal shock resistance, low thermal expansion coefficient, and strong resistance to glass liquid corrosion.

Low-creep clay bricks are now one of the commonly used refractory bricks in blast furnaces and hot blast furnaces, and as the wind temperature increases, the creep resistance of clay bricks increases. Low creep clay bricks are made of coke clinker with dense structure and high initial. And a few impurities as the main raw material, adding part of synthetic mullite and trilithon raw materials to configure into clay, which will be formed under high pressure, dried and fired at high temperature.