Mullite brick

Mullite brick is high alumna refractories whose main crystalline phase is mullite and there are also a little glass phase and cristobalite in the lower aluminium oxide product, while a little corundum in the high aluminium oxide product. Generally,the aluminium oxide is 65%-75%.The refractoriness of mullite brick is above 1790℃ and the refractoriness under load is 1600-1700℃. Cold crushing strength is 70-260MPa and has a good thermal shock resistance.
Mullite bricks is divided into sintered mullite brick and fused mullite brick.sintered mullite brick uses high alumina bauxite clinker as main material, add some clay or raw bauxite as binding agent then is made after molding and firing.The raw material of fused mullite brick are high alumina bauxite, commerial alumina and refractory clay, the reductive agent are charcoal and granular coke , made by electric smelting after molding. The crystal of fused mullite brick is bigger than sintered mullite brick and thermal shock resistance is better.The high temperature property of mullite bricks mainly depends on the content of aluminium oxide and the uniformity between mullite phase and glass phase.