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 with a low alumina content, and a small amount of corundum with a high alumina content. Mainly used for hot blast stove top, blast furnace body and bottom, glass melting furnace regenerator, ceramic sintering kiln, oil cracking system dead corner furnace lining, etc.