According to the different density, mullite insulating bricks are mainly divided into light and heavy mullite bricks. According to the different use temperature, they are mainly divided into 1350 mullite insulating bricks, 1450 mullite insulating bricks, 1550 mullite bricks, etc.
Performance and application of mullite insulating brick: high fire resistance, up to 1790℃. The starting temperature of load softening is 1600-1700℃. The normal temperature compressive strength is 70-260 MPa. Good thermal shock resistance. There are two kinds of sintered mullite brick and electric melting mullite brick. The sintered mullite brick is made of bauxite clinker as the main raw material, a small amount of clay or raw bauxite as the binder, and then formed and fired. The mullite brick is made of high alumina, industrial alumina and refractory clay, adding charcoal or coke fines as reducing agent, and then forming by reducing electrofusion. The crystallinity of the fused mullite is larger than that of the sintered mullite, and its thermal shock resistance is better than that of the sintered products. Their high temperature properties mainly depend on the content of alumina and the homogeneity of mullite phase and glass distribution. It is mainly used in hot blast furnace top, furnace body and bottom, glass furnace regenerator, ceramic sintering furnace, dead angle furnace lining of petroleum cracking system, etc.
