Main types of Alumina silica brick

1. Silica bricks refer to refractory bricks containing more than 93% SiO2, and are the main varieties of acid refractory bricks. It is mainly used for masonry coke ovens, but also for the vaults and other load-bearing parts of thermal kilns of various glass, ceramics, carbon calciners, and refractory bricks. It is used in thermal equipment below 600°C and with large temperature fluctuations.

2. Clay bricks, clay bricks are mainly composed of mullite (25%~50%), glass phase (25%~60%) and cristobalite and quartz (up to 30%). Usually hard clay is used as raw material, clinker is calcined in advance, and then mixed with soft clay, which is shaped by semi-dry method or plastic method, and fired at 1300~1400 C to make clay brick products. A small amount of water glass, cement and other binders can also be added to make unburned products and unshaped materials. It is a commonly used refractory brick in blast furnaces, hot blast stoves, heating furnaces, power boilers, lime kilns, rotary kilns, ceramics and refractory brick firing kilns.

3. High alumina refractory brick, the mineral composition of high alumina refractory brick is corundum, mullite and glass phase, its content depends on the ratio of AL2O3/SiO2 and the type and quantity of impurities, and the grade of refractory bricks can be classified according to the content of AL2O3. The raw materials are high-alumina bauxite and sillimanite natural ores, and there are also fused corundum, sintered alumina, synthetic mullite, and clinker calcined with alumina and clay in different proportions. It is mostly produced by sintering method. But the products also include fused cast bricks, fused bricks, unburned bricks and unshaped refractory bricks. High alumina refractory bricks are widely used in iron and steel industry, non-ferrous metal industry and other industries.

4. Corundum refractory brick, corundum brick refers to a kind of refractory brick with AL2O3 content not less than 90% and corundum as the main phase, which can be divided into sintered corundum brick and fused corundum brick.