The larger amount is silica brick and clay brick. Silica brick is a siliceous product containing 93% or more of SiO2, and the raw materials used are silica, waste silicon brick, and the like. Silica brick has strong erosion resistance to acid slag, but it is easily corroded by alkaline slag. Its load softening temperature is very high, close to its refractoriness. After repeated calcination, the volume does not shrink or even slightly expands, but the resistance
Poor thermal shock. Silica bricks are mainly used in thermal equipment such as coke ovens, glass melting furnaces, and acid steelmaking furnaces. The clay brick contains 30%~46% alumina. It is made of refractory clay as the main raw material, and has a refractoriness of 1580~1770°C. It has good thermal shock resistance and is a weakly acidic refractory material. It has corrosion resistance to acid slag and is widely used. It is the largest class of refractory materials.