Creep of refractories is the deformation of refractories caused by the change of stress effect at high temperature, which includes contraction creep, tensile creep, zigzag creep and torsion creep. Shrinkage creep is commonly used. Large creep reflects large deformation at high temperature, while low creep naturally means small deformation at high temperature. Low creep sintered mullite brick can be made from red stone.
The low-creep sintered mullite brick can be manufactured by using red cornerstone as the aggregate, sillimanite as the central particle, and sillimanite powder, bauxite powder, industrial aluminum oxide powder and clay powder as the base material. Its material formula is as follows: aggregate: central particle: fine powder=50:12:38. The composite binder is added in the ingredients, and is formed by a 260t brick press. The green brick is dried until the residual moisture is less than 1%, and then put into the inverted flame kiln for firing. The firing temperature is 1490 ℃, the bricks are fired at this temperature for 19 hours, the porosity of the product can reach 17.15%, the bulk density is 2.53 g/cm3, the normal temperature compressive strength is 136.5 MPa, and the softening temperature under load is 1627 ℃. The creep rate can reach 0.87% at 1450 ℃ for 50 h. If the firing temperature is 1450 ℃ and the firing time is extended to 26h, the purpose of sintering can also be achieved. However, the physical function target is lower than that of products fired at 1490 ℃. For example, at 1450 ℃,firing 50h the creep rate is 0.98%.
Low-creep mullite bricks are mainly used for hot blast furnace roof, blast furnace shaft and bottom, glass furnace regenerator, ceramic sintering kiln, petroleum cracking system lining, etc.