The castable is developed by the company's exclusive formula, which is produced and used by itself. The aggregate fine powder comes from Shanxi Yangquan and Xiaoyi, and has accumulated tens of thousands of tons of production. The use effect is good. This formula castable is a high-tech refractory developed on the basis of ordinary castables using rheological principles, close-packing theory and ultra-fine powder technology. It has the characteristics of low porosity, small pore size, large density, good volume stability, high strength, and low water content. It overcomes the characteristics of ordinary castables whose strength decreases significantly at 800 ～ 1200 ℃, and it increases with temperature. If it is raised, the thermal shock resistance of the furnace body can be more than doubled. It is used for the furnace roof, furnace wall and other parts of the gas heating furnace, and the warranty starts from two years.