A class of inorganic non-metallic materials with a refractory degree of not less than 1580 ° C. Refractory resistance refers to the Celsius temperature at which the refractory conical specimen resists high temperature without softening and melting without load. However, the definition of refractory alone is no longer a comprehensive description of refractories, and 1580° C is not absolute. It is now defined as a material whose physical and chemical properties allow it to be used in a high-temperature environment, called a refractory material. Refractories are widely used in metallurgy, chemical industry, petroleum, machinery manufacturing, silicate, power and other industrial fields, and are the largest in the metallurgical industry, accounting for 50%~60% of the total output.