A class of inorganic non-metallic materials having a refractoriness of not less than 1580 °C. Refractoriness refers to the Celsius temperature of a refractory cone specimen that resists high temperatures without softening and melting without a load. However, the definition of refractoriness alone cannot fully describe the refractory material, and 1580 °C is not absolute. A material now defined as a physicochemical property that allows it to be used in a high temperature environment is called a refractory material. Refractory materials are widely used in metallurgy, chemical, petroleum, machinery manufacturing, silicate, power and other industrial fields. They are the largest in the metallurgical industry, accounting for 50% to 60% of the total output.