Silicon nitride refractory is a high-grade refractory made of silicon nitride as the main raw material by adding clay, alumina, carbon and other auxiliary raw materials.

A class of inorganic non-metallic materials with a refractoriness not less than 1580 degree . refers to the Celsius temperature at which the conical specimen of refractory material can resist the action of high temperature without softening and melting down under the condition of no load. However, only the definition of refractories can not fully describe refractories, 1580 degree is not absolute.