Definition, classification and use of ferroalloys

Emery, also known as silicon carbide (SiC), is made by high-temperature smelting of raw materials such as quartz sand, petroleum coke (or coal coke), and wood chips (salt is needed to produce green silicon carbide) through a resistance furnace. Silicon carbide also exists in nature, a rare mineral, moissanite. Silicon carbide is also called moissanite. Among the non-oxide high-tech refractory raw materials such as C, N, B, silicon carbide is widely used and economical, and can be called gold steel grit or refractory grit. At present, China's industrial production of silicon carbide is divided into black silicon carbide and green silicon carbide, both of which are hexagonal crystals with a specific gravity of 3.20-3.25 and a microhardness of 2840-3320kg/mm2.

Silicon carbide has stable chemical properties, high thermal conductivity, low thermal expansion coefficient, and good wear resistance. In addition to being used as abrasives, there are many other uses, such as: coating silicon carbide powder on water turbine impellers or cylinder blocks with a special process The inner wall can improve its wear resistance and prolong its service life by 1~2 times; the refractory material made of it has heat shock resistance, small size, light weight and high strength, and has good energy-saving effect. Low-grade silicon carbide (containing about 85% SiC) is an excellent deoxidizer. It can speed up the steelmaking speed, and facilitate the control of chemical composition and improve the quality of steel. In addition, silicon carbide is also widely used to make silicon carbide rods for electric heating elements.