Silicon in the industrial production is indispensable, there are many silicon, with different metals have different roles, below we will give you a brief introduction of silicon in the family of the most common two-metal silicon and Metal Silicon.
Metal silicon is also called industrial silicon or crystalline silicon; metallic luster, high melting point, good heat resistance, high resistivity, has a highly anti-oxidation effect; general granularity in 10~100mm or 2~25mm; industrial silicon produced in the ore-smelting furnace, which is mainly used for preparing alloy, especially aluminum alloy, Production of polycrystalline silicon and silicone and grade refractory.
Metal Silicon is the carbon produced by the reduction reaction of high purity quartz sand and high-quality fine anthracite by resistance furnace, which is characterized by stable chemical properties. High hardness, high-temperature resistance, abrasive and refractory materials and other industries. Due to the stable chemical properties, high thermal conductivity and low thermal expansion coefficient, Metal Silicon good wear resistance, in addition to abrasive, there are many other uses, for example: the special process of Metal Silicon powder coated in the turbine impeller or cylinder body wall, can improve its wear resistance and prolong the service life of more than doubled; refractory, heat shock, Small size, light weight and high strength, energy-saving effect is good. Low-grade Metal Silicon (containing about 85% sic) is an excellent deoxidation agent, which can speed up steelmaking and control chemical composition and improve the quality of steel. In addition, Metal Silicon is also used extensively to make silicon carbon rods for electric heating elements.
Silicon, also known as industrial silicon or crystalline silicon, is usually made from carbon-reducing silica in an electric furnace. Its main use is as a non-ferrous alloy additive and the production of semiconductor silicon, silicone starting materials.
In China, metal silicon is usually classified according to the content of three kinds of main impurities including iron, aluminum and calcium. According to the percentage content of iron, aluminum and calcium in the metal silicon, the metal silicon can be divided into 553, 441, 411, 421, 3303, 3305, 2202, 2502, 1501, 1101, and different grades. (about metal silicon numbering source: The first and second codes are the percentages of iron and aluminum, and the third and 42 digits represent the content of the calcium. For example, 553 represents the content of iron and aluminum calcium 5%, 5%, 3%; 3303 represents the content of iron and aluminum calcium is 3%, 3%, 0.3%)
The metal silicon production uses the carbon heat method, namely uses the silica stone, the carbon reduction agent in the mine furnace smelting the method. The silicon purity of this system is 97%~98%, which can be used in metallurgical applications. If a higher grade silicon is to be obtained, it needs to be refined to remove impurities and to obtain a metal silicon with a purity of 99.7% ~ 99.8%.
The quartz sand is used as raw material for smelting metal silicon, including quartz sand making block, preparing burden and smelting furnace.
In general, high-quality quartz sand will be directly used in the production of high-grade quartz glass products, and even processed into a gem-level such as crystal, tourmaline and other products. The grade is slightly inferior but the reserve is bigger, the mining condition is slightly good, the periphery electricity is cheaper is suitable for the production metal silicon.
At present, China's production of metal silicon carbon thermal method of production routes: the common use of silica as raw materials, petroleum coke, charcoal, wood chips, low ash coal, such as reducing agent, high-temperature smelting in the mine thermoelectric furnace, the reduction of silicon from silica, it is slag-free submerged arc high-temperature melting process.