Silicon metal is a product smelted by quartz and coke in an electric heating furnace. In the process of smelting and wholesale of silicon metal, the content of the main component silicon is about 98% (the content of Si content of 99.99% is also included in the metal silicon), and the remaining impurities are iron , aluminum, calcium, etc. Semiconductor silicon is a high-purity metal silicon which used to make semiconductor devices. It is sold in the form of polycrystalline and single crystal. The former is cheap and the latter is expensive. It is divided into various specifications due to different uses. According to statistics, in 1985, the world consumed about 500,000 tons of metal silicon, of which about 60% was used for aluminum alloys, less than 30% was used for organic silicon, about 3% was used for semiconductors, and the rest was used for Steel smelting and precision ceramics, etc.
Silicon metal smelting is a high-energy-consuming production. Metal silicon production in China has a long history. With the tightening of the national energy policy and the development of energy conservation and emission reduction, as well as the promotion of new energy, metal silicon smelting has become a primary product and Technology, many domestic emerging energy companies have built a series of recycling industry chains such as metal silicon, polysilicon, monocrystalline silicon, solar cells, etc., which will inevitably affect the development of the whole energy field and the application of new energy in China in next few years.
The metal silicon produced in China is mainly metallurgical silicon, and the production of chemical metal silicon has developed since the mid-1990s. In recent years, the output and export of chemical silicon in China have increased rapidly. From 1999 to 2001, China’s chemical silicon exported to Japan has reached 22000 tons, 30000 tons and 40000 tons respectively. In 2001, China’s chemical silicon exports to Japan accounted for more than 40% of Japan’s chemical silicon imports. Now China has begun to join the ranks of chemical silicon producers and suppliers, and the number of companies producing chemical silicon is increasing.
With the continuous development of science and technology, the use of chemical silicon in the production of organic silicon and semiconductors has been continuously expanded. It is widely used in the production of organic silicon monomer and polymer silicone oil, silicone rubber, silicone resin building corrosion prevention, waterproof agent, etc. They have unique properties such as high temperature resistance, electrical insulation, radiation resistance and waterproof, and are used in electrical, aviation, machinery, chemical, pharmaceutical, national defense, construction and other departments. As the core of integrated circuits, more than 95% of electronic components are made of semiconductor silicon. Semiconductors are the backbone of the contemporary information industry. Chemical silicon is widely used as a high-tech field and an important basic industry, and its consumption tends to grow steadily. Under normal circumstances in the international market, the price of chemical silicon per ton is 300-400 US dollars higher than that of metallurgical silicon. Therefore, it is necessary to vigorously develop the production of chemical silicon, whether from meeting export and domestic demand, or from improving the economic benefits of metal silicon enterprises and improving product quality.