Third, the use of silicon products. 1. Industrial silic […]
Third, the use of silicon products.
1. Industrial silicon, commonly known as metal silicon or crystalline silicon. Strictly speaking, industrial silicon does not belong to the ferroalloy industry. Conventionally, industrial silicon is classified into the ferroalloy industry because the smelting of industrial silicon is carried out using a mineral furnace. Industrial silicon refers to pure silicon products with a silicon content of 98.5% or more. Among them, the three impurity contents of iron, aluminum, and calcium (in order) are divided into small categories, such as 553, 441, 331, and 2202. Among them, 553 represents that the industrial silicon contains 0.5% or less of iron, 0.5% or less of aluminum, and 0.3% or less of calcium; 331 industrial silicon represents 0.3% or less of iron, 0.3% or less of aluminum, and calcium or less 0.1%, and so on. For customary reasons, 2202 is also abbreviated as 220 for calcium less than or equal to 0.02%. Industrial silicon starting with 2 is also called chemical silicon.
Industrial silicon is mainly used as an additive for non-ferrous alloys. Industrial silicon is also used as an alloying agent for demanding silicon steel, as a deoxidizer for smelting special steels and non-ferrous-based alloys. After a series of processes, industrial silicon can be drawn into single crystal silicon. It is used in the electron donor industry and used in the chemical industry to produce silicon. Therefore, it is known as magic metal and has a wide range of uses.
Industrial silicon is added to metals such as aluminum and iron to improve or enhance the excellent properties of metals. The demand for industrial silicon for automotive (including motorcycle) aluminum is quite large, so the development of the automotive industry in a region or country has a direct impact on the rise and fall of the industrial silicon market.
Industrial silicon is further purified to more than 99.999% (four more than nine, the more 9 is more valuable), made into polysilicon (cylinder), and then mechanically cut into silicon single wafers, which are widely used in the electronic information industry. Such as various types of IC cards, VCDs, DVDs, etc. At present, the purification technology in China is not very mature, and it basically depends on imports from Japan. That is, Japan imports industrial silicon raw materials from China at a price of about 7300 to 7600 yuan per ton, and further purifies and exports it to China at a price of about 300,000 yuan per ton. Relevant industries (such as monocrystalline silicon plants, etc.). In terms of cutting single crystal silicon wafers, there is still a certain technological gap between China and developed countries, especially in the areas of post-finishing and surface "coating" of silicon wafers.