classification of metal silicon
Metal silicon (Si) is an industrially purified elemental silicon, also known as industrial silicon or crystalline silicon. It is dark gray, has metallic luster, high melting point, good heat resistance, high electrical resistivity and high anti-oxidation effect. Mainly used in the production of silicone, the production of high-purity semiconductor materials and the preparation of special-purpose alloys. Metallic silicon generally has a particle size of 10-100 MM or 2-25 MM.
Commercially, silicon is generally divided into metallic silicon and semiconductor silicon. Metal silicon is mainly used to make compounds of polycrystalline silicon, monocrystalline silicon, silicon aluminum alloy and silicon steel alloy.
Metal silicon is usually classified according to the content of three main impurities of iron, aluminum and calcium. According to the content of iron, aluminum and calcium in the metal silicon, the metal silicon can be divided into different grade such as 553, 441, 411, 421, 3303, 3305, 2202, 2502, 1501 and 1101.
Industrial silicon grades, such as 553, 441, 331, 2202, etc., refer to sub-categories of three impurity contents of iron, aluminum, and calcium (in order) under the premise that the silicon content is greater than or equal to 98.5%.
553 represents that the industrial silicon contains less than or equal to 0.5% iron, aluminum content is less than or equal to 0.5%, calcium content is less than or equal to 0.3%;
331 industrial silicon represents iron content less than or equal to 0.3%, aluminum content is less than or equal to 0.3%, and calcium content is less than or equal to 0.1%, and so on.
For customary reasons, 2202 is also abbreviated as 220 to represent calcium less than or equal to 0.02%. The industrial silicon at the beginning of 2 is generally called chemical silicon.
