Chlorosilane refining system and method

Abstract

The invention discloses a chlorosilane refining system. The chlorosilane refining system comprises a first rectifying tower, a cooling and stirring device, a settling separation device and a second rectifying tower. Tower kettle liquid of the first rectifying tower is delivered to the cooling and stirring device for cooling crystallization treatment to obtain a crystalline mixture; the crystallinemixture is delivered to the settling separation device for standing settling separation; crystalline slag separated by standing settling is discharged from a slag discharge port of the settling separation device; liquid separated by standing settling is then delivered to the second rectifying tower for rectifying treatment; and refined chlorosilane is extracted from the top of the second rectifying tower. According to the chlorosilane refining system, the tower kettle liquid subjected to rectification treatment is subjected to cooling crystallization and standing settling separation, metal chloride is effectively removed, high-purity chlorosilane is obtained through refining, the purity of the chlorosilane is improved, the discharge waste of the chlorosilane is reduced, the refining efficiency of the chlorosilane is improved, the resource consumption is reduced, and the production cost is also reduced.

Description

technical field [0001] The invention relates to the technical field of polysilicon production, in particular to a chlorosilane refining system and refining method. Background technique [0002] In the semiconductor industry, chlorosilane is used as an important raw material for the production of polysilicon. The raw material contains impurities, mainly metal chlorides. The existence of impurities will affect the purity of polysilicon products. In the prior art, cascaded rectification towers are used to refine and purify chlorosilanes. The difficulty in the purification of chlorosilanes lies in the fact that impurities and chlorosilanes have close boiling points, which are difficult to be effectively removed by traditional rectification methods, and the purification effect is poor, wasting more chlorosilanes. Contents of the invention [0003] The technical problem to be solved and the technical task proposed by the present invention are to improve the existing technology ...

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Problems solved by technology

[0003] The technical problem to be solved and the technical task proposed by the present invention are to improve the existing technology and provide a chlorosilane refining system, which solves the problems of the chlorosilane refining system in the current technology that it is difficult to effectively remove impurities, the refining effect is poor, and the loss of chlorosilane is large The problem

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