Polycrystalline silicon production method and equipment based on improved Siemens method

Abstract

The invention discloses a polycrystalline silicon production method and polycrystalline silicon production equipment based on improved Siemens method, and belongs to the technical field of polycrystalline silicon production. The problems that the purity of trichlorosilane participating in a reduction reaction is low and first-time conversion rate of trichlorosilane is influenced to cause high production cost of the polycrystalline silicon are solved. According to the technical scheme, the polycrystalline silicon production method comprises the following steps: step 1, performing reduction and deposition on trichlorosilane to acquire polycrystalline silicon and exhausting tail gas; step 2, performing multilevel condensation on the tail gas to acquire non-condensable gas and condensate liquid, introducing the non-condensable gas into an absorption tower, absorbing HCL in the non-condensable gas and enabling a chlorosilane pregnant solution to flow out; after mixing the condensate liquid with the chlorosilane pregnant solution, enabling the condensate liquid to flow into an analyzing tower; step 3, performing a disproportionation reaction on at least a portion of chlorosilane barren liquid flowing out of the analyzing tower, so that the mass percentage content of dichlorosilane in the chlorosilane barren liquid is reduced; step 4, enabling the chlorosilane barren liquid after reaction to flow into a rectifying tower and pouring a product acquired in the rectifying tower into a reduction furnace.

Description

technical field [0001] The invention belongs to the technical field of polysilicon production, and in particular relates to a polysilicon production method based on an improved Siemens method and a polysilicon production equipment. Background technique [0002] Polysilicon is a form of elemental silicon. When molten elemental silicon is solidified under supercooled conditions, silicon atoms are arranged in the form of diamond lattices to form many crystal nuclei. If these crystal nuclei grow into crystal grains with different crystal plane orientations, these crystal grains combine to crystallize into polycrystalline silicon. . [0003] The production technologies of polysilicon are mainly improved Siemens method and silane method. The Siemens method produces columnar polysilicon by vapor deposition. In order to improve the utilization rate of raw materials and be environmentally friendly, a closed-loop production process, namely the improved Siemens method, is adopted on ...

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Problems solved by technology

[0006] In view of this, the embodiment of the present invention provides a polysilicon production method and polysilicon production equipment based on the improved Siemens method, the main purpose of which is to solve the problem that the purity of trichlorosilane participating in the reduction reaction is low, thereby affecting the primary conversion rate of trichlorosilane, Problems leading to high production cost of polysilicon

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