Treatment system and treatment method of chlorosilane slurry raffinate

Abstract

The invention provides a treatment system and a treatment method of chlorosilane slurry raffinate. The treatment method comprises the following steps: carrying out solid-liquid separation on chlorosilane slurry raffinate to obtain a first filtrate and a first solid phase solid phase; carrying out subsection distillation on the first filtrate to obtain a silicon tetrachloride crude product and a hexachlorodisilane crude product; mixing the first solid phase and water, and filtering to obtain a second filtrate and a silicon powder; mixing the second filtrate and an alkaline substance containing an amino group, and filtering to obtain a third filtrate and a second solid phase; and heating the third filtrate to obtain copper hydroxide. In comparison with the prior art, chlorosilane is separated from the silicon powder and a metal chloride impurity through solid-liquid separation, silicon tetrachloride and hexachlorodisilane are separated due to different boiling points, and simultaneously, copper ion in the metal chloride is separated from other metals by forming cuprammonium-ion so as to recycle a catalyst. The treatment method is simple and low-cost. In addition, consumption of lye and water resources for treating raffinate are also minimized, and environmental stress is greatly reduced.

Description

technical field [0001] The invention belongs to the field of chlorosilane production, and in particular relates to a treatment system and a treatment method for chlorosilane slag residue. Background technique [0002] In recent years, with the rapid development of the photovoltaic industry, the demand for semiconductor silicon (including polycrystalline silicon, single crystal silicon and thin film silicon) for solar cells is also increasing. Crystalline silicon is the most important photovoltaic material, with a market share of more than 90%, and it will still be the mainstream material for solar cells for a long period of time in the future. [0003] At present, the main process of producing crystalline silicon materials in the world is chemical method, including the relatively mature Siemens method and the rapidly developing silane method and fluidized bed method. Chlorosilanes are necessary intermediate products for the production of crystalline silicon materials by the...

AI Technical Summary

Problems solved by technology

[0007] The preparation of trichlorosilane by cold hydrogenation is more efficient than thermal hydrogenation, but a catalyst needs to be added in the reaction, and the discharge of the slurry residue has also increased a lot

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