System and method for removing metal chlorides by chloro-silicane raffinate quenching

Abstract

The invention discloses a system and a method for removing metal chlorides by chloro-silicane raffinate quenching. The system comprises a static mixer, a gas-liquid separating tank and a filter, wherein the static mixer is provided with a chloro-silicane raffinate inlet, a liquid nitrogen inlet and a metal-containing chloride suspended solid as well as a nitrogen gas raffinate outlet; a gas-phasespace and a liquid-phase space are formed in the gas-liquid separating tank from top to bottom; a liquid inlet and a solution outlet for the metal-containing chloride suspended solid are arranged in the liquid-phase space; the liquid inlet is connected with the raffinate outlet for the metal-containing chloride suspended solid and the nitrogen gas; a liquid level meter is arranged in the liquid-phase space; a nitrogen gas outlet is arranged in the gas-phase space; the filter is provided with a solution inlet for the metal-containing chloride suspended solid, a metal chloride outlet, a chloro-silicane clear liquor outlet and a filter element; and the solution inlet for the metal-containing chloride suspended solid is connected with the solution outlet for the metal-containing chloride suspended solid.

Description

technical field [0001] The invention belongs to the field of polysilicon production, in particular, the invention relates to a system and a method for rapidly cooling chlorosilane raffinate to remove metal chlorides. Background technique [0002] The Siemens process for polysilicon production is based on the principle of reducing high-purity trichlorosilane with high-purity hydrogen on a high-purity silicon core at a temperature of about 1100 ° C to generate polysilicon and deposit it on the silicon core. The improved Siemens process is based on the traditional Siemens process, and it also has energy saving, consumption reduction, and recycling of a large amount of H produced during the production process. 2 , HCl, SiCl 4 And other by-products and a supporting process for a large amount of by-product heat. In the process of producing polysilicon by the improved Siemens method, a large amount of by-product silicon tetrachloride will be produced. At present, more than 90% o...

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Problems solved by technology

[0004] The main disadvantage of the raffinate flash evaporation process is that metal chlorides adhere to the inner wall of equipment and pipelines, which are easy to block equipment and are very difficult to handle, which in turn leads to difficulty in recovery of chlorosilane raffinate and low recovery rate

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