Device for recovering high-concentration hydrochloric acid from chlorine-containing tail gas and working method

Abstract

The invention provides a device for recovering high-concentration hydrochloric acid from chlorine-containing tail gas, which comprises a chlorine-containing tail gas supply system, a water supply system, a circulating absorption system, a secondary absorption system and a product storage and filling system, the circulating absorption system is respectively connected with the chlorine-containing tail gas supply system, the water supply system, the secondary absorption system and the product storage and filling system, and the secondary absorption system is also respectively connected with the water supply system and the product storage and filling system. The method is reasonable in design and simple to operate, the problem that a large amount of low-concentration waste hydrochloric acid is generated in the treatment process of chlorine-containing tail gas such as hydrogen chloride, boron trichloride and silicon tetrachloride is solved, and the concentration of waste acid is effectively increased to the industrial grade; the concentrated hydrochloric acid can be used for steel pickling and other processes, and can also be used for subsequent purification processes, so that the purity of the hydrochloric acid is further improved.

Description

technical field [0001] The invention relates to a device and a working method for recovering high-concentration hydrochloric acid from chlorine-containing tail gas. Background technique [0002] Electronic grade hydrogen chloride, boron trichloride, trichlorosilane and chlorosilane play an important role in the semiconductor manufacturing process. With the rapid development of my country's semiconductor-related industries, their usage is also increasing year by year. In the production, purification and polysilicon production of the above-mentioned products, the emission of chlorine-containing tail gas cannot be ignored. If the exhaust gas is directly evacuated, a large amount of chlorine-containing gas in the exhaust gas will react violently with the moisture in the air to generate irritating acid mist and other particulate pollutants, which will have a bad impact on the environment. In chemical production, chlorine-containing tail gas is mainly treated by hydrolysis method...

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Problems solved by technology

[0004] The present invention improves the above-mentioned problems, that is, the technical problem to be solved by the present invention is to provide a device and working method for recovering high-concentration hydrochloric acid from chlorine-containing tail gas, which solves the problems of hydrogen chloride, boron trichloride, silicon tetrachloride, etc. A large amount of low-concentration waste hydrochloric acid is produced during the treatment of chlorine-containing tail gas, effectively increasing the concentration of waste acid to industrial grade

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