Waste gas washing treatment method and device in polycrystalline silicon industry

Abstract

The invention provides a chlorosilane-containing waste gas washing treatment method and device in a polycrystalline silicon production process. The device comprises a waste gas buffer tank, a chlorosilane-containing waste gas supply pipeline connected with an inlet of the waste gas buffer tank, and a normal waste gas spraying system, an accidental waste system spraying system and an emergency washing system which are connected with an outlet of the waste gas buffer tank. The chlorosilane-containing waste gas is fed into a spray tower and is washed by spraying 10-30 percent of sodium hydroxide. The gas generated after spraying is discharged into atmosphere through a water-sealed tank. According to the method, the problem that hydrogen chloride escapes is effectively solved, the problem that the pipeline is blocked by silicon dioxide generated in the traditional washing process is solved, and harmlessness of environmental protection is realized. According to the device, the chlorosilane waste gas can be effectively and harmlessly treated, escape of hydrogen chloride can be effectively reduced, and sodium silicate generated in the reaction is relatively convenient to remove.

Description

technical field [0001] The invention relates to a water washing method for pollution-free treatment of chlorosilane waste gas produced in the polysilicon production process, and a water washing treatment device for the chlorinated silane waste gas produced in the polysilicon production process. Background technique [0002] The waste gas produced in the production process of the polysilicon industry contains a large amount of chlorosilane. In order to effectively treat the waste gas and make the tail gas discharge up to the standard, the traditional washing process is mainly used in China at present, that is, the flue gas is washed with industrial water and the waste gas is hydrolyzed. Chlorosilanes in. Although the industrial water washing method has a high hydrolysis efficiency for chlorosilanes, a large amount of hydrogen chloride and silicon dioxide solids are produced after hydrolysis of chlorosilanes. Part of the hydrogen chloride will escape from the water into the a...

AI Technical Summary

Problems solved by technology

Although the industrial water washing method has a high hydrolysis efficiency for chlorosilanes, a large amount of hydrogen chloride and silica solids after hydrolysis of chlorosilanes

Part of the hydrogen chloride will escape from the water into the atmosphere while being dissolved in industrial water, causing pollution to the environment; and the industrial wastewater formed after the industrial water absorbs hydrogen chloride is acidic, which causes great difficulties for subsequent sewage treatment, resulting in Silica solids are more difficult to remove from the system

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