Process for recycling high-purity arsenic process tail gas and tail gas recycling system

Abstract

The invention provides a process for recycling high-purity arsenic process tail gas. The process comprises the following steps: filtering, washing, spraying, drying and pressurizing tail gas generated in high-purity arsenic production, and recycling hydrogen chloride and hydrogen for producing high-purity arsenic. The invention further provides a tail gas recycling system, and the process for recycling the high-purity arsenic process tail gas is realized through the tail gas recycling system so that the waste gas can be recycled, the cost is saved, and the emission is reduced.

Description

technical field [0001] The invention relates to the field of high-purity arsenic preparation, in particular to a high-purity arsenic process tail gas recovery and recycling process and a tail gas recovery system. Background technique [0002] High-purity arsenic is a kind of high-purity arsenic with a purity of not less than 99.9999% (6N). Due to its excellent electrical properties, it is used in semiconductors, national defense, aerospace and other cutting-edge fields. [0003] The liquid phase-chlorination reduction method is a method for preparing high-purity arsenic. The process of this method is: sublimate crude white arsenic (that is, diarsenic trioxide with a purity of about 99%) to produce refined white arsenic; then refine white arsenic Add concentrated hydrochloric acid to dissolve and generate arsenic trichloride. The chemical equation (1) of this reaction is: As 2 o 3 +6HCl=2AsCl 3 +3H 2 O; the generated arsenic trichloride is dechlorinated and rectified, and...

AI Technical Summary

Problems solved by technology

Usually, the tail gas is passed into lye for neutralization to treat hydrogen chloride, and then the waste liquid is discharged, which costs a lot of cost to treat the tail gas and brings great environmental pressure.

After hydrogen chloride is neutralized, the remaining hydrogen is usually discharged directly to the atmosphere. Since the excess hydrogen is 0.8-1 times in the high-purity arsenic production process, the amount of hydrogen discharged is quite large, which will also cause safety hazards

At present, in the field of high-purity arsenic preparation, there are no relevant patents or paper reports on tail gas recovery and utilization

Moreover, it can be known from formulas (1) and (2) that hydrogen chloride (dissolved in water to form concentrated hydrochloric acid) and hydrogen are raw materials for the production of high-purity arsenic. If they cannot be recycled, it will not only cause environmental problems, but also waste raw materials. Increased manufacturing cost of high-purity arsenic

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