Method for recycling hydrochloric acid pickling waste gas

Abstract

The invention relates to the technical field of treating hydrochloric acid pickling waste liquid-gas, in particular to a method for recycling dilute hydrochloric acid from the hydrochloric acid pickling waste liquid-gas. The method generally comprises a process of progressively downstream hydrochloric acid pickling waste gas produced by pickling lines, a process of allowing absorption liquid to progressively flow back and a process of blending and recycling. The method has the advantages that the method can recycle HCL available resources in the pickling waste gas, recover and prepare the HCL available resources into the dilute hydrochloric acid and return the dilute hydrochloric acid to production lines so as to avoid the waste of resources, and compared with a lye-spraying method, the method avoids consuming a large amount of medicament cost and has obvious economic benefit. As treated clean air is returned to the production lines as blasts so as to realize the zero-emission closed cycle of the whole waste gas treatment, waste-gas emission chimneys no longer need to be arranged outside the production lines, thus the method has strong significance for environmental protection.

Description

technical field [0001] The invention relates to the technical field of hydrochloric acid pickling waste liquid waste gas treatment, in particular to a method for recovering dilute hydrochloric acid from hydrochloric acid pickling waste liquid waste gas. Background technique [0002] Pickling is an important process in metal surface treatment. Due to the strong corrosiveness of hydrochloric acid, almost all metals can react with it under high temperature conditions. Therefore, most of the pickling industry in my country uses hydrochloric acid as the pickling medium to remove the oxide layer on the metal surface. And because hydrochloric acid has strong volatility, pickling often needs to be carried out at a higher temperature, so the volatilization of hydrochloric acid is accelerated. The volatile acid liquid enters the air, meets the moisture in the air and condenses, forming fine mist droplets. In addition, due to the chemical reaction in the pickling solution, a large n...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art, to provide a method that can absorb the HCL in the hydrochloric acid pickling waste gas liquid into dilute hydrochloric acid and recycle it, and can reuse the purified clean air to the pickling car Recycling of waste gas from hydrochloric acid pickling, and then solving the problem of treatment and disposal of waste gas from hydrochloric acid pickling in the sense of environmental protection, a method of recycling and utilizing waste gas from hydrochloric acid pickling that can bring tangible economic benefits to enterprises

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