Sintering flue gas ammonia desulfurization system and process

Abstract

The invention relates to a sintering flue gas ammonia desulfurization system and a sintering flue gas ammonia desulfurization process. The sintering flue gas ammonia desulfurization system comprises an ammonia supply system, an absorption system, a filtration system and an oxidation system, wherein the ammonia supply system is connected with the absorption system which is connected with the filtration system; and the filtration system is connected with the oxidation system. The sintering flue gas ammonia desulfurization system can effectively remove sulfur dioxide from flue gas, and reduces the escape degree of ammonia; a generated byproduct ammonium sulfite is filtered, is subjected to impurity removal and then is subjected to low-concentration normal-pressure oxidation, so that the conversion rate of ammonia sulfate is guaranteed, and a qualified raw material solution is provided for a next-stage ammonia sulfate preparation system; the sintering flue gas ammonia desulfurization system has a reasonable structure, ensures that the flue gas reaches standard to discharge and reduces secondary pollution caused by escaped ammonia; and the qualified raw material solution is provided for the next-stage ammonia sulfate preparation system through the pretreatment process of the byproduct of filtering first and then oxidizing, so that the quality of a byproduct ammonia sulfate is ensured.

Description

technical field [0001] The invention relates to a desulfurization system and process, in particular to an ammonia desulfurization system and process for sintering flue gas, belonging to the field of flue gas desulfurization. Background technique [0002] Sulfur dioxide in sintering flue gas is one of the main sources of air pollution. Ammonia desulfurization uses absorption liquid to react with flue gas, which is currently a better method for treating sulfur dioxide in flue gas. In the current commonly used ammonia method, the oxidation of ammonium sulfite is usually carried out in the desulfurization tower, the oxidation efficiency is low, and the air consumption is large; the problem of ammonia escape in the desulfurization tower cannot be solved by an effective method; Improper treatment of dust in the air affects the color and quality of ammonium sulfate. [0003] Chinese patent CN 101053760A discloses an ammonia desulfurization system for sintering flue gas. Because th...

AI Technical Summary

Problems solved by technology

In the current commonly used ammonia method, the oxidation of ammonium sulfite is usually carried out in the desulfurization tower, the oxidation efficiency is low, and the air consumption is large; the problem of ammonia escape in the desulfurization tower cannot be solved by an effective method; Improper treatment of dust in the air affects the color and quality of ammonium sulfate

[0003] Chinese patent CN 101053760A discloses an ammonia desulfurization system for sintering flue gas. Because the system adopts the low-temperature ammonia method for desulfurization, the position of supplementing ammonia is in the spray layer, which is more focused on the top of the entire desulfurization tower, which is likely to cause ammonia gas to be exhausted. Complete reaction, that is, escape with the volatilization of flue gas, so the loss of ammonia is relatively serious; and the overall system adopts the process of first oxidizing ammonium sulfite, then concentrating and filtering the ammonium sulfate solution

The ammonium sulfite solution contains dust, which will reduce the oxidation efficiency, and the conversion of ammonium sulfate is not complete, which will affect the purity of the product

During the concentration process, the ammonium sulfate solution absorbs part of the sulfur dioxide in the flue gas and makes the solution more acidic, which intensifies the corrosion of the subsequent equipment; at the same time, most of the dust in the flue gas will enter the solution to form a colloidal state with ammonium sulfate , and because the concentration of ammonium sulfate solution becomes larger, the filtration operation is more difficult; there is no treatment plan for the filtered filter residue, which will not only form new pollution, but also affect the overall yield of ammonium sulfate

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