Desulfurization waste liquid acid making system and method

Abstract

The invention provides a desulfurization waste liquid acid making system and method, which relate to the field of acid making. The system comprises a pretreatment unit, a concentration unit, a pulpingunit, an incineration unit, a purification unit and a dry absorption conversion unit, wherein a dilute sulfuric acid outlet in the purification unit is connected with a filtrate storage tank for storing filtrate in the pretreatment unit. The acid making method comprises a pretreatment step for separating the desulfurization waste liquid from the desulfurization unit into a sulfur paste and a filtrate, a concentration step for concentrating the filtrate to obtain a concentrated solution, a pulping step for mixing the sulfur paste and the concentrated solution into a slurry, an incineration step for incinerating the slurry to produce SO2 gas, a purification step for washing the SO2 gas, and a dry absorption conversion step for preparing concentrated sulfuric acid from the purified SO2 gas.Dilute sulfuric acid generated in the purification step is returned to the filtrate to be neutralized. According to the method, dilute sulfuric acid and ammonia contained in the filtrate are directlysubjected to a neutralization reaction, the raw material SO2 is further obtained through incineration, and the sulfur recovery rate and the concentrated sulfuric acid yield are increased.

Description

technical field [0001] The invention relates to the field of acid production, in particular to a system and method for acid production from desulfurization waste liquid. Background technique [0002] At present, the technology of producing industrial sulfuric acid by using the desulfurization waste liquid and sulfur paste produced by the coke oven gas desulfurization system of the coking plant can be roughly divided into two categories: the first category is to dry the sulfur foam to turn it into sulfur, sulfur The mixture of ammonium cyanate and ammonium thiosulfate is dry powder, and then the mixture of sulfur, ammonium thiocyanate and ammonium thiosulfate is sprayed into the incinerator to burn to obtain sulfur dioxide for the production of sulfuric acid. This process has the following disadvantages: one is that the drying system is huge and the investment is high; the other is that the sulfur foam contains about 90% of water, so it needs to consume a lot of energy to dry...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a system and method for producing acid from desulfurization waste liquid, so as to solve the problem that the dilute sulfuric acid produced in the purification section cannot be directly used when the spraying incineration process is used to produce acid in the prior art, causing secondary pollution and waste of resources etc.

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