System for preparing sulfuric acid from sulfur foam and desulfurization waste liquid by semi-dry method and acid preparation method

Abstract

The invention discloses a system for preparing sulfuric acid from sulfur foam and desulfurization waste liquid by a semi-dry method and an acid preparation method. The system is formed by sequentiallyconnecting a separation unit, an incineration unit, a purification unit, a dry absorption unit and a tail absorption unit. Sulfur is extracted from sulfur foam, mixed with salt and sent to an incinerator to be incinerated for acid making, and dissolved clear liquid obtained after the sulfur is extracted and mixed with salt meets the requirement for returning to a desulfurization section to be recycled or entering a cold drum section.

Description

technical field [0001] The invention relates to the field of recovery and reuse of solid waste and liquid waste resources, in particular to a system and method for producing sulfuric acid by a semi-dry method of sulfur foam and desulfurization waste liquid. Background technique [0002] In the existing sulfur foam and desulfurization waste liquid acid production, there are mainly two types: dry acid production and wet acid production. The dry acid production process is: sulfur foam—filter—dryer—screening—crushing—incinerator—waste heat boiler—power wave scrubber—cooling scrubber—dry suction tower—electric demister—fan—converter—absorption Tower (two suctions) - sulfuric acid storage tank. Although the amount of dilute acid produced by the dry method is small, the dilute acid is of poor quality and contains too many impurities and cannot be used in the ammonium sulfate section. The drying pretreatment process causes the decomposition of salts, which makes it difficult to tre...

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Problems solved by technology

[0005] 1. It is impossible to separate the pulverized coal in the sulfur foam. If the pulverized coal has poor fluidity and is brought into the pipeline, it will block the pipeline. After being brought into the incineration system, it cannot be decomposed. After high temperature, carbon knots block the fire tube of the waste heat boiler. Dilute acid affects the quality of dilute acid

[0006] 2. The above two process routes cannot separate the impurities and coal powder in the sulfur foam. The mixing of elemental sulfur and coal powder impurities together causes the particles to increase and contain crystal water. After entering the incinerator, they cannot burn quickly. In this case, in order to Rapid and complete combustion in the incinerator can only increase the combustion temperature (usually the combustion temperature is controlled at 1150 ° C) to avoid the generation of sublimated sulfur entering the purification process to block the power wave scrubber, but the formation of nitrogen oxides will increase exponentially after the combustion temperature is too high , Nitrogen oxides enter the purification section and mix with dilute acid to form nitric acid. Because nitric acid is highly corrosive, the material of the existing equipment in the ammonium sulfate section cannot meet the requirements of nitric acid, so the dilute acid becomes waste.

[0007] 3. The above two kinds of process materials cannot burn and release heat quickly after entering the incinerator. In addition to the requirements of combustion temperature, in the normal production process, external fuel combustion is required to maintain the incinerator at a constant temperature state, and it is necessary to add a large amount of gas Combustion, increased operating costs

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