Method for regenerating and recovering sulfuric acid from waste acid

Abstract

The invention relates to a method for regenerating and recovering sulfuric acid from waste acid generated in the production of the sulfuric acid or waste acid collected from waste lead-acid storage batteries, comprising the following steps of: firstly preparing purified gas containing H2S with volume percent of 2.5%-5%, CO2 with volume percent of 20%-45% and N2 with volume percent of 50%-77.5; supplying the purified gas to a waste acid solution with the flow rate of 10-20 m3/h and the stirring speed of 300-400 rpm at the speed of 400-600 L/h so that heavy metal impurities in the waste acid solution and S2+ react to generate a sulfide; precipitating, filtering and separating the generated sulfide so that the sulfide is purified and removed from a dilute sulfuric acid solution; and replenishing the filtered dilute sulfuric acid solution which replaces new water into the dry-adsorbing procedure of a flue gas acid making systemso that the sulfuric acid in the waste acid solution is recovered into industrial sulfuric acid. The method has the advantages of low production cost, short flow, high cyclic utilization rate, low energy consumption, treatment of wastes by using wastes, small environmental pollution and high level of automation.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for regenerating and recycling sulfuric acid from waste dirty acid into industrial sulfuric acid from dirty acid produced in the production process of sulfuric acid or waste acid collected in waste lead-acid batteries, which belongs to the industry The category of waste recycling. Background technique [0002] With the rapid development of the automobile industry, used up waste batteries contain a large amount of heavy metals and electrolytes. Whether they are buried deep or piled up with bare leaks, the heavy metals and electrolytes in them will pollute groundwater, soil and the surrounding environment and endanger human health. , but at the same time waste batteries are valuable secondary resources that can be used by human beings, so the comprehensive utilization of waste batteries is of great significance. At present, the scale of domestic seco...

AI Technical Summary

Problems solved by technology

The treatment methods for waste electrolyte solution are: ① The internationally advanced CX integrated system is used to deal with waste lead-acid batteries. 2 CO 3 The solution reacts with dilute sulfuric acid, and then processed into sodium sulfate. This treatment method also has shortcomings. If it is necessary to build a sulfate production plant, it will increase investment, and at the same time, the production of sulfate needs to increase raw materials, and the production chain will be extended.

②Extraction is used to separate the sulfuric acid in the electrolyte, and the sulfuric acid produced can be reused or sold as the electrolyte; this method is technically feasible, but the cost is high, and there is no large-scale production application

③ Domestic application (patent) No. 200710300074.7 proposes and implements the method of pouring out, collecting and recycling the electrolyte in the waste storage battery, and reclaims sulfuric acid quickly and effectively, but this method affects the quality of sulfuric acid, and the lead content in sulfuric acid increases greatly

④ Some secondary lead production units use alkali neutralization to neutralize the waste electrolyte and then discharge it. Although there is no pollution to water resources, a large amount of solid waste is generated when alkali such as lime is used to neutralize the electrolyte. cause secondary pollution

Regarding the polluted acid produced in the acid production process, there has been no report on the regeneration of sulfuric acid

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