Method for synthesizing novel water purifying agent by utilizing steel acid pickling waste liquid

Abstract

The invention discloses a method for synthesizing a novel water purifying agent by utilizing steel acid pickling waste liquid. The method specifically comprises the following steps: (1) enabling the concentration of hydrogen ions in the acid pickling waste liquid to be not higher than 2mol / L and the total iron concentration to be not lower than 0.5g / L by adopting a physical or chemical method; (2)carrying out electrolytic treatment on the acid pickling waste liquid by taking one noble electrode as a positive electrode and the other noble electrode or an iron electrode as a negative electrode,and depositing iron ions in the negative electrode in a form of an iron element or iron compound; (3) putting the negative electrode in a strong alkaline electrolyte after depositing a certain amountof iron or iron compound on the negative electrode, carrying out electrolytic treatment by as a positive electrode, and converting iron on the positive electrode into strong-oxidation ferrate by utilizing oxidation of the positive electrode; (4) enabling the ferrate to exist in a strong alkaline solution in a form of a solute or an insoluble substance, and forming the novel water purifying agent.The method disclosed by the invention has the advantages that emission of industrial waste is reduced, the resource is saved, high-value utilization of the iron ions can be realized, and a very goodapplication prospect is obtained.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a method for synthesizing a new type of water purifying agent by using iron and steel pickling waste liquid. Background technique [0002] Iron and steel pickling waste liquid usually contains a relatively high concentration of iron ions and inorganic strong acids (such as hydrochloric acid, sulfuric acid, nitric acid, etc.), which are highly acidic and corrosive, and have been included in the "National List of Hazardous Wastes". If the steel pickling waste liquid is discharged directly without treatment, it will not only cause waste of resources, but also cause serious harm to the environment. [0003] At present, the treatment methods of steel pickling waste liquid mainly include neutralization method, evaporation crystallization method, direct roasting method and so on. However, the above-mentioned methods all have their own defects. The neutralization metho...

AI Technical Summary

Problems solved by technology

However, the above methods have their own defects

The neutralization method not only needs to consume a large amount of alkali (such as lime, sodium hydroxide, etc.), but also produces high-concentration waste brine and a large amount of solid waste, and the comprehensive treatment cost is very high

Evaporation and crystallization can recover part of the acid and iron ions in the pickling waste liquid, but it requires high equipment, large investment, high energy consumption, high operating cost, and the market value of recovered products is very low

The direct roasting method can convert waste acid into regenerated acid and iron oxide, but it is only suitable for volatile acids (such as hydrochloric acid), and the equipment investment and operation costs are high, so only a few large domestic enterprises adopt it