A waste acid recovery process and its supporting equipment

Abstract

The invention relates to a waste acid recycling process and a matching device thereof, belonging to the technical field of water treatment. The waste acid recycling process comprises the following steps of: carrying out pre-treatment on waste acid by virtue of ultrafiltration membrane air flotation; vertically mounting an ultrafiltration membrane assembly, and then feeding the waste acid from thelower part of the ultrafiltration membrane assembly by utilizing a gas-liquid hybrid power device to carry out ultrafiltration membrane air flotation purification treatment; and recycling the waste acid by adopting air flotation dialysis after the pre-treatment, thus having the advantages of low energy consumption, strong operability, good effluent quality, small waste acid recycling volume, highconcentration and the like. The matching device comprises a waste acid tank and a pre-treatment ultrafiltration membrane assembly which is vertically arranged, wherein the pre-treatment ultrafiltration membrane assembly is connected with a penetrating fluid discharge pipe, the lower part of the pre-treatment ultrafiltration membrane assembly is connected with a feeding pipe, the upper part of thepre-treatment ultrafiltration membrane assembly is connected with a concentrated solution discharge pipe, the other end of the feeding pipe of the pre-treatment ultrafiltration membrane assembly is communicated with the waste acid tank, and the feeding pipe is provided with the gas-liquid hybrid power device. The device has a compact structure, is stable in operation and simple in management and is applicable to recycling of multiple waste acids.

Description

technical field [0001] The invention belongs to the technical field of water treatment, and in particular relates to a process for recovering waste acid and a device matched with the process. Background technique [0002] Before surface electroplating and spraying, steel component blanks are generally pickled to remove surface oxides, and a large amount of pickling waste is generated at the same time. The types of workpieces and processing requirements are different, and the requirements for pickling liquid are also different, among which hydrochloric acid cleaning is the most common. The hydrochloric acid cleaning waste mainly contains Fe 2+ 、H + and Cl - Ions, in addition to a certain amount of oil and silicon powder, carbon and other suspended matter. If these pickling waste liquids are directly discharged without treatment, it will not only waste resources, but also cause serious environmental pollution. [0003] For the pickling waste liquid in the iron and steel i...

AI Technical Summary

Problems solved by technology

However, these treatment methods generally have problems such as high investment and operating costs, and unsatisfactory treatment effects. Among them, the cooling crystallization method, evaporation crystallization method, and spray-burning decomposition method also have defects such as high energy consumption and difficult equipment maintenance. A large amount of waste gas and waste residue; ion exchange method and dialysis method have poor operation stability and acid recovery is not complete; solvent extraction method and neutralization method need to consume a large amount of chemical reagents, which is easy to cause secondary pollution

[0004] It can be seen that the traditional waste acid treatment method can no longer meet the national policy requirements of "circular economy", and the market urgently needs a new waste acid treatment technology with small investment, high recovery rate, small volume of recovered acid, and low operating cost

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