Method for recycling pure acid from metallic ion containing waste acid and regenerating alkali

Abstract

Disclosed is a method which recovers pure acid from the waste acid contains metallic ion and reproduces alkaline, and belongs to the environmental protection field. The process steps include that: (a) the waste acid solution with the acid concentration 10%-40% is processed with the first level diffusion dialysis; (b) the residue after the step a is processed with the second level diffusion dialysis; the volume ratio of the first level (or the second level) waste acid (or the first level diffusion residue) in the first level (or the second level) diffusion dialysis groove residue and the acid recovery chamber collected solution is 1:0.5-1:3.0; the flow rate of the waste acid (or the first level diffusion residue) is enabled to be 0.2-0.6L / h; the flow rate of the acid recovery chamber collected solution is 0.1-1.8L / h; (c) the second residue after the step b is processed with neutralization and deposition; (d) the neutralized filtrate after the solid-liquid separation-filtration is fed to the three compartment electrodialysis groove middle chamber, the electrodialysis is processed for 1-3h under the voltage 5-15V to obtain the reproduction acid and reproduction alkaline. The method which recovers pure acid from the waste acid contains metallic ion and reproduces alkaline has the advantages of high acid recovery rate, low production cost and energy-consumption, less film pollution, saving water, reducing discharge and no secondary pollution.

Description

technical field [0001] The invention belongs to the field of environmental protection, and relates to a method for regenerating pure acid from waste acid containing metal ions by using a combined process of two-stage diffusion dialysis-neutralization precipitation-three-compartment electrodialysis. Background technique [0002] Waste acids containing metal ions are produced in various manufacturing processes and processing engineering. Such as sulfuric acid waste liquid from non-ferrous metal ore or metal processing, hydrochloric acid waste liquid from extraction or acid leaching process, hydrofluoric acid waste liquid from lead processing, chromium-containing waste liquid from electroplating process, etc. Especially in the pickling process, aluminum anodizing process, aluminum titanium etching process, metal refining process and battery production process, etc. will produce waste acid solution with high acid content. [0003] The treatment and utilization methods of waste ...

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Problems solved by technology

But there are the following problems: 1. in this method, the raffinate after diffusion dialysis is used as the supply liquid (dilute chamber) of the bipolar membrane electrodialysis cell, due to the initial H 2 SO 4 The concentration is still high, the energy consumption of the electrodialysis cell and the H transferred (recovered) 2 SO 4 Proportional to the amount

③After bipolar membrane electrodialysis, a certain volume of electrodialysis raffinate still needs to be discharged, and the raffinate still contains a very low concentration of H 2 SO 4 , the metal ions intercepted in the diffusion dialysis stage are also retained in the raffinate (equivalent to secondary pollutants), and should not be discharged directly; if it is discharged after neutralization with alkali, it will consume alkali and produce brine that is difficult to recycle. Thereby increasing sewage charges and wasting water resources

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