Method for treating wastewater in production of corrosion foil for aluminum electrolytic capacitor

Abstract

The invention provides a method for treating wastewater in production of corrosion foil for an aluminum electrolytic capacitor. The method comprises the following steps: (1) injecting wastewater produced in the production of the corrosion foil for the aluminum electrolytic capacitor into a second-order reaction tank, a first-order reaction tank and a fourth-order reaction tank respectively according to the generation order; (2) adding CaCO3 to the first-order reaction tank to regulate the pH value to 2 to 4, and filtering; (3) adding the filtrate in step (2) to the second-order reaction tank, and filter pressing; (4) injecting the filtrate in step (3) to a third-order reaction tank, adding Al2O3 to regulate the pH value of a solution to 2 to 4, and filtering by an ultrafiltration membrane; (5) adding Al2O3 to the fourth-order reaction tank to regulate the pH value of a solution to 2 to 4, filtering by an ultrafiltration membrane, and concentrating by heating. The method has the advantages that the cost is low, the treated wastewater can be discharged directly, and CaSO4, Al (NO3) 3 and a concentrated AlCl3 solution produced in the treatment process have relatively high purity, and can be used as industrial raw materials to be directly sold.

Description

Technical field [0001] The present invention is the field of wastewater treatment technology, which involves a method of making wastewater treatment for a corrosive foil for an aluminum electrolytic capacitor. Background technique [0002] Aluminum electrolytic capacitors use a variety of acids during the production process of corrosive foil, and at the same time produce aluminum salt. For example, during the first -level corrosion process, hydrochloric acid and sulfuric acid should be used to react with aluminum reactions.Aluminum salt is generated; nitric acid is also used during the process of treatment, so the wastewater produced in the production process contains a large amount of sulfuric acid, hydrochloric acid, nitric acid, and aluminum salt from other people.A big influence. [0003] At present, the processing method of the wastewater is to collect the concentrated collection of sulfuric acid, hydrochloric acid, nitric acid and other aluminum salt, enter the reaction poo...

AI Technical Summary

Problems solved by technology

However, the materials used in this process are fine CaO and NaOH, the cost is high, and the CaSO produced in the process 4 , Al(OH) 3 And the mixed sediment of insoluble matter in fine CaO, not only has no use value, but also needs outsourcing treatment, if not handled properly, it will cause secondary pollution to the environment, and will also make the wastewater treatment system run more expensive