Recovery treating method for treating wastewater before coating sheet metal part

Abstract

The invention discloses a recovery treating method for treating wastewater before coating a sheet metal part. The recovery treating method comprises the following steps: adding 1 to 15 parts by mass of aluminium polychlorid to 100 to 3000 parts by mass of wastewater treated before coating at the normal temperature; uniformly stirring; standing for 24 hours, thus obtaining recycle water and precipitate; separating the recycle water from the precipitate; and pressing the precipitate into a solid waste through a filter press. According to the recovery treating method, a certain amount of aluminium polychlorid is correspondingly added to the wastewater produced during treating before coating the sheet metal part and is uniformly stirred to realize the reaction between the added aluminium polychlorid and the impurities in the wastewater to obtain the precipitate, thus realizing the separation treatment of the wastewater, the separated recycle water can be recycled, and the precipitate is pressed into the solid waste by the filter press. Compared with the prior art, the recovery treating method has the advantages that the recycle of the wastewater treated before coating is realized, and the solid waste small in size and convenient to transport is produced, so that the cost of treating the wastewater before coating is greatly reduced as well as reducing the manufacture cost of an enterprise.

Description

Technical field: [0001] The invention relates to waste water treatment technology, in particular to a method for recycling and treating waste water before spraying of sheet metal parts. Background technique: [0002] Sheet metal is a comprehensive cold working process for thin metal sheets (usually below 6mm), including shearing, punching / cutting / compositing, folding, welding, riveting, splicing, forming (such as automobile body), etc. Its distinctive feature is the same part Consistent thickness. Sheet metal parts are thin plate hardware parts, that is, parts processed by stamping, bending, stretching and other means. [0003] Spraying and baking paint on the surface of sheet metal parts can achieve the purpose of preventing rust and oxidation. At present, before spraying and baking paint on sheet metal parts, it is necessary to remove the rust and oil stains on the surface, and then carry out phosphating film treatment, so that a protective film can be coated on the surf...

AI Technical Summary

Problems solved by technology

[0004] However, at present, in the process of degreasing, derusting and phosphating film treatment on the surface of sheet metal parts, chemical potions need to be used, and a large amount of waste water will be generated after chemical potion treatment. At present, the treatment methods for this kind of waste water in the industry are usually It is transported to a professional wastewater treatment company for treatment, but due to the large volume of wastewater occupied, high transportation costs, and high wastewater treatment costs, the manufacturing costs of sheet metal parts manufacturers have been greatly increased