Resourceful treatment method of phosphating waste liquid

Abstract

The invention discloses a resourceful treatment method of phosphating waste liquid. The method is as follows: adding phosphoric acid into the phosphating waste liquid, filtering after reaction, addinghydrogen peroxide into filtrate, and continuously reacting; putting the reacted solution into a reaction kettle for reduced pressure distillation, and stirring for reaction to obtain slurry; filtering the slurry to obtain a first filtrate and a first filter residue, adding sodium hydroxide into the first filtrate, reacting, precipitating and filtering to obtain a second filtrate and a second filter residue, adding sulfuric acid into the second filter residue, dissolving to obtain a dissolved solution, adding ammonia water into the dissolved solution to adjust the pH value of the solution, stirring, reacting, and filtering to obtain a third filtrate and a third filter residue; adding pure water into the first filter residue for slurrying and washing, and drying, sintering, smashing, screening and deironing the washed filter residue to obtain battery-grade iron phosphate; and returning the second filtrate to prepare a phosphating solution. Resource utilization of nitrate radicals, zinc,iron and the like can be achieved, meanwhile, the wastewater can be returned to be used for preparing the phosphating solution, the treatment cost is low, and the environmental protection property isgood.

Description

technical field [0001] The invention relates to a resource treatment method for phosphating waste liquid, belonging to the field of waste resource utilization. Background technique [0002] Phosphating is commonly used as a protective layer for automobile shells. Phosphating is a process in which chemical and electrochemical reactions form a phosphate chemical conversion film. The phosphating process mainly includes alkaline cleaning to remove oil, pickling to remove rust, phosphating and passivation treatment, etc. process. Phosphating treatment is the pretreatment process of electrophoresis and painting in the production process of automobile shells. The main purpose of phosphating is to provide protection for the base metal and prevent the metal from being corroded to a certain extent; The adhesion and corrosion resistance of the film layer. [0003] Phosphating is the most important part of the entire pretreatment process. Its reaction mechanism is complex and the amou...

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Problems solved by technology

[0005] However, the above ideas only use the idea of ​​wastewater treatment to deal with these waste liquids, without considering resource utilization. The above-mentioned methods of treating waste liquids are costly and have not realized resource treatment of phosphorus, iron, etc.

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