Process for treating phosphate coating wastewater of steel pipes

Abstract

The invention relates to a process for treating phosphate coating wastewater of steel pipes, which comprises the following steps of: (1) regulating the pH value, namely regulating the pH value of the wastewater to be in a coagulant applicable range by quantitatively adding lime; (2) adding PAM coagulant solution and PAC coagulant solution for coagulation; (3) introducing into a sloping plate settling tank for settlement; (4) adding the PAM coagulant solution and PAC coagulant solution again for coagulation; (5) introducing into a floatation device for floatation treatment; (6) meeting the standard and discharging water after the pH value is regulated; and (7) performing solid-liquid separation on sediments in the sloping plate settling tank and dross in the floatation device by using a plate-and-frame filter press. According to the process for treating the phosphate coating wastewater of the steel pipes, physical and chemical treatment technology and a production process are closely combined, and the batch treatment of the phosphate coating wastewater of the steel pipes is realized. The process has the advantages that: one-time investment is low, the treatment effect is stable, the production running cost is low, the process is easy and convenient to implement and the like.

Description

technical field [0001] The invention relates to a waste water treatment process in the metallurgical manufacturing industry, in particular to a steel pipe phosphating waste water treatment process. Background technique [0002] The early application of phosphating process was anti-rust. After phosphating, a layer of phosphating film was formed on steel parts to prevent rust. Steel pipe phosphating wastewater refers to the comprehensive wastewater generated when steel pipes are washed after pre-degreasing, degreasing, surface conditioning, and phosphating. The main components in the wastewater are heavy metals (such as zinc, manganese, etc.), phosphate ions, oil, etc., and the pH value of the wastewater is about 3-11. At present, this kind of wastewater is generally only treated by sedimentation, and some pollutants in the treated water still exceed the standard, and it is often diluted with clean water before it can be discharged. [0003] Patent Publication No. CN10116846...

AI Technical Summary

Problems solved by technology

At present, this kind of wastewater is generally only treated by sedimentation, and some pollutants in the treated water still exceed the standard, and it is often diluted with clean water before being discharged.

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