Method for treating sulfuric acid wastewater in the production process of poly-p-phenylene terephthalamide fiber and its treatment device

Abstract

The invention relates to a treatment method and treatment device of sulfuric acid wastewater in a production process of polyphenylene terephthalamide fibers, belongs to the field of chemical engineering, and particularly relates to a sulfuric acid wastewater treatment technology. The main points of the treatment method are as follows: coagulation bath waste liquid, fiber water washing waste liquid and fiber neutralizing waste liquid generated in the production process of the polyphenylene terephthalamide fibers are mixed in a static mixer and introduced into a waste liquid storage tank; the wastewater in the waste liquid storage tank is pumped to a neutralizing reaction kettle through a centrifugal pump and neutralized by calcium hydroxide until the PH value is 6-9; and the neutralizing waste liquid in the neutralizing reaction kettle is conveyed to a plate and frame filter through the centrifugal pump for filtering, the filtrate is discharged as industrial wastewater, and the filter residues are unloaded to a filter residue hopper. The treatment device comprises the neutralizing reaction kettle and the plate and frame filter. The treatment method and treatment device provided by the invention have the positive effects that: a continuous treatment device for a large amount of sulfuric acid wastewater generated in large-scale continuous preparation of polyphenylene terephthalamide fibers is provided; and one set of simple treatment system is used, the cost is saved, and the operation is convenient.

Description

Technical field: [0001] The invention belongs to the field of chemical engineering and relates to the treatment technology of waste water, specifically the treatment method and its treatment device for sulfuric acid waste water in the production process of poly-p-phenylene terephthalamide fiber. technical background: [0002] Poly-paraphenylene terephthalamide fiber is also called para-aramid fiber. Para-aramid fiber is the most widely used and most demanded fiber among high-performance fibers in the world. The first choice for special protective materials, widely used in aerospace, aviation, military industry, electromechanical, construction, automobile, sporting goods and other fields. [0003] In the industrial production process of para-aramid fiber, since concentrated sulfuric acid is used as the spinning solvent, a large amount of sulfuric acid-containing wastewater will inevitably be produced. Theoretically, these sulfuric acid wastewater can be gradually evaporated ...

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Problems solved by technology

The advantage of this method is that the sulfuric acid in the wastewater can be used repeatedly, which saves the amount of sulfuric acid, but the disadvantage is that during the evaporation of dilute sulfuric acid, the energy consumption is high and the cost is high. On the other hand, 95-98% of concentrated sulfuric acid needs to be fed into SO 3 The gas can further remove the moisture in the concentrated sulfuric acid to make the sulfuric acid concentration reach 100%. For para-aramid fiber production enterprises, use SO 3 Gas is very unrealistic, therefore, it is difficult to realize the concentrated recovery of sulfuric acid wastewater in the actual industrial production process of para-aramid

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