Method for producing naphthol AS and recycling wastes

Abstract

The invention relates to a method for producing naphthol AS and recycling wastes. The method comprises the step of transferring a condensation material into an alkali cooking pot to carry out alkali cooking to obtain an alkali cooking matter and a distillate and also comprises the following steps: carrying out vacuum flirtation on the alkali cooking matter to obtain a naphthol AS filter cake and naphthol AS mother liquor; drying the naphthol AS filter cake to obtain naphthol AS; recycling the naphthol AS mother liquor to obtain 2-hydroxy-3-naphthoic acid; recycling the distillate to obtain aniline black. According to method for producing the naphthol AS and recycling the wastes, the 2-hydroxy-3-naphthoic acid with high purity can be obtained from the naphthol AS mother liquor, so that the utilization rate of the raw materials is improved, and the production cost is reduced; the aniline black can also be recycled and prepared from the distillate, so that not only is industrial wastewater treated, but also a new useful pigment is obtained; the quality of the naphthol AS product is also improved, and the enterprise production benefit is improved.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for producing naphthol AS and recycling waste. Background technique [0002] Naphthol AS is an important dye intermediate, mainly used in the production of organic pigments and dyeing and printing of cotton fibers, viscose fibers and some synthetic fibers. Naphthol AS is 2-hydroxy-3-naphthoic acid and aniline In chlorobenzene solution, phosphorus trichloride is used as a catalyst for condensation reaction. [0003] The naphthol AS mother liquor produced during the production of naphthol AS is as high as 40,000 mg / L, with a chroma of 500 times, and contains a considerable amount of 2-hydroxy-3-naphthoic acid; if these naphthol AS mother liquors are not treated, they are directly discharged into Sewers not only seriously pollute the environment, but also waste some chemical raw materials; [0004] Therefore, the mother liquor treatment of naphthol ...

AI Technical Summary

Problems solved by technology

[0003] During the production of naphthol AS, the mother liquor of naphthol AS is as high as 40,000 mg / L, with a color of 500 times, and contains a considerable amount of 2-hydroxy-3- Naphthoic acid; if these naphthalene AS mother liquors are not treated and directly discharged into the sewer, it will not only seriously pollute the environment, but also waste some chemical raw materials;

[0004]Therefore, the treatment of the mother liquor of naphthol AS has been paid more and more attention by manufacturers, and organic wastewater is generally treated by biochemical methods, but the mother liquor of naphthol AS cannot be directly treated by biochemical methods Treatment must be pretreated. The advanced treatment method is the step-by-step acid analysis method to treat the naphthol AS mother liquor and recover 2-hydroxy-3-naphthoic acid. The color removal rate of the mother liquor after treatment is 95%, and the naphthol AS mother liquor removes The rate is 50%, but after two acid analysis, the content of 2-hydroxy-3-naphthoic acid in the filter cake is less than 90%, which has a certain gap with the actual quality of 2-hydroxy-3-naphthoic acid

[0005] During the caustic boiling process of naphthol AS, its distilled product, chlorobenzene and aniline, are all distilled out along with the water vapor. Generally, the aniline solution is The lime is directly disposed of, which also causes a certain waste of raw materials