Preparation method of anthranilic acid recovered from saccharin wastewater

Abstract

The invention relates to a preparation method of anthranilic acid recovered from saccharin wastewater, and the preparation method comprises the following steps of: uniformly mixing an anthranilic acid crude product obtained through the preparation, alkali fusion, pressure filtration, decoloring, suction filtration, acid separation and drying processing of copper salt with water, and then adding hydrochloric acid to dissolve the anthranilic acid crude product; adding active carbon for decoloring till filter liquor is colorless and transparent to obtain decoloring filter liquor; filtering; washing a filter cake by using the water to obtain filtering filter liquor; adding a sodium carbonate solution, stirring, standing to form a crystal, and then filtering; and pumping, washing and drying the filter cake to obtain the anthranilic acid. The preparation method disclosed by the invention is simple and easy and convenient to operate. According to the invention, an alkaline separation clear solution and washing water used for refining and purification need to be discharged into a mother solution tank because a part of the anthranilic acid is still contained in the alkaline separation clear solution and the washing water and are circularly recovered by being used as the raw materials of the copper salt together, so that the yield is increased; and the recovery rate of the prepared anthranilic acid achieves more than 95.0%, and the purity of the recovered anthranilic acid achieves more than 97.0%, so that the basis is provided for the wide use of the anthranilic acid.

Description

technical field [0001] The invention belongs to the field of chemical industry and relates to anthranilic acid, in particular to a preparation method for recovering anthranilic acid from saccharin waste water. Background technique [0002] Anthranilic acid, also known as anthranilic acid, 2-aminobenzoic acid, chemical formula: C 7 h 7 NO 2 , is an amino aromatic carboxylic acid, white crystal powder at room temperature, used as an intermediate for medicine, dyes, spices and pesticides. [0003] Anthranilic acid is white to light yellow odorless crystalline powder with sweet taste, soluble in hot water, ethanol and ether, slightly soluble in benzene, hardly soluble in cold water. Heating sublimation, decomposition into aniline and carbon dioxide during distillation. Can form chelates with metal ions. In glycerin solution, it shows amethyst fluorescence. [0004] Anthranilic acid can be used as an intermediate in medicine, dye, fragrance and pesticide. In terms of dyes,...

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Problems solved by technology

In this way, it will not only cause a waste of beneficial resources, make the waste not fully utilized, but also increase the pressure on the wastewater treatment system.

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