After-treatment clean process for purifying vat blue 66 dye

Abstract

The invention relates to an after-treatment clean process for purifying vat blue 66 dye. The clean process comprises the steps: levigating a vat blue 66 crude product, filtering the levigated vat blue 66 by adopting a 300-mesh sieve, adding he filtered vat blue 66 in a sulfuric acid concentrated solution, wherein the weight ratio of the vat blue 66 crude product and the sulfuric acid concentrated solution is 1: (13-15), and the concentration of the sulfuric acid concentrated solution is 70 to 75 percent by weight; heating the mixed solution to 70 to 90 DEG C, stirring and insulating the mixed solution for 4 to 6 hours, when the vat blue 66 crude product is stirred and insulated in the sulfuric acid concentrated solution, the color of the mixed solution is turned from dark blue to olivine, cooling the mixed solution to the temperature of 50 DEG C after the mixed solution is thermally insulated, stirring the mixed solution for 4 to 8 hours, filtering the mixed solution, washing filter cake by utilizing the70% to 75% sulfuric acid concentrated solution or the sulfuric acid solution which is identical in the concentration, adding water to the filter cake, pulping the filter cake, heating the pulp to the temperature of 80 DEG C, preserving the pump for 0.5 to 1 hour, and drying the filter cake at the temperature of 90 DEG C to obtain a vat blue 66 dye dry product. The sulfuric acid concentrated solution with the concentration of 70 to 75 percent is obtained by after-processing the sulfuric acid concentrated mother solution obtained by purifying the vat blue 66. The invention provides the after-treatment clean production process of the vat blue 66.

Description

technical field [0001] The invention relates to a post-treatment cleaning process for purifying vat blue 66 dye, and belongs to the technical field of dye production. Background technique [0002] Vat blue 66 (CAS: 32220-82-9) is a high-quality blue vat dye, and its purification method has been reported in literature, see CN1737063. That is, the crude product of Vat Blue 66 is completely dissolved in concentrated sulfuric acid, diluted with water, and the acidity is controlled at 40% to 50% by weight, then cooled, crystallized, and dried to obtain high-purity Vat Blue 66 dye. In the above purification, about 12 tons of sulfuric acid with a concentration of about 95% is consumed per ton of vat blue 66 crude product, and about 25 tons of 45% waste acid is produced, which contains unreacted raw materials, impurities of unknown structure and a small amount of products, which cannot be completely cured at present. Contents of the invention [0003] The purpose of the present ...

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Problems solved by technology

In the above purification, about 12 tons of sulfuric acid with a concentration of about 95% is consumed per ton of vat blue 66 crude product, and about 25 tons of 45% waste acid is produced, which contains unreacted raw materials, impurities of unknown structure and a small amount of products, which cannot be completely cured at present