Indigo blue product mixed alkali recovery device

Abstract

The invention relates to an indigo blue product mixed alkali recovery device comprising a pressure filtration water recovery device and a washing water recovery device. A concentration device is connected to an indigo blue post-treatment pressure filter water outlet port and a sodium-potassium ratio regulation device. The sodium-potassium ratio regulation device is connected with a dehydration device. The dehydration device is connected with an indigo blue oxidation reactor. A water inlet of a washing alkaline water tank is connected with a water outlet of an indigo blue post-treatment pressure filter. A water outlet of the washing alkaline water tank is connected with a water inlet of a suspended-matter-filtering alkaline water tank through a suspended matter filter. A water outlet of the suspended-matter-filtered alkaline water tank is connected with a water inlet of an organic-matter-filtered alkaline water tank through an organic matter filter. A water outlet of the organic-mater-filtered alkaline water tank is connected with a cooled alkaline water tank through a cooling tower. The cooled alkaline water tank is connected to the indigo blue oxidation reactor. According to indigo blue oxidation process requirements, pressure filtration filtrate is concentrated; sodium-potassium ratio is regulated; and the filtrate is returned to and reused in the indigo blue oxidation process. Low-concentration mixed alkali liquid after pressure filtration and washing are collected and applied as washing water and alkali fusion material dilution water. Recycling and utilization are carried out, such that low-concentration mixed alkali full recovery and surplus mixed alkali utilization are realized. Therefore, purposes of reducing emission and reducing fresh tap water consumption are realized.

Description

[0001] This application is a divisional application of the patent name: a device for recovering mixed alkali from indigo products, the application date is 2013-11-6, and the patent application number is 201310543782.9. technical field [0002] The invention belongs to a device for recovering raw materials for indigo production, in particular to a device for recovering mixed lye in the post-treatment washing process of vat dyes such as indigo. Background technique [0003] Indigo is an environmentally friendly vat dye with a long history, which is widely used in the dyeing of cotton fabrics, especially the warp yarns of indigo denim products. [0004] The current industrial production is to prepare indigo through the oxidation of 3-indoxyl salt. The reaction process includes a certain amount of aniline acetate, sodium amide, and a mixed alkali of sodium hydroxide and potassium hydroxide at 220~250°C. Reaction to obtain 20-30% alkali melt of 3-indoxyl salt, dissolve the alkali...

AI Technical Summary

Problems solved by technology

According to tracking statistics and analysis, during the post-treatment and washing process of indigo, the filter cake washing causes a large amount of alkali loss, and a large amount of tap water is required to dilute and wash the material. After the lost alkali enters the sewage treatment device, a large amount of acid is required. For neutralization, the treatment cost and production cost are high, and the formed inorganic salt is difficult to biochemically treat, which wastes alkali resources and causes large environmental pollution

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