Purification method of Lyocell spinning coagulating bath recovery liquid

A technology of recovery liquid and coagulation bath, which is applied in the field of purification of Lyocell spinning coagulation bath recovery liquid, can solve problems such as rising cost of NMMO solution recovery, reduced service life of ion resin, and increased acid-base usage of regeneration liquid, etc., to achieve good decolorization effect, the effect of lowering the conductivity and prolonging the service life

Pending Publication Date: 2020-11-17
CHINESE TEXTILE ACAD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] As a result, problems such as a decrease in the ion exchange rate, an increase in the amount of acid and alkali used in the regeneration solution, and a decrease in the service life of the ion resin have directly led to an increase in the recovery cost of the NMMO solution.

Method used

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  • Purification method of Lyocell spinning coagulating bath recovery liquid
  • Purification method of Lyocell spinning coagulating bath recovery liquid
  • Purification method of Lyocell spinning coagulating bath recovery liquid

Examples

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Effect test

Embodiment 1

[0043] The present embodiment adopts the following method to purify the liquid to be recovered from the coagulation bath:

[0044] Add 100ppm decolorizing agent dicyandiamide formaldehyde polymer-polymerized aluminum sulfate (the decolorizing agent shown in corresponding formula (IV) and the inorganic-organic compound that is compounded with aluminum salt in the NMMO coagulation bath to be recovered liquid that mass fraction is 18% Polymer decolorizer), fully stirred for 10min, then added flocculant polyacrylamide 10ppm, removed scum by air flotation to obtain a clear liquid, and then passed the clear liquid into an anion and cation exchange resin for recovery.

Embodiment 2

[0046] The present embodiment adopts the following method to purify the liquid to be recovered from the coagulation bath:

[0047] Add 120ppm decolorizer dicyandiamide formaldehyde resin (decolorizer shown in corresponding formula (IV)) in the coagulation bath to be recovered liquid that mass fraction is 20% NMMO, fully stir 12min, then add flocculant polyferrous sulfate 50ppm and Polyacrylamide 15ppm, remove scum by air flotation to obtain a clear liquid, and then pass the clear liquid into an anion and cation exchange resin for recovery.

Embodiment 3

[0049] The present embodiment adopts the following method to purify the liquid to be recovered from the coagulation bath:

[0050] Add 150ppm decolorizing agent melamine-dicyandiamide-formaldehyde resin (corresponding decolorizing agent shown in formula (III)) to the liquid to be recovered in the coagulation bath of 25% NMMO by mass fraction, fully stir for 15min, then add flocculant polymerization chlorination Iron 60ppm and polyacrylamide 20ppm, scum is removed by air flotation to obtain a clear liquid, and then the clear liquid is passed into an anion and cation exchange resin for recovery.

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Abstract

The invention discloses a purification method of a Lyocell spinning coagulating bath recovery liquid. The method comprises the following steps: adding a decolorizing agent into a coagulating bath to-be-recovered liquid after Lyocell spinning to perform decolorizing treatment, flocculating and clarifying the decolorized solution, and introducing ion exchange resin to recover. According to the purification method provided by the invention, the decolorizing agent with a special structure is adopted to remove the chromophoric substances with high solubility in the coagulating bath to-be-recoveredliquid, and after purification, the change of the conductivity of the to-be-recovered liquid is relatively small, so that the service lifetime of ion exchange resin used in a subsequent recovery stepcan be greatly prolonged, and the purification method is suitable for popularization and application.

Description

technical field [0001] The invention belongs to the technical field of textiles, and in particular relates to a method for purifying the liquid recovered from a Lyocell spinning coagulation bath. Background technique [0002] Lyocell fiber is a fiber made by dissolving cellulose with NMMO as a solvent. Lyocell fiber has the advantages of high strength, high modulus, good affinity to the skin, and can be blended with most fibers, and its manufacture is also non-toxic and non-polluting. [0003] Cellulose forms a mixed solution with high-concentration NMMO at high temperature, and the mixed solution is precipitated in an aqueous spinning bath, wherein the cellulose is precipitated as fiber tow, and the high-concentration NMMO is dissolved in water to form a 10-30% NMMO solution . To ensure the economics of the production process, the NMMO solution at this concentration needs to be recovered and concentrated for reuse. [0004] In the above process, in addition to NMMO being...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F1/56C02F1/20C02F103/30
CPCC02F1/56C02F1/20C02F2103/30
Inventor 郭瑶仙蔡剑孙天琦邢立强孙玉山徐纪刚迟克栋董留涛
Owner CHINESE TEXTILE ACAD
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