A recovery process of cation exchange resin in nmmo solvent recovery process in lyocell fiber production

Abstract

The invention provides a recovering technology of cation exchange resin in a solvent recovery process. The recovering technology comprises recovery of cation exchange resin. The cation exchange resin is recovered by the aid of a cation exchange resin recovery solution; the concentration of sodium hydroxide in the recovery solution is 2%-3%. The recovery technology is an innovation and is simple to operate and extremely low in use cost, and equipment investment is avoided; the replacement of cation resin (10 m<3>) costs about 190,000 yuan each time while recovery costs about 8,000 yuan. The safety performance is high during usage and the resin and operation safety of workers cannot be damaged; adverse effects caused by change of the original structure of equipment on a cation bed can be avoided. The service life of the resin recovered with the method is long; the treatment capacity of new cation exchange resin (10 m<3>) can reach 65,000 m<3>.

Description

technical field [0001] The present invention relates to a recovery process of anion-cation exchange resin, in particular to a recovery process of cation exchange resin in the NMMO solvent recovery process in Lyocell fiber production. Background technique [0002] In the production of Lyocell fiber, the solvent (NMMO) needs to be purified and recovered. Anion and cation exchange resins are used for solvent purification. Anion and cation exchange resins will be polluted or poisoned after a long period of operation. Anion and cation exchange resins are mainly affected by the recovery of iron in solvents, etc. High-valent metal ions and various high-molecular organic substances generate intolerant deposits and deposit into the resin, blocking the ion exchange channel, thus affecting the normal ion exchange process of the resin. The specific performance is that the color of the resin becomes darker and the volume expands; Prolongation, difficulty in regeneration operation; increa...

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Problems solved by technology

[0005] 1. Ion exchange resin will be polluted or poisoned after long-term use;

[0006] 2. In the prior art, after long-term use of the ion exchange resin, high-valent metal ions and various high-molecular organic matter generate intolerant deposits and deposit inside the resin, blocking the ion exchange channel and reducing the purification and recovery effect of the resin;

[0007] 3. As the ion exchange resin is used for a long time, the color of the resin will become darker and the volume will expand; the washing time will be prolonged, the conductivity will increase, and the regeneration operation will be difficult;

[0008] 4. The cost of replacing a new ion exchange resin is relatively high, which increases production costs

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