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CN-122011254-A - Chelate resin for removing calcium and magnesium ions with high selectivity and preparation method thereof

CN122011254ACN 122011254 ACN122011254 ACN 122011254ACN-122011254-A

Abstract

The application belongs to the field of chelating resin materials, and in particular relates to a chelating resin for removing calcium and magnesium ions with high selectivity and a preparation method thereof. The raw materials of the chelate resin for removing calcium and magnesium ions with high selectivity comprise carrier resin, chloromethylation agent, methylolation agent, catalyst, first chelate base, second chelate base and composite functional agent. The chelate resin for removing calcium and magnesium ions with high selectivity is used for removing calcium and magnesium ions with high selectivity, the concentration of calcium and magnesium ions of the treated product is reduced to below 0.5ppm, the whole long-term stability and mechanical properties are more excellent, and the higher performance requirements of the prior art on the chelate resin are fully met.

Inventors

  • LIN GUANGYUE
  • LIN XIONGSHUI
  • CHANG KAI

Assignees

  • 同舟纵横（厦门）流体技术有限公司

Dates

Publication Date
20260512
Application Date
20260306

Claims (10)

  1. 1. The chelate resin for removing calcium and magnesium ions with high selectivity is characterized by comprising, by mass, 90-120 parts of carrier resin, 100-130 parts of chloromethylating agent, 10-20 parts of methylol agent, 10-15 parts of catalyst, 20-35 parts of first chelate base, 15-25 parts of second chelate base and 6.5-12.5 parts of composite functional agent, wherein the chloromethylating agent is chloromethyl trimethylsilane, the methylol agent is paraformaldehyde, the first chelate base is iminodiacetic acid, the second chelate base is 2-phosphonobutane-1, 2, 4-tricarboxylic acid, and the composite functional agent is a composition of polyepoxysuccinic acid and polyvinylpyrrolidone, and the mass ratio of the composite functional agent is (4-6) and (2-3).
  2. 2. The chelating resin for high-selectivity removal of calcium and magnesium ions according to claim 1, wherein the mass ratio of the carrier resin to the chloromethylating agent to the methylolating agent is (10-11.5): (11-12): (1.2-1.6).
  3. 3. The chelate resin for removing calcium and magnesium ions with high selectivity according to claim 2 is characterized by comprising the following steps of S1, adding styrene, a cross-linking agent, an initiator and a pore-forming agent into a reaction kettle, mixing and stirring uniformly to obtain an oil phase, S2, adding deionized water and a dispersing agent into another reaction kettle, heating to 50-55 ℃ and stirring for 5-10 min to obtain a water phase, mixing the water phase and the oil phase, mixing and stirring for 10-15 min at 300-400 rpm, heating to 75-78 ℃ and preserving heat for 4-4.5 h, heating to 82-85 ℃ and reacting for 5-6 h, finally curing for 2-3 h at 90-92 ℃, cooling to room temperature after curing is completed, filtering to obtain a product, washing deionized water and absolute ethyl alcohol for 2-3 times respectively, and drying in vacuum to constant weight to obtain the spherical carrier resin.
  4. 4. The chelating resin for removing calcium and magnesium ions with high selectivity according to claim 3, wherein the mass ratio of the styrene, the cross-linking agent, the initiator, the pore-forming agent and the dispersing agent is (75-85): 20-25): 0.8-1.1): 40-50): 1-2.
  5. 5. The chelating resin for high selectivity removal of calcium and magnesium ions according to claim 4, wherein said crosslinking agent is divinylbenzene and/or trivinylbenzene.
  6. 6. The high selectivity calcium magnesium ion removing chelating resin according to claim 5, wherein said porogen is at least one of n-heptane, toluene and n-octanol.
  7. 7. The chelating resin with high selectivity for calcium and magnesium ion removal according to claim 6, wherein said dispersing agent is at least one of gelatin, polyvinyl alcohol and hydroxyethyl cellulose.
  8. 8. The high selectivity calcium magnesium ion removing chelating resin according to claim 7, wherein said catalyst is at least one of anhydrous aluminum trichloride, zinc chloride and tin tetrachloride.
  9. 9. The chelating resin for high selectivity removal of calcium and magnesium ions according to claim 8, wherein said first chelating group is iminodiacetic acid and said second chelating group is 2-phosphonobutane-1, 2, 4-tricarboxylic acid.
  10. 10. A preparation method of the chelate resin for removing calcium and magnesium ions with high selectivity is characterized by comprising the steps of S1, putting carrier resin into a reaction container with a stirring and condensing reflux device, adding chloromethylation agent, stirring and swelling at room temperature, adding catalyst three times, heating and stirring to fully wash and dry to obtain chloromethylation resin, S2, mixing the chloromethylation resin with a first chelate base, adding alkali liquor, stirring, heating and keeping the reaction, finishing the reaction, filtering out the resin to obtain intermediate resin, S3, adding intermediate resin, a second chelate base and hydroxymethyl agent into a polytetrafluoroethylene reaction kettle, adding acid liquor to react with deionized water, repeatedly washing, S4, adding deionized water into a compound functional agent, stirring and uniformly mixing to obtain a mixed solution, immersing the resin obtained in the mixed solution, fully adsorbing and loading, filtering out the resin, draining, loading the resin into a glass column, soaking and rotating, vacuum drying and screening to obtain particles with the particle size ranging from 0.6 mm to 1.2 mm, and obtaining the chelate resin with high selectivity for removing calcium and magnesium ions.

Description

Chelate resin for removing calcium and magnesium ions with high selectivity and preparation method thereof Technical Field The application belongs to the field of chelating resin materials, and in particular relates to a chelating resin for removing calcium and magnesium ions with high selectivity and a preparation method thereof. Background In the zero discharge and recycling treatment process of high-salt sewage, in order to realize salt recovery and recycling, the high-salt wastewater after biochemical treatment and membrane concentration is usually subjected to salt separation treatment to separate valuable components such as magnesium sulfate, sodium sulfate and the like. The salt solution obtained after salt separation still contains a certain concentration of calcium and magnesium ions, and the existence of the divalent metal ions can cause adverse effects on the subsequent bipolar membrane treatment and other processes, such as membrane pollution, product purity reduction and stable operation of a system. Therefore, the concentration of calcium and magnesium ions must be tightly controlled to a low level, typically less than 0.5ppm, prior to entering the bipolar membrane process. Chelating resin adsorption is often used in the prior art to deeply remove calcium and magnesium ions in wastewater. The chelate resin has high selectivity and adsorption capacity because the functional group can form stable coordination bond with metal ions, and is suitable for removing low-concentration heavy metal ions. In practical engineering applications, chelating resins are usually packed in fixed bed adsorption columns, and a salt solution containing calcium and magnesium ions is caused to flow through the resin layer, so that ion interception is realized through ion exchange and coordination. After the resin is adsorbed and saturated, the resin can be regenerated by means of acid washing and the like to recover the adsorption performance, so that the recycling is realized. However, in high salt systems, particularly complex solutions where sodium sulfate and magnesium sulfate coexist, the existing chelating resins still face several technical problems in practical operation. On one hand, the selectivity of the resin to calcium and magnesium ions is still to be improved, monovalent cations such as sodium ions with high concentration compete with calcium and magnesium ions to adsorb sites, the adsorption efficiency and the deep removal effect of the resin to target ions are affected, and on the other hand, the regeneration performance and the service life of the resin are also affected by a high-salt environment and frequent regeneration operation, so that loss of functional groups or structural degradation can be caused, the treatment effect is unstable, and the running cost is increased. In addition, the dynamic adsorption performance and mechanical strength of the resin also need to be further optimized to meet the requirements of continuous and efficient engineering application. Disclosure of Invention In summary, developing a chelating resin with excellent selectivity and stability under high-salt environment is of great significance in promoting the overall efficiency improvement of high-salt wastewater recycling technology. The chelating resin for removing calcium and magnesium ions with high selectivity provided by the application is used for removing calcium and magnesium ions with high selectivity, the concentration of calcium and magnesium ions of the treated product is reduced to below 0.5ppm, the whole long-term stability and mechanical properties are more excellent, and the higher performance requirements of the prior art on the chelating resin are fully met. The application provides a chelate resin for removing calcium and magnesium ions with high selectivity, which comprises, by mass, 90-120 parts of a carrier resin, 100-130 parts of a chloromethylating agent, 10-20 parts of a methylol agent, 10-15 parts of a catalyst, 20-35 parts of a first chelate base, 15-25 parts of a second chelate base and 6.5-12.5 parts of a composite functional agent, wherein the chloromethylating agent is chloromethyl trimethylsilane, the methylol agent is paraformaldehyde, and the composite functional agent is a composition of polyepoxysuccinic acid and polyvinylpyrrolidone, and the mass ratio of the composite functional agent is (4-6) to (2-3). Preferably, the mass ratio of the carrier resin to the chloromethylating agent to the methylolating agent is (10-11.5): 11-12): 1.2-1.6. Preferably, the mass ratio of the carrier resin to the chloromethylating agent to the methylolating agent is (10-10.5): 11-11.5): 1.2-1.4. The preparation method of the carrier resin specifically comprises the following steps of S1, adding styrene, a cross-linking agent, an initiator and a pore-forming agent into a reaction kettle, mixing and stirring uniformly to obtain an oil phase, S2, adding deionized water and a dispersing agent into another r