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CN-117960126-B - Short-chain molecular brush modified activated carbon and preparation method and application thereof

CN117960126BCN 117960126 BCN117960126 BCN 117960126BCN-117960126-B

Abstract

The invention provides a short-chain molecular brush modified activated carbon, and a preparation method and application thereof, wherein the preparation method comprises the following steps of mixing the activated carbon with an acid solution, and then sequentially carrying out standing, solid-liquid separation and activation to obtain the acid modified activated carbon; mixing silane coupling agent, solvent and the acid modified activated carbon, regulating pH, performing first reaction to obtain intermediate product, mixing short-chain molecular brush, initiator, solvent and intermediate product, and performing second reaction to obtain the short-chain molecular brush modified activated carbon. The prepared short-chain molecular brush modified activated carbon not only can be used for efficiently separating and recovering rare earth elements, but also has good stability, recycling property and good economical efficiency, and the pH value of the used adsorption environment is matched with that of actual low-concentration rare earth element industrial wastewater.

Inventors

  • JU PEIHAI
  • ZHANG TIANCI
  • SHI SHAOYUAN
  • YUAN WENJING
  • ZHENG ZHI
  • SUN JIAXUAN
  • ZHOU CHENLIANG

Assignees

  • 中国科学院赣江创新研究院

Dates

Publication Date
20260505
Application Date
20240320

Claims (20)

  1. 1. The preparation method of the short-chain molecular brush modified activated carbon is characterized by comprising the following steps of: (1) Mixing the activated carbon with an acid solution, and then sequentially carrying out standing, solid-liquid separation and activation to obtain acid modified activated carbon; (2) Mixing a silane coupling agent, a solvent and the acid modified activated carbon in the step (1), then adjusting the pH, and then performing a first reaction to obtain an intermediate product; (3) Mixing a short-chain molecular brush, an initiator, a solvent and the intermediate product in the step (2), and then performing a second reaction to obtain the short-chain molecular brush modified activated carbon; the silane coupling agent in the step (2) comprises a vinyl silane coupling agent; The short chain molecular brush of step (3) comprises vinyl phosphoric acid and/or cis-propenyl phosphoric acid.
  2. 2. The method of claim 1, wherein the acid solution of step (1) comprises any one or a combination of at least two of nitric acid, hydrochloric acid, or sulfuric acid.
  3. 3. The method according to claim 1, wherein the volume ratio of the activated carbon to the acid solution in the step (1) is (0.2-1): 1.
  4. 4. The method according to claim 1, wherein the time of the standing in the step (1) is 6 to 48 hours.
  5. 5. The method of claim 1, wherein the activation in step (1) is carried out at a temperature of 500-1000 ℃.
  6. 6. The method according to claim 5, wherein the activation in step (1) is carried out at a temperature of 500 to 700 ℃.
  7. 7. The method according to claim 1, wherein after the solid-liquid separation in step (1), washing and drying are sequentially performed before the activation.
  8. 8. The method according to claim 1, wherein in the step (2), the silane coupling agent is added in an amount of 0.5 to 15% by volume of the solvent.
  9. 9. The method according to claim 1, wherein in the step (2), the volume ratio of the acid-modified activated carbon to the solvent is (0.05-1): 1.
  10. 10. The method of claim 1, wherein the mixing in step (2) is specifically carried out by adding the acid-modified activated carbon to a solvent, followed by dispersing, and then adding a silane coupling agent thereto.
  11. 11. The method of claim 10, wherein the dispersing means comprises ultrasound.
  12. 12. The method of claim 10, wherein the dispersing time is 1-20min.
  13. 13. The method of claim 1, wherein the pH is adjusted to 3-6 in step (2).
  14. 14. The method of claim 13, wherein the pH is adjusted to 3-5 in step (2).
  15. 15. The process of claim 1, wherein the temperature of the first reaction in step (2) is 25-85 ℃.
  16. 16. The method of claim 1, wherein the first reaction in step (2) is performed for a period of 1 to 14 hours.
  17. 17. The method according to claim 1, wherein the first reaction in the step (2) further comprises washing and drying in sequence.
  18. 18. The method of claim 1, wherein the initiator of step (3) comprises dibenzoyl peroxide.
  19. 19. The method according to claim 1, wherein the mass-to-volume ratio of the intermediate product and the short-chain molecular brush in the step (3) is (0.2-1): 1g/mL.
  20. 20. The method of claim 19, wherein the mass to volume ratio of the intermediate product of step (3) to the short chain molecular brush is (0.3-1) 1g/mL.

Description

Short-chain molecular brush modified activated carbon and preparation method and application thereof Technical Field The invention belongs to the field of rare earth element recovery, relates to a short-chain molecular brush material, and in particular relates to a short-chain molecular brush modified activated carbon, and a preparation method and application thereof. Background Rare earth elements are an important strategic mineral resource and are widely applied to the high-tech fields such as electronics, instruments, optical and magnetic materials and the like. The unique electronic structure of the rare earth alloy endows rare earth elements with special chemical and physical properties, so that the rare earth alloy has irreplaceable functions in material science and engineering. The existence of rare earth ions in the water environment is mainly from the exploitation and smelting processes of the rare earth ores, and the release of the rare earth ions has a certain threat to the quality of the water environment due to certain toxicity and bioavailability to the environment. Therefore, the recovery of rare earth ions has important significance in protecting water environment and realizing sustainable development. Currently, various technical methods such as chemical precipitation, ion exchange, electrochemical methods, and adsorption materials have been used for recovery of rare earth ions. CN108893625A discloses a process for preparing high purity lanthanum by extraction method, said process uses 3N industrial grade lanthanum chloride aqueous solution as feed liquid, P204-TBP as composite extractant, and uses fractional extraction separation NaMgCaBaPbZn/La, fractional extraction separation La/CEPRNDALSMFE, and back extraction section 1 and back extraction section 2, through the implementation of said process, separation of lanthanum and metal elements of cerium, praseodymium, neodymium, samarium, iron, aluminium, zinc, lead, barium, calcium, magnesium and sodium can be smoothly implemented, the relative purity of high purity lanthanum chloride solution is higher, but the extraction flow is complex, and cost is higher. CN105861831a discloses a method for recovering rare earth from rare earth salt solution by precipitation, which comprises the steps of adding a precipitant containing calcium and/or magnesium alkaline compound and an ammonium-containing solution into the rare earth salt solution, carrying out mixed precipitation reaction, wherein the dosage of the precipitant is 101-130% of the theoretical dosage of rare earth in the precipitated rare earth salt solution, the precipitant is solid or water slurry, then carrying out solid-liquid separation after rare earth precipitation to obtain rare earth precipitate and precipitation mother liquor, and calcining the rare earth precipitate to obtain rare earth oxide. The method adopts the calcium and/or magnesium alkaline compound precipitants which are cheap and easy to obtain, the preparation process is simple and controllable, the ammonium substance dosage is greatly reduced, and the ammonia nitrogen pollution is reduced. However, the method adopts a chemical reaction mode to precipitate and enrich rare earth elements, chemical substances are inevitably introduced in the process, and precipitation waste liquid is generated. CN114807601a discloses a method for adsorbing rare earth lanthanum by using phosphoric acid modified kaolin, the method comprises mixing kaolin raw material and modifier, ball milling, washing and drying in sequence to obtain the phosphoric acid modified kaolin, then desorbing the material for recycling, but the material has obvious structural instability under the conditions of high salt and high acid, and the practical application is poor. In the prior art, there are few researches on a process method for efficiently extracting rare earth elements. In addition, in a high-salt high-acid solution system in the actual wastewater, the adsorption effect of the conventional material on low-concentration rare earth elements in the high-salt high-acid wastewater is obviously reduced due to the influence of coexisting ions. Therefore, developing a material for efficiently recovering rare earth elements and a preparation method thereof is a problem to be solved by those skilled in the art. Disclosure of Invention The invention aims to provide a short-chain molecular brush modified activated carbon, a preparation method and application thereof, and the prepared short-chain molecular brush modified activated carbon not only can efficiently recycle rare earth elements, but also can selectively adsorb low-concentration rare earth elements in a high-salt high-acid solution, and an adsorption material can be reused. In order to achieve the aim of the invention, the invention adopts the following technical scheme: in a first aspect, the invention provides a method for preparing a short-chain molecular brush modified activated carbon, which compr