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CN-117448570-B - Eutectic extractant and application thereof in extraction and purification of yttrium element

CN117448570BCN 117448570 BCN117448570 BCN 117448570BCN-117448570-B

Abstract

The invention relates to the field of rare earth element separation, and discloses a method for preparing eutectic extractant and extracting and purifying yttrium element, the eutectic extractant prepared by the invention has small water solubility and low viscosity, saponification treatment is not needed in the extraction process, the rare earth element is not required to be diluted by using an organic solvent, the rare earth element extraction capacity is strong, the selectivity is good, the preparation is easy, the efficient green separation and purification of yttrium element without soap and solvent are realized, the generation of soap waste water is avoided, and the separation cost is low.

Inventors

  • SUN XIAOQI
  • NI SHUAINAN
  • GAO YUN
  • Yu Guisu

Assignees

  • 厦门稀土材料研究所

Dates

Publication Date
20260505
Application Date
20220718

Claims (7)

  1. 1. A method for extracting and purifying rare earth elements comprises the steps of mixing a eutectic extractant with a rare earth solution containing yttrium elements, performing multistage extraction, washing and back extraction, obtaining a raffinate phase and a loaded eutectic extractant organic phase after extraction, wherein the raffinate phase is high-purity yttrium elements, and obtaining an easily-extracted rare earth element solution and/or rare earth precipitate through washing and back extraction of the loaded eutectic extractant organic phase; The eutectic extractant comprises a hydrogen bond donor, a hydrogen bond acceptor and a co-extractant; The hydrogen bond donor is selected from one of 2-hexyl capric acid, capric acid and oleic acid; the hydrogen bond acceptor is selected from one of decyl alcohol and dodecyl alcohol; the co-extractant is one of primary amine N1923 and diisooctylamine; the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 1 (1-9); the co-extractant accounts for 10% -30% of the total volume of the hydrogen bond donor and the hydrogen bond acceptor.
  2. 2. The method according to claim 1, wherein the rare earth solution containing yttrium is a leaching solution or an enrichment solution of ionic rare earth ore, a leaching solution of mineral type rare earth ore, a secondary resource leaching solution containing rare earth element; And/or the pH value of the rare earth solution is 1-6.
  3. 3. The method of claim 1, wherein the washing process uses a washing solution that is one or more of deionized water, hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid, citric acid, lactic acid, malic acid, EDTA.
  4. 4. The method according to claim 3, wherein the concentration of hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid, citric acid, lactic acid, malic acid, EDTA is 0.01 mol/L to 2mol/L.
  5. 5. The method according to claim 1, wherein the stripping agent used in the stripping process is one or more of deionized water, ammonium fluoride, ammonium bifluoride, sodium fluoride, sodium oxalate, oxalic acid, hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid, citric acid, lactic acid, malic acid, EDTA.
  6. 6. The method according to claim 5, wherein the concentration of ammonium fluoride, ammonium bifluoride, sodium fluoride, sodium oxalate, oxalic acid, hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid, citric acid, lactic acid, malic acid, EDTA is 0.01 mol/L to 6mol/L.
  7. 7. The method according to claim 1, wherein the volume ratio of the eutectic extractant to the rare earth solution containing yttrium element is 1:10-10:1, and the volume ratio of the washing liquid used for washing or the stripping liquid used for stripping to the eutectic extractant is 1:10-10:1.

Description

Eutectic extractant and application thereof in extraction and purification of yttrium element Technical Field The invention relates to the field of rare earth element separation, in particular to a eutectic extractant and application thereof in extraction and purification of yttrium element. Background The current process for purifying yttrium element mainly adopts a saponified naphthenic acid extraction process. When separating yttrium element by extraction, naphthenic acid needs to be saponified by alkali, such as ammonia water. The process can produce a large amount of saponification wastewater, and has high ammonia nitrogen and salt content and difficult treatment. In addition, the naphthenic acid belongs to byproducts of the petroleum industry, the components are complex, and the naphthenic acid produced by different factories has the problem of large component difference, so that the separation performance is different when the yttrium element is extracted and separated, the process conditions need to be explored again, and the use difficulty is increased. And the saponified naphthenic acid is easy to emulsify after extraction, and the loss is large due to the water solubility, so that fresh naphthenic acid needs to be frequently added to meet the extraction capacity of an organic phase. And the naphthenic acid dissolved in water not only pollutes the water body, but also increases the production cost. Therefore, some novel extractants and extraction processes are used for separation and purification of yttrium element, as in patent document "a method for separating rare earth element" (CN 113430373 a), N-dihydrocarbylaminocarboxylic acid compounds are reported as extractants for separating rare earth element, which can separate and purify yttrium element from mixed rare earth solution. In addition, phenoxyacetic acid extractant CA12 and CA100 are also used for separating and purifying yttrium element. However, the above-mentioned carboxylic acid-based extractant cannot avoid saponification problems, and the phenoxycarboxylic acid extractant such as CA12 and CA100 has an insufficient separation coefficient for yttrium and heavy rare earth elements, and is inevitably extracted by using a volatile and toxic organic solvent as a diluent. Disclosure of Invention In order to solve the technical problems, the invention provides a eutectic extractant which comprises a hydrogen bond donor, a hydrogen bond acceptor and a co-extractant; According to embodiments of the present invention, the hydrogen bond donor includes, but is not limited to, one, two or more of long chain fatty acids and derivatives thereof, drug derivatives such as ibuprofen, gemfibrozil, and the like, long chain dicarboxylic acids, such as 2-hexyldecanoic acid, decanoic acid, oleic acid, laurinediacid, sebacic acid; according to embodiments of the present invention, the hydrogen bond acceptors include, but are not limited to, one, two or more of long chain alcohols, long chain phenols, sulfonic acids, diketones, pyridine carboxylic acid esters, hydroxyquinolines, aldoxime, ketoxime, long chain fatty acids, amides, ibuprofen, gemfibrozil, lecithin, long chain alkyl phosphoric acid, long chain alkyl phosphinic acids, primary amines, tertiary amines, secondary amines, hydrophobic quaternary phosphonium salts, hydrophobic quaternary ammonium salts, tributyl phosphate (TBP), and the like; According to embodiments of the present invention, the co-extractant includes, but is not limited to, one, two or more of primary amines (such as primary amine N1923, dodecyl amine, etc.), secondary amines (di-N-hexylamine, di-N-octylamine, di-iso-octylamine, etc.), tertiary amines (N235, trioctylamine, tri (dodecyl) amine, etc.), lidocaine, 1, 8-bis-dimethylaminonaphthalene, etc. According to an embodiment of the invention, the molar ratio of hydrogen bond donor to hydrogen bond acceptor is 1 (0.1-20), for example 1 (0.5-10), exemplary 1:1, 1:2, 1:3, 1:4, 1:5, 1:9; According to an embodiment of the invention, the co-extractant comprises 1% to 100%, for example 5% to 50%, 10% to 30%, and illustratively 20% of the total volume of the hydrogen bond donor and hydrogen bond acceptor. The invention also provides a preparation method of the eutectic extractant, which comprises the following steps of mixing the hydrogen bond donor, the hydrogen bond acceptor and the co-extractant to obtain the eutectic extractant, preferably mixing the hydrogen bond donor and the hydrogen bond acceptor to obtain a eutectic mixture, and then mixing the eutectic mixture with the co-extractant to activate to obtain the eutectic extractant; according to embodiments of the present invention, the means of activation include, but are not limited to, one, two or more of direct mixing, warming, mechanical agitation, mechanical milling, ultrasound, microwaves, ultraviolet irradiation radiation, and the like. The invention also provides application of the eutectic extractant in extraction and pur