A two-component synergistic organic phosphorus (phosphonic) acid extractant and its preparation method and application

Abstract

The invention discloses a two-component synergistic novel organic phosphorus (phosphonic acid) extractant and its preparation method and application, belonging to the field of material preparation and separation technology. The present invention selects lauric acid, thymol, and DL-menthol as oxygen-containing hydrogen bond acceptors; organic phosphorus (phosphonic acid) substances Cyanex272, P204, and P507 as hydrogen bond donors, and develops a novel preparation method of a two-component synergistic organic phosphorus (phosphonic acid) rare earth separation extractant regulated by oxygen-containing hydrogen bond acceptors. After mixing the oxygen-containing hydrogen bond acceptor and the hydrogen bond donor according to the ratio, a two-component synergistic phosphorus (phosphonic acid) rare earth separation extractant is obtained through a one-step reaction. The two-component synergistic phosphorus (phosphonic acid) extractant prepared by the present invention has the advantages of good extraction and separation effect, simple operation, easy preparation, non-volatile, green and environmentally friendly, and can be recycled for many times, and has outstanding performance in the research work of separating rare earth ions by solvent extraction.

Description

Technical Field

[0001] The invention belongs to the technical field of material preparation and separation, and relates to a two-component synergistic organic phosphorus (phosphonic) acid extractant, a preparation method and application thereof, and in particular to a two-component synergistic organic phosphorus (phosphonic) acid extractant regulated by an oxygen-containing hydrogen bond receptor, a preparation method thereof and application thereof in solvent extraction separation. Background Art

[0002] Rare earth separation methods mainly include: chemical separation, solvent extraction, adsorption separation, ion exchange and membrane separation. Among them, solvent extraction, as a technology for recovering and enriching rare earth elements, has simple equipment, convenient operation and large processing capacity. The solvent extraction process is to separate and enrich a certain rare earth ion through coordination between the extractant and the rare earth ion, but there are also some problems, such as: incomplete stripping, low selectivity for heavy rare earths, and waste caused by high solubility of the extractant. At present, a convenient and efficient method is still needed to achieve the separation and enrichment of rare earth ions. At the same time, the commonly used extractants for rare earth separation include neutral extractants, acidic extractants, alkaline extractants, etc., but they all involve acid-base reagents and volatile organic solvents, which will cause serious environmental burdens. Therefore, in order to improve the green cleanliness of the process, it is urgent to develop green and efficient rare earth recovery technology.

[0003] Inspired by low eutectic solvents, oxygen-containing hydrogen bond acceptors, such as commonly used organic alcohols, organic phenols and organic acids, are used to regulate the extraction and stripping abilities of hydrogen bond acceptor organic phosphate rare earth extractants. This type of solvent has the advantages of strong designability, simple and green preparation, etc. It has certain research significance in the separation of rare earths in solvent extraction. It can improve the extraction and stripping rates and optimize the separation performance of heavy rare earths. However, at present, based on the idea of ​​synthesizing low eutectic solvents, there is no report on the method of regulating the acidity and coordination and complexing ability of a single organic phosphate rare earth extractant to achieve efficient separation of rare earth ions by utilizing oxygen-containing hydrogen bonds. Therefore, the synthesis concept of this type of green reagent and its application in the separation of rare earth ions have great application potential. Summary of the invention

[0004] In view of some deficiencies in the prior art, the present invention provides a two-component synergistic organic phosphorus (phosphonic acid) extractant and a preparation method and application thereof, in particular, the preparation of a two-component synergistic organic phosphorus (phosphonic acid) extractant regulated by an oxygen-containing hydrogen bond receptor and its application in rare earth separation. The present invention selects a variety of oxygen-containing hydrogen bond receptors and organic phosphorus (phosphonic acid) extractants with high selectivity for rare earth ions as hydrogen bond donors, prepares a variety of two-component synergistic novel organic phosphorus (phosphonic acid) separation extractants regulated by oxygen-containing hydrogen bond receptors, and achieves the effect of separating rare earth ions through solvent extraction.

[0005] In order to achieve the above technical objectives, the present invention provides the following technical solutions:

[0006] The invention provides a two-component synergistic organic phosphorus (phosphonic) acid extractant regulated by an oxygen-containing hydrogen bond acceptor. The extractant comprises an oxygen-containing hydrogen bond acceptor and a hydrogen bond donor, wherein the oxygen-containing hydrogen bond acceptor comprises lauric acid, thymol or DL-menthol; and the hydrogen bond donor is an organic phosphorus (phosphonic) acid ester structure substance.

[0007] Furthermore, the organic phosphorus (phosphonic) ester structure substance includes bis (2-ethylhexyl) phosphate (P204), 2-ethylhexyl phosphate mono-2-ethylhexyl ester (P507) or di (2,4,4-trimethylpentyl) phosphonic acid (Cyanex272).

[0008] The present invention also provides a method for preparing the two-component synergistic organic phosphorus (phosphonic) acid extractant regulated by the oxygen-containing hydrogen bond receptor, the method comprising the following steps:

[0009] The oxygen-containing hydrogen bond acceptor and the hydrogen bond donor are mixed in a certain molar ratio, and reacted at a certain temperature for a period of time until a uniform transparent liquid is formed, thereby obtaining a two-component synergistic organic phosphorus (phosphonic) acid extractant.

[0010] Furthermore, the molar ratio of the oxygen-containing hydrogen bond acceptor to the hydrogen bond donor is 1:1-3.

[0011] Furthermore, the oxygen-containing hydrogen bond acceptor includes lauric acid, thymol or DL-menthol; the organic phosphorus (phosphonic) ester structure substance includes bis (2-ethylhexyl) phosphate (P204), 2-ethylhexyl phosphate mono-2-ethylhexyl ester (P507) or di (2,4,4-trimethylpentyl) phosphonic acid (Cyanex272).

[0012] Furthermore, the temperature is 60°C-120°C.

[0013] Furthermore, the reaction time is 2-24h.

[0014] The present invention also provides the use of the two-component synergistic organic phosphorus (phosphonic acid) extractant or the two-component synergistic organic phosphorus (phosphonic acid) extractant prepared by the preparation method in rare earth separation, including the use in the efficient separation of adjacent heavy rare earth ions.

[0015] Furthermore, the rare earth ions include: Nd 3+ 、Sm 3+ or Dy 3+ .

[0016] The extraction agent obtained by the present invention is also verified by extraction in the present invention:

[0017] Including the extraction and stripping experiments of rare earth ions using two-component synergistic organic phosphoric acid extractants:

[0018] A fixed volume of extractant was placed in a 10 mL centrifuge tube, and then an equal volume of rare earth stock solution was taken as the aqueous phase and placed in a centrifuge tube for mixing. At the required temperature, it was placed in a constant temperature water bath oscillator. After standing for phase separation, a certain volume of aqueous phase was taken to analyze the rare earth ion concentration. -1 -4.0mol L -1 Hydrochloric acid is used as the stripping solution to regenerate the organic phase loaded with rare earth ions. The solution is shaken in a water bath until equilibrium is reached, and then centrifuged to separate the phases, and the rare earth concentration in the aqueous phase is analyzed.

[0019] In addition, a cyclic experiment of solvent extraction of rare earth ions using a two-component synergistic organic phosphoric acid extractant was also verified:

[0020] After the first extraction, the organic phase loaded with rare earth ions is stripped multiple times, with a certain concentration of HCl solution as the stripping solution. After the first stripping, the extractant needs to be regenerated by using a certain concentration of hydrochloric acid to elute the uncompletely stripped loaded rare earth ions repeatedly 1-3 times, and then washed with deionized water 1-3 times until the acidity of the aqueous phase reaches neutral, and then the second extraction is carried out.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention is the first to use lauric acid, thymol or DL-menthol as oxygen-containing hydrogen bond acceptors and rare earth ion efficient extractants P204, P507 or Cyanex 272 as hydrogen bond donors to prepare a two-component synergistic organic phosphorus (phosphonic) acid rare earth separation extractant.

[0023] (2) Considering the optimal effects of extraction and stripping performance, lauric acid + P204 has an extraction rate of 99.6% and a stripping efficiency of 77.2% among the nine two-component synergistic extractants. At the same time, compared with the performance of rare earth separation of single lauric acid and P204, at the same initial acidity (pH = 1.0), the extraction rate of the two-component synergistic extractant is increased by 97% compared with P204; at the same extraction concentration (0.001 mol L -1 ), the extraction rate of the two-component synergistic extractant was increased by 39% compared with P204. It was proved that the solvent extraction performance of the two-component synergistic novel organic phosphorus (phosphonic) acid rare earth separation extractant was improved under the action of the hydrogen bond acceptor of organic acid.

[0024] (3) The two-component synergistic organic phosphorus (phosphonic acid) acid extractant regulated by oxygen-containing hydrogen bond receptors has the strongest extraction ability for rare earth elements and is much higher than that of a single organic phosphorus (phosphonic acid) ester material extractant, and has excellent separation performance. The separation coefficient of the two-component synergistic extractant for neodymium (Nd) and samarium (Sm) is β (Sm / Nd) = 1.68, and the separation coefficient for neodymium (Nd) and dysprosium (Dy) is β (Dy / Nd) = 1.85. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the infrared spectra of lauric acid, P204 and two-component synergistic organic phosphorus (phosphonic) acid extractant.

[0026] Figure 2 The hydrogen nuclear magnetic resonance spectrum (a) and carbon nuclear magnetic resonance spectrum (b) of lauric acid, P204 and two-component synergistic organic phosphorus (phosphonic) acid extractant.

[0027] Figure 3 The effects of different extractants on Nd in aqueous phase 3+ The extraction rate and stripping rate are as follows: 1: lauric acid + Cyanex272; 2: lauric acid + P507; 3: lauric acid + P204; 4: DL-menthol + Cyanex272; 5: DL-menthol + P507; 6: DL-menthol + P204; 7: thymol + Cyanex272; 8: thymol + P507; 9: thymol + P204.

[0028] Figure 4 Figure 2 shows the effects of lauric acid, P204 and two-component organic phosphorus (phosphonic) acid extractants on Nd under different aqueous phase acidity (left) and extractant concentration (right) conditions. 3+ Extraction and separation effect diagram.

[0029] Figure 5 Nd under different HCl concentration conditions 3+ Stripping efficiency diagram.

[0030] Figure 6 Cyclic performance diagram of two-component synergistic organic phosphorus (phosphonic) acid extractant, where 1-6 represent the number of cycles respectively. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred embodiments of the present invention are described in detail below, but the following embodiments do not limit the protection scope of the present invention.

[0032] In the embodiments of the present invention, those that are not described in detail are all completed by conventional experimental methods, and those processes involved in the embodiments that are not described in detail are all understandable and easily implementable by those skilled in the art based on the product instructions or basic knowledge in the field, and therefore are not described in detail again.

[0033] In the embodiment of the present invention, the rare earth oxide is obtained by dissolving in hydrochloric acid and removing the acid, and is prepared to a concentration of 0.01 mol L -1The specific method of preparing the rare earth stock solution is as follows: weigh rare earth oxide (Nd2O3, Sm2O3 or Dy2O3) and dissolve it in dilute hydrochloric acid, and heat it in an oil bath at 80°C until the solution is clear and transparent. Then, raise the temperature to 140°C and heat to drive out the acid until rare earth chloride crystals appear in the bottle, and then cool it to room temperature and make up the volume.

[0034] In the embodiment of the present invention, the concentration of rare earth ions is measured by measuring the ultraviolet absorbance of the solution, and the specific method is as follows: 0.2 mL of the corresponding rare earth solution is transferred into a 25 mL volumetric flask, a drop of 0.1 wt.% thymol blue indicator is added, and 3 mL of chloroacetic acid-sodium hydroxide buffer solution and 1 mL of 0.1 wt.% arsenazo (III) color developer are added to make up the volume. After color development for 15 minutes, the concentration is measured by an ultraviolet spectrophotometer at a wavelength of 654 nm.

[0035] In the embodiment of the present invention, the following method is used to examine the relevant solvent extraction and separation performance of the extractant, and the specific method is: prepare a two-component synergistic organic phosphorus (phosphonic) acid extractant solution of the required concentration with n-heptane, transfer 4mL into a small centrifuge tube, and then take an equal volume of rare earth solution as the aqueous phase and mix it in a small centrifuge tube. At room temperature, place it in a constant temperature water bath oscillator and oscillate for 1 hour. After standing for phase separation, take the aqueous phase to analyze the rare earth ion concentration, and calculate the rare earth ion concentration extracted in the organic phase by subtraction. The organic back-extraction experiment uses a certain concentration of hydrochloric acid as the stripping solution to regenerate the organic phase loaded with rare earth ions. The water bath is shaken to equilibrium, centrifuged for phase separation, and the rare earth concentration of the aqueous phase is analyzed.

[0036] The calculation formulas for distribution ratio D, extraction rate E% and separation coefficient β are as follows:

[0037]

[0038] Where RE stands for rare earth ions, and the subscripts i, a, o, and e represent the initial concentration, aqueous phase concentration, organic phase concentration, and equilibrium concentration, respectively. (e,o) represents the rare earth concentration in the organic phase after extraction equilibrium, which is obtained by subtracting the rare earth ion concentration in the aqueous phase after equilibrium from the initial rare earth concentration in the aqueous phase; RE (e,a) is the rare earth concentration in the aqueous phase after extraction equilibrium, RE (i,a) is the initial concentration of rare earth ions in the aqueous phase before extraction, D (RE)1 and D (RE)2 The ratio is the separation coefficient, (RE)1 and (RE)2 represent two different rare earth ions respectively.

[0039] Embodiment 1:

[0040] A series of two-component synergistic organic phosphorus (phosphonic) acid extractant solutions were prepared, using lauric acid as an oxygen-containing hydrogen bond acceptor and different organic phosphorus (phosphonic) acid ester structure substances as hydrogen bond donors.

[0041] The different organic phosphorus (phosphonic) ester substances are: P204, P507 or Cyanex272.

[0042] When the molar ratio of lauric acid to the three organic phosphorus (phosphonic) esters was set to 1:2 or 1:3, the reactants were mixed and placed in a round-bottom flask, and reacted at 80°C for 12 hours to form a uniform transparent liquid. After the mixture was cooled to room temperature, it was placed in a vacuum drying oven to remove the residual moisture inside and sealed. When the molar ratio of lauric acid to the three organic phosphorus (phosphonic) esters was set to 1:1, it was found that whether it was P204, P507 or Cyanex272, the two-component synergistic organic phosphorus (phosphonic) acid extractant formed was unstable and easy to crystallize after being cooled to room temperature and stored.

[0043] Figure 1 The infrared spectra of lauric acid, P204 and two-component synergistic organic phosphorus (phosphonic) acid extractant are shown in Figure 1. As can be seen from the figure, after the two-component organic phosphorus (phosphonic) acid extractant is formed, the characteristic peak of P204 is blue-shifted to 1163cm -1 and 1033cm -1 The C=O of lauric acid blue shifts to 1710 cm -1 This indicates that the formation of the two-component synergistic organic phosphorus (phosphonic) acid extractant may be related to the formation of hydrogen bonds between the above functional groups.

[0044] In the two-component synergistic organic phosphorus (phosphonic acid) extractant extraction experiment, when the two-component synergistic organic phosphorus (phosphonic acid) extractant was used to extract Nd 3+ After that, the P=O double bond stretching vibration peak shifted to 1171cm -1 At 1028 cm, P-OH splits -1 and 1066cm -1 The two peaks prove that both P=O and P-OH participate in the two-component synergistic organic phosphorus (phosphonic) acid extraction of Nd 3+ reaction.

[0045] Figure 2 The H NMR spectra (a) and C NMR spectra (b) of lauric acid, P204 and a two-component synergistic organic phosphorus (phosphonic acid) acid extractant are shown. The chemical shifts of the corresponding H atoms of the corresponding precursors (lauric acid and P204) can be clearly observed in the organic phosphorus (phosphonic acid) acid extractant, which proves the successful synthesis of the two-component synergistic organic phosphorus (phosphonic acid) acid extractant. In the figure, the left structural formula in Figure a and Figure b represents lauric acid, and the right structural formula represents P204; a, b, c, d and A, B, C, D in Figure a represent H atoms at different positions, and a, b, c in Figure b represent C atoms at different positions.

[0046] Embodiment 2:

[0047] A series of two-component synergistic organic phosphorus (phosphonic acid) acid extractants were prepared with thymol as an oxygen-containing hydrogen bond acceptor and different organic phosphorus (phosphonic acid) ester structure substances as hydrogen bond donors.

[0048] The different organic phosphorus (phosphonic) ester substances are: P204, P507 or Cyanex272.

[0049] The molar ratio of thymol to three kinds of organic phosphorus (phosphonic) acid esters is set to 1:3. After the reactants are mixed, they are placed in a round-bottom flask and reacted at 120°C for 24 hours to form a uniform transparent liquid. After the mixture is cooled to room temperature, it is placed in a vacuum drying oven to dry to remove residual moisture inside and sealed. In the case where the two-component synergistic organic phosphorus (phosphonic) acid extractant formed under other molar ratios is prone to crystallization after cooling to room temperature or during use, the molar ratio of 1:3 is selected as the best in the embodiment.

[0050] Embodiment 3:

[0051] A series of two-component synergistic organic phosphorus (phosphonic) acid extractants were prepared with DL-menthol as an oxygen-containing hydrogen bond acceptor and different organic phosphorus (phosphonic) acid ester structure substances as hydrogen bond donors.

[0052] The different organic phosphorus (phosphonic) ester substances are: P204, P507 or Cyanex272.

[0053] The reactants are mixed and placed in a round-bottom flask, and reacted at 60°C for 2 hours. When the molar ratio of DL-menthol to the organic phosphorus (phosphonic) acid ester is 1:1, 1:2 or 1:3, a stable, uniform, transparent liquid two-component synergistic organic phosphorus (phosphonic) acid extractant can be formed. After the mixture is cooled to room temperature, it is placed in a vacuum drying oven to dry to remove residual moisture inside, and then sealed.

[0054] Embodiment 4:

[0055] From the perspective of saving the amount of organic phosphorus (phosphonic) acid ester, taking into account the stability of the synthesized two-component synergistic organic phosphorus (phosphonic) acid extractant and the energy consumption and time consumption of the synthesis conditions, in this embodiment, 9 two-component synergistic organic phosphorus (phosphonic) acid extractants synthesized when the molar ratio of oxygen-containing hydrogen bond acceptor to organic phosphorus (phosphonic) acid ester substance is 1:2 are uniformly selected for comparative study of extraction and back-extraction performance.

[0056] Place 4 mL of 9 two-component synergistic organic phosphorus (phosphonic) acid extractants of the same concentration in a small centrifuge tube and take an equal volume of 0.01 mol L -1NdCl3 solution was placed in a centrifuge tube as the aqueous phase and mixed. It was placed in a constant temperature water bath oscillator at 25°C. After standing for phase separation, 0.2 mL of the aqueous phase was taken to analyze the rare earth ion concentration, and the equilibrium rare earth ion concentration in the organic phase was calculated by subtraction. In the organic back extraction experiment, hydrochloric acid was used as the stripping solution to regenerate the organic phase loaded with rare earth ions. The water bath was shaken to equilibrium, the phases were separated by centrifugation, and the rare earth concentration of the aqueous phase was analyzed.

[0057] Figure 3 The results show that 9 two-component synergistic organic phosphorus (phosphonic) acid extractants can effectively extract Nd in aqueous phase. 3+ The figure shows that under the same aqueous phase and organic phase concentration and extraction conditions, the extractants with P507 and P204 as hydrogen bond donors have good extraction and stripping abilities, while the extraction and stripping abilities of Cyanex272 are weak. The three extractants synthesized with different oxygen-containing hydrogen bond acceptors have good extraction and stripping abilities for Nd 3+ The extraction capacity of the samples (thymol + P204) was similar to that of Nd 3+ With the best separation performance, the extractant can achieve 100% extraction rate and 73% stripping rate at the same time; with lauric acid as the oxygen-containing hydrogen bond acceptor, sample 3 (lauric acid + P204) has the best separation performance for Nd 3+ The extraction solvent has the best separation performance, and can simultaneously achieve an extraction rate of 99.6% and a stripping rate of 77.2%. DL-menthol is used as an oxygen-containing hydrogen bond acceptor, and the sample (DL-menthol + P204) has a strong affinity for Nd 3+ With the best separation performance, the extractant can simultaneously achieve 100% extraction rate and 76% stripping rate. In comparison, the stripping efficiency of lauric acid as an oxygen-containing hydrogen bond acceptor is higher. The extractant of sample No. 3 (lauric acid + P204) can simultaneously achieve 99.6% extraction rate and 77.2% stripping rate, and has better extraction and stripping efficiency among the 9 two-component synergistic organic phosphorus (phosphonic) acid extractants.

[0058] Embodiment 5:

[0059] Adjust the water phase (0.01 mol L -1 The effects of lauric acid, P204 and the two-component synergistic organic phosphorus (phosphonic) acid extractant (lauric acid + P204) obtained by the present invention on the extraction of NdCl3 solution as aqueous phase and the concentration of the two-component synergistic organic phosphorus (phosphonic) acid extractant (lauric acid + P204) were studied under different conditions. 3+ The extraction capacity was determined to determine the optimal conditions for the extraction process. The pH was 0.5-3.0 and the concentration of the extractant was 0.0002 mol L -1 -0.0010mol L -1 .

[0060] Figure 4 The results show that lauric acid, P204 and the two-component synergistic organic phosphorus (phosphonic acid) acid extractant (lauric acid + P204) obtained by the present invention have different effects on Nd 3+ The extraction and separation effect diagram. It can be seen from the figure that with the increase of water phase acidity and extractant concentration, P204 and extractant have a greater impact on Nd 3+ The extraction rate of lauric acid to Nd 3+ The extraction capacity of is almost 0, indicating that it does not directly participate in the coordination of rare earth ions, but mainly changes the coordination environment through hydrogen bonding with P204. At the same time, under low pH conditions, the extractant is more effective than P204 for Nd 3+ It has better extraction ability.

[0061] Using the same method, Nd 3+ 、Sm 3+ 、Dy 3+ A comparative analysis of extraction experiments was performed.

[0062] Table 1 shows the extraction distribution ratios of lauric acid + P204 and its precursors single lauric acid and P204 for Nd, Sm, and Dy under the same experimental conditions. Lauric acid has almost no extraction ability for rare earth elements, and the two-component synergistic extractant has the strongest extraction ability for rare earth elements, which is much higher than P204. The extraction order of the three rare earth elements by the three extractants conforms to the extraction law of acidic phosphonic acid extractants, that is, the extraction ability increases from Nd to Dy with the increase of atomic number. After calculation, the separation coefficient β of the two-component synergistic extractant for Nd and Sm is (Sm / Nd) =1.68, separation coefficient β for Nd and Dy (Dy / Nd) =1.85.

[0063] Table 1. Effect of lauric acid, P204 and two-component synergistic organic phosphorus (phosphonic) acid extractants on Nd under the same experimental conditions 3+ 、Sm 3 + 、Dy 3+ The distribution ratio

[0064]

[0065] Embodiment 6:

[0066] Adjust the concentration of HCl to study the effect of Nd 3+ The effect of stripping efficiency. HCl concentration is 0.5 mol L -1 -4.0mol L -1 .

[0067] Figure 5The results show that Nd 3+ Stripping efficiency diagram. It can be seen from the figure that when the HCl concentration is 0.5 mol L -1 When Nd 3+ The stripping efficiency can reach more than 80%, indicating that the two-component synergistic organic phosphorus (phosphonic) acid extractant (lauric acid + P204) has an effective stripping effect on Nd 3+ It has good stripping ability. The stripping acidity continues to increase, and the stripping rate drops significantly. The possible reason is the occurrence of the acid extraction competition reaction of the two components and the new organic phosphorus (phosphonic) acid extractant.

[0068] Embodiment 7:

[0069] The cyclic performance of the two-component synergistic organic phosphorus (phosphonic) acid extractant (lauric acid + P204) was studied by adjusting the deionized water and acid washing several times. -1 Repeat elution with hydrochloric acid and deionized water 1-3 times.

[0070] like Figure 6 The figure is a cycle performance diagram of the two-component synergistic organic phosphorus (phosphonic) acid extractant (lauric acid + P204). After the above extraction-stripping experimental operation was cycled, the extraction rate and stripping efficiency decreased by 9.0% and 5.5% respectively. This may be due to the partial entrainment loss of the organic phase of the extractant during the repeated operation. The results show that the two-component synergistic organic phosphorus (phosphonic) acid extractant (lauric acid + P204) has good cyclic performance.

Claims

1. A two-component synergistic organic phosphorus (phosphonic) acid extractant, characterized in that: The extractant comprises an oxygen-containing hydrogen bond acceptor and a hydrogen bond donor, wherein the oxygen-containing hydrogen bond acceptor comprises lauric acid, thymol or DL-menthol; the hydrogen bond donor is an organic phosphorus (phosphonic) ester structure substance; the organic phosphorus (phosphonic) ester structure substance comprises P204, P507 or Cyanex272.

2. A method for preparing the extractant according to claim 1, characterized in that: The method comprises: The oxygen-containing hydrogen bond acceptor and the hydrogen bond donor are mixed in a certain molar ratio, and reacted at a certain temperature for a period of time until a uniform transparent liquid is formed, thereby obtaining a two-component synergistic organic phosphorus (phosphonic) acid extractant.

3. The method according to claim 2, characterized in that The molar ratio of the oxygen-containing hydrogen bond acceptor to the hydrogen bond donor is 1:1-3.

4. The method according to claim 2, characterized in that: The temperature is 60°C-120°C.

5. The method according to claim 2, characterized in that: The reaction time is 2-24h.

6. Use of the extractant according to claim 1 or the extractant prepared by the method according to any one of claims 2 to 5 in the separation of rare earth ions.

7. The use according to claim 6, characterized in that: The applications include application in the efficient separation of adjacent heavy rare earth ions.

8. The use according to claim 6, characterized in that: Rare earth ions include: Nd 3+ 、Sm 3+ or Dy 3+ .

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