Ionic liquid-liquid phase separation system and application thereof in aspect of separating strontium and yttrium

Abstract

The invention relates to the technical field of separation, in particular to an ionic liquid-liquid phase separation system and application of the ionic liquid-liquid phase separation system to separation of strontium and yttrium. The ionic liquid-liquid phase separation system comprises an anionic surfactant and organic alkali; the octanol-water partition coefficient (log P) of the anionic surfactant and the organic base is greater than or equal to 1.0. The invention provides an ionic liquid-liquid phase separation system and an application thereof in the aspect of separating strontium and yttrium. The separation of strontium and yttrium can be efficiently realized in an environment-friendly manner.

Description

Technical Field

[0001] This application relates to the field of separation technology, and in particular to an ion-type liquid-liquid phase separation system and its application in the separation of strontium and yttrium. Background Technology

[0002] Strontium-90 ( 90 Sr is one of the main fission products in high-level radioactive waste, exhibiting significant biotoxicity and environmental migration capabilities. Its decay product, yttrium-90 (Sr), is... 90 Y) is a pure β - The emitter, with a maximum beta ray energy of 2.28 MeV, has extremely important applications in nuclear medicine fields such as cancer radioimmunotherapy and radioembolization therapy. 90 High-purity Sr was obtained by separation. 90 Y (“Cow” technology) is the means to achieve 90 A key step in ensuring a stable supply of Y.

[0003] Currently, common techniques for separating strontium and yttrium include precipitation, extraction chromatography, and solvent extraction. While precipitation is simple, it is cumbersome, has limited yield, and is prone to introducing impurities. Extraction chromatography reduces organic solvent usage by immobilizing the extractant on a solid support, but suffers from high resin preparation costs, poor irradiation stability, decreased column efficiency, and complex elution processes. Solvent extraction is one of the most mature strontium-yttrium separation processes, with typical extractants including di-(2-ethylhexyl)phosphoric acid (HDEHP), crown ethers, and phosphonates. This method relies on the different affinities of metal ions between the organic and aqueous phases to achieve separation, resulting in a high separation coefficient. However, this technology requires the use of large amounts of volatile organic solvents (such as n-dodecane, kerosene, and xylene) as diluents, posing safety risks such as fire and explosion. Furthermore, solvent evaporation and irradiation degradation generate secondary organic waste, increasing the cost of treating radioactive organic waste and adversely affecting the environment and operational safety. Summary of the Invention

[0004] This application provides an ion-type liquid-liquid phase separation system and its application in the separation of strontium and yttrium, which can achieve the separation of strontium and yttrium efficiently and in an environmentally friendly manner.

[0005] The technical solution of this application is implemented as follows: The first aspect of this application provides an ionic liquid-liquid phase separation system, which includes an anionic surfactant and an organic base; wherein the anionic surfactant and the organic base have an octanol-water partition coefficient (log P) greater than or equal to 1.0.

[0006] In some embodiments, the organic base includes one or more of dodecyl primary amine, benzylamine, n-octylamine, and diphenylethylenediamine.

[0007] In some embodiments, the anionic surfactant includes one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, sodium stearate, and sodium phosphatidyl ester.

[0008] In some embodiments, the molar ratio of the anionic surfactant to the organic base is 1:(0.5~2).

[0009] The second aspect of this application provides the application of the aforementioned ionic liquid-liquid phase separation system in the separation of strontium and yttrium, comprising: mixing anionic surfactant, organic base, and a mixed metal salt solution to obtain a mixed solution; wherein the metal ions in the mixed metal salt solution include strontium ions and yttrium ions, and strontium includes... 84 Sr、 86 Sr、 87 Sr、 88 Sr、 89 Sr and 90 One or more of Sr, including yttrium 89 Y、 90 Y and 86 One or more of Y.

[0010] In some embodiments, the mass concentration ratio of strontium ions to yttrium ions in the mixed metal salt solution is (1~5000):1.

[0011] In some embodiments, the mass concentration of strontium ions in the mixed metal salt solution is 1 mg / L to 100,000 mg / L; and / or, the mass concentration of yttrium ions is 1 mg / L to 100 mg / L.

[0012] In some embodiments, the pH of the mixed solution is 6.5 to 9.

[0013] In some embodiments, the original pH of the mixed metal salt solution is below 6.

[0014] In some embodiments, the method for separating strontium and yttrium includes: mixing an anionic surfactant, an organic base, a mixed metal salt solution with a pH value below 6, and a pH adjuster at 5°C to 55°C to obtain a mixed solution with a pH value of 6.5 to 9; the mass-to-volume ratio of the mixture of the anionic surfactant and the organic base to the mixed metal salt solution is 0.1 g / mL to 0.5 g / mL; wherein the metal ions in the mixed metal salt solution include strontium ions and yttrium ions, and strontium includes... 90 Sr, yttrium includes 90 Y.

[0015] This application has the following beneficial effects: This application provides an ion-type liquid-liquid phase separation system and its application in the separation of strontium and yttrium, which can achieve the separation of strontium and yttrium efficiently and in an environmentally friendly manner. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, this application will be described in further detail below. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] To reduce solvent usage and improve environmental compatibility, researchers have proposed aqueous two-phase systems based on nonionic surfactants or water-soluble polymers for the separation of metal ions. This system utilizes amphiphilic intermolecular interactions to induce liquid-liquid phase separation in a single aqueous phase, thereby achieving the enrichment and distribution of metal ions or organic ligands. Compared to traditional organic extraction methods, aqueous two-phase systems, using water as the primary medium, offer greater safety and environmental friendliness, mitigating the pollution and safety hazards associated with organic solvents to some extent. Therefore, they are considered a more environmentally friendly option for the separation of radioactive metals.

[0018] Although aqueous two-phase systems represent a theoretical advancement from organic extraction to green separation technology, their phase structure is easily disrupted in complex radioactive systems, leading to decreased separation performance and unstable selectivity. This makes it difficult to meet the requirements for separation efficiency and durability in high-radioactive environments, thus limiting their application. Furthermore, these systems typically use nonionic surfactants (such as polyethylene glycol, Triton-114, and Tween-80) as phase separation building blocks, resulting in weak system interactions and low phase separation driving forces. This leads to a large condensed phase volume, limited enrichment ratio, and unclear phase interfaces.

[0019] Therefore, existing aqueous two-phase extraction systems still struggle to simultaneously achieve high efficiency, selectivity, and environmental safety in some scenarios. Developing a novel separation system capable of spontaneously forming a stable phase separation within a single aqueous phase through strong intermolecular interactions has become a key direction for achieving efficient separation of strontium and yttrium.

[0020] Liquid-liquid phase separation systems constructed with ionic surfactants offer a novel technical approach to solving the aforementioned problems. In this system, surfactant molecules with opposite charges can form stable supramolecular assembly structures through electrostatic attraction, hydrophobic interactions, and dipole interactions, spontaneously forming condensed and diluted phases in the aqueous phase. The condensed phase enriches the surfactant and its coordination environment, selectively loading and enriching specific metal ions or their complexes, achieving a highly efficient and controllable separation process without organic solvents. This method combines the greenness of aqueous two-phase systems with the high efficiency of organic extraction, providing a new pathway for the separation of strontium-yttrium and their radioactive metal ions.

[0021] Specifically, this application has the following technical solution: The first aspect of this application provides an ionic liquid-liquid phase separation system, which includes an anionic surfactant and an organic base; wherein the anionic surfactant and the organic base have an octanol-water partition coefficient (log P) greater than or equal to 1.0.

[0022] In this application, for the first time, the significant selectivity differences of anionic surfactants and organic base supramolecular assemblies for different metal ions were discovered and utilized to achieve different metal ions (especially Y) 3+ and Sr 2+ This system achieves highly efficient separation of yttrium ions and strontium. It can construct two immiscible phases within a single aqueous phase. The coupling effect between yttrium and the organic base, and between yttrium and the anionic surfactant, strengthens the coordination of yttrium ions with the aggregated phase. Strontium, however, has weak ion coordination ability and is therefore less likely to coordinate with the anionic surfactant or form stable ion pairs. Furthermore, by controlling the partitioning tendency of the organic base between the n-octanol and aqueous phases, this application controls the hydrophobicity of the organic base, which helps to regulate the supramolecular interactions between cations and anions in the mixed system, further adjusting the system's ability to separate different metal ions.

[0023] In this application, the octanol-water partition coefficient "Kow", also denoted as "P", is the ratio of the equilibrium molar concentrations of a chemical in n-octanol and water in a dilute solution at a given temperature. This value is typically expressed as the decimal logarithm of the coefficient, denoted as "log Kow", or "log P". The octanol-water partition coefficient is a measure of the hydrophobicity and hydrophilicity of a substance. Nonpolar (hydrophobic) compounds have high log P, while polar (hydrophilic) compounds have low log P, and moderately polar compounds have log P that falls between nonpolar and polar compounds.

[0024] In this application, the octanol-water partition coefficient (log P) can be obtained using conventional testing methods in the art. For example, it can be determined by testing according to ASTM Standard Test Method for Partition Coefficient (N-Octanol / Water) Estimation by Liquid Chromatography, Designation E 1147-92.

[0025] In some embodiments, the organic base includes one or more of dodecyl primary amine, benzylamine, n-octylamine, and diphenylethylenediamine.

[0026] In this application, the structural formula of the organic base is as follows:

[0027] In some embodiments, the anionic surfactant includes one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, sodium stearate, and sodium phosphatidyl ester.

[0028] In this application, the structural formula of the anionic surfactant is as follows:

[0029] This application eliminates the volatile organic solvents relied upon in traditional solvent extraction, greatly improving operational safety and reducing the generation of secondary organic waste, making it a greener and safer technology. Furthermore, the anionic surfactants and organic base reagents used are relatively inexpensive, and the separation process requires no complex equipment, only mixing and settling, significantly simplifying the operation and reducing operating costs.

[0030] In some embodiments, the molar ratio of the anionic surfactant to the organic base is 1:(0.5~2). Controlling the molar ratio of the anionic surfactant to the organic base within the above range helps the anionic surfactant and the organic base form stable ion pairs or supramolecular assembly structures, thereby providing a stable driving force for subsequent phase separation. Exemplarily, the molar ratio of the anionic surfactant to the organic base can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2.0, or a value within a range of any two of these. Optionally, the molar ratio of the anionic surfactant to the organic base is 1:(1~2). Optionally, the molar ratio of the anionic surfactant to the organic base is 1:(1.4~2).

[0031] The second aspect of this application provides the application of the aforementioned ionic liquid-liquid phase separation system in the separation of strontium and yttrium, comprising: mixing anionic surfactant, organic base, and a mixed metal salt solution to obtain a mixed solution; wherein the metal ions in the mixed metal salt solution include strontium ions and yttrium ions, and strontium includes... 84 Sr、 86 Sr、 87 Sr、 88 Sr、 89 Sr and 90 One or more of Sr, including yttrium 89 Y、 90 Y and86 One or more of Y.

[0032] In some implementations, strontium includes 90 Sr, yttrium includes 90 Y.

[0033] This application constructs two immiscible phases in a single aqueous phase. The coupling effect of the specific coordination of yttrium with an organic base and the strong electrostatic interaction between yttrium and anionic surfactant enhances the coordination of yttrium ions with the condensed phase aggregates. Strontium, due to its smaller charge and weaker ion coordination ability, is less likely to coordinate with anionic surfactants or form stable ion pairs. Therefore, the supramolecular assembly of anionic surfactants and organic bases is used to coordinate yttrium with the aggregates of the condensed phase. 3+ and Sr 2+ The huge selectivity difference in Y enables Y 3+ and Sr 2+ Highly efficient separation.

[0034] In some embodiments, the mass concentration ratio of strontium ions to yttrium ions in the mixed metal salt solution is (1~7000):1. Exemplarily, the mass concentration ratio of strontium ions to yttrium ions can be a numerical ratio between any two of the following ranges: 1:1, 500:1, 1000:1, 1500:1, 2000:1, 2500:1, 3000:1, 3500:1, 4000:1, 4500:1, 5000:1, 5500:1, 6000:1, 6500:1, 7000:1. Optionally, the mass concentration ratio of strontium ions to yttrium ions in the mixed metal salt solution is (1000~5000):1.

[0035] In some embodiments, the mass concentration of strontium ions in the mixed metal salt solution is 1 mg / L to 100,000 mg / L; exemplaryly, the mass concentration of strontium ions can be 1 mg / L, 5,000 mg / L, 10,000 mg / L, 15,000 mg / L, 20,000 mg / L, 25,000 mg / L, 30,000 mg / L, 35,000 mg / L, 40,000 mg / L, 45,000 mg / L, 50,000 mg / L, 55,000 mg / L, 60,000 mg / L, 65,000 mg / L, 70,000 mg / L, 75,000 mg / L, 80,000 mg / L, 85,000 mg / L, 90,000 mg / L, 95,000 mg / L, 100,000 mg / L, or a value within a range of any two of these.

[0036] In some embodiments, the mass concentration of yttrium ions in the mixed metal salt solution is 1 mg / L to 100 mg / L. Exemplarily, the mass concentration of yttrium ions can be a value within a range of 1 mg / L, 5 mg / L, 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L, 50 mg / L, 55 mg / L, 60 mg / L, 65 mg / L, 70 mg / L, 75 mg / L, 80 mg / L, 85 mg / L, 90 mg / L, 95 mg / L, 100 mg / L, or any combination thereof.

[0037] In some embodiments, the pH value of the mixed solution is 6.5 to 9. Exemplarily, the pH value of the mixed solution can be a value within a range of 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, or any combination thereof. Optionally, the pH value of the mixed solution is 7 to 9.

[0038] In some embodiments, the original pH of the mixed metal salt solution is below 6. The pH of the mixed solution can be a value between 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, or any combination thereof.

[0039] In some embodiments, the method for separating strontium and yttrium includes: mixing an anionic surfactant, an organic base, a mixed metal salt solution with a pH value below 6, and a pH adjuster at 5°C to 55°C to obtain a mixed solution with a pH value of 6.5 to 9; the mass-to-volume ratio of the mixture of the anionic surfactant and the organic base to the mixed metal salt solution is 0.1 g / mL to 0.5 g / mL; wherein the metal ions in the mixed metal salt solution include strontium ions and yttrium ions, and strontium includes... 90 Sr, yttrium includes 90 Y.

[0040] For example, the mixing temperature can be a value between 5°C, 7°C, 9°C, 12°C, 15°C, 18°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 53°C, 55°C, or any combination of two of them.

[0041] For example, the mass-to-volume ratio of the mixture of the anionic surfactant and the organic base to the mixed metal salt solution can be 0.10 g / mL, 0.15 g / mL, 0.20 g / mL, 0.25 g / mL, 0.30 g / mL, 0.35 g / mL, 0.40 g / mL, 0.45 g / mL, 0.50 g / mL, or any combination thereof. Optionally, the mass-to-volume ratio of the mixture of the anionic surfactant and the organic base to the mixed metal salt solution is 0.2 g / mL to 0.3 g / mL.

[0042] In some implementations, nitric acid and / or sodium hydroxide can be used to adjust the pH of the mixed solution; a pH of 6.5 to 9 helps to improve the separation of strontium and yttrium.

[0043] In some embodiments, the method for separating strontium and yttrium further includes: shaking or stirring the mixed solution at 5°C to 55°C to ensure uniform mixing of the components in the mixed solution, for a mixing time of 30 min to 120 min. Exemplarily, the time can be 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, or a value within a range of any two of these.

[0044] In this application, the shaking of the mixed solution can be achieved by a constant temperature water bath shaker or vortex shaker at a rotation speed of 200 rpm to 2000 rpm, or by mechanical stirring on a magnetic stirrer. For example, the rotation speed can be 200 rpm, 300 rpm, 400 rpm, 500 rpm, 600 rpm, 800 rpm, 1000 rpm, 1200 rpm, 1500 rpm, 1800 rpm, 2000 rpm, or a value within a range of any two of these.

[0045] In some embodiments, after the mixed solution reaches extraction equilibrium, phase separation is achieved by centrifugation or static settling, wherein the upper layer is a diluted phase containing strontium ions and the lower layer is a condensed phase containing yttrium ions. Centrifugation is performed by centrifuging at 5000 rpm to 10000 rpm for 5 to 10 minutes; static settling is performed by allowing the mixed solution to stand horizontally for at least 2 hours.

[0046] In this application, the concentration of metal ions is measured by inductively coupled plasma atomic emission spectrometry (ICP-OES).

[0047] In this application, the mixed metal salt solution may be a high-level radioactive waste liquid containing strontium and yttrium, a mixed metal salt solution containing strontium and yttrium simulating high-level radioactive waste liquid, or a solution obtained from ore leaching solution containing strontium and yttrium, etc. Those skilled in the art can separate strontium and yttrium in any mixed solution containing strontium ions and yttrium ions.

[0048] In some embodiments, the mixed metal salt solution also contains Na. + , , The counter ions contained in the components of the system are 0~5M; the counter salt ions mainly remain in the diluted phase after phase separation.

[0049] To further illustrate the technical solution of this application, the following embodiments are provided: In the following examples, at room temperature and pressure, dodecyl primary amine, benzylamine, n-octylamine and diphenylethylenediamine have low solubility in water, and their octanol-water partition coefficients (log P) are all greater than or equal to 1.0.

[0050] In the following examples, the formulas for calculating the extraction rate, partition ratio, and separation factor are as follows: Extraction rate (E) calculation formula:

[0051] The formula for calculating the allocation ratio (D) is as follows:

[0052] Separation factor (SF) calculation formula:

[0053] Example 1 This embodiment provides an ionic liquid-liquid phase separation system, comprising 0.1154g sodium dodecyl sulfate powder and 0.1698g diphenylethylenediamine powder.

[0054] This embodiment further provides the application of the above-mentioned ionic liquid-liquid phase separation system in the separation of strontium and yttrium, specifically including the following steps: Prepare a solution containing 3800 mg / L Sr using deionized water. 2+ and 1 mg / LY 3+ The mixed metal salt solution, in which all metal ions are prepared using nitrates.

[0055] Take 10 mL of the above mixed metal salt solution into a 15 mL centrifuge tube, add 0.1154 g of sodium dodecyl sulfate powder (final concentration 40 mM) and 0.1698 g of diphenylethylenediamine powder (final concentration 80 mM) to obtain a mixed solution. The molar ratio of sodium dodecyl sulfate to diphenylethylenediamine in the mixed solution is 1:2. Adjust the pH of the mixed solution to 7 using HNO3 and NaOH, and vortex for 2 h to ensure complete extraction. Centrifuge at 6000 rpm for 5 min; the system clearly separates into two phases: a lower condensed phase with a volume of approximately 0.27 mL and an upper diluted phase with a volume of approximately 9.73 mL, a volume ratio of approximately 1:32. Analyze the diluted phase using ICP-OES, and calculate the Sr content in the condensed phase using the difference method. 2+ Y 3+ The concentration of Sr was calculated. 2+ Y 3+ The distribution ratio, extraction rate, and separation factor of the two are shown in Table 1.

[0056] Examples 2-8 This embodiment uses the ionic liquid-liquid phase separation system of Example 1 to separate strontium and yttrium from a mixed metal salt solution. The difference is that HNO3 and NaOH are used to adjust the pH values ​​of the mixed solution to 4, 5, 6, 6.5, 7.5, 8, and 9, respectively.

[0057] The diluted phase was analyzed by ICP-OES, and the Sr content in the condensed phase was calculated by the difference method. 2+ Y 3+ The concentration of Sr was calculated. 2+ Y 3+ The distribution ratio, extraction rate, and separation factor of the two are shown in Table 1. For comparison, Table 1 lists the results of Examples 1-8.

[0058] Table 1

[0059] As shown in Table 1, the strontium-yttrium separation effect is better when the pH value of the mixed solution is 6.5-9, especially 7-9.

[0060] Examples 9-12 This embodiment uses the mixed metal salt solution from Example 1 to separate strontium and yttrium, the difference being that the anionic surfactant and organic base in the ionic liquid-liquid phase separation system are replaced in equimolar amounts according to Table 1. The diluted phase is analyzed by ICP-OES, and the Sr content in the condensed phase is calculated using the difference method. 2+ Y 3+ The concentration of Sr was calculated. 2+ Y 3+The distribution ratio, extraction rate, and separation factor of the two components are shown in Table 2. For comparison, the results of Example 1 are also listed in Table 2.

[0061] Table 2

[0062] As shown in Table 2, when the above-mentioned anionic surfactant is selected in combination with the above-mentioned organic base with logP greater than or equal to 1, the system has a better separation effect of strontium and yttrium.

[0063] Examples 13-14 This embodiment uses the mixed metal salt solution from Example 1 to separate strontium and yttrium, the difference being that the molar amounts of the anionic surfactant and organic base are adjusted according to Table 2. The diluted phase is analyzed by ICP-OES, and the Sr content in the condensed phase is calculated using the difference method. 2+ Y 3+ The concentration of Sr was calculated. 2+ Y 3+ The distribution ratio, extraction rate, and separation factor of the two components are shown in Table 4. For comparison, the results of Example 1 are also listed in Tables 3 and 4.

[0064] Table 3

[0065] Table 4

[0066] As shown in Table 4, when the molar ratio of surfactant to organic base is 1:(0.5~2), especially 1:(1.4~2), it has a better strontium-yttrium separation effect.

[0067] Examples 15-17 This embodiment uses the ionic liquid-liquid phase separation system of Example 1, the difference being that the concentrations of strontium and yttrium ions in the mixed metal salt solution are adjusted according to Table 3. The diluted phase is analyzed by ICP-OES, and the concentration of Sr in the condensed phase is calculated using the difference method. 2+ Y 3+ The concentration of Sr was calculated. 2+ Y 3+ The distribution ratio, extraction rate, and separation factor of the two components are shown in Table 5. For comparison, the results of Example 1 are also listed in Table 5.

[0068] Table 5

[0069] As shown in Table 5, the separation effect is better when the ratio of strontium ion concentration to yttrium ion concentration is controlled at (1~7000):1.

[0070] Meanwhile, this application found that when the initial pH value of the mixed metal salt solution is greater than 6, it will also affect the subsequent separation effect to some extent.

[0071] Comparative Example 1 The difference between this comparative example and Example 1 is that diphenylethylenediamine was replaced with an equimolar amount of tetrabutylammonium fluoride, whose octanol-water partition coefficient (log P) is less than 1.0. Under the same experimental conditions as in Example 1, no significant phase separation occurred.

[0072] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. An ion-type liquid-liquid phase separation system, characterized in that, The ionic liquid-liquid phase separation system includes anionic surfactants and organic bases; the octanol-water partition coefficient (logP) of the anionic surfactants and the organic bases is greater than or equal to 1.

0.

2. The ionic liquid-liquid phase separation system according to claim 1, characterized in that, The organic base includes one or more of dodecyl primary amine, benzylamine, n-octylamine, and diphenylethylenediamine.

3. The ionic liquid-liquid phase separation system according to claim 1 or 2, characterized in that, The anionic surfactant includes one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, sodium stearate, and sodium phosphatidyl ester.

4. The ion-type liquid-liquid phase separation system according to any one of claims 1 to 3, characterized in that, The molar ratio of the anionic surfactant to the organic base is 1:(0.5~2).

5. The application of the ionic liquid-liquid phase separation system according to any one of claims 1 to 3 in the separation of strontium and yttrium, characterized in that, include: An anionic surfactant, an organic base, and a mixed metal salt solution are mixed to obtain a mixed solution; The metal ions in the mixed metal salt solution include strontium ions and yttrium ions. Strontium includes 84 Sr、 86 Sr、 87 Sr、 88 Sr、 89 Sr and 90 One or more of Sr Yttrium includes 89 Y、 90 Y and 86 One or more of Y.

6. The application of the ionic liquid-liquid phase separation system according to claim 5 in the separation of strontium and yttrium, characterized in that, In the mixed metal salt solution, the mass concentration ratio of strontium ions to yttrium ions is (1~5000):

1.

7. The application of the ionic liquid-liquid phase separation system according to claim 5 or 6 in the separation of strontium and yttrium, characterized in that, In the mixed metal salt solution, the mass concentration of strontium ions is 1 mg / L to 100,000 mg / L; and / or, The mass concentration of the yttrium ions is 1 mg / L to 100 mg / L.

8. The application of the ionic liquid-liquid phase separation system according to any one of claims 5 to 7 in the separation of strontium and yttrium, characterized in that, The pH value of the mixed solution is 6.5~9.

9. The application of the ionic liquid-liquid phase separation system according to any one of claims 5 to 8 in the separation of strontium and yttrium, characterized in that, The original pH of the mixed metal salt solution was below 6.

10. The application of the ionic liquid-liquid phase separation system according to any one of claims 5 to 8 in the separation of strontium and yttrium, characterized in that, Methods for separating strontium and yttrium include: An anionic surfactant, an organic base, a mixed metal salt solution with a pH below 6, and a pH adjuster are mixed at 5℃~55℃ to obtain a mixed solution with a pH of 6.5~9; the mass-to-volume ratio of the mixture of the anionic surfactant and organic base to the mixed metal salt solution is 0.1g / mL~0.5g / mL; wherein the metal ions in the mixed metal salt solution include strontium ions and yttrium ions, and strontium includes... 90 Sr, yttrium includes 90 Y.

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