An oe-dap hen ligand, and a preparation method and application thereof

Abstract

The application belongs to the technical field of extraction separation, and particularly relates to an OE-DAPhen ligand, a preparation method and application thereof. The application develops a novel DAPhen ligand through specific structure design from the design of a ligand molecular structure. The separation factor (SF) of the OE-DAPhen ligand for lanthanide and actinide elements is more than 400, and the OE-DAPhen ligand exhibits excellent separation performance. The application provides a new perspective for in-depth understanding of lanthanide and actinide separation mechanism, and provides technical support for establishing an advanced spent nuclear fuel reprocessing system and realizing efficient utilization of minor actinide elements. Eu / Am ).

Description

Technical Field

[0001] This invention belongs to the field of extraction and separation technology, specifically relating to an OE-DAPhen ligand, its preparation method, and its application. Background Technology

[0002] In the extraction and separation of rare earth elements and the separation and recovery of lanthanides and actinides in the nuclear industry, solvent extraction is the most widely used and mature separation technology. It has gradually replaced traditional fractional crystallization and ion exchange methods, becoming the mainstream separation method in this field. The core principle of solvent extraction is based on the difference in solubility of complexes formed by different lanthanide and actinide ions with the extractant in the organic and aqueous phases, resulting in different partition coefficients for each ion. Through a liquid-liquid two-phase extraction process, selective separation and extraction of different ions are achieved. This method has advantages such as high separation efficiency, large processing capacity, simple operation, and ease of industrial-scale application, and has been widely used in nuclear fuel reprocessing, rare earth metallurgy, and other fields.

[0003] However, current solvent extraction methods for separating lanthanides and actinides still suffer from low separation factors and poor separation efficiency. Summary of the Invention

[0004] In view of this, the present invention provides an OE-DAPhen ligand, its preparation method and application. The present invention has a high separation factor and good separation effect for lanthanides and actinides.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides an OE-DAPhen ligand having the structure shown in Formula I: Formula I.

[0006] This invention also provides a method for preparing the OE-DAPhen ligand described in the above technical solution, comprising the following steps: Methyl 2,9-dicarboxylate-1,10-phenanthroline, 2,2'-oxobis(ethylamine), and an alcohol solvent were mixed and subjected to an amidation reaction to obtain the OE-DAPhen ligand.

[0007] Preferably, the molar ratio of methyl 2,9-dicarboxylate-1,10-phenanthroline and 2,2'-oxobis(ethylamine) is 1:2.1~3.

[0008] Preferably, the amidation reaction is carried out at a temperature of 70-80°C for 12-24 hours.

[0009] Preferably, the amidation reaction is followed by concentration, and the concentrated crude product is purified by column chromatography; the mobile phase for column chromatography purification is a mixture of HUBERT system, methanol, water and ammonia; the volume ratio of HUBERT system, methanol and water is 7:2:1; the volume of ammonia is 5% of the sum of the volumes of HUBERT system, methanol and water.

[0010] Preferably, the HUBERT system is composed of ethyl acetate, ethanol, acetone and water; the volume ratio of ethyl acetate, ethanol, acetone and water in the HUBERT system is 7:4:4:1.

[0011] This invention also provides the application of the OE-DAPhen ligand described in the above technical solution or the OE-DAPhen ligand prepared by the preparation method described in the above technical solution in the separation of lanthanides and actinides.

[0012] Preferably, the lanthanide elements include europium, and the actinide elements include americium.

[0013] This invention also provides a method for separating americium and europium from waste liquid, comprising the following steps: Acidic waste liquid containing americium and europium was mixed with DAPhen ligands to obtain an aqueous phase containing DAPhen ligands; Europium was extracted from the aqueous phase containing the DAPhen ligand into the organic phase using an organic phase to separate americium and europium.

[0014] Preferably, the acidity of the aqueous phase containing DAPhen ligand is 0.1~1.0 M; the concentration of DAPhen ligand in the aqueous phase containing DAPhen ligand is 10~30 mM; and the volume ratio of the organic phase to the aqueous phase containing DAPhen ligand is 1:1.

[0015] This invention starts with ligand molecular structure design and develops a novel DAPhen ligand through specific structural design. This ligand exhibits a separation factor (SF) for lanthanides and actinides. Eu / Am With a concentration exceeding 400, it exhibits excellent separation performance. This invention provides a new perspective for a deeper understanding of the lanthanum-actinium separation mechanism and offers technical support for establishing an advanced spent nuclear fuel reprocessing system and achieving efficient utilization of minor actinides. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0017] Figure 1 The hydrogen NMR spectrum of OE-DAPhen; Figure 2 The carbon NMR spectrum of OE-DAPhen; Figure 3 The mass spectrum of OE-DAPhen; Figure 4 High-resolution mass spectrum of OE-DAPhen; Figure 5 (a) shows the acidity test results, and (b) shows the ligand concentration extraction results. Detailed Implementation

[0018] This invention provides an OE-DAPhen ligand having the structure shown in Formula I: Formula I.

[0019] The present invention also provides a method for preparing the OE-DAPhen ligand described above, comprising the following steps: Methyl 2,9-dicarboxylate-1,10-phenanthroline, 2,2'-oxobis(ethylamine), and an alcohol solvent were mixed and subjected to an amidation reaction to obtain the OE-DAPhen ligand.

[0020] In one embodiment of the present invention, the alcohol solvent includes methanol; the molar ratio of methyl 2,9-dicarboxylate-1,10-phenanthroline and 2,2'-oxobis(ethylamine) can be 1:2.1~3, specifically 1:2.2; In one embodiment of the present invention, the temperature of the amidation reaction can be 70~80℃, specifically 75℃, and the time can be 12~24 h, specifically 12 h.

[0021] In one embodiment of the present invention, the amidation reaction further includes concentration, and the concentrated crude product is purified by column chromatography to obtain the OE-DAPhen ligand. In another embodiment of the present invention, the mobile phase for column chromatography purification is a mixture of the HUBERT system, methanol, water, and ammonia; the HUBERT system may consist of ethyl acetate, ethanol, acetone, and water; the volume ratio of ethyl acetate, ethanol, acetone, and water in the HUBERT system may be 7:4:4:1; the volume ratio of the HUBERT system, methanol, and water in the mixture is 7:2:1; and the volume of ammonia is 5% of the sum of the volumes of the HUBERT system, methanol, and water.

[0022] This invention also provides the application of the OE-DAPhen ligand described above or the OE-DAPhen ligand prepared by the preparation method described above in the separation of lanthanides and actinides. As one embodiment of this invention, the lanthanides include europium, and the actinides include americium.

[0023] This invention also provides a method for separating americium and europium from waste liquid, comprising the following steps: Acidic waste liquid containing americium and europium was mixed with DAPhen ligands to obtain an aqueous phase containing DAPhen ligands; Europium was extracted from the aqueous phase containing the DAPhen ligand into the organic phase using an organic phase to separate americium and europium.

[0024] In one embodiment of the present invention, the acidity of the aqueous phase containing DAPhen ligand can be 0.1~1.0 M; the concentration of DAPhen ligand in the aqueous phase containing DAPhen ligand can be 10~30 mM; and the volume ratio of the organic phase to the aqueous phase containing DAPhen ligand can be 1:1. In another embodiment of the present invention, the organic phase includes TODGA, kerosene, and n-octanol; the volume ratio of kerosene to n-octanol in the organic phase can be 95:5; and the concentration of TODGA in the organic phase can be 0.2 M.

[0025] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0026] Example 1 0.50 g (1.69 mmol) of methyl 2,9-dicarboxylate-1,10-phenanthroline and 407 mg (3.71 mmol, 2.2 eq) of 2,2'-oxobis(ethylamine) were weighed into a 100 mL round-bottom flask, and 10 mL of methanol and a stir bar were added. The mixture was stirred at 75 °C for 12 h. The solvent was removed by rotary evaporation, and the crude product was purified by column chromatography using a HUBERT system-methanol-water-ammonia solution as the mobile phase. The HUBERT system consisted of ethyl acetate, ethanol, acetone, and water in a volume ratio of 7:4:4:1; the volume ratio of the HUBERT system, methanol, and water was 7:2:1; and the volume of ammonia solution was 5% of the sum of the volumes of the HUBERT system, methanol, and water. Product R f The value was approximately 0.60. After separation, 0.37 g of a colorless, transparent, oily product was obtained, with a yield of 50%.

[0027] The synthesis route is as follows: See the data analysis chart for OE-DAPhen. Figures 1-4 .

[0028] Elemental analysis results of the product: C, 59.99; H, 6.41; N, 19.08; O, 14.53. Found: C, 53.98; H, 6.69; N, 14.52; The NMR and mass spectrometry data of the product are as follows: 1 H NMR (400 MHz, DMSO) δ (ppm): 9.47 (s, 2H),8.74-8.72 (d, J = 8.3 Hz, 2H), 8.46-8.44 (d, J = 8.3 Hz, 2H), 8.18 (s, 2H), 3.69-3.68 (d, J = 4.7 Hz, 4H), 3.66-3.65 (d, J = 5.2 Hz, 4H),, 3.52-3.49 (m, 4H), 2.76-2.74 (m, 4H), 1.79 (s, 4H); 13 C NMR (600 MHz, DMSO) δ (ppm): 164.15 (2C), 149.79 (2C), 143.73(2C), 138.29 (2C), 130.29 (2C), 127.94 (2C), 121.19 (2C), 72.40 (2C), 68.61(2C), 41.07(2C), 39.06(2C); MS(ESI + ) m / z calcd. for [M+H] + : 441.22, found: 441.2247, MS(ESI + ) m / z calcd. for [M+2H] 2+ : 221.11, found: 221.1159; HRMS (ESI) + ) m / z calcd. for [M+H] + : 441.22, found: 441.2247.

[0029] test: 1. Raw materials The HNO3 used was analytical grade. The deionized water used had low conductivity (18.2 MΩ). The 241Am tracer (americium tracer) used was obtained from the School of Nuclear Science and Technology, Nanhua University, with a radioactivity concentration of 34319 Bq / mL. Elemental analysis was performed on the products, confirming the purity of the OE-DAPhen ligand to be 80.5 wt%. All aqueous phases contained the ligand. 241 Am and europium nitrate, as well as different concentrations of HNO3. All extraction experiments were performed in 10 mL centrifuge tubes. 241 The activity of Am was counted using a Tri-Carb4910 TR (Revvity) liquid scintillation counter. Eu was measured using an ICPE-9810 (SHIMADZU) inductively coupled plasma atomic emission spectrometer.

[0030] 2. Stock solution A ligand stock solution was prepared by dissolving 175.1 mg of OE-DAPhen ligand (purity: 80.5 wt%) in 8 mL of pure water, resulting in a concentration of 40 mM.

[0031] Containing 0.01 M nitric acid 241 Am(NO3)3 stock solution.

[0032] 1 mM Eu(NO3)3 stock solution.

[0033] The HNO3 stock solutions are available in 1 M and 4 M forms.

[0034] 0.2 M TODGA (N,N,N′,N′-tetraoctyl-3-oxopramethylenediamide) organic phase: 3.521 g TODGA was dissolved in 30 mL of kerosene / n-octanol (95:5, v / v) solution.

[0035] 3. Two types of tests: 3.1 Acidity test to determine the effect of nitric acid concentration on the partition ratio and SF6. Eu / Am The impact.

[0036] For all ligands, acidity studies were conducted at nitric acid concentrations of 0.1, 0.25, 0.5, 0.75, and 1.0 M, with a standard concentration of 10 mM for the ligands.

[0037] 3.2 Ligand concentration extraction studies to determine the ligand concentration-partition ratio and SF. Eu / Am The impact.

[0038] The aqueous phase contained nitric acid with a constant acidity (0.50 M) and ligand concentrations of 10, 20 and 30 mM.

[0039] Mix 0.8 mL of the aqueous phase and 0.8 mL of the TODGA organic phase (0.2 M) in centrifuge tubes, vortex (standard 30 min), and then centrifuge (3000 rpm, 2 min) to completely separate the two phases. Samples from both the aqueous and organic phases are then collected, and the radioactivity in different channels is counted using LSC to distinguish them. 241 Am exhibits alpha radioactivity. The concentration of Eu can be determined using ICP-OES. The count ratios in the two phases are then interpreted as extraction parameters D. Am and D Eu , and SF Eu / Am The calculation is D. Eu / D Am Compare.

[0040] 3.3 Solvent Extraction Results Figure 5 (a) shows the acidity test results, and (b) shows the ligand concentration extraction results. The optimal acidity for OE-DAPhen is 0.50 M, the optimal ligand concentration is 30 mM, and the separation factor (SF) is... Eu / Am With a resolution exceeding 400, it exhibits excellent separation performance.

[0041] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An OE-DAPhen ligand having the structure shown in Formula I: Equation I.

2. The method for preparing the OE-DAPhen ligand according to claim 1, comprising the following steps: Methyl 2,9-dicarboxylate-1,10-phenanthroline, 2,2'-oxobis(ethylamine), and an alcohol solvent were mixed and subjected to an amidation reaction to obtain the OE-DAPhen ligand.

3. The preparation method according to claim 2, characterized in that, The molar ratio of methyl 2,9-dicarboxylate-1,10-phenanthroline and 2,2'-oxobis(ethylamine) is 1:2.1~3.

4. The preparation method according to claim 2, characterized in that, The amidation reaction is carried out at a temperature of 70-80°C for 12-24 hours.

5. The preparation method according to claim 2, characterized in that, The amidation reaction is followed by concentration, and the concentrated crude product is purified by column chromatography. The mobile phase for column chromatography purification is a mixture of HUBERT system, methanol, water and ammonia. The volume ratio of HUBERT system, methanol and water is 7:2:

1. The volume of ammonia is 5% of the sum of the volumes of HUBERT system, methanol and water.

6. The preparation method according to claim 5, characterized in that, The HUBERT system is composed of ethyl acetate, ethanol, acetone and water; the volume ratio of ethyl acetate, ethanol, acetone and water in the HUBERT system is 7:4:4:

1.

7. The application of the OE-DAPhen ligand according to claim 1 or the OE-DAPhen ligand prepared by any one of claims 2 to 6 in the separation of lanthanides and actinides.

8. The application as described in claim 7, characterized in that, The lanthanides include europium, and the actinides include americium.

9. A method for separating americium and europium from waste liquid, characterized in that, Includes the following steps: Acidic waste liquid containing americium and europium was mixed with DAPhen ligands to obtain an aqueous phase containing DAPhen ligands; Europium was extracted from the aqueous phase containing the DAPhen ligand into the organic phase using an organic phase to separate americium and europium.

10. The application as described in claim 9, characterized in that, The acidity of the aqueous phase containing DAPhen ligand is 0.1~1.0 M; the concentration of DAPhen ligand in the aqueous phase containing DAPhen ligand is 10~30 mM; and the volume ratio of the organic phase to the aqueous phase containing DAPhen ligand is 1:1.

Images