A method for preparing a kilogram-scale water-soluble nitrogen-containing actinide extractant

Abstract

This invention relates to a method for preparing a kilogram-scale water-soluble nitrogen-containing actinide element extractant, comprising the following steps: S1. Synthesizing amide hydrazone via nucleophilic addition reaction: Adding hydrazine hydrate or anhydrous hydrazine to a dimethyl nitrile solution, performing a nucleophilic addition reaction, and then separating the solid and liquid phases to obtain the amide hydrazone; S2. Synthesizing pyridine triazine derivative via condensation cyclization reaction: Dispersing or dissolving the ground amide hydrazone and diphenylethylene glycol in a solvent, performing a condensation cyclization reaction, and then separating the solid and liquid phases to obtain the pyridine triazine derivative; S3. Obtaining the extractant via substitution reaction: Adding a sulfonating agent to the pyridine triazine derivative, refluxing to perform a substitution reaction, and then slowly adding the reaction mixture dropwise to a phase inversion agent to precipitate the extractant. Compared with the prior art, the preparation method of this invention is simple and feasible, with a simple reaction system, high product yield, short production cycle, simple processing technology, low energy consumption, inexpensive and readily available raw materials, and easy to industrialize, showing broad application prospects in the field of high-level radioactive waste disposal.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and specifically to a method for preparing a kilogram-scale water-soluble nitrogen-containing actinide element extractant. Background Technology

[0002] High-level radioactive waste contains large amounts of transuranic elements; separating and extracting high-value nuclides A / C could generate significant economic benefits. 1m 3 The waste liquid contains approximately 70g of aflatoxin (A), with a market value exceeding 100 million yuan. Furthermore, extracting large quantities of A (A target raw material) from spent fuel, and mastering the core technology and independent production capabilities, is of significant strategic importance to my country's economic and social development. High-level radioactive waste (HLLW) is a complex, multi-component system with high nitrification and strong radioactivity. Furthermore, MA(III) and Ln(III) have similar ionic radii and oxidation states, resulting in very similar chemical properties, making their separation extremely difficult. To solve the MA / Ln separation problem, the development and performance verification of extractants have gradually become a research hotspot. According to the hard-soft acid-base theory, both MA(III) and Ln(III) belong to hard acids, but compared to lanthanides, actinides have soft acid properties. This softer property makes MA(III) interact more strongly with ligands containing soft coordinating atoms N or S. Using reagents containing N-containing soft ligands holds promise for achieving the separation of MA(III) and Ln(III). Studies have found that polynitrogen triazine derivatives exhibit strong coordination ability and high selectivity for MA in nitric acid media, and show promising application prospects in MA / Ln separation.

[0003] Solvent extraction is the mainstream method for the separation of lanthanum and actinium. Since the 1960s, extensive research has been conducted both domestically and internationally on the development of extractants for lanthanum-actinium separation. BTP, BTBP, and BTPhen are nitrogen-containing ligand compounds based on pyridine and the 1,2,4-triazine system. Experimental studies on the preparation of these extractants have been conducted both domestically and internationally, but low yields are a common problem. Domestic research on R-BTP extractants started relatively late, with most literature reports appearing after 2000 or even 2010. Domestic research mainly focuses on the synthesis of R-BTP extractants with alkyl straight-chain and alkyl branched-chain structures, with a small amount of research on the synthesis of bridged-ring substituent R-BTP. The yield of the extractant is closely related to factors such as the substituent and the reaction solvent. The lanthanum-actinium separation coefficients of BTP, BTBP, and BTPhen extractants generally increase with the length of the alkyl chain. Lanthanum-actinium separation performance is often higher for cycloalkyl or aryl-substituted extractants than for alkyl-substituted extractants. However, the poorer solubility of aryl-substituted extractants in organic phases limits their application in lanthanum-actinium separation. Currently, there are no detailed reports in China on the synthesis processes of aromatic ring-substituted BTP, BTBP, and BTPhen.

[0004] Invention CN103087049 A discloses a method for preparing a novel triazine compound, namely 2,6-bis[(5,6-dialkyl)-1,2,4-triazin-3-yl]-pyridine (BTP). In this invention, the substituent of the BTP extractant is C. n H 2n+1 Or C m H 2m X, n are integers from 1 to 15, m are integers from 2 to 4, and X is cyclopentyl or cyclohexyl. In this invention, the reaction is carried out under inert gas protection, and 4A molecular sieves are added to promote the reaction. After the reaction, the solvent is removed under reduced pressure, and then impurities are removed by column purification. The product yield is between 31% and 65%. The reaction conditions are harsh, the processing flow is complex, the product yield is low, and the energy consumption is high.

[0005] Currently reported synthesis methods for BTP, BTBP, and BTPhen extractants are mostly targeted at alkyl substituents, and generally suffer from drawbacks such as low yield, long reaction time, and complex processing, failing to meet the demand for highly efficient extractants in the separation of lanthanum and actinium from high-level radioactive waste. Furthermore, extractants for high-level radioactive waste treatment should possess both good solubility and extraction performance. Aryl-substituted extractants, while exhibiting better extraction performance, suffer from poorer solubility in organic phases, limiting their application in lanthanum and actinium separation. Since high-level radioactive waste treatment requires large quantities of extractants, there is an urgent need to develop a simple and feasible extractant production process. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a kilogram-scale water-soluble nitrogen-containing actinide element extractant. The preparation method is simple and feasible, with high product yield, short production cycle and low energy consumption.

[0007] The objective of this invention can be achieved through the following technical solution: a method for preparing a kilogram-scale water-soluble nitrogen-containing actinide element extractant, comprising the following steps:

[0008] S1. Synthesis of amide hydrazone via nucleophilic addition reaction: Add hydrated or anhydrous hydrazine to a dimethyl nitrile solution, perform a nucleophilic addition reaction, and then separate the solid and liquid phases to obtain amide hydrazone;

[0009] S2. Synthesis of pyridine triazine derivatives Ph-BTP, Ph-BTBP or Ph-BTPhen via condensation cyclization reaction: The ground amide hydrazone and diphenylethylene glycol are dispersed or dissolved in a solvent, and after condensation cyclization reaction, solid-liquid separation is performed to obtain the pyridine triazine derivatives.

[0010] S3. Obtaining the extractant via substitution reaction: Add a sulfonating agent to a pyridine triazine derivative, reflux to carry out the substitution reaction, and then slowly add the reaction mixture dropwise to a phase inversion agent to precipitate and obtain the extractant;

[0011] The dimethyl nitrile has the following structure:

[0012]

[0013] The amide hydrazone has the following structure:

[0014]

[0015] The pyridine triazine derivative has the following structure:

[0016]

[0017] The extractant has the following structure:

[0018]

[0019] Preferably, the extractant is used for the treatment of high-level radioactive waste liquid.

[0020] Preferably, in step S1, dimethylnitrile is added to the jacketed reactor, and then a solvent is added to dissolve or disperse it. When the temperature inside the reactor is controlled at about 0°C, hydrazine hydrate or anhydrous hydrazine is added dropwise. After the dropwise addition is completed, the temperature is raised to 15-50°C and the reaction is stirred for 6-24 hours. After the reaction is completed, the mixture is pumped into a filter press or hydrocyclone for solid-liquid separation. After the filter cake is washed several times, it is quickly dried in a drying device.

[0021] More preferably, the detergent used for washing is a non-solvent of the product being washed.

[0022] Preferably, after the reaction in step S1 is completed, the mixture is filtered or poured into a filter press for solid-liquid separation. After washing several times, the product is introduced into a fluidized bed for rapid drying or the filter cake is placed in a vacuum drying oven for drying.

[0023] The nucleophilic addition reaction described above has a product production capacity of more than 1 kg / batch.

[0024] Preferably, in step S2, the ground amide hydrazone and diphenylethylene glycol are dispersed or dissolved in a solvent according to the specified ratio, and reacted at 40-110°C for 3-72 hours. After the reaction is completed, the mixture is pumped into a filter press or hydrocyclone for solid-liquid separation. The filter cake is washed several times and then dried in a drying device.

[0025] More preferably, the detergent used for washing is a non-solvent of the product being washed.

[0026] The condensation cyclization reaction described herein has a product production capacity of more than 1 kg / batch.

[0027] Preferably, in step S3, the pyridine triazine derivative obtained in step S2 is added to a jacketed reactor equipped with a reflux condenser. A sulfonating agent is added to the above system, mechanical stirring is started, and the reaction is refluxed at 50-200°C for 0.5-8 hours. After the reaction system is cooled to room temperature, the reaction mixture is slowly added dropwise to the phase inversion agent, the product precipitates, and after pressure filtration, washing, and drying, a solid product is obtained.

[0028] More preferably, the reaction temperature is 90–150°C.

[0029] More preferably, the detergent used for washing is a non-solvent of the product being washed.

[0030] More preferably, the purity of the solid product obtained by drying in step S3 is further improved by recrystallization.

[0031] Preferably, the recrystallization solvent during the purification of the product in step S3 is one of water, methanol, or ethanol, and the purity of the sulfonated product after recrystallization can reach more than 98%.

[0032] Preferably, the preparation method is used for production with a capacity of 0.1–1000 kg / batch. The process route and parameters of the nucleophilic addition, condensation cyclization, and substitution steps in the preparation method are suitable for production with a capacity of 0.1–1000 kg / batch.

[0033] Preferably, the solvent in the diformonitrile solution in step S1 is one or a mixture of two or more of the following: tetrahydrofuran, anhydrous ethanol, benzene, dimethyl sulfoxide, dichloromethane, chloroform, dioxane, petroleum ether, and deionized water.

[0034] More preferably, the volume molar ratio of the solvent to the xylene nitrile is 0.2–50 L / mol, that is, the amount of solvent used during the reaction is 0.2–50 L / mol (solvent / xylene nitrile).

[0035] More preferably, the volume molar ratio of the solvent to xylene nitrile is 2–10 L / mol.

[0036] Preferably, in step S1, the volume molar ratio of hydrazine hydrate or anhydrous hydrazine to dimethyl nitrile is 0.1–5 L / mol, that is, the amount of hydrazine hydrate / anhydrous hydrazine used during the reaction is 0.1–5 L / mol (hydrazine hydrate or anhydrous hydrazine / dimethyl nitrile).

[0037] Preferably, the solvent in step S2 is one or more of benzene, toluene, chloroform, dichloromethane, dichloroethane, 1,1-difluoro-1,2-dichloroethane, trichloroethane, tetrachloroethane, dioxane, dimethyl sulfoxide, tetrahydrofuran, and anhydrous ethanol.

[0038] Preferably, the volume molar ratio of the solvent to the amide hydrazone in step S2 is 0.5–100 L / mol, that is, the amount of solvent used during the reaction is 0.5–100 L / mol (solvent / amide hydrazone).

[0039] More preferably, the volume molar ratio of the solvent to the amide hydrazone in step S2 is 1–10 L / mol. Different solvents and solvent amounts will affect the reaction cycle, product yield, and purity. The corresponding process parameters should be adjusted according to equipment conditions, cost, and the use of extractant.

[0040] Preferably, the sulfonating agent in step S3 is one of concentrated sulfuric acid (98%) or fuming sulfuric acid (5% to 65% SO3).

[0041] Preferably, the volume molar ratio of the sulfonating agent to the pyridine triazine derivative in step S3 is 1-100 L / mol, that is, the amount of sulfonating agent used is 1-100 L / mol (sulfonating agent / raw material).

[0042] More preferably, the volume molar ratio of the sulfonating agent to the pyridine triazine derivative is 4–50 L / mol.

[0043] Preferably, the phase inversion agent in step S3 is one or more of methyl formate, ethyl acetate, dioxane, tetrahydrofuran, acetone, chloroform, dichloromethane, benzene, toluene, xylene, pyridine, and alkanes.

[0044] Preferably, the volume molar ratio of the phase inversion agent to the target extractant in step S3 is 100-1500 L / mol, that is, the amount of phase inversion agent used is 100-1500 L / mol (phase inversion agent / product).

[0045] More preferably, the volume molar ratio of the phase inversion agent to the reaction mixture in step S3 is 400–600 L / mol.

[0046] Preferably, in the preparation method, no catalyst is added in the three steps of nucleophilic addition, condensation cyclization and substitution, the reaction process does not require inert gas protection, and the reaction system is relatively simple.

[0047] Preferably, in the preparation method, the yields of the three steps of nucleophilic addition, condensation cyclization, and substitution are 93% to 98%.

[0048] This invention addresses the problems of long reaction time, harsh reaction conditions (catalyst, inert gas protection), low yield, complex processing procedures and high energy consumption in the preparation of extractants in the prior art. In order to reduce the cost of extractant use, solve the market supply shortage problem, and thus achieve lanthanum-actinium separation and reduce the impact of radioactivity on the treatment and disposal of high-level radioactive waste, this invention discloses a simple and efficient kilogram-scale synthesis method for water-soluble lanthanum-actinium separation extractant.

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] 1. This invention provides a kilogram-scale synthesis method for highly efficient water-soluble BTP, BTBP, and BTPhen-type extractants for the separation of lanthanum and actinium from radioactive waste liquid. This method breaks through the technical bottleneck in extractant production and the constraints on market supply, reduces its production and use costs, ensures the sustainable development of nuclear energy, and enables the recovery and reuse of high-value-added minor actinide nuclides in high-level radioactive waste liquid by improving the solubility of the extractant.

[0051] 2. The extraction agent preparation method of the present invention is simple and feasible, and has the advantages of simple reaction system, high product yield, short production cycle, simple processing technology and low energy consumption. The raw materials are inexpensive and easy to obtain, and easy to industrialize. It can meet the requirements of extraction agent for the separation of lanthanum and actinium in high-level radioactive waste liquid, and has broad application prospects in the field of high-level radioactive waste liquid treatment.

[0052] 3. Aromatic ring-substituted BTP, BTBP, and BTPhen have poor solubility in organic phases, which limits their application in the separation of lanthanum and actinium from high-level radioactive waste. This invention solves the solubility problem of the extractant by introducing a hydrophilic group, thus expanding the application of aromatic ring-substituted BTP, BTBP, and BTPhen extractants in the field of actinide element back-extraction agents.

[0053] 4. This invention does not require the use of a catalyst or inert gas protection; it can achieve short cycles and high yields for nucleophilic addition and condensation cyclization steps simply by adjusting the type and amount of solvent.

[0054] 5. This invention lowers the reaction temperature of the substitution reaction by changing the sulfonating agent, while maintaining a high yield;

[0055] 6. This invention employs phase inversion to separate and purify (substitution reaction products), pressure filtration for solid-liquid separation, fluidized bed drying, and other product processing methods, resulting in a short production cycle and low energy consumption;

[0056] 7. This invention can increase the purity of sulfonated products to over 98% through simple recrystallization;

[0057] 8. This invention discloses for the first time a kilogram-scale synthesis method for water-soluble BTP, BTBP, and BTPhen extractants, solving the problem of extractant market supply, reducing extractant usage costs, and is of great significance for the treatment of high-level radioactive waste liquid and the extraction of high-value-added nuclides.

[0058] 9. The raw materials for the extractant of this invention are inexpensive and widely available in the market. The market price of aryl-substituted hydrophilic BTP / BTBP / BTPhen is approximately 3 million RMB / kg, and there is a shortage of supply. The in-house synthesis of this type of extractant can reduce its usage cost by two orders of magnitude (<20,000 RMB / kg). Attached Figure Description

[0059] Figure 1 The hydrogen NMR spectrum of Ph-BTP;

[0060] Figure 2 ESI-MS image of Ph-BTP in positive ion mode;

[0061] Figure 3 This is the positive ion mode ESI-MS image of sulfonated Ph-BTP. Detailed Implementation

[0062] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc., used can be purchased from chemical companies or prepared by existing methods.

[0063] Example 1

[0064] Synthesis of hydrophilic sulfonated Ph-BTP

[0065] Nucleophilic addition: 0.77 kg of diformonium I (2,6-pyridinediformonium), 8 L of anhydrous ethanol, and 2 L of tetrahydrofuran were added to a jacketed reactor. The cryogenic cooling liquid circulation pump was started, and when the temperature inside the reactor was around 0 °C, 3 L of hydrazine hydrate was added dropwise. After the hydrazine hydrate addition was completed, the temperature inside the reactor was maintained at 30 °C, and the mixture was stirred for 12 hours. After the reaction was completed, solid-liquid separation was performed using a filter press. The product was washed with pretreated ethanol and finally dried in a drying oven to obtain 1.09 kg of the target product, amide hydrazone I, with a yield of 95%.

[0066] Condensation cyclization: 2.2 kg of phenylethylene glycol and 70 L of tetrahydrofuran were added to a jacketed reactor equipped with a reflux condenser. Then, 1.0 kg of powdered amide hydrazone I was added while stirring. The reaction was carried out at 70 °C for 5 hours with stirring. After the reaction was completed and cooled to room temperature, the product was separated and dried according to the method described in the nucleophilic addition step above, finally yielding 2.72 kg of the target product Ph-BTP, with a yield of 96.9%. The 1H NMR spectrum of the target product Ph-BTP is shown below. Figure 1 The positive ion mode ESI-MS image is shown below. Figure 2 .

[0067] Sulfonation: 0.9 kg of Ph-BTP was added to a jacketed reactor equipped with a reflux condenser. 35 L of 20% fuming sulfuric acid was slowly added dropwise to the system, and mechanical stirring was started. After the addition was complete, the mixture was refluxed at 180 °C for 1.5 h. After the reaction system cooled to room temperature, the reaction mixture was added dropwise to 800 L of acetone, and the product precipitated. The product was then separated and dried according to the method described in the nucleophilic addition step above, yielding 1.39 kg of the target product, with a yield of 97%. The positive ion mode ESI-MS chromatogram of sulfonated Ph-BTP is shown below. Figure 3 .

[0068] Example 2

[0069] Synthesis of hydrophilic sulfonated Ph-BTP

[0070] Nucleophilic addition: 0.77 kg of diformonium I (2,6-pyridinediformonium), 49 L of anhydrous ethanol, and 1 L of chloroform were added to a jacketed reactor. The cryogenic cooling liquid circulation pump was started, and when the temperature inside the reactor reached approximately 0 °C, 5 L of hydrazine hydrate was added dropwise. After the addition of hydrazine hydrate was completed, the temperature inside the reactor was maintained at 35 °C, and the mixture was stirred for 6 hours. After the reaction was completed, solid-liquid separation was performed using a filter press. The product was washed with pretreated ethanol and finally dried in a drying oven to obtain 1.08 kg of the target product, amide hydrazone I, with a yield of 94%.

[0071] Condensation cyclization: 4.4 kg of phenylethylene glycol, 20 L of tetrahydrofuran, and 0.5 L of chloroform were added to a jacketed reactor equipped with a reflux condenser. Then, 1.0 kg of powdered amide hydrazone I was added while stirring, and the mixture was stirred at 70 °C for 15 hours. After the reaction was completed and cooled to room temperature, the product was separated and dried according to the method described in the nucleophilic addition step above, finally yielding 5.44 kg of the target product Ph-BTP, with a yield of 97%.

[0072] Sulfonation: 0.9 kg of Ph-BTP was added to a jacketed reactor equipped with a reflux condenser. 5 L of 50% fuming sulfuric acid was slowly added dropwise to the system while mechanical stirring was started. After the addition was complete, the mixture was refluxed at 150 °C for 0.5 h. After the reaction system cooled to room temperature, the reaction mixture was added dropwise to 600 L of ethyl acetate, and the product precipitated. The product was then separated and dried according to the method described in the nucleophilic addition step above, yielding 1.33 kg of the target product, with a yield of 93%.

[0073] Example 3

[0074] Synthesis of hydrophilic sulfonated Ph-BTP

[0075] Nucleophilic addition: 3.5 kg of diformonium I, 59 L of anhydrous ethanol, and 1 L of dimethyl sulfoxide were added to a jacketed reactor. The cryogenic cooling liquid circulation pump was started, and when the temperature inside the reactor reached approximately 0 °C, 15 L of hydrazine hydrate was added. After the hydrazine hydrate addition was completed, the temperature inside the reactor was maintained at 30 °C, and the mixture was stirred for 15 hours. After the reaction was completed, solid-liquid separation was performed using a filter press. The product was washed with pretreated ethanol and finally dried in a drying oven to obtain 5.1 kg of the target product, amide hydrazone I, with a yield of 97%.

[0076] Condensation cyclization: 9 kg of phenylethylene glycol, 69 L of anhydrous ethanol, and 1 L of chloroform were added to a jacketed reactor equipped with a reflux condenser. Then, 4.1 kg of powdered amide hydrazone I was added while stirring, and the mixture was stirred at 80 °C for 12 hours. After the reaction was completed and cooled to room temperature, the product was separated and dried according to the method described in the nucleophilic addition step above, finally yielding 11.26 kg of the target product Ph-BTP, with a yield of 98%.

[0077] Sulfonation: 0.9 kg of Ph-BTP was added to a jacketed reactor equipped with a reflux condenser. 20 L of 20% fuming sulfuric acid was slowly added dropwise to the system, and mechanical stirring was started. After the addition was complete, the mixture was refluxed at 150 °C for 2 h. After the reaction system cooled to room temperature, the reaction mixture was added dropwise to 500 L of tetrahydrofuran, and the product precipitated. The product was then separated and dried according to the method described in the nucleophilic addition step above, yielding 1.29 kg of the target product, with a yield of 90%.

[0078] Example 4

[0079] Nucleophilic addition: Anhydrous ethanol was used as the solvent, and the operation steps and other process parameters were the same as in Example 2, with a final yield of 98%.

[0080] Condensation cyclization: 4.5 kg of phenylethylene glycol and 35 L of anhydrous ethanol / dimethyl sulfoxide mixed solvent (anhydrous ethanol / dimethyl sulfoxide = 6 g / L) were added to a jacketed reactor equipped with a reflux condenser. Then, 2 kg of powdered amide hydrazone I was added while stirring, and the mixture was stirred at 80 °C for 8 hours. After the reaction was completed and cooled to room temperature, the product was separated and dried according to the method described in the nucleophilic addition step above, finally yielding 5.44 kg of the target product Ph-BTP, with a yield of 97%.

[0081] Sulfonation: The reaction temperature was 90°C. The phase inversion agent used for product treatment was an acetone / benzene (49 / 1) mixed solvent, with a volume of 500 L. The operating steps and other process parameters were the same as in Example 2, and the final yield was 94%.

[0082] Example 5

[0083] Synthesis of hydrophilic sulfonated Ph-BTBP

[0084] Nucleophilic addition: 0.8 kg of diformonium II (2,2′-bipyridine-6,6′-diformonium) and 50 L of anhydrous ethanol were added to a jacketed reactor. The cryogenic cooling liquid circulation pump was started, and 6 L of hydrazine hydrate was added when the temperature inside the reactor reached approximately 0 °C. After the hydrazine hydrate was added dropwise, the temperature inside the reactor was maintained at 40 °C, and the mixture was stirred for 10 hours. After the reaction was completed, the product was filtered, washed, and dried to obtain 0.98 kg of the target product, amide hydrazone II, with a yield of 93%.

[0085] Condensation cyclization: 0.78 kg of phenylethylene glycol, 1.5 L of dimethyl sulfoxide, and 68.5 L of tetrahydrofuran were added to a jacketed reactor equipped with a reflux condenser. Then, 0.5 kg of powdered amide hydrazone II was added while stirring, and the mixture was stirred at 70 °C for 5 hours. After the reaction was completed and cooled to room temperature, the product was separated and dried according to the method described in the nucleophilic addition step above, finally yielding 1.08 kg of the target product Ph-BTBP, with a yield of 94%.

[0086] Sulfonation: 1.4 kg of Ph-BTBP was added to a jacketed reactor equipped with a reflux condenser. 5.7 L of 50% fuming sulfuric acid was slowly added dropwise to the system while mechanical stirring was started. After the addition was complete, the mixture was refluxed at 130 °C for 1 h. After the reaction system cooled to room temperature, the reaction mixture was added dropwise in 1100 L of a mixed solvent of acetone / ethyl acetate, causing the product to precipitate. The product was then separated and dried according to the method described in the nucleophilic addition step above, yielding 1.98 kg of the target product, with a yield of 93%.

[0087] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for the preparation of a kilogram-scale water-soluble nitrogen-containing actinide extractant, characterized in that, Includes the following steps: S1. Synthesis of amide hydrazone via nucleophilic addition reaction: Add hydrated or anhydrous hydrazine to a dimethyl nitrile solution, perform a nucleophilic addition reaction, and then separate the solid and liquid phases to obtain amide hydrazone; S2. Synthesis of pyridine triazine derivatives via condensation cyclization reaction: The ground amide hydrazone and diphenyl ethylene glycol are dispersed or dissolved in a solvent, and after condensation cyclization reaction, the pyridine triazine derivatives are obtained by solid-liquid separation. S3. Obtaining the extractant via substitution reaction: Add a sulfonating agent to a pyridine triazine derivative, reflux to carry out the substitution reaction, and then slowly add the reaction mixture dropwise to a phase inversion agent to precipitate and obtain the extractant; The dimethyl nitrile has the following structure: The amide hydrazone has the following structure: The pyridine triazine derivative has the following structure: The extractant has the following structure: Step S1: Add dimethylnitrile to the jacketed reactor, then add solvent to dissolve or disperse it. When the temperature inside the reactor is controlled at -2℃ to 2℃, add hydrazine hydrate or anhydrous hydrazine dropwise. After the dropwise addition is completed, raise the temperature to 15 to 50℃ and stir the reaction for 6 to 24 hours. After the reaction is completed, pump the mixture into a filter press or hydrocyclone for solid-liquid separation. After washing the filter cake several times, dry it in a drying device. The solvent in the dicarboxynitrile solution in step S1 is one or a mixture of two or more of the following: tetrahydrofuran, anhydrous ethanol, benzene, dimethyl sulfoxide, dichloromethane, chloroform, dioxane, petroleum ether, and deionized water. Step S2: The ground amide hydrazone and diphenyl ethylene glycol are dispersed or dissolved in a solvent and reacted at 40–110°C for 3–72 h. After the reaction is completed, the mixture is pumped into a filter press or hydrocyclone for solid-liquid separation. The filter cake is washed several times and then dried in a drying device. The solvent mentioned in step S2 is one or more of the following: benzene, toluene, chloroform, dichloromethane, dichloroethane, 1,1-difluoro-1,2-dichloroethane, trichloroethane, tetrachloroethane, dioxane, dimethyl sulfoxide, tetrahydrofuran, and anhydrous ethanol. Step S3: Add the pyridine triazine derivative obtained in step S2 to a jacketed reactor equipped with a reflux condenser, add the sulfonating agent, start mechanical stirring, and reflux the reaction at 50-200°C for 0.5-8 hours. After the reaction system cools to room temperature, slowly add the reaction mixture dropwise to the phase inversion agent. The product precipitates, and after pressure filtration, washing, and drying, a solid product is obtained. The sulfonating agent mentioned in step S3 is one of concentrated sulfuric acid and fuming sulfuric acid; The phase inversion agent mentioned in step S3 is one or more of the following: methyl formate, ethyl acetate, dioxane, tetrahydrofuran, acetone, chloroform, dichloromethane, benzene, toluene, xylene, pyridine, and alkanes. The preparation method described herein is used for production with a capacity of 0.1 to 1000 kg / batch.

2. The method for preparing the kilogram-scale water-soluble nitrogen-containing actinide element extractant according to claim 1, characterized in that, The solid product obtained by drying in step S3 is further purified by recrystallization. The recrystallization solvent used in the product purification is one of water, methanol, or ethanol.

3. The method for preparing the kilogram-scale water-soluble nitrogen-containing actinide element extractant according to claim 1, characterized in that, In step S1, the volume molar ratio of the solvent to the dimethyl nitrile is 0.2–50 L / mol. In step S1, the volume molar ratio of hydrazine hydrate or anhydrous hydrazine to dimethylnitrile is 0.1–5 L / mol.

4. The method for preparing the kilogram-scale water-soluble nitrogen-containing actinide element extractant according to claim 1, characterized in that, In step S2, the volume molar ratio of the solvent to the amide hydrazone is 0.5–100 L / mol.

5. The method for preparing the kilogram-scale water-soluble nitrogen-containing actinide element extractant according to claim 1, characterized in that, The volume molar ratio of the sulfonating agent to the pyridine triazine derivative in step S3 is 1-100 L / mol.

6. The method for preparing the kilogram-scale water-soluble nitrogen-containing actinide element extractant according to claim 1, characterized in that, The volume molar ratio of the phase inversion agent to the extractant in step S3 is 100-1500 L / mol.

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