A method for separating rhenium and technetium

Abstract

The present invention uses ReO 4 ‑ and / or 99 T8h 4 ‑ The amide extractant with unique extraction effect is used for liquid phase extraction, with high extraction and stripping rates, which can achieve ReO 4 ‑ and / or 99 T8h 4 ‑ This type of extractant has good selectivity under high acid conditions. For example, D2EHAG extractant is different from previous extractants in that it can 3 ‑ with ReO 4 ‑ The selectivity of D2EHAG to ReO 4 ‑ The removal rate is still close to 70%, and the extraction effect is very good). This type of extractant has a good extraction effect under high acid conditions (when the acid concentration is 1-6 mol / L), among which PELLAG extractant has the best extraction effect under high acid conditions of 1 mol / L. This type of extractant can directly separate ReO with an alkaline stripping agent in one step. 4 ‑ and / or 99 T8h 4 ‑ The process is simple, requires few equipments and is suitable for industrial use.

Description

Technical Field

[0001] The present invention belongs to the field of separation and extraction technology, and specifically relates to a method for efficiently separating ReO4 - and 99 TcO4 - method. Background Art

[0002] Radioactive artificial nuclide technetium-99 ( 99 Tc) is mainly composed of 235 U is produced by fission, which has a high fission yield (6.13%) and a long half-life (2.13×10 5 a) High solubility in water (11.3 mol / L), mainly TcO4 - Form exists. 99 Tc exhibits high mobility in groundwater and biological systems and is extremely easy to volatilize and leak during post-treatment. 99 If Tc leaks into the environment, it will accumulate in groundwater, soil, microorganisms, and plants and animals, posing a long-term potential hazard to humans and the entire ecosystem. Therefore, Tc is one of the most important radionuclides in the environmental radioactivity safety assessment process. In recent years, with the continuous vigorous development of the nuclear industry, radionuclides 99 Tc content continues to soar. How to effectively and selectively remove it from high-level radioactive wastewater? 99 TcO4 - It has become one of the essential key technologies in the nuclear industry. Summary of the Invention

[0003] To solve the above technical problems, the present invention first provides a compound shown in the following formula I:

[0004]

[0005] wherein R is selected from the following groups which are unsubstituted or optionally substituted by one, two or more Rs: 1-12 Alkyl, C 6-20 Aryl or 5-20 membered heteroaryl;

[0006] Rs is selected from halogen, -CN, C 1-12 Alkyl, C 1-12 Alkoxy or halogenated C 1-12 alkyl;

[0007] a and b are the same or different and are independently selected from 1, 2, 3, 4, 5 or 6.

[0008] In some embodiments of the present invention, R is selected from C 1-8 Alkyl or C 6-12 Aryl; a, b are the same or different and are independently selected from 1, 2 or 3.

[0009] In some preferred embodiments of the present invention, R is selected from phenyl or the following groups:

[0010] * indicates the connection site; a and b are 1.

[0011] The present invention also provides a method for preparing the compound represented by formula I, comprising the following steps:

[0012]

[0013] Wherein, R, a, and b have the above definitions; L is a leaving group;

[0014] Compound Ia reacts with compound Ib to obtain compound Ic, and compound Ic further reacts with compound Id to obtain compound I.

[0015] In some embodiments of the present invention, L is a halogen, such as chlorine.

[0016] In some embodiments of the present invention, the molar ratio of Compound Ia to Compound Ib is 1:1-5.

[0017] In some embodiments of the present invention, the reaction of Compound Ia with Compound Ib is carried out in the presence of an acid binder, for example, in the presence of triethylamine.

[0018] In some embodiments of the present invention, the reaction of Compound Ia and Compound Ib is carried out at room temperature for 1-12 hours, for example, 2-6 hours.

[0019] In some embodiments of the present invention, the reaction of Compound Ic with Compound Id is carried out in a methanolic sodium hydroxide solution.

[0020] In some embodiments of the present invention, the reaction temperature of Compound Ic and Compound Id is 40-80° C., and the reaction time is 1-24 h.

[0021] The present invention also provides a compound represented by the above formula I or a compound represented by the following formula I' for separating and extracting ReO4 - and / or 99 TcO4 - Use in

[0022] Wherein, the compound represented by formula I' is selected from the following structures:

[0023]

[0024] Wherein, R1 and R2 are the same or different and are independently selected from the following groups which are unsubstituted or optionally substituted by one, two or more Rq:1-12 Alkyl, C 6-20 Aryl or 5-20 membered heteroaryl;

[0025] Rq is selected from halogen, -CN, C 1-12 Alkyl, C 1-12 Alkoxy or halogenated C 1-12 alkyl;

[0026] c and d are the same or different and are independently selected from 1, 2, 3, 4, 5 or 6.

[0027] In some embodiments of the present invention, the compound represented by Formula I' is D2EHAG.

[0028] The present invention also provides a method for separating and extracting ReO4 from the compound represented by formula I or formula I'. - and / or 99 The method of Tc comprises the following steps:

[0029] Containing ReO4 - and / or 99 TcO4 - and competitive anion NO3 - 、Cl - 、SO4 2- Spent fuel reprocessing waste liquid or containing ReO4- and / or 99 The metal solution of TcO4-, H2SO4, HCl, HNO3 high acid is mixed with the compound shown in formula I or formula I', shaken, centrifuged, ReO4 - and / or 99 TcO4 - into the extractant.

[0030] In some embodiments of the present invention, the method further comprises a stripping step, wherein a stripping agent is added to the extractant layer for stripping, oscillation, centrifugation, and ReO4 - and / or 99 TcO4 - It is back-extracted into the aqueous phase;

[0031] The stripping agent is selected from one of HCl, H2SO4, HNO3 and NH4OH solution.

[0032] In some embodiments of the invention, the extraction is performed at room temperature.

[0033] In some embodiments of the present invention, the pH of the system during extraction is less than 8, preferably less than 7 or 4.

[0034] In some embodiments of the present invention, ReO4 - and / or 99 TcO4- Competitive anion SO4 2- 、NO3 - 、Cl - The concentration ratio (ppm) of each is 1:1~10000, and ReO4 - and / or 99 TcO4 - Competing anion SO4 2- 、NO3 - 、Cl - The total concentration ratio of the mixture is 1:1~10000, where C SO42- :C NO3- :C Cl- =1:1:1, for example, 1:10, 1:100, 1:1000.

[0035] In some embodiments of the present invention, the concentration of the acid in the highly acidic metal solution is 0.01-6M, such as 0.1-3M, for example 1-1.5M.

[0036] In some embodiments of the present invention, the concentration of the extractant is 10-60 mmol, such as 20-50 mmol, such as 30-40 mmol.

[0037] In some preferred embodiments of the present invention, the stripping agent used in the stripping is selected from NH4OH solution.

[0038] In some embodiments of the present invention, the concentration of the stripping agent is 0.001-0.01, for example 0.05 mol / L.

[0039] In some embodiments of the present invention, the method further comprises the step of activating the extractant with an acidic reagent, such as H2SO4, after the stripping is completed, and then recycling the extractant.

[0040] In one embodiment of the present invention, the separation of ReO4 - and / or 99 TcO4 - The method comprises the following steps: using D2EHAG or M2EHAG or PELLAG as an extractant, during the extraction: at room temperature and pH less than 8.0 (pH of PELLAG < 8), - and / or 99 TcO4 - 、NO3 - 、Cl - 、SO4 2- (C ReO4- :C 竞争阴离子=1:n (n=1, 10, 100, 1000, 10000)) or spent fuel reprocessing wastewater containing a large number of competitive anions or ReO4 - / 99 TcO4 - , H2SO4, HCl, HNO3 (concentration of 0.01-6M) and other high acid metal solutions are mixed with different concentrations (10-50mmol) of D2EHAG or M2EHAG or PELLAG extractants, and shaken on a shaker at 150-200rpm for 1-5min; after shaking, centrifuge at 2500-5000rpm, ReO4 - and / or 99 TcO4 - Enter the extractant; during back extraction: add alkaline reagent (0.01-6M) to the extractant layer for back extraction, oscillate on an oscillator at 150-200rpm, and the oscillation time is within 1-5min; after the oscillation is completed, centrifuge at 2500-5000rpm, ReO4 - and / or 99 TcO4 - The metal ion concentration in the aqueous phase was measured using an inductively coupled plasma atomic emission spectrometer (ICP-OES).

[0041] Beneficial effects of the present invention:

[0042] (1) The present invention uses ReO4 - and / or 99 TcO4 - The amide extractant with unique extraction effect is used for liquid phase extraction, with high extraction and stripping rates, which can achieve ReO4 - and / or 99 TcO4 - recycling.

[0043] (2) This type of extractant has unsaturated metal sites and contains four elements: C, H, O, and N. It is low-cost, environmentally friendly, and highly soluble. It contains different organic ligands such as oxygen and nitrogen and has different extraction properties.

[0044] (3) This type of extractant has good selectivity under high acid conditions. For example, D2EHAG extractant is different from previous extractants in that it has good selectivity under competitive anion NO3 - With ReO4 - The selectivity of D2EHAG to ReO4 is as high as 1000:1. - The removal rate is still close to 70%, and the extraction effect is very excellent).

[0045] (4) This type of extractant has a good extraction effect under high acid conditions (acid concentration is 1-6 mol / L), among which PELLAG extractant has the best extraction effect under high acid conditions of 1 mol / L.

[0046] (5) This type of extractant can be used to directly separate ReO4 using an alkaline stripping agent in one step. - and / or 99 TcO4 - The process is simple, requires few equipment, and is suitable for industrial use.

[0047] In summary, the extractant of the present invention has a fast extraction speed (≤1 min), high selectivity, and the D2EHAG extraction rate can reach 98%, which has broad application prospects.

[0048] Definitions and Explanations of Terms

[0049] Unless defined otherwise, all technical and scientific terms herein have the same meaning as commonly understood by one of ordinary skill in the art to which the claimed subject matter belongs.

[0050] because 99 TcO4 - It is radioactive, and rhenium (ReO4 - ) were studied, so although the extraction target of the compound of the present application is ReO4 - However, those skilled in the art will appreciate that this compound is also suitable for extracting 99 TcO4 - , and with ReO4 - The extraction effect is comparable.

[0051] "Halogen" means fluorine, chlorine, bromine or iodine.

[0052] The term "C 1-12 "Alkyl" is understood to mean a straight-chain or branched saturated monovalent hydrocarbon group having 1 to 12 carbon atoms. For example, "C 1-6 The term "alkyl" refers to straight-chain and branched alkyl groups having 1, 2, 3, 4, 5, or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, or isomers thereof.

[0053] The term "C1-12 "Alkoxy" should be understood as -OC 1-12 Alkyl, where C 1-12 The alkyl group has the same definition as above.

[0054] The term "C 6-20 "Aryl" is understood to mean a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring having 6 to 20 carbon atoms, preferably "C 6-14 Aryl". The term "C 6-14 "Aryl" is understood to mean preferably a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring ("C 6-14 or a ring having 9 carbon atoms ("C9 aryl"), for example indanyl or indenyl, or a ring having 10 carbon atoms ("C 10 aryl) such as tetrahydronaphthyl, dihydronaphthyl or naphthyl, or a ring having 13 carbon atoms ("C 13 aryl), such as fluorenyl, or a ring having 14 carbon atoms ("C 14 aryl”), such as anthracenyl. When the C 6-20 When the aryl group is substituted, it may be monosubstituted or polysubstituted. Furthermore, there is no limitation on the position of substitution, and for example, substitution may be at the ortho, para or meta position.

[0055] The term "5-20 membered heteroaryl" is understood to include monovalent monocyclic, bicyclic or tricyclic aromatic ring systems having 5 to 20 ring atoms and containing 1 to 5 heteroatoms independently selected from N, O and S, for example "5-14 membered heteroaryl". The term "5-14 membered heteroaryl" is understood to include monovalent monocyclic, bicyclic or tricyclic aromatic ring systems having 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 ring atoms, in particular 5 or 6 or 9 or 10 carbon atoms, and containing 1 to 5, preferably 1 to 3 heteroatoms each independently selected from N, O and S and, in addition, in each case may be benzo-fused. In particular, the heteroaryl group is selected from thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thia-4H-pyrazolyl and the like and benzo derivatives thereof, such as benzofuranyl, benzothienyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, benzotriazolyl, indazolyl, indolyl, isoindolyl and the like; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl and the like and benzo derivatives thereof, such as quinolyl, quinazolinyl, isoquinolyl and the like; or acininyl, indolizinyl, purinyl and the like and benzo derivatives thereof; or cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is the structural diagram of M2EHAG, PELLAG, and D2EHAG.

[0057] Figure 2 FT-IR images of M2EHAG, PELLAG and D2EHAG prepared in the present invention.

[0058] Figure 3 The results of the reaction of M2EHAG, PELLAG and D2EHAG on ReO4 at different times when the pH value of the aqueous phase is 0.5 are shown in FIG. - extraction rate.

[0059] Figure 4 The M2EHAG, PELLAG and D2EHAG in the present invention are different acid types and concentrations of ReO4 in the aqueous phase. - The extraction rate below.

[0060] Figure 5 The M2EHAG, PELLAG and D2EHAG of the present invention extract ReO4 when the pH value of the aqueous phase is 0.5-8. - extraction rate.

[0061] Figure 6The M2EHAG of the present invention has different competitive anions in different proportions in the aqueous phase for ReO4 - The extraction rate (of which SO4 2- / NO3 - / Cl - represents the sum of the three ion concentrations).

[0062] Figure 7 The PELLAG of the present invention has different competitive anions in different proportions in the aqueous phase for ReO4 - The extraction rate (of which SO4 2- / NO3 - / Cl - represents the sum of the three ion concentrations).

[0063] Figure 8 The D2EHAG of the present invention has different competitive anions in different proportions in the aqueous phase to ReO4 - The extraction rate (of which SO4 2- / NO3 - / Cl - represents the sum of the three ion concentrations).

[0064] Figure 9 The effects of different stripping agents on ReO4 at different concentrations of D2EHAG in the aqueous phase are shown in the following table: - stripping rate.

[0065] Figure 10 This is a cyclic extraction experiment of D2EHAG in the present invention. DETAILED DESCRIPTION

[0066] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0067] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0068] The calculation method of the removal rate and extraction rate in the following example is:

[0069] Among them, C0 and C e represent the initial concentration and equilibrium concentration of metal ions (mg / L), respectively.

[0070] The stripping rate is calculated as:

[0071] Among them, C0 and Ce represent the initial concentration and equilibrium concentration of metal ions (mg / L), respectively.

[0072] Unless otherwise stated, in this application, inductively coupled plasma atomic emission spectrometry (ICP-OES) was used to measure the concentration of metal ions in the aqueous phase.

[0073] Example 1

[0074] The extractants of the present invention (M2EHAG, PELLAG, D2EHAG) are synthesized by chemical synthesis method, and the specific implementation steps are as follows:

[0075] Dissolve diisooctylamine (30.5 mL, 0.1 mol) and triethylamine (14 mL, 0.1 mol) in dichloromethane, then slowly add chloroacetyl chloride (9.6 mL, 0.12 mol) and stir at room temperature for 3 hours (500-1000 rpm). Add a small amount of activated carbon to the resulting mixture, filter it, and wash it several times with approximately 0.1 mol / L hydrochloric acid to remove unreacted amine salts. The organic phase is washed several times with deionized water. Rotary evaporation removes the dichloromethane and water from the solution to obtain CDEHAA (2-chloro-N,N-di(2-ethylhexyl)-acetamide), a yellow liquid. Dissolve glycine (15 g, 0.2 mol) and sodium hydroxide (8 g, 0.2 mol) in methanol, then add the CDEHAA solution (12.658 g, 0.04 mol) dropwise to the mixture, stirring at 60°C for 15 hours (500-1000 rpm). The methanol in the solution was removed by rotary evaporation, and dichloromethane was added to dissolve the mixture. A small amount of activated carbon was added to the solution, which was then filtered and washed multiple times with 1.0 mol / L sulfuric acid. The organic phase was washed multiple times with deionized water. The dichloromethane and water in the solution were removed by rotary evaporation to obtain D2EHAG, a yellow viscous liquid, which was then freeze-dried. The synthesis methods of M2EHAG and PELLAG are similar to those of D2EHAG, except that diisooctylamine is replaced with isooctylamine or β-phenylethylamine.

[0076] The structure of the newly obtained extractant is as follows Figure 1 The extractant was characterized by Fourier transform infrared spectroscopy (FT-IR), and the results were as shown in Figure 2 As shown in the figure, the presence of the main functional groups in the FT-IR spectra of D2EHAG, M2EHAG and PELLAG proves that their synthesis is successful. D2EHAG: FT-IR (v / cm -1 ),1730(-C=O),1650(NC=O); M2EHAG:FT-IR(v / cm -1 ),1660(-C=O),1560(NC=O),3280(-NH); PELLAG: FT-IR(v / cm -1), 1640 (-C=O), 1540 (N-C=O), 3280 (-NH).

[0077] Example 2

[0078] Several highly efficient extractants for separating ReO4 - Test on extraction reaction time of extractants

[0079] Add 50 mmol / L of the three extractants prepared in Example 1 to a metal mixed solution containing 10 ppm of ReO4 - respectively. Shake the mixture in a shaker at room temperature of 200 rpm, and detect the extraction amount of metals by inductively coupled plasma atomic emission spectroscopy. The results are as Figure 3 shown. All three extractants can quickly reach extraction equilibrium within 1 minute. All three extractants have good extraction ability for ReO4 - , and the extraction ability increases in the order of PLLAG < M2EHAG < D2EHAG.

[0080] Example 3

[0081] Several highly efficient extractants for separating ReO4 - Test on acid resistance of extractants

[0082] The types and concentrations of acids in the extraction aqueous phase have the following effects on the extraction of ReO4 by three amido acid extractants - as Figure 4 shown. The results show that as the concentrations of H2SO4, HCl, and HNO3 in the aqueous phase increase from 0.01 mol / L to 6 mol / L, the removal rates of ReO4 by M2EHAG decrease from 86.75% to 58.06%, from 88.07% to 29.31%, and from 84.02% to 10.61% respectively; the removal rates of ReO4 by D2EHAG decrease from 98.29% to 59.43%, from 98.7% to 40.31%, and from 97.41% to 14.52% respectively; since PELLAG is sensitive to pH, with the increase of acid concentration, it shows a trend of first increasing and then decreasing, generally reaching a peak at 1 mol / L. The removal rates of ReO4 increase from 54.46% to 65.70% and then decrease to 55.81%, from 37.90% to 53.39% and then decrease to 33.64%, from 30.07% to 28.66% and then decrease to 11.85% respectively. The influence of pH on the extraction of ReO4 - is as - shown. As the pH increases, the extraction rate of PELLAG continuously decreases. When the pH is about 4, for ReO4 - the extraction rate is as follows: it increases from 54.46% to 65.70% and then decreases to 55.81%, from 37.90% to 53.39% and then decreases to 33.64%, from 30.07% to 28.66% and then decreases to 11.85%. The influence of pH on the extraction of ReO4 - is as Figure 5 shown. As the pH increases, the extraction rate of PELLAG continuously decreases. When the pH is about = 4, for ReO4 -The extraction rate is reduced to 0%. Under the conditions of pH = 0.5 - 7.0, for M2EHAG and D2EHAG, the extraction rate of ReO4 - shows little change, and the extraction rates fluctuate around 95% and 80% respectively. However, when pH ≥ 7, the extraction rate drops steeply, and almost no ReO4 - is extracted.

[0083] Generally speaking, the three amido acid extractants still have good extraction ability for ReO4 - under high acid conditions, and the influence of acidity increases in the order of H2SO4 < HCl < HNO3. Under acidic conditions, the extraction ability of the D2EHAG extractant is better than that of M2EHAG and PLLAG.

[0084] Example 4

[0085] Testing of competitive anions of several extractants for efficient separation of ReO4 - The test results of the extraction behavior of D2EHAG, M2EHAG and PELLAG for ReO4

[0086] in the presence of high-strength competitive anions SO4 2- , NO3 - , Cl - are shown as follows (since PELLAG is sensitive to pH, the pH of its aqueous phase is set to 0.5). - As shown. Figure 6-8 As shown in the figure.

[0087] Figure 6 The results show that: as the concentration ratio (ppm) of SO4 2- , NO3 - and Cl - to ReO4 - in the aqueous phase increases from 1:1 to 10000:1, the removal rates of ReO4 - by M2EHAG decrease from 83.60% to 68.08%, from 83.60% to 23.47%, and from 84.29% to 38.60% respectively.

[0088] Figure 7 The results show that: at pH = 0.5, as the concentration ratio (ppm) of SO4 2- , NO3 - and Cl - to ReO4 - in the aqueous phase increases from 1:1 to an extreme 10000:1, the removal rates of ReO4 - by PELLAG decrease from 68.43% to 65.79%, from 68.21% to 14.22%, and from 66.14 to 1.63% respectively.

[0089] Figure 8 The results show that when the concentration ratio (ppm) of SO4 in the aqueous phase 2- to ReO4 - is from 1:1 to 10000:1, the removal rate of ReO4 by D2EHAG - is above 90%, showing very excellent selectivity. When the concentration ratio of Cl - to ReO4 - increases from 1:1 to 10000:1, the removal rate of ReO4 - only decreases from 98.98% to 72.72%, that is, it shows good selectivity. When the concentration ratio of NO3 in the aqueous phase - to ReO4 - is as high as 1000:1, the removal rate of ReO4 by D2EHAG - is still close to 70%, that is, the selectivity is very excellent. Therefore, we increased the concentration ratio of NO3 - to ReO4 - to an extreme 10000:1, which is the most extreme condition reported. The results show that the extraction rate of ReO4 by D2EHAG - can still reach 37.18%, and the extraction effect is very excellent.

[0090] Generally speaking, the three amido acid extractants still have good extraction ability for ReO4 - under the condition of the presence of competitive anions, and the extraction ability increases in the order of PLLAG < M2EHAG < D2EHAG. The influence order of competitive anions in the aqueous phase on the extraction of ReO4 by amido acid extractants - is NO3 - > Cl - > SO4 2- . The extraction ability and selectivity effect of the D2EHAG extractant are better than those of M2EHAG and PLLAG.

[0091] Example 4

[0092] Extraction cycle experiment of D2EHAG for ReO4 - Specifically, in the stripping process, the upper-layer extractant was taken for filtration, and different concentrations of HCl, H2SO4, HNO3 and NH4OH solutions were added for stripping. The mixture was placed in a shaker at room temperature of 200 rpm for 1 min, centrifuged for 3 min, and the aqueous solution was filtered. The stripping amount of metals was detected by inductively coupled plasma atomic emission spectrometry. The results are as Figure 9 ​​​When HCl, H2SO4, and HNO3 were used as the stripping aqueous phase, the stripping effect was poor. Even under 6M HCl, H2SO4, and HNO3, the stripping rates were only 50%, 20%, and 80%, respectively. When ammonia water was used as the stripping aqueous phase, a stripping rate of 98.73% was achieved at an ammonia concentration of 0.05 mol / L. Therefore, ammonia water is a good stripping agent, and 0.05 mol / L ammonia solution was selected as the stripping aqueous phase in subsequent cycle experiments.

[0094] like Figure 10 As shown, the stripping regeneration process first utilizes a 0.05 mol / L ammonia solution, followed by activation of D2EHAG with 0.05 M H2SO4. Experimental results show that after five extraction-stripping cycles, the extraction yield of D2EHAG remains around 98%. Although the stripping efficiency decreases slightly, it remains consistently above 95%. This demonstrates the excellent recyclability of D2EHAG and its promising industrial application prospects.

[0095] The present invention uses M2EHAG, PELLAG and D2EHAG as extractants to screen a - and / or 99 TcO4 - The extractant has a unique extraction effect. The extractant was subjected to continuous extraction experiments and repeated five times, and the extraction capacity did not change significantly. In acidic media, it can be almost completely stripped out, achieving ReO4 - and / or 99 TcO4 - It can be fully recycled and still has good extraction ability under high acid conditions, proving that it is very practical and has good industrial application prospects.

[0096] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. Separation and extraction of ReO4 from the compound represented by formula I - and / or 99 TcO4 - The method is characterized in that The steps include: Containing ReO4 - and / or 99 TcO4 - and competitive anion NO3 - , Cl - 、SO4 2- Spent fuel reprocessing waste liquid or containing ReO4 - and / or 99 TcO4 - , H2SO4, HCl, HNO3 high acid metal solution and the compound shown in formula I are mixed, shaken, centrifuged, ReO4 - and / or 99 TcO4 - Entering into the extractant; Wherein, R is selected from phenyl; a, b are the same or different and are independently selected from 1, 2 or 3; The acid concentration in the highly acidic metal solution is 1-6M; ReO4 - and / or 99 TcO4 - Competitive anion SO4 2- 、NO3 - , Cl - The concentration ppm ratio of each is 1:1~10000, and ReO4 - and / or 99 TcO4 - Competing anion SO4 2- 、NO3 - , Cl - The total mixed concentration ratio is 1:1 to 10000.

2. The method according to claim 1, characterized in that: The invention also includes a stripping step, in which a stripping agent is added to the extractant layer for stripping, oscillation, centrifugation, ReO4 - and / or 99 TcO4 - It is stripped into the aqueous phase; The stripping agent is selected from one of HCl, H2SO4, HNO3 and NH4OH solution.

3. The method according to claim 1, characterized in that: The stripping agent used in the stripping is selected from NH4OH solution.

4. The method according to claim 3, characterized in that: The concentration of the stripping agent is 0.001-0.01 mol / L.

5. The method according to claim 1, characterized in that: The acid concentration in the highly acidic metal solution is 1-1.5M.

6. The method according to claim 1, characterized in that: The extraction was carried out at room temperature.

7. The method according to any one of claims 1 to 6, characterized in that: The method further comprises the step of activating the extractant with an acidic reagent after the stripping is completed, and then recycling the extractant.

8. The method according to claim 7, characterized in that: The method further comprises the step of activating the extractant with H2SO4 after the stripping is completed, and then recycling the extractant.

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