Application method of polyionic liquid gel material in uranium-rhenium adsorption separation

Abstract

The present invention belongs to the field of adsorption and recovery of rare metal elements, and discloses an application method of a polyionic liquid gel material in the adsorption and separation of uranium and rhenium. Specifically, the +7-valent rhenium element Re+7 and / or the +6-valent uranium element U+6 exist in the form of anions, and the polyionic liquid gel material is specifically an alkenyl imidazole-based polyionic liquid gel; the application specifically involves adding the alkenyl imidazole-based polyionic liquid gel to a solution to be treated for adsorption, so that anions containing Re+7 and / or anions containing U+6 are adsorbed onto the polyionic liquid gel material to achieve adsorption and separation. By using an alkenyl imidazole-based polyionic liquid gel with a specific structural general formula, the present invention can add the alkenyl imidazole-based polyionic liquid gel to a solution containing rhenium or uranium to perform anion-exchange-based adsorption of rhenium or uranium in the solution, achieving the adsorption and separation of rhenium and uranium, and particularly achieving the selective adsorption and separation of rhenium in a uranium-rhenium system.

Description

Technical Field

[0001] The invention belongs to the field of rare metal element adsorption recovery, and more specifically, relates to an application method of a polyionic liquid gel material in uranium-rhenium adsorption separation. The polyionic liquid gel material is specifically an ethylene imidazole type polyionic liquid gel. Background Art

[0002] At present, the main methods for recovering rhenium and uranium from aqueous solutions are precipitation, solvent extraction and adsorption. Among them, the chemical precipitation method has poor selectivity and is difficult to separate multiple metal ions; the solvent extraction method has a complicated process and uses a lot of toxic and volatile solvents, which is easy to cause secondary pollution; the adsorption method is considered to be one of the most effective methods due to its low cost, good selectivity and simple process. In recent years, some research progress has been made in the separation and recovery of uranium and rhenium using adsorbents, but most adsorbent materials still have some shortcomings. For example, there are few types of adsorbents, the adsorbents contain a large amount of non-functional matrix, the adsorption capacity and rate cannot be combined, and the cost is high.

[0003] Ionic liquids are a commonly used green solvent and have also been widely studied in the field of metal separation due to their high stability, designable structure and functional groups. The existing applications of ionic liquids in metal recovery and separation can be mainly divided into the following types: one is to use it as a free component in the extraction system, but the liquid state greatly limits its application range, and there are problems of leaching, excessive consumption and recovery during use; in addition, ionic liquids are often grafted onto a certain solid substrate (i.e., solid-supported ionic liquids) to prepare uranium-rhenium adsorbents. These adsorbents are mainly resins and nanomaterials, such as the prior art "Recovery of rhenium from sulfuric acid solution by TOPO-impregnated silicasorbents" (DOI: 10.1080 / 01496395.2020.1718709) and "Simultaneous elimination ofcationic uranium(VI)and anionic rhenium(VII))by graphene oxide–poly(ethyleneimine) macrostructures: a batch, XPS, EXAFS, and DFT combined study" (DOI: 10.1039 / C8EN00677F). Although the metal recovery performance of immobilized ionic liquid adsorbents is better than that of free ionic liquids, their adsorbent performance is still generally limited by non-functional matrices. Furthermore, most of these studies are limited to the adsorption of rhenium or uranium from the solution alone (and do not involve the selective separation of rhenium or uranium in the rhenium-uranium system), or simulated adsorption of high-level radioactive liquid waste. 99 technetium( 99 Tc), or the separation of rhenium from elements such as nickel, molybdenum, and platinum, but there is little research on the separation and recovery of uranium rhenium. Polyionic liquid gel is a solid material that combines the functional advantages of ionic liquids and the three-dimensional network structure of gels. It can achieve high adsorption capacity and also easy to achieve fast adsorption kinetics. It has been reported that polyionic liquid gel is used to adsorb rhenium to evaluate its effect on shower wastewater in nuclear facilities. 99 The recovery of technetium is still unrecognized, but the use of polyionic liquid gel for separation of uranium and rhenium in uranium ore leachate has not been reported. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the object of the present invention is to provide an application method of a polyionic liquid gel material in the adsorption and separation of uranium and rhenium, wherein by using an ethylene imidazole type polyionic liquid gel having a specific structural general formula, an ethylene imidazole type polyionic liquid gel can be added to a solution containing rhenium or uranium to adsorb rhenium or uranium in the solution mainly by anion exchange, thereby achieving the adsorption and separation of rhenium and uranium. The imidazole type polyionic liquid gel involved in the present invention is only composed of ionic liquids, has a high density of functional groups (i.e., imidazole rings), and has a three-dimensional porous network structure, which not only has a high adsorption capacity for both rhenium and uranium, but also can achieve very fast adsorption equilibrium. On the other hand, more importantly, the adsorbent can selectively separate rhenium from a to-be-treated solution (uranium ore acid leaching solution) containing both rhenium and uranium. The method of the present invention is simple to operate, saves resources, is economical and environmentally friendly, and the adsorbent has good reusability.

[0005] To achieve the above object, according to the present invention, there is provided an application of a polyionic liquid gel material in the adsorption separation of rhenium and / or uranium, characterized in that the +7 valence rhenium element Re +7 and / or uranium +6 +6 The existing form in the aqueous solution includes anions, and the polyionic liquid gel material is specifically an ethylene imidazole type polyionic liquid gel, and its structural formula is shown below:

[0006]

[0007] Wherein, m and n are independently selected from integers between 1 and 12; X = Cl, Br, NO 3 ,BF 4 ,NTf 2 ,PF 6 ;

[0008] The application is specifically to add the vinyl imidazole type polyionic liquid gel to the solution to be treated, thereby adsorbing the Re +7 anions and / or containing U +6 The anions are adsorbed to the polyionic liquid gel material to achieve adsorption separation.

[0009] As a further preferred embodiment of the present invention, the solution to be treated contains rhenium; before application, the pH value of the solution to be treated is adjusted to 2 to 12; when applied, the polyionic liquid gel material can absorb the rhenium-containing +7 anions to separate rhenium from the solution.

[0010] As a further preferred embodiment of the present invention, the solution to be treated contains uranium; before application, the pH value of the solution to be treated is adjusted to 5 to 12; when applied, the polyionic liquid gel material can adsorb the uranium-containing+6 anions to separate uranium from the solution.

[0011] As a further preferred embodiment of the present invention, the solution to be treated contains both rhenium and uranium. When used, the pH value of the solution to be treated is first adjusted to 2 to 4. When used, the polyionic liquid gel material can selectively adsorb the Rhenium-containing +7 Anions are produced to separate rhenium from uranium;

[0012] Preferably, the solution to be treated is uranium ore leaching solution.

[0013] As a further preferred embodiment of the present invention, after the adsorption is completed, the method further comprises using an eluent to elute and separate the corresponding polyionic liquid gel material adsorbed with the target anion, so as to regenerate the polyionic liquid gel material; the regenerated polyionic liquid gel material can be repeatedly used in the adsorption and separation of rhenium and / or uranium;

[0014] Preferably, the eluent is HNO with a concentration of 0.1 to 4 mol / L. 3 Solution or HCl solution with a concentration of 0.1 to 4 mol / L.

[0015] As a further preferred embodiment of the present invention, the alkenyl imidazole type polyionic liquid gel is obtained by polymerizing and cross-linking alkenyl imidazole type ionic liquid monomers and a cross-linking agent; wherein,

[0016] The crosslinking agent is selected from any one of an olefinic ionic liquid containing a double C=C bond and an olefinic chemical crosslinking agent containing a double C=C bond; preferably, the olefinic ionic liquid containing a double C=C bond is 1-allyl-3-vinylimidazolium salt or 3,3'-divinyl-1,1'(1,6-hexanediyl)diimidazolium salt; the olefinic chemical crosslinking agent containing a double C=C bond is a divinylalkyl chemical crosslinking agent or a divinylbenzene chemical crosslinking agent;

[0017] The polymerization cross-linking is specifically radiation cross-linking, which is achieved by first inducing C=C bonds to generate free radicals, and then further initiating polymerization and cross-linking between molecular chains of ionic liquid monomers and cross-linking agents, thereby forming a polyionic liquid gel.

[0018] As further preferred of the present invention, the alkenyl-containing imidazolium ionic liquid monomer is 1-vinyl-3-methyl-imidazole bromide, 1-vinyl-3-methyl-imidazole chloride, 1-vinyl-3-methyl-imidazole nitrate, 1-vinyl-3-methyl-imidazole tetrafluoroborate, 1-vinyl-3-methyl-imidazole hexafluorophosphate, 1-vinyl-3-methyl-imidazole bistrifluoromethylsulfinate, 1-vinyl-3-ethyl-imidazole bromide, 1-vinyl-3-ethyl-imidazole chloride, 1-vinyl-3-ethyl-imidazole nitrate, 1-vinyl-3-ethyl-imidazole tetrafluoroborate, 1-vinyl-3-ethyl-imidazole hexafluorophosphate, 1-vinyl-3-ethyl-imidazole bistrifluoromethylsulfinate, 1-vinyl-3-propyl-imidazole bromide.

[0019] As a further preference of the present invention, the polymerization cross-linking reaction is specifically carried out in an aqueous solution, ethanol, methanol, DMSO, or DMF solution, and the reaction temperature is room temperature; before the polymerization cross-linking occurs, the concentration of the alkenyl-containing imidazole-type ionic liquid monomer in the solution system is 6 to 80 wt%.

[0020] As a further preferred embodiment of the present invention, the radiation crosslinking is specifically carried out by 60 The irradiation dosage of Coγ-ray, electron beam or X-ray is 10-300 kGy; the gel fraction of the corresponding polyionic liquid gel is above 60%.

[0021] Compared with the prior art, the above technical solution conceived by the present invention can achieve the following beneficial effects:

[0022] 1) The vinyl imidazole polyionic liquid gel provided by the present invention can comprehensively recover rhenium and uranium and can be used in a wide range of acid and alkali. Different from the solid-supported ionic liquid, the present invention adopts a polyionic liquid gel with a specific chemical structure. Since the polyionic liquid gel is only composed of ionic liquids and has a high density of functional groups (i.e., imidazole rings), it has a higher adsorption capacity for rhenium and uranium. In addition, the polyionic liquid gel has a three-dimensional porous network structure, which is conducive to the flow of rhenium and uranium ions inside the gel, so it also has a faster adsorption rate for rhenium and uranium. The vinyl imidazole polyionic liquid gel in the present invention adsorbs rhenium or uranium in the solution through anion exchange (rhenium or uranium exists in the solution in the form of Re (VII) and U (VI) anions, respectively), and has a very fast adsorption rate, which can reach equilibrium within 1 min and 4 min, respectively. The vinyl imidazole type polyionic liquid gel in the present invention only relies on the positively charged imidazole ring as an adsorption group, but cannot adsorb positively charged metal ions. It is particularly suitable for uranium ore acid leaching solution containing rhenium. The coexisting metals such as uranium, calcium, magnesium, aluminum, and iron contained in the uranium ore acid leaching solution are all present in the form of cations (if uranium exists in the form of anions in the initial solution, the uranium can be converted into a cation by adjusting the pH value), and rhenium exists in the form of anions. Therefore, the polyionic liquid gel in the present invention can achieve high-selective adsorption and separation of rhenium from the uranium ore acid leaching solution.

[0023] 2) Based on the present invention, the alkenyl imidazole type polyionic liquid gel can be used to selectively separate rhenium from the rhenium-containing uranium ore acid leachate. In the specific operation, the pH of the solution to be treated (e.g., uranium ore leachate) can be adjusted to 2-4 (of course, if the initial solution pH value has met this condition, there is no need to add a pH regulator), and the different ionic forms of uranium and rhenium in the solution can be used to selectively adsorb and separate rhenium from the leachate. In other words, the alkenyl imidazole type polyionic liquid gel provided by the present invention can selectively adsorb the associated rhenium in the rhenium-containing uranium ore acid leachate.

[0024] 3) The vinyl imidazole type polyionic liquid gel of the present invention has a simple preparation method, easy control of conditions, low energy consumption, safety and environmental protection, and is suitable for mass production. The present invention also optimizes the synthesis method of the vinyl imidazole type polyionic liquid gel. The preparation process of the vinyl imidazole type polyionic liquid gel of the present invention is different from most reported gel synthesis methods, mainly reflected in the application of electron beam radiation crosslinking technology, using the high-energy electron beam emitted by the irradiation device to directly induce the generation of free radicals and initiate polymerization and crosslinking between molecular chains. Compared with conventional chemical methods, no chemical initiator or catalyst is required. Furthermore, the present invention can especially use vinyl imidazole type ionic liquid containing double C=C bonds as a functional crosslinking agent. Unlike conventional chemical crosslinking agents that only have a crosslinking effect, the vinyl imidazole type ionic liquid containing double C=C bonds can provide both a crosslinking effect and an adsorption effect, thereby effectively increasing the density of the adsorption functional group, so the gel has a large adsorption capacity for rhenium and uranium and a fast adsorption speed.

[0025] 4) The raw materials of the vinyl imidazole type polyionic liquid gel obtained by the present invention are easily available, low in cost, green and environmentally friendly, and will not cause secondary pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an analysis diagram of the adsorption experiment of rhenium and uranium by the vinyl imidazole polyionic liquid gel prepared in Example 1 at different acidities.

[0027] Figure 2 The isotherm adsorption experiment and fitting analysis diagram of rhenium and uranium by the vinyl imidazole type polyionic liquid gel prepared in Example 1 are shown respectively; wherein, Figure 2 (a) corresponds to rhenium Re(VII), Figure 2 (b) corresponds to uranium U(VI). The concentration on the horizontal axis of the figure is the remaining concentration in the solution after the adsorption reaction is completed (i.e. C e ).

[0028] Figure 3 These are respectively the experimental analysis diagrams of the adsorption kinetics of rhenium and uranium by the vinyl imidazole type polyionic liquid gel prepared in Example 1; wherein, Figure 3 (a) corresponds to rhenium Re(VII), Figure 3 (b) in the figure corresponds to uranium U(VI).

[0029] Figure 4 This is an experimental analysis diagram of the adsorption and separation of rhenium in a simulated uranium ore solution by the vinyl imidazole type polyionic liquid gel prepared in Example 1.

[0030] Figure 5 is the reusability of vinyl imidazole type polyionic liquid gel for Re and U; wherein, Figure 5 (a) corresponds to rhenium Re(VII), Figure 5 (b) corresponds to uranium U(VI); Figure 5 In the figure, any group of columns indicates from left to right the adsorption amount (Q adsorption ) and elution volume (Q desorption ).

[0031] Figure 6 This is the Fourier infrared spectrum of the vinyl imidazole type polyionic liquid gel prepared in Example 1.

[0032] Figure 7 The SEM images of the vinyl imidazole polyionic liquid gel prepared in Example 1 at different magnifications are shown; wherein, Figure 7 (a) in the figure corresponds to a magnification of 50 times. Figure 7 (b) corresponds to a magnification of 200 times. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] The alkenyl imidazole polyionic liquid gel in the present invention is obtained by polymerizing and crosslinking an alkenyl imidazole ionic liquid monomer and a crosslinking agent; wherein the crosslinking agent can be selected from any one of alkenyl ionic liquids and alkenyl chemical crosslinking agents containing double C=C bonds, preferably 1-allyl-3-vinyl imidazolium salt, 3,3'-divinyl-1,1'(1,6-hexanediyl) diimidazolium salt in ionic liquids and divinyl alkyl chemical crosslinking agents and divinylbenzene chemical crosslinking agents in chemical crosslinking agents. The preparation method can be radiation crosslinking, first inducing C=C bonds to generate free radicals, further initiating polymerization and crosslinking between the molecular chains of the ionic liquid monomer and the crosslinking agent, thereby forming a polyionic liquid gel. Radiation crosslinking can be specifically adopted 60 The irradiation dosage of Coγ-ray, electron beam or X-ray is 10-300 kGy; the gel fraction of the prepared polyionic liquid gel is above 60%.

[0035] In addition, the vinyl imidazole type ionic liquid monomer structure is as follows:

[0036]

[0037] Wherein, n is an integer between 1 and 12, X=Cl, Br, NO 3 ,BF 4 ,NTf 2 ,PF 6 .

[0038] For example, the alkenyl-containing imidazolium-type ionic liquid monomer is 1-vinyl-3-methyl-imidazolium bromide, 1-vinyl-3-methyl-imidazolium chloride, 1-vinyl-3-methyl-imidazolium nitrate, 1-vinyl-3-methyl-imidazolium tetrafluoroborate, 1-vinyl-3-methyl-imidazolium hexafluorophosphate, 1-vinyl-3-methyl-imidazolium bistrifluoromethylsulfinate, 1-vinyl-3-ethyl-imidazolium bromide, 1-vinyl-3-ethyl-imidazolium chloride, 1-vinyl-3-ethyl-imidazolium nitrate, 1-vinyl-3-ethyl-imidazolium tetrafluoroborate, 1-vinyl-3-ethyl-imidazolium hexafluorophosphate, 1-vinyl-3-ethyl-imidazolium bistrifluoromethylsulfinate, and 1-vinyl-3-propyl-imidazolium bromide.

[0039] The polymerization cross-linking reaction can be carried out in an aqueous solution of an imidazole type ionic liquid with a concentration of 6 to 80 wt %, ethanol, methanol, DMSO, or DMF solution, and the reaction temperature is room temperature.

[0040] In addition, for a rhenium-containing or uranium-containing solution, rhenium or uranium exists in the solution in the form of Re(VII) and U(VI) ions, respectively.

[0041] The following are specific embodiments:

[0042] Example 1 Preparation of vinyl imidazole type polyionic liquid gel

[0043] 1) Add 1-vinyl-3-ethylimidazolium bromide and 1-allyl-3-vinylimidazolium bromide into 1 mL of deionized water, with the concentrations of 80% and 4.9% respectively. After ultrasonic dissolution, pour the uniform solution into a polyethylene bag and purify it with N 2 Seal after degassing.

[0044] 2) Use an electron accelerator to irradiate with electron beams, so that the vinyl groups generate active free radicals that can be used for polymerization and cross-linking reactions, inducing polymerization and cross-linking of the reactant molecular chains to form a polyionic liquid gel. Irradiation conditions: irradiation voltage 10 MeV, irradiation dose 80 kGy, dose rate 10 kGy / pass. The obtained gel is dried at 50°C to constant weight, then immersed in deionized water to remove the sol part, and dried again at 50°C to constant weight. The gel fraction of the obtained polyionic liquid gel is 78%.

[0045] The obtained vinyl imidazole type polyionic liquid gel structure is as follows:

[0046]

[0047] The structures of the reactant ionic liquids 1-vinyl-3-ethylimidazolium bromide and 1-allyl-3-vinylimidazolium bromide as well as the obtained vinyl imidazole type polyionic liquid gel were tested by Fourier transform infrared spectroscopy (FTIR). Figure 6 As shown, 3060cm -1 The peaks on the left and right belong to the CH vibration peaks on the imidazole ring and the side chain of the imidazole ring, 1162cm -1 The peaks at 1650cm are characteristic peaks of the imidazole ring. These two infrared peaks exist in the spectra of the reactants and gel products, indicating that these groups have not undergone chemical changes before and after the reaction. -1 and 1000~900cm -1 The peaks at are the characteristic peaks of vinyl in the ionic liquid, but these peaks disappear in the spectrum of the gel product, proving that the polymerization cross-linking reaction occurs successfully.

[0048] In addition, the morphology of the obtained vinyl imidazole type polyionic liquid was characterized by scanning electron microscopy (SEM). Figure 7 As shown, it can be observed that the obtained vinyl imidazole type polyionic liquid gel has a typical three-dimensional porous network structure with a large pore size.

[0049] Example 2 Experiment on pH adsorption effect of vinyl imidazole type polyionic liquid gel

[0050] Potassium perrhenate (KReO 4 ) and uranyl nitrate (UO 2 (NO 3 ) 2 6H 2 O) Solid reagents are used to prepare aqueous solutions containing Re and / or U required for the adsorption experiment (the following adsorption experiments are all prepared with potassium perrhenate and uranyl nitrate reagents), and the pH is adjusted to 1 to 12 with dilute acid and dilute alkali. Weigh 10 mg of the prepared vinyl imidazole type polyionic liquid gel and put it into 10 mL of the pH-adjusted aqueous solution containing Re or U to carry out a static adsorption test. The above adsorption test is carried out in a water bath oscillator at 25°C. After 48 hours of adsorption, the clear solution is taken and the concentration of rhenium or uranium in the solution is detected by UV to calculate the gel adsorption amount (Q e ).

[0051] The adsorption of rhenium and uranium by the vinyl imidazole polyionic liquid gel of Example 1 is affected by pH. Figure 1 As shown. We can see that the vinyl imidazole type polyionic liquid gel can effectively adsorb rhenium and uranium in the range of pH 2-12 and pH 5-12 respectively.

[0052] Example 3 Isotherm adsorption experiment of vinyl imidazole type polyionic liquid gel

[0053] 10 mg of vinyl imidazole type polyionic liquid gel was added to 10 mL of a series of rhenium solutions (natural pH) with different initial concentrations (40-1600 ppm, specifically 40, 80, 120, 200, 300, 400, 600, 800, 1000, 1200, 1300, 1400, 1500, 1600 ppm) and a series of uranium solutions (pH = 7) with different initial concentrations (20-300 ppm, specifically 20, 40, 80, 100, 120, 200, 250, 300 ppm; the maximum initial concentration was 300 ppm mainly because higher concentrations would lead to precipitation) in a water bath oscillator at 25°C. After adsorption for 48 hours, the clear solution was taken and the residual concentration of rhenium or uranium in the solution was detected by UV (C e ), and thus calculate the gel adsorption amount (Q e ).

[0054] The isotherm adsorption and fitting curves of the vinyl imidazole type polyionic liquid gel of Example 1 for rhenium and uranium are as follows: Figure 2 As shown, its theoretical maximum adsorption capacity for rhenium and uranium is as high as 892.9 mg / g and 243.9 mg / g respectively.

[0055] Example 4 Kinetic adsorption experiment of vinyl imidazole type polyionic liquid gel

[0056] 10 mg of vinyl imidazole type polyionic liquid gel was added to 10 mL of rhenium solution with an initial concentration of 100 ppm and natural pH, and 10 mL of uranium solution with an initial concentration of 20 ppm and pH = 7, respectively, and the reaction was carried out within 1 to 15 minutes. The clear solution was taken and the residual concentration of Re or U in the solution was detected by UV to calculate the gel adsorption amount (Q e ).

[0057] The kinetic adsorption curves of the vinyl imidazole polyionic liquid gel of Example 1 for Re and U are as follows: Figure 3 As shown, it can be seen that the adsorption equilibrium time for Re and U is 1min and 4min respectively.

[0058] Example 5 Adsorption and separation of rhenium from simulated uranium ore leachate by vinyl imidazole type polyionic liquid gel

[0059] Rhenium is often associated with a variety of metal ions in uranium ore, so we prepared a simulated uranium ore acid leaching solution (in addition to potassium perrhenate and uranyl nitrate, anhydrous calcium chloride, magnesium chloride hexahydrate, aluminum chloride hexahydrate, ferric chloride hexahydrate, sodium sulfate, sulfuric acid), which contains the following elements or substances: rhenium (0.005mmol / L), uranium (0.5mmol / L), calcium (5mmol / L), magnesium (5mmol / L), aluminum (5mmol / L), iron (1mmol / L), sodium sulfate (104mmol / L) and sulfuric acid (18mmol / L), the solution pH = 2. Take 10mg of vinyl imidazole type polyionic liquid gel and add it to 10mL of the simulated solution. After adsorption for 48h, take the clear solution and use ICP to detect the concentration of each metal ion in the solution to calculate the gel adsorption amount (Q e ).

[0060] The adsorption results of the vinyl imidazole polyionic liquid gel of Example 1 on various metal ions in the simulated liquid are as follows: Figure 4 As shown, it can be seen that it has good adsorption selectivity for rhenium, while basically does not adsorb other coexisting metal ions. The reason why it does not adsorb uranium and other coexisting metal ions is mainly because when pH = 2-4, uranium and other coexisting metal ions exist in the form of cations, and rhenium always exists in the form of anions. Therefore, in the uranium ore acid leaching solution with pH = 2, the polyionic liquid gel can adsorb rhenium but not other metal ions. Especially for rhenium and uranium, in the aqueous solution system, the +7 valence rhenium element is in the form of ReO 4 - anionic form (regardless of pH conditions); and +6 uranium can exist in anionic form (i.e., (UO 2 ) 3 (OH) 7 - , or UO 2 (OH) 3 - ), and may also exist in cationic form (i.e., UO 2 2+ ,(UO 2 ) 3 (OH) 5 + , UO 2 OH + , or (UO 2 ) 4 (OH) 7 + ), the complex ion form of the uranium element with a valence of +6 changes with the change of pH. For example, it is a cation when the pH value is 1 to 4, it is both an anion and a cation when the pH value is 4-10, and it is an anion when the pH value is 10-12. Figure 4 It is not difficult to see that when the pH is 2-4, the polyionic liquid gel of the present invention can have a considerable selective adsorption effect on rhenium.

[0061] Example 6 Regeneration Experiment of Vinylimidazole Polyionic Liquid Gel

[0062] 10 mg of vinyl imidazole polyionic liquid gel was added to 10 mL of rhenium solution with an initial concentration of 200 ppm and natural pH, and 10 mL of uranium solution with a concentration of 100 ppm and pH = 7. After adsorption, it was washed three times with deionized water and then washed with 3 mol / L HNO 3 The rhenium and uranium on the gel were eluted with 0.1 mol / L HCl. After each adsorption and elution experiment, the gel was washed three times with deionized water and then the next cycle was carried out. This cycle was repeated five times. The clear solution after adsorption and elution was taken and the concentration of Re or U in the solution was detected by UV to calculate the adsorption amount (Q adsorption ) and elution volume (Q desorption ).

[0063] The adsorption-desorption results of the vinyl imidazole type polyionic liquid gel of Example 1 on rhenium and uranium are as follows: Figure 5 As shown, it can be seen that the gel has good reusability.

[0064] Example 7 Effect of irradiation dose on the preparation and properties of vinyl imidazole type polyionic liquid gel

[0065] A series of uniformly mixed aqueous solutions containing 80% 1-vinyl-3-ethylimidazolium bromide and 4.9% 1-allyl-3-vinylimidazolium bromide were prepared and placed in polyethylene bags and sealed with N 2 After degassing and sealing, the samples were irradiated with different absorbed doses (up to 300 kGy) using electron accelerators with energies of 1 MeV and 10 MeV, and effective gel products were obtained. The gel fraction of vinyl imidazole polyionic liquid gel was above 60%, and their adsorption of rhenium and uranium could achieve comparable adsorption experimental results.

[0066] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Application of a polyionic liquid gel material in the adsorption and separation of rhenium and / or uranium, characterized in that: +7-valent rhenium element Re +7 and / or uranium +6 +6 The existing form in the aqueous solution includes anions, and the polyionic liquid gel material is specifically an ethylene imidazole type polyionic liquid gel, and its structural formula is shown below: Wherein, m and n are independently selected from integers between 1 and 12; X = Cl, Br, NO3, BF4, NTf2, PF6; The application is specifically to add the vinyl imidazole type polyionic liquid gel to the solution to be treated, thereby adsorbing the Re +7 anions and / or containing U +6 The anions are adsorbed to the polyionic liquid gel material to achieve adsorption separation.

2. The use according to claim 1, characterized in that: The solution to be treated contains rhenium; before application, the pH value of the solution to be treated is adjusted to 2-12; when applied, the polyionic liquid gel material can absorb the rhenium-containing +7 anions to separate rhenium from the solution.

3. The use according to claim 1, characterized in that: The solution to be treated contains uranium; before application, the pH value of the solution to be treated is adjusted to 5 to 12; when applied, the polyionic liquid gel material can absorb the uranium-containing +6 anions to separate uranium from the solution.

4. The use according to claim 1, characterized in that: The solution to be treated contains both rhenium and uranium. When used, the pH value of the solution to be treated is first adjusted to 2-4. When used, the polyionic liquid gel material can selectively absorb the Rhenium-containing +7 anions to separate rhenium from uranium.

5. The use according to claim 4, characterized in that: The solution to be treated is uranium ore leaching solution.

6. The use according to claim 1, characterized in that: After the adsorption is completed, the method further includes using an eluent to elute and separate the corresponding polyionic liquid gel material adsorbed with the target anions, so as to regenerate the polyionic liquid gel material; the regenerated polyionic liquid gel material can be repeatedly used in the adsorption and separation of rhenium and / or uranium.

7. The use according to claim 6, characterized in that The eluent is a HNO3 solution with a concentration of 0.1 to 4 mol / L or a HCl solution with a concentration of 0.1 to 4 mol / L.

8. The use according to claim 1, characterized in that The alkenyl imidazole type polyionic liquid gel is obtained by polymerizing and cross-linking alkenyl imidazole type ionic liquid monomers and cross-linking agents; wherein, The crosslinking agent is selected from any one of an olefinic ionic liquid containing a double C=C bond and an olefinic chemical crosslinking agent containing a double C=C bond; The polymerization cross-linking is specifically radiation cross-linking, which is achieved by first inducing C=C bonds to generate free radicals, and then further initiating polymerization and cross-linking between molecular chains of ionic liquid monomers and cross-linking agents, thereby forming a polyionic liquid gel.

9. The use according to claim 8, characterized in that The olefinic ionic liquid containing double C=C bonds is 1-allyl-3-vinylimidazolium salt or 3,3'-divinyl-1,1'(1,6-hexanediyl)diimidazolium salt; the olefinic chemical crosslinking agent containing double C=C bonds is a divinylalkyl chemical crosslinking agent or a divinylbenzene chemical crosslinking agent.

10. The use according to claim 8, characterized in that The alkenyl-containing imidazolium-type ionic liquid monomer is 1-vinyl-3-methyl-imidazole bromide, 1-vinyl-3-methyl-imidazole chloride, 1-vinyl-3-methyl-imidazole nitrate, 1-vinyl-3-methyl-imidazole tetrafluoroborate, 1-vinyl-3-methyl-imidazole hexafluorophosphate, 1-vinyl-3-methyl-imidazole bistrifluoromethylsulfinate, 1-vinyl-3-ethyl-imidazole bromide, 1-vinyl-3-ethyl-imidazole chloride, 1-vinyl-3-ethyl-imidazole nitrate, 1-vinyl-3-ethyl-imidazole tetrafluoroborate, 1-vinyl-3-ethyl-imidazole hexafluorophosphate, 1-vinyl-3-ethyl-imidazole bistrifluoromethylsulfinate, and 1-vinyl-3-propyl-imidazole bromide.

11. The use according to claim 8, characterized in that: The polymerization cross-linking reaction is specifically carried out in an aqueous solution, ethanol, methanol, DMSO, or DMF solution at room temperature; before the polymerization cross-linking occurs, the concentration of the alkenyl-containing imidazole-type ionic liquid monomer in the solution system is 6 to 80 wt%.

12. The use according to claim 8, characterized in that: The radiation crosslinking is specifically carried out by 60 The irradiation dosage of Coγ-ray, electron beam or X-ray is 10-300 kGy; the gel fraction of the corresponding polyionic liquid gel is above 60%.

Images