CN110331291B

CN110331291B - Method for separating and/or extracting lanthanide

Info

Publication number: CN110331291B
Application number: CN201910652899.8A
Authority: CN
Inventors: 孙海燕; 冯美玲; 黄小荥
Original assignee: Fujian Institute of Research on the Structure of Matter of CAS
Current assignee: Fujian Institute of Research on the Structure of Matter of CAS
Priority date: 2019-07-19
Filing date: 2019-07-19
Publication date: 2020-06-09
Anticipated expiration: 2039-07-19
Also published as: CN110331291A

Abstract

The application discloses a method for separating and/or extracting lanthanide, comprising the following steps: contacting a water treatment agent with a solution containing lanthanide, and separating and/or extracting the lanthanide by the water treatment agent through adsorption; the water treatment agent is [ V ]₃O₇]_n ^n‑A layered framework material.

Description

Method for separating and/or extracting lanthanide

Technical Field

The invention belongs to the field of lanthanide water treatment, and particularly relates to a method for efficiently and selectively extracting and separating lanthanide from water by using a water treatment agent capable of being synthesized in batches.

Background

Energy and environment are always two major problems in the current society. With the development of society, the demand of human beings for energy is gradually increased, however, fossil energy is not renewable, and a lot of environmental problems are caused in the utilization process. Nuclear power is favored in many countries for its high efficiency and cleanliness. However, the development of nuclear energy brings problems of nuclear waste liquid treatment and the like. The relevant environmental problems caused by the nuclear waste liquid become important and difficult points of concern of various countries, and radioactive ions are easily released into water and soil, so that pollution is caused and meanwhile serious threats are caused to aquatic organisms and human health. Lanthanides are one of the major nuclear fission products, causing long contamination periods, difficult biodegradation, high radioactivity levels, and difficult repair (arab. j. geosci.2017,10 (13); j. anal. at. spectra.2017, 32(12), 2360-.^152-154Eu radioisotope (¹⁵²The half-life of Eu is about 13.3 years;¹⁵⁴eu half-life of about 8.6 years) as representative of lanthanides can alter the normal physiological processes in the human body by disrupting synaptic transmitter transport and release, blocking transmission of certain membrane receptors, such as GABA and glutamate receptors (Acta biochem. pol.2000,47(4), 1107-1114).^152-154Eu、¹³⁷Cs (half-life of about 30.2 years) and⁹⁰sr (half-life of about 28.8 years) is a major product of nuclear fission, often accompanied by their efficient separation, which is critical to achieving volume reduction and resource recovery of highly radioactive nuclear effluents (Environ. Sci. Technol.2009,43(9), 3115-. In addition, since lanthanides and actinides have similar ionic radii and adsorption behavior,^152-154eu is often used as a substitute for long-lived radioactive actinides for research (j.radio.nuclear.chem.2014, 302(1), 441-449).

On the other hand, lanthanides are considered to be modern "gold" or "industrial vitamins" (geosy. eng.2014,17(3), 178-. With the increasing application range of lanthanides, the global demand for lanthanides has increased at a rate of 3.7 to 8.6% per year (crit. rev. env. sci. tec.2015,45(7), 749-. Therefore, the development of the cyclic utilization of lanthanide elements has important significance for human health, energy recycling and environmental protection.

At present, the methods for extracting and separating lanthanide from water mainly include: chemical precipitation, liquid membrane, biological treatment, adsorption, ion exchange, etc. (Metall. Mater. Trans. B2003, 34 (5), 611-. Among them, the adsorption and ion exchange methods are widely concerned because of their simple operation, low cost and no secondary pollution. Currently, zeolites, insoluble ferrocyanides and heteropolyacid salts have been used for the extraction and separation of lanthanides, but these materials already available have the disadvantages of poor selectivity, narrow acid and alkali resistance range, and poor ability to separate radioactive ions, which hinders their further applications (j.am.chem.soc.2017,139(12), 4314-. In particular, the high-level radioactive waste liquid is highly acidic, and most of water treatment agents have greatly reduced adsorption capacity to lanthanide under acidic conditions (J.Am.chem.Soc.2017,139(46), 16494-16497). Therefore, the development of an acid-base-resistant and irradiation-resistant lanthanide water treatment agent is urgently needed to realize the high-efficiency and high-selectivity extraction and separation of lanthanide.

Disclosure of Invention

According to one aspect of the present application, the present invention provides a method for utilizing batch-synthesizable [ V ]₃O₇]_n ^n-A method for efficiently extracting and separating lanthanide from an aqueous solution by using a layered framework material. The method can realize high adsorption capacity (especially under acidic condition) and high speed for lanthanide extractionKinetic response and excellent selectivity. The layered vanadate water treatment agent has excellent irradiation resistance and acid and alkali resistance, and can elute the absorbed lanthanide by a cheap, easy-to-operate and environment-friendly method, thereby realizing high-efficiency extraction and separation of the lanthanide in the aqueous solution.

The method for separating and/or extracting lanthanide is characterized in that it comprises the following steps:

contacting a water treatment agent with a solution containing lanthanide, and separating and/or extracting the lanthanide by the water treatment agent through adsorption;

the water treatment agent is [ V ]₃O₇]_n ^n-A layered framework material.

A method for efficiently and selectively removing, separating and recovering lanthanide in water by using a water treatment agent synthesized in batches to obtain [ V ]₃O₇]_n ^n-The layered framework material is a water treatment agent for treating lanthanide (including lanthanide in an acidic aqueous solution) in water, and the lanthanide and the water treatment agent are contacted for a certain time to complete adsorption of the lanthanide; the [ V ] is₃O₇]_n ^n-Layered framework material and material containing K⁺、Na⁺、Ca²⁺、Mg²⁺、Cs⁺、Sr²⁺The lanthanide aqueous solution of the interfering ions is mixed, so that the selective adsorption of the water treatment agent on the lanthanide can be realized. The selected water treatment agent is based on [ V ]₃O₇]_n ^n-A layered framework vanadate material.

Specifically, [ V ] utilized in a method for extracting and separating lanthanoid₃O₇]_n ^n-Layered framework materials are characterized in that the readily exchangeable organic amine cations R are located between the layers of a two-dimensional layered framework (J. mater. chem.2004,14(19), 2922-2928). Preferably, said R is optionally a nitrogen-containing organic cation, such as: at least one of a dimethylammonium cation, an ethylammonium cation, and a piperidinyl cation.

Optionally, the water treatment agent is [ Me₂NH₂]V₃O₇。

Optionally, the temperature for separating and/or extracting the lanthanide by the water treatment agent is 20-80 ℃;

the contact time is 2-12 hours.

Optionally, the water treatment agent is contacted with a lanthanide-containing solution to achieve adsorption equilibrium within 2 hours. The method for extracting and separating the lanthanide has rapid kinetics, and the lanthanide can be removed in 2h to reach an equilibrium state.

Optionally, the lanthanide-containing solution includes industrial wastewater, radioactive wastewater, drinking water. The solution containing lanthanide element contains one or more lanthanide elements except Pm, and the treated water solution includes industrial waste water, radioactive waste water, drinking water, etc.

Optionally, the pH of the stable solution of the water treatment agent is 1-12.

The concentration of the lanthanide in the lanthanide-containing solution is 0.2-3000 ppm.

Optionally, the lanthanide-containing solution has a pH of 2.0-8.1.

Optionally, the lanthanide-containing solution has a pH of 2.5.

The water treatment agent is stable in the pH range of 1-12, and the temperature for adsorbing lanthanide is about 20-80 deg.C, preferably 50 deg.C.

Optionally, the pH value of the water treatment agent for separating and/or extracting the lanthanide is 2.0-8.1.

Optionally, the water treatment agent separates and/or extracts the lanthanide at a pH of 2.5.

Optionally, the manner of contacting comprises:

the powder and/or crystal water treatment agent is contacted with the solution containing the lanthanide element for a certain time.

Optionally, the manner of contacting comprises:

passing the lanthanide-containing solution through a chromatography column, and separating and/or extracting the lanthanide from the solution in the chromatography column;

and the chromatographic column is filled with a water treatment agent. The extraction and separation of lanthanumMethod of using element system [ V ]₃O₇]_n ^n-The ion separation chromatographic column filled with the layered framework material has the capability of removing the lanthanide mixed solution, and the removal rate can reach 88.7 percent at the highest at normal temperature.

Optionally, the lanthanide-containing solution includes Eu³⁺、Sm³⁺；

Under the neutral condition, the water treatment agent is Eu³⁺Adsorption capacity of not less than 161mg/g for Sm³⁺The adsorption capacity is not lower than 135 mg/g;

under the acidic condition, the water treatment agent is Eu³⁺The adsorption capacity of the adsorbent is not less than 75 mg/g.

The method for extracting and separating lanthanide has high adsorption capacity to lanthanide and Eu³⁺、 Sm³⁺The adsorption capacity of the ions can reach 161mg/g and 135mg/g respectively.

The method for extracting and separating lanthanide has good acid and alkali resistance, and can be used for Eu at pH of about 2.5³⁺The adsorption capacity of the ions reaches 75 mg/g.

Optionally, the lanthanide-containing solution further includes Cs⁺And/or Sr²⁺；

Said lanthanide and Cs⁺And/or Sr²⁺Has a separation factor of more than 100.

Optionally, Cs in said lanthanide-containing solution⁺And/or Sr²⁺The molar ratio of the ions to the lanthanide is 0.4-54.8.

Optionally, the lanthanide-containing solution further includes alkali metal ions and/or alkaline earth metal ions;

the lanthanide element has a separation coefficient from alkali metal ions and/or alkaline earth metal ions of greater than 100.

Optionally, the molar ratio of the alkali metal ion or alkaline earth metal ion to the lanthanide in the lanthanide-containing solution is 1.9-58.7. The method for extracting and separating lanthanoid is carried out at Eu³⁺With a plurality of ions, e.g. K⁺、Na⁺、Ca²⁺、Mg²⁺、Cs⁺、Sr²⁺One ofFor Eu under the condition of coexistence of one or more ions³⁺The ions have high selectivity: under the environment of simulating polluted water, the removal rate is as high as 96.9%; selectively adsorbing Eu in aqueous solution with excessive alkali metal and/or alkaline earth metal being 1.9-58.7 times³⁺Ions in Na⁺、K⁺、Ca²⁺、Mg²⁺For Eu when ions exist alone³⁺The ion removal rates are respectively as high as 97.8%, 98.0%, 98.7% and 98.3%, and the separation factor SF_Eu/Na、SF_Eu/K、 SF_Eu/Ca、SF_Eu/MgUp to 16292, 1397, 990, 644, respectively; in radioactive Cs⁺Or Sr²⁺The Eu can be selectively removed in the aqueous solution with the ion excess of 31.6 and 54.8 times³⁺Ion, to Eu³⁺The ion removal rate reaches 94.3 percent and 94.4 percent, and the separation factor SF_Eu/Cs、SF_Eu/SrUp to 113 and 102, respectively.

Optionally, the water treatment agent has a lanthanide removal rate of not less than 80% after being irradiated by high-dose/low-dose β rays and/or gamma rays, and the method for extracting and separating lanthanide has good irradiation resistance, and can still effectively remove Eu after the water treatment agent is irradiated by high-intensity β or gamma rays (200kGy β and 50kGy gamma rays)³⁺The removal rate of the ions is as high as 84.1 percent and 89.4 percent respectively when the initial concentration of the solution is 125.7 ppm.

Optionally, the water treatment agent is recycled through treatment of an inorganic salt solution;

the separated and/or extracted lanthanide is eluted and recovered by treatment with an inorganic salt solution.

The water treatment agent after the treatment of the aqueous solution containing the inorganic salt is used for separating and/or extracting the lanthanide again. The method for extracting and separating lanthanide can be used for extracting [ V ] by a cheap, easy-to-operate and environment-friendly method₃O₇]_n ^n-The lanthanide adsorbed by the layered framework material elutes. To extract Eu³⁺For example, [ V ] can be converted into water by using an aqueous solution of an inorganic salt such as KCl₃O₇]_n ^n-Eu extracted from layered framework material³⁺Ion is completely eluted backAnd (6) harvesting.

The beneficial effects that this application can produce include:

1) the method for efficiently and selectively removing, separating and recovering the lanthanide in the water by using the water treatment agent synthesized in batches is provided by the application to [ V ]₃O₇]_n ^n-The layered framework material is a water treatment agent for treating lanthanide (including lanthanide in an acidic aqueous solution) in water, and the lanthanide and the water treatment agent are contacted for a certain time to complete adsorption of the lanthanide; the [ V ] is₃O₇]_n ^n-Layered framework material and material containing K⁺、Na⁺、Ca²⁺、 Mg²⁺、Cs⁺、Sr²⁺The lanthanide aqueous solution of the interfering ions is mixed, so that the selective adsorption of the water treatment agent on the lanthanide can be realized.

2) The method for extracting and separating lanthanide provided by the application is at Eu³⁺With a plurality of ions, e.g. K⁺、Na⁺、Ca²⁺、Mg²⁺、Cs⁺、Sr²⁺In the presence of one or more ions, to Eu³⁺The ions have high selectivity: under the environment of simulating polluted water, the removal rate is as high as 98.9%; selectively adsorbing Eu in aqueous solution with excessive alkali metal and/or alkaline earth metal being 1.9-58.7 times³⁺Ions in Na⁺、K⁺、Ca²⁺、Mg²⁺For Eu when ions exist alone³⁺The ion removal rates are respectively as high as 97.8%, 98.0%, 98.7% and 98.3%, and the separation factor SF_Eu/Na、SF_Eu/K、SF_Eu/Ca、 SF_Eu/MgUp to 16292, 1397, 990, 644, respectively; in radioactive Cs⁺Or Sr²⁺The Eu can be selectively removed in the aqueous solution with the ion excess of 31.6 and 54.8 times³⁺Ion, to Eu³⁺The ion removal rate reaches 94.3 percent and 94.4 percent, and the separation factor SF_Eu/Cs、SF_Eu/SrUp to 113 and 102, respectively.

3) The method for extracting and separating lanthanide provided by the application has good radiation resistance, and can still realize high efficiency after being irradiated by high-intensity β or gamma rays (200kGy β and 50kGy gamma)Removing Eu³⁺The removal rate of the ions is as high as 84.1 percent and 89.4 percent respectively when the initial concentration of the solution is 125.7 ppm.

Drawings

FIG. 1 (a) is a diagram of sample No. 1 product; FIG. 1 (b) shows sample No. 1 with Eu removed³⁺Kinetics and removal rate of ions.

FIG. 2 (a) shows sample No. 1 with Eu removed³⁺A graph of an adsorption model of ions; (b) sm removal for sample No. 1³⁺And (4) an adsorption model diagram of ions.

FIG. 3 shows the removal of Eu under acidic conditions in sample No. 1³⁺And (4) an adsorption model diagram of ions.

FIG. 4 shows sample No. 1 at different molar ratios Cs⁺Or Sr²⁺Eu with ion excess³⁺Removing Eu from ionic solution³⁺A plot of the partition coefficient of the ions; wherein, (a) is different molar ratios Cs⁺Eu with ion excess³⁺Removing Eu from ionic solution³⁺A plot of the partition coefficient of the ions; (b) in different molar ratios of Sr²⁺Eu with ion excess³⁺Removing Eu from ionic solution³⁺Distribution coefficient of ions.

FIG. 5 shows sample No. 1 for Eu removal in the presence of different alkali/alkaline earth ions or simulated contaminated water³⁺A plot of the partition coefficient of the ions; wherein (a) is sample No. 1 in simulated polluted water to remove Eu³⁺A plot of the partition coefficient of the ions; (b) removal of Eu in the presence of different alkali/alkaline-earth ions for sample No. 1³⁺Distribution coefficient of ions.

FIG. 6 shows sample No. 1 with Eu removed over a wide pH range³⁺Distribution coefficient of ions.

Fig. 7 (a) is an XRD pattern of sample #1 before and after irradiation with high-intensity radiation; in the figure, (b) is the Eu pairs before and after irradiation of sample No. 1#³⁺Ion removal rate.

FIG. 8 is a diagram of a simulated chromatographic column set-up of sample # 1.

FIG. 9 is a graph showing the removal rate of each lanthanide from the mixed lanthanide solution by the sample #1 simulated chromatography column.

FIG. 10 (a) is an energy dispersive X-ray spectroscopy (EDS) chart of sample 1# -Eu; (b) is the energy dispersive X-ray spectrum of sample # 1-Eu-elution.

FIG. 11 shows Eu removal before and after one cycle of sample No. 1³⁺Ion removal rate.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials and catalysts in the examples of the present application were all purchased commercially.

The analysis method in the examples of the present application is as follows:

atomic absorption spectroscopy was performed on a Thermo 7400 apparatus.

Inductively coupled plasma emission spectroscopy was performed on an XSeriseII device.

Energy dispersive X-ray spectroscopy (EDS) tests were performed on a JEOL JSM-6700F scanning electron microscope and HITACHI FE-SEMSU8010 machine.

X-ray powder diffraction phase analysis (XRD) was performed on a Miniflex type II X-ray diffractometer at 30kV, 15mV, Cu target, K α radiation source

The separation coefficient in the examples of the present application is calculated in the following manner;

the removal rate in the embodiment of the present application is calculated in the following manner;

in the formula (1), K_d ^AAnd K_d ^BK represents Compounds A and B, respectively_dA value; in the formula (2), C₀And C_eRespectively representing the initial and equilibrium concentrations of the lanthanide solution.

Example 1[ V₃O₇]_n ^n-Preparation of layered framework materials

Mixing a vanadium source, lithium hydroxide, an N, N-dimethylformamide solution and water uniformly according to a certain molar ratio, fully stirring at room temperature, putting the mixture into a stainless steel reaction kettle with a polytetrafluoroethylene lining, reacting at constant temperature for a certain time, naturally cooling to room temperature, filtering the obtained sample, washing with distilled water and ethanol in sequence, and naturally air-drying to obtain [ Me ]₂NH₂]V₃O₇(sample # 1). The kinds of reactants, the ratio of reactants, the reaction time, the reaction temperature and the yield are shown in Table 1.

TABLE 1

Yield ═ mass of the resulting sample #1 ÷ (moles of vanadium element in the vanadium source ÷ 2 × theoretical molecular weight of the product) × 100%.

The concentration of the N, N-dimethylformamide solution may be adjusted as desired, for example 40% by weight.

Example 2 kinetic testing for extraction and isolation of lanthanides Using sample #1

After grinding, the powder of sample #1 was mixed with 116.9ppm of Eu³⁺Aqueous solutions of the ions were mixed, the mixture was stirred at 50 ℃, V (volume of solution): and m (mass of exchanger) is 1000 mL/g. Taking a small amount of supernatant of the mixture at certain intervals, and measuring Eu in the supernatant by inductively coupled plasma emission spectrometry³⁺The ion concentration. FIG. 1 (a) is a photograph of sample No. 1; in FIG. 1, (b) is Eu over time³⁺Change of ion concentration and Eu³⁺Ion removal rate profile. FIG. 1 (b) shows that sample No. 1 is for Eu³⁺The removal of ions can reach equilibrium within 2 h.

Example 3 adsorption model test for extraction and separation of lanthanides Using sample No. 1

After grinding, the powder of sample No. 1 is mixed with Eu in an amount of 2.2-756.2 ppm³⁺、Sm³⁺The ionic aqueous solutions were mixed and the mixture was stirred at 50 ℃ for 3h, V (volume of solution): and m (mass of exchanger) is 1000 mL/g. Reaction ofAfter the completion, taking the supernatant and the initial solution, and respectively measuring Eu by inductively coupled plasma emission spectrometry³⁺、Sm³⁺The concentration of the ions. The experimental results are shown in FIG. 2, in which (a) and (b) of FIG. 2 show sample No. 1 vs. Eu, respectively³⁺、Sm³⁺The maximum adsorption capacity of the ions can reach 161mg/g and 135mg/g respectively.

Example 4 adsorption model test for extraction and separation of lanthanides in high acid solution using sample #1

Adjusting the aqueous solution to a certain acidity by using hydrochloric acid solution, and using high-concentration Eu³⁺Diluting the ionic aqueous solution into Eu with different concentrations³⁺Ionic water solution, the pH of the diluted solution is about 2.5. After grinding, the powder of sample No. 1 was mixed with Eu at different initial concentrations³⁺The ionic aqueous solutions were mixed and the mixture was stirred at 50 ℃ for 3h, V (volume of solution): and m (mass of exchanger) is 1000 mL/g. After the reaction is finished, taking supernatant and initial solution, and respectively measuring Eu by inductively coupled plasma emission spectrum³⁺The concentration of the ions. The experimental results are shown in FIG. 3, sample No. 1 vs. Eu³⁺The maximum adsorption capacity of the ions reaches 75mg/g under high-acid solution, and the method for extracting and separating the lanthanide from the water provided by the application can still keep the lanthanide removal under the acid condition.

Example 5 test of the Selectivity Capacity for extraction and separation of lanthanides Using sample #1

After grinding, the powder of sample No. 1 was mixed with Na containing alkali metal and/or alkaline earth metal in different concentrations⁺、K⁺、Ca² ⁺、Mg²⁺Ionic or radioactive Cs⁺、Sr²⁺The ionic aqueous solutions were mixed and the mixture was stirred at 50 ℃ for 3h, V (volume of solution): and m (mass of exchanger) is 1000 mL/g. And after the reaction is finished, taking the supernatant and the initial solution, and measuring the ion concentration by using an inductively coupled plasma emission spectrum and an atomic absorption spectrum respectively. The test results are shown in FIG. 4 and FIG. 5 for competitive Na⁺、K⁺、 Ca²⁺、Mg²⁺Ionic or radioactive Cs⁺Or Sr²⁺In the presence of excess ions (FIG. 5 (a)), sample No. 1 still selectively removes Eu³⁺The ions are selected from the group consisting of,and the Separation Factor (SF) is greater than 100, it is believed that two ions can be separated with SF > 100 for both ions (fig. 5 (b)). FIG. 4 (a) shows that SF > 100 at a Cs/Eu molar ratio of 0.3 to 31.6. FIG. 4 (b) shows that SF > 100 at a Sr/Eu molar ratio of 1.2 to 54.8. The method for extracting and separating lanthanide from water provided by the application can be used for separating Eu³⁺Ions with alkali metal and/or alkaline earth metal ions Na⁺、 K⁺、Ca²⁺、Mg²⁺And radioactive ion Cs⁺Or Sr²⁺And (4) separating, and realizing the recycling of lanthanide and the volume reduction of radioactive waste.

Sample # selectivity to simulated contaminated water experimental procedure: after milling, the powder of sample #1 was mixed with the contaminated aqueous solution and the mixture was stirred at 50 ℃ for 3h, V (volume of solution): and m (mass of exchanger) is 1000 mL/g. And after the reaction is finished, taking the supernatant and the initial solution, and measuring the ion concentration by using an inductively coupled plasma emission spectrum and an atomic absorption spectrum respectively. The test results are shown in FIG. 5(b) and Table 2:

TABLE 2

The results show that in contaminated aqueous solution (excess K)⁺、Na⁺、Ca²⁺、Mg²⁺In the presence of competitive ions), sample #1 can still selectively remove Eu³⁺Ions and the removal rate is as high as 96.9 percent, and the method for extracting and separating the lanthanide element in the water provided by the application is used for Eu under the condition of polluted aqueous solution³⁺The ions still have stronger removal capability and high selectivity.

Example 6 ability to extract and separate lanthanides at different pH values Using sample No. 1

After grinding, the powder of sample No. 1 is mixed with Eu of different pH values³⁺The ionic aqueous solutions were mixed and the mixture was stirred at 50 ℃ for 3h, V (volume of solution): and m (mass of exchanger) is 1000 mL/g. After the reaction is finished, taking supernatant and initial solution, and respectively measuring Eu by inductively coupled plasma emission spectrum³⁺The concentration of the ions. The test results are shown in FIG. 6, and sample No. 1 can maintain the pH value of Eu within the range of 2.0-8.1³⁺Removal activity of ions. For Eu, even when pH is 2.0³⁺The ions still maintain a high partition coefficient (K)_d＝5.0×10⁴mL/g) and high removal (98.0%). The method for extracting and separating lanthanide from water provided by the application is used for Eu in a wide pH range³⁺The ions have stronger removal capability.

Example 7 ability to extract and separate lanthanides Using sample No. 1 after high intensity irradiation

After milling, sample No. 1 and its powder after gamma-ray irradiation at 200kGy β, 100kGy β or 50kGy were treated with 83.4ppm and 125.7ppm Eu³⁺The ionic aqueous solutions were mixed and the mixture was stirred at 50 ℃ for 3h, V (volume of solution): and m (mass of exchanger) is 1000 mL/g. After the reaction is finished, taking supernatant and initial solution, and respectively measuring Eu by inductively coupled plasma emission spectrum³⁺The concentration of the ions. The test results are shown in FIG. 7, and sample No. 1 is irradiated with Eu³⁺The water treatment agent provided by the application has excellent radiation resistance, and can be used for treating Eu after being irradiated by high-intensity β and gamma rays³⁺The ions still have stronger removal capability.

Example 8 simulated ion exchange column applications

As shown in fig. 8, about 4 g of sample #1 preparative exchange column was packed in a flash chromatography column with an inner diameter of 13.4 mm. And (3) allowing a lanthanide mixed solution of 2-5 ppm and 1.98L to flow through the exchange column, collecting the solution at the outlet of the column at different intervals of filtrate volume, and sampling to determine the concentration of lanthanide by inductively coupled plasma emission spectroscopy.

FIG. 9 shows the results of co-processing 440 bed volumes of a mixed lanthanide solution in a simulated column experiment. Obviously, sample No. 1 has adsorption performance for low concentration (2-5 ppm) lanthanide. And sample No. 1 has certain regularity to the removal of lanthanide, and the removal rate of the compound to lanthanide gradually decreases with the increase of the atomic number and the column volume, which shows that the method for extracting and separating lanthanide from water provided by the present application has removal performance to lanthanide.

Example 9 use of [ V ]₃O₇]_n ^2n-Ion exchange elution and elution adsorption experiment after elution of method for removing and recovering lanthanide from layered framework material

After milling, samples 1#100mg and 100mL contained 1000ppm Eu³⁺Mixing the ionic aqueous solutions, and stirring the mixture at 50 deg.C for 3 hr to obtain Eu-removed solution³⁺The ionized product is designated as sample No. 1-Eu. Mixing sample No. 1-Eu with 0.85M KCl solution, stirring the mixture at 25 deg.C for 6h to obtain eluted Eu³⁺The ionized product is designated as sample # 1-Eu-elution. Samples # 1-Eu and # 1-Eu-elution test EDS, respectively, are treated with KCl solution, as shown in FIG. 10, and europium element in sample # 1-Eu is completely eluted.

Sample 1# -Eu-elution with Eu contained in 83.4ppm and 125.7ppm³⁺Aqueous solutions of the ions were mixed and the mixture was stirred at 50 ℃ for 3h, V (volume of solution): and m (mass of exchanger) is 1000 mL/g. After the reaction is finished, taking the supernatant and the initial solution, and respectively measuring by using inductively coupled plasma emission spectroscopy. The test results are shown in FIG. 11, sample # 1-Eu-elution vs. Eu³⁺The ion removal rate remains high. The water treatment agent provided by the application can be recycled.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. A method for separating and/or extracting a lanthanide, characterized in that it comprises the following steps:

the water treatment agent is [ V ]₃O₇]_n ^n-A layered framework material.

2. The method for separating and/or extracting lanthanide elements according to claim 1, wherein the temperature of said water treatment agent for separating and/or extracting said lanthanide elements is 20-80 ℃;

the contact time is 2-12 hours.

3. The method for separating and/or extracting lanthanoid elements according to claim 1, characterized in that said water treatment agent is brought into contact with a solution containing lanthanoid elements, reaching an adsorption equilibrium within 2 hours.

4. The method for separating and/or extracting lanthanides according to claim 1, characterized in that said solution containing lanthanides comprises industrial waste water, radioactive waste water, drinking water.

5. The method for separating and/or extracting lanthanoid elements according to claim 1, characterized in that the concentration of lanthanoid elements in the solution containing lanthanoid elements is 0.2 to 3000 ppm;

preferably, the pH of the lanthanide-containing solution is 2.0-8.1.

6. The method for separating and/or extracting lanthanoid elements according to claim 5, characterized in that the solution containing lanthanoid elements has a pH of 2.5.

7. The method for separating and/or extracting a lanthanide according to claim 1, characterized in that said contact means comprise:

passing the lanthanide-containing solution through a chromatography column, and separating and/or extracting the lanthanide from the solution in the chromatography column; and the chromatographic column is filled with a water treatment agent.

8. The dispenser of claim 1Method for isolating and/or extracting lanthanides, characterized in that said solution containing lanthanides comprises Eu³⁺、Sm³⁺；

9. The method for separating and/or extracting lanthanoid elements according to claim 1, characterized in that said solution containing lanthanoid elements also comprises Cs⁺And/or Sr²⁺；

Said lanthanide and Cs⁺And/or Sr²⁺Has a separation factor of more than 100;

preferably, Cs in said lanthanide-containing solution⁺And/or Sr²⁺The molar ratio of the ions to the lanthanide is 0.4-54.8.

10. The method for separating and/or extracting lanthanoid elements according to claim 1, characterized in that said solution containing lanthanoid elements also comprises ions of alkali metals and/or alkaline-earth metals;

the separation coefficient of the lanthanide from the alkali metal ion and/or alkaline earth metal ion is greater than 100;

preferably, the molar ratio of the alkali metal ion or the alkaline earth metal ion to the lanthanide in the lanthanide-containing solution is 1.9-58.7.

11. The method for separating and/or extracting lanthanoid elements according to claim 1, wherein the water treatment agent has a lanthanoid element removal rate of not less than 80% after being irradiated with β rays and/or gamma rays at a high dose and/or a low dose.

12. The method for separating and/or extracting lanthanoid elements according to claim 1, characterized in that said water treatment agent is recycled by treatment with an inorganic salt solution;