A macroporous adsorption resin for extracting and enriching rubidium and cesium and a preparation method thereof

Abstract

The application provides a macroporous adsorption resin for extracting and enriching rubidium and cesium and a preparation method thereof. The macroporous adsorption resin is modified with specific adsorption groups on the skeleton structure, and is prepared in two steps. In the first step, a resin precursor containing specific reaction groups is prepared through polymerization. In the second step, the specific adsorption groups are introduced on the skeleton structure of the resin through the reaction of the reaction groups with t-butyl phenol. The prepared macroporous adsorption resin has the advantages of high selectivity, high adsorption capacity, reusability, simple operation and no organic pollution in the extraction and enrichment of rubidium and cesium.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a macroporous adsorption resin for extracting and enriching rubidium and cesium and its preparation method. Background Technology

[0002] Rubidium and cesium are highly reactive metallic elements. Due to their unique atomic structure, they have strong chemical activity and excellent photoelectric properties, and are widely used in fields such as synthetic catalysis, special glasses, medical and health care, optoelectronic materials, and biochemistry.

[0003] Currently, solid ores are the main source of rubidium and cesium in China; however, it is undeniable that rubidium and cesium exist widely in the form of soluble salts in salt lakes and underground brine in Qinghai, Tibet, Sichuan, and Hubei provinces, accounting for approximately 90% of the total reserves. For a long time, the extraction of rubidium and cesium from salt lake brine has not been fully industrialized, resulting in a serious waste of resources. The rational utilization of rubidium and cesium resources in salt lakes is of great significance.

[0004] Methods for separating and extracting rubidium and cesium mainly include precipitation, solvent extraction, and ion exchange. Precipitation methods suffer from drawbacks such as complex processes, low product purity and stability, and high cost. Among extraction methods, phenolic reagents are the most mature and selective for rubidium and cesium; however, the extraction process often uses organic solvents, which can easily remain in industrial recycling systems, and the high cost of these solvents limits their industrial application. Ion exchange methods, due to their continuous operation and high selectivity, have become one of the most promising methods for the industrial extraction of rubidium and cesium. They commonly use organic exchangers such as strongly acidic ion exchange resins or inorganic ion exchangers such as zeolites and polyvalent metal acid salts, but generally suffer from poor adsorption selectivity and low adsorption capacity. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a macroporous adsorption resin for extracting and enriching rubidium and cesium. This resin has the ability to selectively adsorb and enrich rubidium and cesium in complex saline systems, and is simple to operate, has high adsorption selectivity, large adsorption capacity, reusable adsorbent, and no organic pollution.

[0006] To achieve the objectives of the invention described above, the present invention adopts the following technical solution:

[0007] An adsorption resin for extracting and enriching rubidium and cesium, the resin comprising the structure of formula 1:

[0008]

[0009] Wherein, R is a long polymer chain, and the long polymer chain contains a cross-linked structure.

[0010] In this invention, the long-chain structure of the adsorption resin is obtained by polyvinylbenzene reaction, preferably by divinylbenzene polymerization.

[0011] In this invention, the hydroxyl value of the adsorption resin is 20-160 mg KOH / g, preferably 40-100 mg KOH / g.

[0012] Compared to existing inorganic ion exchangers such as zeolites and polyvalent metal acid salts, the adsorption resin in this invention consists of spherical particles with easily controllable particle size, making it more suitable for column packing operations. It also boasts lower energy consumption and cost, and its porous structure results in a higher specific surface area and thus a greater adsorption capacity. Unlike existing strongly acidic ion exchange resins, the adsorption resin in this invention has chemically bonded groups in its framework that specifically adsorb rubidium and cesium. This is achieved through the reaction of unreacted double bonds in polyvinylbenzene with tert-butylphenol. The resin possesses suitable polarity and pore structure, and its molecular structure exhibits moderate steric hindrance. It specifically adsorbs hydrated rubidium and cesium ions, while showing weaker adsorption of sodium and potassium ions with larger hydrated ion radii. This results in advantages such as high adsorption capacity, strong adsorption selectivity, and stable adsorption performance.

[0013] Another object of the present invention is to provide a method for preparing the adsorption resin.

[0014] A method for preparing an adsorption resin, the method comprising the following steps:

[0015] S1: The aqueous phase containing dispersant is mixed with the oil phase containing polyvinylbenzene, initiator and porogen, and the reaction is carried out to obtain macroporous adsorption resin precursor;

[0016] S2: React the macroporous adsorption resin precursor with tert-butylphenol to obtain an adsorption resin containing the structure of Formula 1.

[0017] In one embodiment, the adsorbent resin can be prepared by suspension polymerization. The reaction formula between the resin precursor and tert-butylphenol is shown below. After the polyvinylbenzene reacts to obtain a cross-linked long-chain polymer, the double bonds in the unreacted styrene structure continue to react with tert-butylphenol:

[0018]

[0019] In this invention, the dispersant in the aqueous phase S1 is one or more of gelatin, polyvinyl alcohol, polyacrylate, polymethacrylate, talc, and kaolin; preferably, the mass concentration of the dispersant in the aqueous phase is 0.2wt%-0.8wt%.

[0020] In this invention, the polyvinylbenzene in the S1 oil phase is one or more of m-divinylbenzene, p-divinylbenzene, o-divinylbenzene, trivinylbenzene, divinyltoluene, and divinylxylene, preferably m-divinylbenzene and / or p-divinylbenzene.

[0021] In this invention, the initiator in the S1 oil phase is one or more of oil-soluble azo radical initiators, oil-soluble peroxide radical initiators, and oil-soluble redox initiation systems, preferably one or more of azobisisoheptanenitrile, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, and N,N-dibutylaniline.

[0022] In this invention, the pore-forming agent in the S1 oil phase is toluene, xylene, ethylbenzene, or 200... # Solvent oil, 3 # One or more of white oil, C7-C20 alkanes, and C7-C20 alkanols; preferably, the amount of initiator added to the oil phase is 0.2wt%-2wt% of the mass of polyvinylbenzene, and the amount of porogen is 100wt%-200wt% of the mass of polyvinylbenzene; preferably, the volume ratio of the aqueous phase to the oil phase is (3-4):1.

[0023] In this invention, the reaction temperature of S1 is 40-95℃ and the reaction time is 2-10h; preferably, the reaction temperature is 60-80℃ and the reaction time is 4-7h.

[0024] In one embodiment, the macroporous adsorption resin precursor described in S1 undergoes conventional post-treatment, including extraction, solvent washing, and water washing, with the preferred post-treatment being methyl acetal extraction, ethanol washing, and pure water washing.

[0025] In this invention, the tert-butylphenol in S2 is one or more of o-tert-butylphenol, p-tert-butylphenol, and m-tert-butylphenol, preferably p-tert-butylphenol; preferably, the mass of tert-butylphenol is 10wt%-30wt% of the mass of the macroporous adsorption resin precursor.

[0026] In this invention, S2 is added to a catalyst, which is an acidic catalyst, preferably a strong acid and / or a medium-strong acid catalyst, more preferably concentrated phosphoric acid and / or aluminum chloride; preferably, the amount of catalyst added is 15wt%-25wt% of the mass of tert-butylphenol.

[0027] In this invention, water is added to S2, preferably in a volume 5-15 times that of the resin precursor.

[0028] In this invention, the reaction temperature of S2 is 90-120℃ and the reaction time is 2-8h; preferably, the reaction temperature is 100-110℃ and the reaction time is 5-7h.

[0029] In one embodiment, the adsorbent resin obtained in S2 showed an IR test result at 3540 cm⁻¹. -1 The presence of a distinct hydroxyl stretching vibration peak indicates that tert-butylphenol is bonded to the resin backbone.

[0030] Another object of the present invention is to provide an adsorption resin for extracting and enriching rubidium and cesium.

[0031] The use of an adsorption resin for extracting and enriching rubidium and cesium, wherein the adsorption resin is the adsorption resin described above or an adsorption resin prepared by the method described above, the adsorption resin is used for extracting and enriching rubidium and cesium, preferably for selectively adsorbing and enriching rubidium and cesium in complex saline systems, and more preferably for extracting and enriching rubidium and cesium in salt lakes.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] The macroporous adsorption resin prepared by the above techniques not only has a high adsorption capacity of 1.56 mmol / mL for rubidium and cesium extraction and enrichment, but also selectively separates rubidium and cesium in systems containing sodium and potassium. Furthermore, it has the advantages of being reusable, easy to operate, and free from organic pollution. Attached Figure Description

[0034] Figure 1 The image shows the infrared spectrum of the adsorption resin prepared in Example 3. The obtained adsorption resin showed an infrared spectrum at 3540 cm⁻¹. -1 The presence of a distinct hydroxyl stretching vibration peak indicates that tert-butylphenol is bonded to the resin backbone. Detailed Implementation

[0035] The technical solutions of the present invention are illustrated by the following examples; however, these examples do not constitute a limitation of the present invention.

[0036] Main raw material information:

[0037] Polyvinylbenzene Aladdin 80％ Benzoyl peroxide, lauryl peroxide Aladdin Analytical Pure Azobisisobutyronitrile, N,N-dibutylaniline Inokai Analytical Pure <![CDATA[3 # White oil Fengzhulin 99％ <![CDATA[200 # Solvent oil Nanjing Reagent 99％ Toluene Comio Analytical Pure Polyvinyl alcohol Aladdin Analytical Pure tert-butylphenol Aladdin 99％ Anhydrous aluminum chloride Aladdin 98％ concentrated phosphoric acid Aladdin 85％ concentrated hydrochloric acid Comio 36％ D001 resin Bring glory - Natural clinoptilolite Liaoning Chaoyang Climatic Zeolite Mine -

[0038] Hydroxyl value test method for resin: The hydroxyl value is determined by titration with an indicator according to the phthalic anhydride method in GB / T 7383-2020.

[0039] Fourier transform infrared spectrometer: Thermo Fisher Scientific, Nicolet iS5.

[0040] Example 1

[0041] Dissolve 1.308 g of polymethyl methacrylate in 650 mL of water to prepare an aqueous phase. Add 200 g of p-divinylbenzene, 0.4 g of benzoyl peroxide, and 200 g of 3... #After the white oil is mixed evenly, it is used as the oil phase. Stirring is used to disperse the oil phase into the aqueous phase. Then the temperature is raised to 95°C and the reaction is carried out for 2 hours. The reaction is stopped and the material is cooled and discharged. The resin is washed with methyl acetal column for 10 times the resin volume, ethanol column for 10 times the resin volume, and pure water column for 15 times the resin volume to obtain the macroporous adsorption resin precursor.

[0042] The resin was centrifuged at 2000 r / min for 5 min to remove free water. 50 g of the macroporous adsorption resin precursor (after removing free water), 15 g of p-tert-butylphenol, 2.25 g of aluminum chloride, and 1.5 g of concentrated hydrochloric acid were mixed in 1070 mL of pure water and heated to 90 °C for 8 h. The reaction was then stopped, the mixture was cooled, and the product was discharged. The resin was washed with a pure water column for 20 times its volume to obtain the macroporous adsorption resin for the extraction and enrichment of rubidium and cesium. The hydroxyl value of the resin was 32 mg KOH / g.

[0043] Take 50 mL of the above macroporous adsorption resin and pack it into a 26 mm diameter chromatography column using a wet packing method with pure water. The column is then ready for evaluation.

[0044] Example 2

[0045] Dissolve 6.976 g of gelatin in 870 mL of water to prepare an aqueous phase. Add 200 g of m-divinylbenzene, 2.7 g of lauryl peroxide, 1.3 g of N,N-dibutylaniline, and 400 g of 200... # The solvent oil is mixed evenly and used as the oil phase. The oil phase is dispersed into the aqueous phase by stirring. The temperature is then raised to 40°C and reacted for 10 hours. The reaction is stopped and the product is cooled and discharged. The resin is washed with methyl acetal for 10 times the resin volume, ethanol for 10 times the resin volume, and pure water for 15 times the resin volume to obtain the macroporous adsorption resin precursor.

[0046] The resin was centrifuged at 2000 r / min for 5 min to remove free water. 50 g of the macroporous adsorption resin precursor (after removing free water), 5 g of p-tert-butylphenol, and 0.75 g of concentrated phosphoric acid were mixed in 357 mL of pure water and heated to 120 °C for 2 h. The reaction was then stopped, the mixture was cooled, and the product was discharged. The resin was washed with a pure water column for 20 times its volume to obtain the macroporous adsorption resin for the extraction and enrichment of rubidium and cesium. The hydroxyl value of the resin was 148 mg KOH / g.

[0047] Take 50 mL of the above macroporous adsorption resin and pack it into a 26 mm diameter chromatography column using a wet packing method with pure water. The column is then ready for evaluation.

[0048] Example 3

[0049] 3.815 g of polyvinyl alcohol was dissolved in 762 mL of water to prepare an aqueous phase. 200 g of p-divinylbenzene, 1.6 g of azobisisobutyronitrile, and 300 g of toluene were mixed evenly to form an oil phase. The oil phase was dispersed into the aqueous phase by stirring, and then the temperature was raised to 75 °C and reacted for 6 h. The reaction was stopped, and the product was cooled and discharged. The resin was washed with methyl acetal for 10 times the resin volume, with ethanol for 10 times the resin volume, and with pure water for 15 times the resin volume to obtain a macroporous adsorption resin precursor.

[0050] The resin was centrifuged at 2000 rpm for 5 min to remove free water. 50 g of the dehydrated macroporous adsorption resin precursor, 10 g of p-tert-butylphenol, 1.3 g of aluminum chloride, and 0.7 g of concentrated hydrochloric acid were mixed in 500 mL of pure water and heated to 105 °C for 6 h. The reaction was then stopped, the mixture was cooled, and the product was discharged. The resin was washed with a pure water column for 10 times its volume to obtain the macroporous adsorption resin for the extraction and enrichment of rubidium and cesium. The hydroxyl value of the resin was 72 mg KOH / g. The IR characterization results of the resin are shown below. Figure 1 .

[0051] Take 50 mL of the above macroporous adsorption resin and pack it into a 26 mm diameter chromatography column using a wet packing method with pure water. The column is then ready for evaluation.

[0052] Example 4

[0053] 3.815 g of polyvinyl alcohol was dissolved in 762 mL of water to prepare an aqueous phase. 200 g of trivinylbenzene, 1.6 g of azobisisobutyronitrile, and 300 g of toluene were mixed evenly to form an oil phase. The oil phase was dispersed into the aqueous phase by stirring, and then the temperature was raised to 75 °C and reacted for 6 h. The reaction was stopped, and the product was cooled and discharged. The resin was washed with methyl acetal for 10 times the resin volume, with ethanol for 10 times the resin volume, and with pure water for 15 times the resin volume to obtain a macroporous adsorption resin precursor.

[0054] The resin was centrifuged at 2000 r / min for 5 min to remove free water. 50 g of the macroporous adsorption resin precursor (after removing free water), 10 g of p-tert-butylphenol, 1.3 g of aluminum chloride, and 0.7 g of concentrated hydrochloric acid were mixed in 500 mL of pure water and heated to 105 °C for 6 h. The reaction was then stopped, the mixture was cooled, and the product was discharged. The resin was washed with a pure water column for 10 times its volume to obtain the macroporous adsorption resin for the extraction and enrichment of rubidium and cesium. The hydroxyl value of the resin was 44 mg KOH / g.

[0055] Take 50 mL of the above macroporous adsorption resin and pack it into a 26 mm diameter chromatography column using a wet packing method with pure water. The column is then ready for evaluation.

[0056] Example 5

[0057] 3.815 g of polyvinyl alcohol was dissolved in 762 mL of water to prepare an aqueous phase. 200 g of p-divinylbenzene, 1.6 g of azobisisobutyronitrile, and 300 g of toluene were mixed evenly to form an oil phase. The oil phase was dispersed into the aqueous phase by stirring, and then the temperature was raised to 75 °C and reacted for 6 h. The reaction was stopped, and the product was cooled and discharged. The resin was washed with methyl acetal for 10 times the resin volume, with ethanol for 10 times the resin volume, and with pure water for 15 times the resin volume to obtain a macroporous adsorption resin precursor.

[0058] The resin was centrifuged at 2000 r / min for 5 min to remove free water. 50 g of the macroporous adsorption resin precursor (after removing free water), 10 g of o-tert-butylphenol, 1.3 g of aluminum chloride, and 0.7 g of concentrated hydrochloric acid were mixed in 500 mL of pure water and heated to 105 °C for 6 h. The reaction was then stopped, the mixture was cooled, and the product was discharged. The resin was washed with a pure water column for 10 times its volume to obtain the macroporous adsorption resin for the extraction and enrichment of rubidium and cesium. The hydroxyl value of the resin was 72 mg KOH / g.

[0059] Take 50 mL of the above macroporous adsorption resin and pack it into a 26 mm diameter chromatography column using a wet packing method with pure water. The column is then ready for evaluation.

[0060] Comparative Example 1

[0061] Take 50 mL of D001 strong acid macroporous resin and pack it into a 26 mm diameter chromatography column using a wet packing method with pure water. Wash the column with 1 mol / L hydrochloric acid for 8 times the resin volume, and then wash with pure water until the eluent is neutral. Wash the column with 1 mol / L sodium hydroxide solution for 8 times the resin volume, and then wash with pure water until the eluent is neutral.

[0062] Comparative Example 2

[0063] Natural clinoptilolite was ground to 0.25-0.42 mm. 50 mL of the ground zeolite was packed into a 26 mm diameter chromatography column using a wet packing method with pure water. The column was washed with 8 times the volume of resin using a 2 mol / L ammonium bicarbonate aqueous solution and then washed with pure water until the eluent was neutral.

[0064] Evaluation of adsorption resins:

[0065] A mixed salt solution was prepared as the adsorption mother liquor, wherein the concentrations of RbCl, CsCl, KCl, and NaCl were all 0.01 mol / L. The adsorption mother liquor was passed through the chromatography columns of Examples 1-5 and Comparative Examples 1-2 at a flow rate of 3 ml / min. Adsorption saturation was defined as the concentrations of rubidium and cesium ions at the outlet of the chromatography column remaining constant. The saturated adsorption capacity of the adsorbent for each ion was then measured.

[0066] Example 1: Resin saturation adsorption capacity (mmol / mL) 0.55 0.64 0.20 0.26 Example 2: Resin saturation adsorption capacity (mmol / mL) 0.71 0.85 0.28 0.31 Example 3: Resin saturation adsorption capacity (mmol / mL) 0.66 0.81 0.22 0.30 Example 4: Resin saturation adsorption capacity (mmol / mL) 0.58 0.71 0.21 0.27 Example 5: Resin saturation adsorption capacity (mmol / mL) 0.67 0.80 0.31 0.38 Comparative Example 1: Resin saturation adsorption capacity (mmol / mL) 0.42 0.45 0.30 0.32 Comparative Example 2: Zeolite saturated adsorption capacity (mmol / mL) 0.48 0.52 0.28 0.32

Claims

1. A method for preparing an adsorption resin, characterized in that, The method includes the following steps: S1: The aqueous phase containing dispersant is mixed with the oil phase containing polyvinylbenzene, initiator and porogen, and the reaction is carried out to obtain macroporous adsorption resin precursor; S2: React the macroporous adsorption resin precursor with tert-butylphenol to obtain an adsorption resin containing the structure of Formula 1. The resin comprises the following structure: Formula 1 Wherein, R is a long polymer chain, and the long polymer chain contains a cross-linked structure.

2. The method according to claim 1, characterized in that, The dispersant in the S1 aqueous phase is one or more of gelatin, polyvinyl alcohol, polyacrylate, polymethyl methacrylate, talc, and kaolin. And / or, the polyvinylbenzene in the S1 oil phase is one or more of m-divinylbenzene, p-divinylbenzene, o-divinylbenzene, trivinylbenzene, divinyltoluene, and divinylxylene; And / or, the initiator in the oil phase of S1 is one or more of the following: oil-soluble azo radical initiator, oil-soluble peroxide radical initiator, and oil-soluble redox initiation system; And / or, the pore-forming agent in the S1 oil phase is toluene, xylene, ethylbenzene, or 200 # Solvent oil, 3 # White oil, one or more of C7-C20 alkanes and C7-C20 alkanols.

3. The method according to claim 2, characterized in that, The mass concentration of the dispersant in the S1 aqueous phase is 0.2wt%-0.8wt%; And / or, the polyvinylbenzene in the S1 oil phase is m-divinylbenzene and / or p-divinylbenzene; And / or, the initiator in the S1 oil phase is one or more of azobisisobutyronitrile, azobisisobutyronitrile, benzoyl peroxide, and N,N-dibutylaniline; In S1, the amount of initiator added to the oil phase is 0.2wt%-2wt% of the mass of polyvinylbenzene, and the amount of porogen added is 100wt%-200wt% of the mass of polyvinylbenzene. The volume ratio of the aqueous phase to the oil phase in S1 is (3-4):

1.

4. The method according to claim 1, characterized in that, The reaction temperature of S1 is 40-95℃, and the reaction time is 2-10h.

5. The method according to claim 4, characterized in that, The reaction temperature of S1 is 60-80℃, and the reaction time is 4-7h.

6. The method according to claim 1, characterized in that, The tert-butylphenol in S2 is one or more of o-tert-butylphenol, p-tert-butylphenol, and m-tert-butylphenol; And / or, S2 is added with a catalyst, which is an acidic catalyst; And / or, water is added to S2.

7. The method according to claim 6, characterized in that, The tert-butylphenol in S2 is p-tert-butylphenol; The mass of tert-butylphenol in S2 is 10wt%-30wt% of the macroporous adsorption resin precursor. And / or, the catalyst in S2 is a strong acid and / or a medium-strong acid catalyst; The amount of catalyst added in S2 is 15wt%-25wt% of the mass of tert-butylphenol; And / or, the volume of water in S2 is 5-15 times the volume of the resin precursor.

8. The method according to claim 7, characterized in that, The catalyst in S2 is concentrated phosphoric acid and / or aluminum chloride.

9. The method according to claim 1, characterized in that, The reaction temperature in S2 is 90-120℃, and the reaction time is 2-8h.

10. The method according to claim 9, characterized in that, The reaction temperature in S2 is 100-110℃, and the reaction time is 5-7h.

11. An adsorption resin for extracting and enriching rubidium and cesium, said adsorption resin being prepared by the method according to any one of claims 1-10, characterized in that, The resin comprises a structure of formula 1: Formula 1 Wherein, R is a long polymer chain, and the long polymer chain contains a cross-linked structure.

12. The adsorption resin according to claim 11, characterized in that, The long-chain structure of the adsorption resin is obtained through a polyvinylbenzene reaction; And / or, the hydroxyl value of the adsorption resin is 20-160 mg KOH / g.

13. The adsorption resin according to claim 12, characterized in that, The long-chain structure of the adsorption resin is obtained by divinylbenzene polymerization; And / or, the hydroxyl value of the adsorption resin is 40-100 mg KOH / g.

14. Use of an adsorption resin for extracting and enriching rubidium and cesium, wherein the adsorption resin is an adsorption resin prepared by the method according to any one of claims 1-10, or an adsorption resin according to any one of claims 11-13, characterized in that, The adsorption resin is used to extract and enrich rubidium and cesium.

15. The use according to claim 14, characterized in that, The adsorption resin is used to selectively adsorb and enrich rubidium and cesium in complex salt water systems.

16. The use according to claim 15, characterized in that, The adsorption resin is used for the extraction and enrichment of rubidium and cesium in salt lakes.

Images