Uranium and thorium specific capturing agent under complex solution system, and synthesis method and application of uranium and thorium specific capturing agent

Abstract

The invention relates to a uranium and thorium specific capturing agent in a complex solution system, the uranium and thorium specific capturing agent is a modified cellulose material containing multiple phosphate groups, and the molecular structural formula of the uranium and thorium specific capturing agent is # imgabs0 #.

Description

Technical Field

[0001] The invention belongs to the field of heavy metal wastewater treatment, and particularly relates to a uranium-thorium specific capture agent in a complex solution system, a synthesis method and application thereof. Background Art

[0002] Uranium and thorium are widely present in the earth's crust. They are important associated metals of tantalum and niobium ores and are common types of heavy metals in wastewater from mining and metallurgical industries. They are radioactive and difficult to treat. They are one of the most harmful pollution to the environment and the human body. Since uranium and thorium cannot be decomposed and destroyed, the current treatment methods are to separate them from wastewater by phase transfer. Among the currently developed uranium and thorium wastewater treatment methods, such as traditional chemical precipitation, chelation adsorption, iron reduction, ion exchange, ion flotation, membrane separation, electrochemical methods, adsorption and biological methods, there are certain disadvantages: for example, they are easy to adsorb large amounts of harmless ions such as iron and aluminum ions, and cannot be washed and reused. Summary of the invention

[0003] In order to solve the above problems, the purpose of the present invention is to solve the defects and shortcomings in the prior art and provide a polymer material having both specific capture and flocculation functions.

[0004] A uranium-thorium specific capture agent in a complex solution system, wherein the uranium-thorium specific capture agent is a modified cellulose material containing multiple phosphate groups, and its molecular structure is: .

[0005] A method for synthesizing a uranium-thorium specific capture agent in a complex solution system: S1: First, take the cellulose product and dry it at 100-120℃ to constant weight and chop it into pieces. Add the above pieces into an anhydrous solvent and then add a calculated amount of organic base. Stir at room temperature for 30 minutes to make it evenly distributed. S2: slowly add an appropriate amount of chlorophosphate at 20-30°C, and keep the temperature for reaction after adding the chlorophosphate; S3: After the reaction is completed, the solvent is removed by filtration, and the obtained modified cellulose product is added into water, stirred and washed, filtered again, and dried at 70-90°C to obtain the product. The reaction equation of the cellulose product and the organic base is as follows: .

[0006] Preferably, the cellulose product is a mixture of one or more of absorbent cotton, filter paper, cotton cloth or other recycled paper.

[0007] Preferably, the reaction solvent is one of tetrahydrofuran, chloroform, dichloromethane or diethyl ether.

[0008] Preferably, the organic base is a mixture of one or more of triethylamine, pyridine, DBU, and DMAP, and the usage ratio of the organic base to the cellulose product is: Organic alkali: cellulose product = 1.5-3:1, calculated by mass.

[0009] Preferably, the ratio of the amount of cellulose product to the amount of solvent is 4-8 L per kg of cellulose.

[0010] Preferably, the chlorophosphate ester is one of dimethyl chlorophosphate, diethyl chlorophosphate, dipropyl chlorophosphate, and dibutyl chlorophosphate.

[0011] Preferably, the dosage ratio of the chlorophosphate ester and the cellulose product is: chlorophosphate ester: cellulose product = 2.7-6.4:1, calculated by mass, and the addition time is 1-5h.

[0012] Preferably, the reaction time of the insulation reaction is 1-5h, and the reaction temperature is 25-60°C.

[0013] The invention discloses an application of a uranium-thorium specific capture agent in a complex solution system, wherein the uranium-thorium specific capture agent is applied to the specific adsorption of uranium-thorium in a complex solution system where multiple ions coexist. Compared with the above method, the chelation flocculation adsorption method has the advantages of simple process, high efficiency and economy, no adsorption of harmless ions such as iron and aluminum ions that exist in large quantities, and can be repeatedly used after elution, and is suitable for the treatment of large-scale uranium-thorium-containing complex wastewater systems, and the key lies in the groups and skeleton structures used.

[0014] Beneficial effects: The present invention can achieve specific adsorption of uranium and thorium in a complex solution system where multiple ions coexist, eliminate interference from common harmless ions such as iron and aluminum that are easily combined with chelating agents, and specifically enrich and recover uranium and thorium elements in a complex system. After treatment by the present invention, the uranium and thorium concentration in the wastewater can be lower than 1 mg / L. This can more effectively improve the flocculation capture of uranium and thorium without interference from foreign ions, greatly reduce the amount of radioactive slag, and improve the treatment of wastewater with excessive uranium and thorium. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the embodiments.

[0016] This scheme is to modify natural cellulose with diethyl chlorophosphate in a weakly alkaline environment to obtain a modified cellulose material containing a large number of phosphate groups. The modified cellulose material can achieve specific adsorption of uranium and thorium, eliminate interference from common harmless ions such as iron and aluminum that are easily combined with chelating agents, and specifically enrich and recover uranium and thorium elements in complex systems. Example

[0017] A uranium-thorium-containing wastewater, in which the uranium content is 563 mg / L, thorium is 20 mg / L, iron is 9300 mg / L, aluminum is 1600 mg / L, and the pH is 1.

[0018] Steps: Take the absorbent cotton and dry it at 105℃ until constant weight, then cut it into pieces, weigh 20g, add it to 100mL tetrahydrofuran under stirring, then add 38.05g pyridine, stir at room temperature for 30min after addition, then add 70.23g diethyl chlorophosphate dropwise for 2h, react at 60℃ for 4h after addition. Filter, take the solid and disperse it in 100mL water, stir at room temperature for 30min, filter and dry at 80℃ to obtain the product.

[0019] The following three samples were used to compare the corresponding experimental parameters: (1) Stock solution: Take 500 ml of the above-mentioned uranium-thorium wastewater, without adding any reactants or performing any treatment, and take the clear solution to measure the heavy metal content.

[0020] (2) Take 500 mL of the above uranium-thorium wastewater, add solid sodium hydroxide to adjust the pH to 2, add 1 g of the above product, stir and react for 10 min, filter, and take the clear liquid to measure the uranium and thorium content.

[0021] (3) Take 500 mL of the above uranium-thorium wastewater, add solid sodium hydroxide to adjust the pH to 2, add 2 g of the above product, stir and react for 10 minutes, filter, and take the clear liquid to measure the uranium and thorium content. The relevant water quality test results are shown in Table 1: Table 1 Water sample test results (unit: mg / L)

[0022] Obviously, the above embodiments of the present invention are merely examples for illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to exhaust all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A uranium-thorium specific capture agent in a complex solution system, characterized in that: The uranium-thorium specific capture agent is a modified cellulose material containing multiple phosphate groups, and its molecular structure is: 。 2. A method for synthesizing a uranium-thorium specific capture agent in a complex solution system according to claim 1, characterized in that: S1: First, take the cellulose product and dry it at 100-120℃ to constant weight and chop it into pieces. Add the above pieces into an anhydrous solvent and then add a calculated amount of organic base. Stir at room temperature for 30 minutes to make it evenly distributed. S2: slowly add an appropriate amount of chlorophosphate at 20-30°C, and keep the temperature for reaction after adding the chlorophosphate; S3: After the reaction is completed, the solvent is removed by filtration, and the obtained modified cellulose product is added into water, stirred and washed, filtered again, and dried at 70-90°C to obtain the product. The reaction equation of the cellulose product and the organic base is as follows: 。 3. The method for synthesizing a uranium-thorium specific capture agent in a complex solution system according to claim 2, characterized in that: The cellulose product is a mixture of one or more of absorbent cotton, filter paper, cotton cloth or other recycled paper.

4. The method for synthesizing a uranium-thorium specific capture agent in a complex solution system according to claim 2, characterized in that: The reaction solvent is one of tetrahydrofuran, chloroform, dichloromethane or ether.

5. The method for synthesizing a uranium-thorium specific capture agent in a complex solution system according to claim 2, characterized in that: The organic base is a mixture of one or more of triethylamine, pyridine, DBU, and DMAP, and the usage ratio of the organic base to the cellulose product is: Organic alkali: cellulose product = 1.5-3:1, calculated by mass.

6. The method for synthesizing a uranium-thorium specific capture agent in a complex solution system according to claim 2, characterized in that: The usage ratio of the cellulose product and the solvent is 4-8 L of solvent per kilogram of cellulose.

7. The method for synthesizing a uranium-thorium specific capture agent in a complex solution system according to claim 2, characterized in that: The chlorophosphate ester is one of dimethyl chlorophosphate, diethyl chlorophosphate, dipropyl chlorophosphate and dibutyl chlorophosphate.

8. The method for synthesizing a uranium-thorium specific capture agent in a complex solution system according to claim 2, characterized in that: The usage ratio of the chlorophosphate ester and the cellulose product is: Chlorophosphate: cellulose product = 2.7-6.4:1, calculated by mass, and the addition time is 1-5h.

9. The method for synthesizing a uranium-thorium specific capture agent in a complex solution system according to claim 2, characterized in that: The reaction time of the heat preservation reaction is 1-5h, and the reaction temperature is 25-60°C.

10. An application of a uranium-thorium specific capture agent in a complex solution system, characterized in that: The uranium-thorium specific capture agent is used for specific adsorption of uranium-thorium in a complex solution system where multiple ions coexist.

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