A Ca-ZrP-1,8-octanediamine composite material and its preparation method and use

Abstract

The present invention belongs to the technical field of nuclide adsorption materials, and specifically discloses a Ca-ZrP-1,8-octanediamine composite material, its preparation method, and use. The composite material is synthesized by intercalation and ion exchange reaction using hydrothermal ZrP as a substrate. Compared with the prior art, the process for preparing the Ca-ZrP-1,8-octanediamine composite material is simple, economical, and does not produce intermediate products that pollute the environment. The prepared Ca-ZrP-1,8-octanediamine composite material has better adsorption performance than pure zirconium phosphate, stable performance in a wide pH range and a high correlation coefficient, and is more effective for Sr at pH = 1. 2+ The adsorption capacity reaches 34.52 mg / g, which is much higher than that of pure ZrP and can be used for the adsorption of radionuclide strontium.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclide adsorption materials, in particular to a Ca-ZrP-1,8-octanediamine composite material and a preparation method and application thereof. Background Art

[0002] Nuclear energy has become one of the world's most important non-fossil energy sources due to its low carbon emissions. However, the development of nuclear energy and the operation of nuclear power plants both generate spent fuel. The Chernobyl accident in the Soviet Union and the Fukushima nuclear power plant accident in Japan released large amounts of radioactive nuclides, causing long-term damage to the ecological environment. According to the "China Nuclear Energy Development and Outlook (2022)" published by the China Nuclear Energy Association, the scale of my country's installed commercial nuclear power plants continues to grow. However, as installed capacity continues to increase, the amount of spent fuel generated during nuclear power operations is also increasing.

[0003] In the nuclear fuel cycle, 90 Sr is 235 One of the U fission products and one of the main sources of radioactivity in spent fuel. 90 Sr has a half-life of 29.14 years and emits particles through beta decay, making it a radioactive nuclide of great concern in nuclear weapons and nuclear accidents. 90 Sr exists in nuclear fuel and radioactive waste from reactors. It has high mobility and toxicity in the environment and can damage the central nervous system, endocrine system, and blood system of the human body. Large doses or long-term exposure can cause significant harm to the human body, increase the risk of cancer, and even endanger life in severe cases. Therefore, radionuclides 90 Sr is a pollutant that should be paid special attention to in the nuclear fuel cycle, spent fuel reprocessing and radioactive waste disposal. 90 Sr is of great significance for the prevention and control of environmental pollution.

[0004] Currently, the capture methods for radioactive nuclides Sr mainly include solvent extraction, chemical precipitation, and ion exchange. The ion exchange method is considered to be an ideal radionuclide adsorption method because it is simple to operate, highly efficient, and has no secondary pollution. Although adsorption materials based on zirconium phosphate have been increasingly used in the adsorption of nuclides Sr over the years, the adsorption performance has not been significantly improved. The present invention aims to utilize small molecule intercalation technology to first increase the interlayer spacing of zirconium phosphate, and then fully exchange the material with the increased interlayer spacing with calcium chloride to achieve the preparation of a composite material, which has significantly improved the adsorption performance of the material for nuclides Sr. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a Ca-ZrP-1,8-octanediamine composite material and a preparation method and use thereof.

[0006] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0007] The first object of the present invention is to provide a method for preparing a Ca-ZrP-1,8-octanediamine composite material, comprising the following steps:

[0008] S1. Dispersing a zirconium source in a phosphoric acid solution at a solid-liquid ratio of 1-4:8.2-24.6 g / ml, reacting at 120-180° C. for 12-18 hours using a hydrothermal method, and washing and drying the product to obtain zirconium phosphate nanosheets with thin-layer properties;

[0009] S2, taking zirconium phosphate nanosheets and 1,8-octanediamine in a mass ratio of 0.5-4:0.1-0.5, adding the zirconium phosphate nanosheets to the 1,8-octanediamine solution, stirring after ultrasonic treatment to allow the 1,8-octanediamine to be fully intercalated into the zirconium phosphate, and washing and drying to obtain a ZrP-1,8-octanediamine composite material;

[0010] S3. Take a ZrP-1,8-octanediamine material and a calcium chloride aqueous solution in a mass ratio of 1~4:10~20, uniformly disperse the ZrP-1,8-octanediamine composite material in the calcium chloride aqueous solution, transfer it to a stirring platform, and fully stir it under certain temperature conditions to allow Ca ions to be intercalated into the ZrP-1,8-octanediamine, and then wash and dry it to obtain a Ca-ZrP-1,8-octanediamine composite material.

[0011] Furthermore, the zirconium source is zirconium oxychloride octahydrate.

[0012] Furthermore, the concentration of the phosphoric acid solution is ≥85wt%.

[0013] Furthermore, the concentration of the 1.8-octanediamine solution is 0.017-0.085 mol / L.

[0014] Furthermore, the concentration of the calcium chloride solution is 2.25-4.5 mol / L.

[0015] Preferably, the washing method is any one of suction filtration washing, centrifugal washing, and ultrasonic sedimentation washing, and the drying method is any one of natural drying, constant temperature drying, and programmed temperature variable drying, and the drying temperature is 50-80°C.

[0016] The second object of the present invention is to provide a Ca-ZrP-1,8-octanediamine composite material prepared by the above method.

[0017] The third object of the present invention is to provide a use of a Ca-ZrP-1,8-octanediamine composite material, wherein the Ca-ZrP-1,8-octanediamine composite material is added to a strontium-containing solution and the strontium nuclide is adsorbed under stirring conditions.

[0018] Compared with the prior art, the process for preparing the Ca-ZrP-1,8-octanediamine composite material of the present invention is simple, economical and does not produce intermediate products that pollute the environment; the prepared Ca-ZrP-1,8-octanediamine composite material has an adsorption performance superior to that of pure zirconium phosphate, is stable in a wide pH range and has a high correlation coefficient, and is particularly effective for Sr at pH = 1. 2+ The adsorption capacity reaches 34.52 mg / g, which is much higher than that of pure ZrP and can be used for the adsorption of radionuclide strontium. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a field emission scanning electron microscope image of the Ca-ZrP-1,8-octanediamine composite material prepared in Example 3.

[0020] Figure 2 The present invention is a flow chart of the preparation method of the Ca-ZrP-1,8-octanediamine composite material.

[0021] Figure 3 XRD patterns of the Ca-ZrP-1,8-octanediamine composite material prepared in Example 3, hydrothermal ZrP, and ZrP+CaCl2.

[0022] Figure 4 The adsorption isotherms of the Ca-ZrP-1,8-octanediamine composite material prepared in Example 3, the adsorption isotherms of hydrothermal ZrP and ZrP+CaCl2;

[0023] Figure 5 This is a graph showing the adsorption capacity and correlation coefficient of the Ca-ZrP-1,8-octanediamine composite material prepared in Example 3 at different pH values. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following Figure 1-Figure 5 The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Example 1

[0025] Step 1: Disperse 1 g of zirconium oxychloride octahydrate powder (98 wt % or more) in 8.2 ml of phosphoric acid solution (85 wt % or more), react at 120° C. for 18 h using a hydrothermal method, and wash and dry the product to obtain zirconium phosphate nanosheets with thin-layer properties.

[0026] Step 2: Add 0.5 g of zirconium phosphate nanosheets to 0.1 g of 0.017 mol / L 1,8-octanediamine solution, perform ultrasonic treatment and stirring to allow 1,8-octanediamine to be fully intercalated into the zirconium phosphate, and obtain a ZrP-1,8-octanediamine composite material after washing and drying;

[0027] Step 3: Evenly disperse 1g of ZrP-1,8-octanediamine composite material in 10g of calcium chloride aqueous solution, transfer to a stirring platform and stir thoroughly under certain temperature conditions to allow Ca ions to be intercalated into ZrP-1,8-octanediamine, and then wash and dry to obtain a Ca-ZrP-1,8-octanediamine composite material. Example 2

[0028] Step 1: Disperse 4 g of zirconium oxychloride octahydrate powder (98 wt % or more) in 24.6 ml of phosphoric acid solution (85 wt % or more), react at 180° C. for 12 h using a hydrothermal method, and wash and dry the product to obtain zirconium phosphate nanosheets with thin-layer properties.

[0029] Step 2: Add 4 g of zirconium phosphate nanosheets to 0.5 g of 0.085 mol / L 1,8-octanediamine solution, perform ultrasonic treatment and stirring to allow 1,8-octanediamine to be fully intercalated into the zirconium phosphate, and obtain a ZrP-1,8-octanediamine composite material after washing and drying;

[0030] Step 3: Evenly disperse 4 g of ZrP-1,8-octanediamine composite material in 20 g of calcium chloride aqueous solution, transfer to a stirring platform and stir thoroughly under certain temperature conditions to allow Ca ions to be intercalated into ZrP-1,8-octanediamine, and then wash and dry to obtain a Ca-ZrP-1,8-octanediamine composite material. Example 3

[0031] Step 1: Disperse 2 g of zirconium oxychloride octahydrate powder (98 wt % or more) in 20 ml of phosphoric acid solution (85 wt % or more), react at 160° C. for 14 h using a hydrothermal method, and wash and dry the product to obtain zirconium phosphate nanosheets with thin-layer properties.

[0032] Step 2: Add 2 g of zirconium phosphate nanosheets to 0.3 g of 0.030 mol / L 1,8-octanediamine solution, perform ultrasonic treatment and stirring to allow 1,8-octanediamine to be fully intercalated into the zirconium phosphate, and obtain a ZrP-1,8-octanediamine composite material after washing and drying;

[0033] Step 3: Evenly disperse 2 g of ZrP-1,8-octanediamine composite material in 15 g of calcium chloride aqueous solution, transfer to a stirring platform and stir thoroughly under certain temperature conditions to allow Ca ions to be intercalated into ZrP-1,8-octanediamine, and then wash and dry to obtain a Ca-ZrP-1,8-octanediamine composite material.

[0034] The Ca-ZrP-1,8-octanediamine composite material obtained in Example 3 was taken as a sample for testing. Figure 1 This is a field emission scanning electron microscope image of the Ca-ZrP-1,8-octanediamine composite material. Figure 1 It can be seen that the composite material is mainly based on ZrP and is in the form of nanosheets. The sheets are stacked on each other and produce many channels.

[0035] Figure 3 The XRD patterns of the Ca-ZrP-1,8-octanediamine composite material, ZrP+CaCl2 and hydrothermal ZrP prepared in Example 3 are shown in the figure. It can be seen from the XRD patterns that only by first intercalating and then introducing Ca ions can a high-purity Ca-ZrP-1,8-octanediamine composite material be synthesized. Figure 1 As can be seen from the figure, the Ca-ZrP-1,8-octanediamine composite prepared in this embodiment has the advantages of being porous and having a wide contact area on the ZrP substrate, which is conducive to adsorption. In addition, ZrP has certain acid resistance and radiation stability.

[0036] Application Examples

[0037] The Ca-ZrP-1,8-octanediamine composite material prepared in Example 3 was added to the strontium-containing solution (C Sr =100ppm), the material and solution are kept at a solid-liquid ratio of mg / mL of 0.5 at room temperature, the pH is adjusted in sequence to 1-10, and the adsorption of radionuclide strontium is carried out under stirring conditions.

[0038] Figure 4 The adsorption isotherms of the Ca-ZrP-1,8-octanediamine composite material prepared in Example 3, hydrothermal ZrP and ZrP+CaCl2 are shown. Figure 4 It can be seen that the Ca-ZrP-1,8-octanediamine composite material prepared in Example 3, ZrP+CaCl2 and hydrothermal ZrP to Sr 2+ The maximum adsorption capacities of the Ca-ZrP-1,8-octanediamine composite material for adsorbing strontium are 201.7 mg / g, 138.9 mg / g, and 118.6 mg / g, respectively. 2+ The adsorption performance is nearly twice that of pure ZrP.

[0039] Figure 5 The Ca-ZrP-1,8-octanediamine composite material prepared in Example 3 has different pH environments for Sr2+ Adsorption amount and correlation coefficient diagram. Figure 5 It can be seen that the adsorption capacity of Ca-ZrP-1,8-octanediamine composite materials is very stable in the pH range of 4-10, and the correlation coefficients are all over 1×10 3 mL / g, and at pH=1, it has an adsorption capacity of 34.52 mg / g, which is much higher than that of pure ZrP.

[0040] In summary, the Ca-ZrP-1,8-octanediamine composite material prepared in the present invention can be used for adsorption of radionuclide strontium.

[0041] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Any technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a Ca-ZrP-1,8-octanediamine composite material, characterized in that: The following steps are involved: S1. Dispersing zirconium oxychloride octahydrate in a phosphoric acid solution at a solid-liquid ratio of 1-4:8.2-24.6 g / mL, reacting at 120-180° C. for 12-18 hours using a hydrothermal method, and washing and drying the product to obtain zirconium phosphate nanosheets with thin-layer properties; S2, taking zirconium phosphate nanosheets and 1,8-octanediamine in a mass ratio of 0.5-4:0.1-0.5, adding the zirconium phosphate nanosheets to the 1,8-octanediamine solution, stirring after ultrasonic treatment to allow the 1,8-octanediamine to be fully intercalated into the zirconium phosphate, and washing and drying to obtain a ZrP-1,8-octanediamine composite material; S3. Take a ZrP-1,8-octanediamine material and a calcium chloride aqueous solution in a mass ratio of 1~4:10~20, uniformly disperse the ZrP-1,8-octanediamine composite material in the calcium chloride aqueous solution, transfer it to a stirring table, and fully stir it under certain temperature conditions to allow Ca ions to be intercalated into the ZrP-1,8-octanediamine, and then wash and dry it to obtain a Ca-ZrP-1,8-octanediamine composite material.

2. The method for preparing the Ca-ZrP-1,8-octanediamine composite material according to claim 1, characterized in that: The concentration of the phosphoric acid solution is ≥85 wt %.

3. The method for preparing the Ca-ZrP-1,8-octanediamine composite material according to claim 1, characterized in that: The concentration of the 1.8-octanediamine solution is 0.017-0.085 mol / L.

4. The method for preparing the Ca-ZrP-1,8-octanediamine composite material according to claim 1, characterized in that: The concentration of the calcium chloride solution is 2.25-4.5 mol / L.

5. The method for preparing the Ca-ZrP-1,8-octanediamine composite material according to claim 1, characterized in that: The washing method is any one of suction filtration washing, centrifugal washing, and ultrasonic sedimentation washing; the drying method is any one of natural drying, constant temperature drying, and programmed temperature-variable drying; and the drying temperature is 50-80°C.

6. A Ca-ZrP-1,8-octanediamine composite material prepared by the method according to any one of claims 1 to 5.

7. Use of the Ca-ZrP-1,8-octanediamine composite material prepared by the preparation method according to claim 1, characterized in that: The Ca-ZrP-1,8-octanediamine composite material is added into a strontium-containing solution, and the nuclide strontium is adsorbed under stirring conditions.

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