A method and system for converting strontium nitrate in a high-level radioactive solution into strontium titanate.

Abstract

This invention provides a method and system for converting strontium nitrate in a high-level radioactive solution into strontium titanate, relating to the field of spent fuel reprocessing. The method includes: obtaining a high-level radioactive solution containing strontium nitrate; adjusting the mass concentration of strontium ions in the high-level radioactive solution to a first preset value to obtain a first solution; adjusting the pH of the first solution to a second preset value to obtain a second solution; obtaining an ammonium bicarbonate solution with a mass fraction of a third preset value according to the first preset value; obtaining a first preset amount of titanium dioxide powder according to the first preset value, and mixing the titanium dioxide powder and the ammonium bicarbonate solution to form a first mixture; placing the first mixture into the second solution for reaction, and obtaining a precipitate of strontium titanate. This invention achieves the conversion of strontium nitrate in a high-level radioactive solution into strontium titanate.

Description

Technical Field

[0001] This invention relates to the field of spent fuel reprocessing, and more specifically to a method and system for converting strontium nitrate in high-level radioactive solutions into strontium titanate. Background Technology

[0002] The reprocessing of spent fuel discharged from nuclear reactors generates large quantities of high-level radioactive waste. This waste is highly radioactive and extremely toxic, containing over 95% of the radioactivity from the spent fuel. It poses a potential hazard to humans and the environment, and its treatment and disposal have become a key factor restricting the sustainable development of nuclear energy. 90 Sr and its daughters 90 Y is entirely a pure beta emitter, making it an ideal material for fabricating beta radiation sources and nuclear batteries. It has specific applications in defense, environmental science, and biomedicine, possessing high practical value and economic significance. Research has found that... 90 Among the various chemical forms of Sr (Sr metal, SrTiO3, SrO, SrF2, Sr2TiO4), SrTiO3 exhibits excellent power, density, thermal stability, and solubility in water, making it essential to obtain SrTiO3. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method and system for converting strontium nitrate in a high-level radioactive solution into strontium titanate, thereby realizing the conversion of strontium nitrate in a high-level radioactive solution into strontium titanate.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] Embodiments of the present invention provide a method for converting strontium nitrate in a high-level radioactive solution into strontium titanate, comprising:

[0006] Obtain a high-level radioactive solution containing strontium nitrate;

[0007] The mass concentration of strontium ions in the high-level radioactive solution is adjusted to a first preset value to obtain a first solution;

[0008] The pH of the first solution is adjusted to a second preset value to obtain a second solution;

[0009] Obtain an ammonium bicarbonate solution with a mass fraction of the third preset value according to the first preset value;

[0010] A first preset amount of titanium dioxide powder is obtained according to the first preset value, and the titanium dioxide powder and the ammonium bicarbonate solution are mixed to form a first mixture;

[0011] The first mixture was placed into the second solution to react and precipitate strontium titanate was obtained.

[0012] Optionally, adjusting the mass concentration of strontium ions in the high-level radioactive solution to a first preset value includes:

[0013] The mass concentration of strontium ions in the high-level radioactive solution is adjusted to a first preset value by dilution or evaporation concentration, wherein the first preset value ranges from 1 to 10 g / L.

[0014] Optionally, adjusting the pH of the first solution to a second preset value includes:

[0015] The pH of the first solution is adjusted to a second preset value by using ammonia water, and the second preset value ranges from 3.5 to 4.5.

[0016] Optionally, obtaining an ammonium bicarbonate solution with a mass fraction of a third preset value according to a first preset value includes:

[0017] According to the chemical reaction formula Sr 2+ +2HCO3 - →SrCO3↓+H2O+CO2↑ and the first preset value are used to calculate the expected amount of ammonium bicarbonate. Based on the expected amount of ammonium bicarbonate, a second preset amount is calculated. The second preset amount is 150% of the expected amount of ammonium bicarbonate. The second preset amount of ammonium bicarbonate is then used to prepare an ammonium bicarbonate solution with a mass fraction of 15% using deionized water.

[0018] Optionally, obtaining a first preset amount of titanium dioxide powder according to the first preset value includes:

[0019] According to the chemical reaction formula Sr 2+ +2HCO3 - The expected amount of titanium dioxide powder is calculated based on the values ​​of →SrCO3↓+H2O+CO2↑, SrCO3+TiO2→SrTiO3↓+CO2↑, and the first preset value. The first preset amount is calculated based on the expected amount of titanium dioxide powder, and the first preset amount is 108% of the expected amount of titanium dioxide powder.

[0020] Optionally, the purity of the titanium dioxide powder is in the range of 90%-100%.

[0021] Optionally, the first mixture is placed in the second solution to react and obtain the precipitate strontium titanate, comprising:

[0022] Heat the second solution to a preset temperature;

[0023] The first mixture is placed in a second solution heated to a preset temperature, and the first mixture and the second solution react at the preset temperature to obtain strontium titanate precipitate.

[0024] Optionally, the preset temperature is 65-75℃.

[0025] Embodiments of the present invention also provide a system for converting strontium nitrate in a high-level radioactive solution into strontium titanate, comprising:

[0026] The first acquisition module is used to acquire a high-level radioactive solution containing strontium nitrate;

[0027] The adjustment module is used to adjust the mass concentration of strontium ions in the high-level radioactive solution to a first preset value to obtain a first solution, and to adjust the pH of the first solution to a second preset value to obtain a second solution.

[0028] The second acquisition module is used to acquire an ammonium bicarbonate solution with a mass fraction of a third preset value according to a first preset value, acquire a first preset amount of titanium dioxide powder according to the first preset value, and mix the titanium dioxide powder and the ammonium bicarbonate solution to form a first mixture.

[0029] The processing module is used to place the first mixture into the second solution for reaction and obtain the precipitate strontium titanate.

[0030] Optionally, the adjustment module modulates the mass concentration of strontium ions in the high-level radioactive solution to a first preset value by dilution or evaporation concentration, wherein the first preset value ranges from 1 to 10 g / L.

[0031] The above-described solution of the present invention has at least the following beneficial effects:

[0032] The method for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to the present invention includes: obtaining a high-level radioactive solution containing strontium nitrate; adjusting the mass concentration of strontium ions in the high-level radioactive solution to a first preset value to obtain a first solution; adjusting the pH of the first solution to a second preset value to obtain a second solution; obtaining an ammonium bicarbonate solution with a mass fraction of a third preset value according to the first preset value; obtaining a first preset amount of titanium dioxide powder according to the first preset value, and mixing the titanium dioxide powder and the ammonium bicarbonate solution to form a first mixture; placing the first mixture into the second solution for reaction, and obtaining precipitate strontium titanate. This method achieves the conversion of strontium nitrate in a high-level radioactive solution, enabling the conversion of strontium nitrate in a high-level radioactive solution to strontium titanate. Attached Figure Description

[0033] Figure 1 This is a schematic flowchart of the method for converting strontium nitrate in a high-level radioactive solution into strontium titanate according to the present invention. Detailed Implementation

[0034] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0035] like Figure 1 As shown, embodiments of the present invention propose a method for converting strontium nitrate in a high-level radioactive solution into strontium titanate, comprising:

[0036] Step 11: Obtain a high-level radioactive solution containing strontium nitrate;

[0037] Step 12: Adjust the mass concentration of strontium ions in the high-level radioactive solution to a first preset value to obtain the first solution;

[0038] Step 13: Adjust the pH of the first solution to a second preset value to obtain a second solution;

[0039] Step 14: Obtain an ammonium bicarbonate solution with a mass fraction of a third preset value according to the first preset value;

[0040] Step 15: Obtain a first preset amount of titanium dioxide powder according to the first preset value, and mix the titanium dioxide powder and the ammonium bicarbonate solution to form a first mixture;

[0041] Step 16: Place the first mixture into the second solution to react and obtain the precipitate strontium titanate.

[0042] In this embodiment, the mass concentration of strontium ions and the pH of the solution in the high-level radioactive waste solution are adjusted to the required values. Then, a mixture of ammonium bicarbonate solution and titanium dioxide powder is used as a precipitant. The desired substance is obtained by reacting the two together to form strontium titanate precipitate. In this way, the conversion of strontium nitrate in the high-level radioactive waste solution is achieved, which can convert strontium nitrate in the high-level radioactive waste solution into strontium titanate. At the same time, the recovery rate of strontium in the high-level radioactive waste liquid is greater than 99%.

[0043] In an optional embodiment of the present invention, adjusting the mass concentration of strontium ions in the high-level radioactive solution to a first preset value includes:

[0044] The mass concentration of strontium ions in the high-level radioactive solution is adjusted to a first preset value by dilution or evaporation concentration, wherein the first preset value ranges from 1 to 10 g / L.

[0045] The pH of the first solution is adjusted to a second preset value by using ammonia water, and the second preset value ranges from 3.5 to 4.5.

[0046] In an optional embodiment of the present invention, obtaining an ammonium bicarbonate solution with a mass fraction of a third preset value according to a first preset value includes:

[0047] According to the chemical reaction formula Sr 2+ +2HCO3 - →SrCO3↓+H2O+CO2↑ and the first preset value are used to calculate the expected amount of ammonium bicarbonate. Based on the expected amount of ammonium bicarbonate, a second preset amount is calculated. The second preset amount is 150% of the expected amount of ammonium bicarbonate. The second preset amount of ammonium bicarbonate is then used to prepare an ammonium bicarbonate solution with a mass fraction of 15% using deionized water.

[0048] In an optional embodiment of the present invention, obtaining a first preset amount of titanium dioxide powder according to the first preset value includes:

[0049] According to the chemical reaction formula Sr 2+ +2HCO3 - The expected amount of titanium dioxide powder is calculated based on the values ​​of →SrCO3↓+H2O+CO2↑, SrCO3+TiO2→SrTiO3↓+CO2↑, and the first preset value. The first preset amount is calculated based on the expected amount of titanium dioxide powder, and the first preset amount is 108% of the expected amount of titanium dioxide powder.

[0050] In this embodiment, when the titanium dioxide powder and the ammonium bicarbonate solution are mixed to form a first mixture, the titanium dioxide powder is added to the ammonium bicarbonate solution, and the mixture is stirred into a slurry using a glass rod to form the first mixture.

[0051] In an optional embodiment of the present invention, the purity of the titanium dioxide powder ranges from 90% to 100%.

[0052] In this embodiment, the preferred purity of the titanium dioxide powder is 99.9%. When using it, the 99.9% titanium dioxide can be ground in a mortar and mortar and filtered through a sieve with a mesh size greater than 200 to obtain titanium dioxide powder with a purity of 99.9%.

[0053] In an optional embodiment of the present invention, the first mixture is placed in the second solution for reaction, and strontium titanate precipitate is obtained, comprising:

[0054] Heat the second solution to a preset temperature;

[0055] The first mixture is placed in a second solution heated to a preset temperature, and the first mixture and the second solution react at the preset temperature to obtain strontium titanate precipitate. The preset temperature is 65-75°C.

[0056] In this embodiment, a magnetic stirring thermostat is used as the reaction vessel for illustration. First, the second solution is placed in the magnetic stirring thermostat and heated to 65-75°C. Then, the first mixture is slowly added to the magnetic stirring thermostat to mix the second solution and the first mixture. At the same time, the temperature inside the magnetic stirring thermostat is maintained at a constant temperature of 65-75°C, so that the second solution and the first mixture react at a constant temperature of 65-75°C. Then, stirring is continued for 0.5 hours. After stirring, a mixed solution of SrCO3 and TiO2 and a precipitate SrTiO3 are obtained. Finally, the desired strontium titanate is obtained by filtration.

[0057] The specific implementation process of the above method is explained below. In one feasible example, the method for converting strontium nitrate in a high-level radioactive solution into strontium titanate includes:

[0058] 1. The mass concentration of strontium ions in the high-level radioactive solution is adjusted to a first preset value by dilution or evaporation concentration to obtain a first solution, wherein the first preset value ranges from 1 to 10 g / L.

[0059] 2. The pH of the first solution is adjusted to a second preset value using ammonia water to obtain a second solution, wherein the second preset value ranges from 3.5 to 4.5.

[0060] 3. Based on the chemical reaction formula Sr 2+ +2HCO3 - →SrCO3↓+H2O+CO2↑ and the first preset value are used to calculate the expected amount of ammonium bicarbonate. Based on the expected amount of ammonium bicarbonate, a second preset amount is calculated. The second preset amount is 150% of the expected amount of ammonium bicarbonate. The second preset amount of ammonium bicarbonate is then used to prepare an ammonium bicarbonate solution with a mass fraction of 15% using deionized water.

[0061] 4. Based on the chemical reaction formula Sr 2+ +2HCO3 - The expected amount of titanium dioxide powder is calculated based on the following formulas: →SrCO3↓+H2O+CO2↑, SrCO3+TiO2→SrTiO3↓+CO2↑, and the first preset value. A first preset amount is then calculated based on this expected amount of titanium dioxide powder, which is 108% of the expected amount of titanium dioxide powder. The titanium dioxide powder is selected to have a purity of 99.9%. During use, titanium dioxide with a purity of 99.9% is ground in a mortar and pestle and filtered through a sieve with a mesh size greater than 200 to obtain the required titanium dioxide powder.

[0062] 5. Add the titanium dioxide powder to the ammonium bicarbonate solution and mix, then stir the mixture into a slurry using a glass rod to form the first mixture.

[0063] 6. Place the second solution into a magnetic stirring thermostat and heat it to 65-75°C. Then, slowly add the first mixture into the magnetic stirring thermostat to mix the second solution and the first mixture. At the same time, maintain the temperature in the magnetic stirring thermostat at a constant temperature of 65-75°C so that the second solution and the first mixture can react at a constant temperature of 65-75°C. Then, continue stirring for 0.5 hours. After stirring, a mixed solution of SrCO3 and TiO2 and a precipitate of SrTiO3 can be obtained. Finally, the desired strontium titanate can be obtained by filtration.

[0064] The method for converting strontium nitrate in high-level radioactive solutions to strontium titanate as described in this invention achieves the conversion of strontium nitrate in high-level radioactive solutions to strontium titanate, while also enabling a strontium recovery rate of more than 99% in high-level radioactive waste liquid.

[0065] Embodiments of the present invention provide a system for converting strontium nitrate in a high-level radioactive solution into strontium titanate, comprising:

[0066] The first acquisition module is used to acquire a high-level radioactive solution containing strontium nitrate;

[0067] The adjustment module is used to adjust the mass concentration of strontium ions in the high-level radioactive solution to a first preset value to obtain a first solution, and to adjust the pH of the first solution to a second preset value to obtain a second solution.

[0068] The second acquisition module is used to acquire an ammonium bicarbonate solution with a mass fraction of a third preset value according to a first preset value, acquire a first preset amount of titanium dioxide powder according to the first preset value, and mix the titanium dioxide powder and the ammonium bicarbonate solution to form a first mixture.

[0069] The processing module is used to place the first mixture into the second solution for reaction and obtain the precipitate strontium titanate.

[0070] In an optional embodiment of the present invention, the adjustment module modulates the mass concentration of strontium ions in the high-level radioactive solution to a first preset value by dilution or evaporation concentration, wherein the first preset value ranges from 1 to 10 g / L.

[0071] Optionally, adjusting the pH of the first solution to a second preset value includes:

[0072] The pH of the first solution is adjusted to a second preset value by using ammonia water, and the second preset value ranges from 3.5 to 4.5.

[0073] Optionally, obtaining an ammonium bicarbonate solution with a mass fraction of a third preset value according to a first preset value includes:

[0074] According to the chemical reaction formula Sr 2+ +2HCO3 - →SrCO3↓+H2O+CO2↑ and the first preset value are used to calculate the expected amount of ammonium bicarbonate. Based on the expected amount of ammonium bicarbonate, a second preset amount is calculated. The second preset amount is 150% of the expected amount of ammonium bicarbonate. The second preset amount of ammonium bicarbonate is then used to prepare an ammonium bicarbonate solution with a mass fraction of 15% using deionized water.

[0075] Optionally, obtaining a first preset amount of titanium dioxide powder according to the first preset value includes:

[0076] According to the chemical reaction formula Sr 2+ +2HCO3 - The expected amount of titanium dioxide powder is calculated based on the values ​​of →SrCO3↓+H2O+CO2↑, SrCO3+TiO2→SrTiO3↓+CO2↑, and the first preset value. The first preset amount is calculated based on the expected amount of titanium dioxide powder, and the first preset amount is 108% of the expected amount of titanium dioxide powder.

[0077] Optionally, the purity of the titanium dioxide powder is in the range of 90%-100%.

[0078] Optionally, the first mixture is placed in the second solution to react and obtain the precipitate strontium titanate, comprising:

[0079] Heat the second solution to a preset temperature;

[0080] The first mixture is placed in a second solution heated to a preset temperature, and the first mixture and the second solution react at the preset temperature to obtain strontium titanate precipitate.

[0081] Optionally, the preset temperature is 65-75℃.

[0082] It should be noted that all implementations of the above method embodiments are applicable to the embodiments of this system and can achieve the same technical effect.

[0083] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for converting strontium nitrate in a high-level radioactive solution into strontium titanate, characterized in that, include: Obtain a high-level radioactive solution containing strontium nitrate; The mass concentration of strontium ions in the high-level radioactive solution is adjusted to a first preset value to obtain a first solution; The pH of the first solution is adjusted to a second preset value to obtain a second solution; Obtain an ammonium bicarbonate solution with a mass fraction of the third preset value according to the first preset value; A first preset amount of titanium dioxide powder is obtained according to the first preset value, and the titanium dioxide powder and the ammonium bicarbonate solution are mixed to form a first mixture; The first mixture was placed into the second solution to react and precipitate strontium titanate was obtained.

2. The method for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to claim 1, characterized in that, Adjusting the mass concentration of strontium ions in the high-level radioactive solution to a first preset value includes: The mass concentration of strontium ions in the high-level radioactive solution is adjusted to a first preset value by dilution or evaporation concentration, wherein the first preset value ranges from 1 to 10 g / L.

3. The method for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to claim 1, characterized in that, Adjusting the pH of the first solution to a second preset value includes: The pH of the first solution is adjusted to a second preset value by using ammonia water, and the second preset value ranges from 3.5 to 4.

5.

4. The method for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to claim 1, characterized in that, Obtain an ammonium bicarbonate solution with a mass fraction of a third preset value according to a first preset value, including: According to the chemical reaction formula Sr 2+ +2HCO3 - →SrCO3↓+H2O+CO2↑ and the first preset value are used to calculate the expected amount of ammonium bicarbonate. Based on the expected amount of ammonium bicarbonate, a second preset amount is calculated. The second preset amount is 150% of the expected amount of ammonium bicarbonate. The second preset amount of ammonium bicarbonate is then used to prepare an ammonium bicarbonate solution with a mass fraction of 15% using deionized water.

5. The method for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to claim 1, characterized in that, Obtaining a first preset amount of titanium dioxide powder according to the first preset value includes: According to the chemical reaction formula Sr 2+ +2HCO3 - The expected amount of titanium dioxide powder is calculated based on the values ​​of →SrCO3↓+H2O+CO2↑, SrCO3+TiO2→SrTiO3↓+CO2↑, and the first preset value. The first preset amount is calculated based on the expected amount of titanium dioxide powder, and the first preset amount is 108% of the expected amount of titanium dioxide powder.

6. The method for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to claim 1, characterized in that, The purity of the titanium dioxide powder ranges from 90% to 100%.

7. The method for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to claim 1, characterized in that, The first mixture is placed in the second solution to react and obtain strontium titanate precipitate, comprising: Heat the second solution to a preset temperature; The first mixture is placed in a second solution heated to a preset temperature, and the first mixture and the second solution react at the preset temperature to obtain strontium titanate precipitate.

8. The method for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to claim 7, characterized in that, The preset temperature is 65-75℃.

9. A system for converting strontium nitrate in a high-level radioactive solution into strontium titanate, characterized in that, include: The first acquisition module is used to acquire a high-level radioactive solution containing strontium nitrate; The adjustment module is used to adjust the mass concentration of strontium ions in the high-level radioactive solution to a first preset value to obtain a first solution, and to adjust the pH of the first solution to a second preset value to obtain a second solution. The second acquisition module is used to acquire an ammonium bicarbonate solution with a mass fraction of a third preset value according to a first preset value, acquire a first preset amount of titanium dioxide powder according to the first preset value, and mix the titanium dioxide powder and the ammonium bicarbonate solution to form a first mixture. The processing module is used to place the first mixture into the second solution for reaction and obtain the precipitate strontium titanate.

10. The system for converting strontium nitrate in a high-level radioactive solution to strontium titanate according to claim 9, characterized in that, The adjustment module modulates the mass concentration of strontium ions in the high-level radioactive solution to a first preset value by dilution or evaporation concentration, the first preset value being in the range of 1-10 g / L.

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