Preparation method and application of granular potassium fluoromagnesium oxide adsorbent

Abstract

The present invention relates to the technical field of spent fuel dry post-processing, and discloses a preparation method and application of a granular potassium fluoromagnesiumate adsorbent. In this method, anhydrous potassium fluoride and anhydrous magnesium fluoride are used to prepare a substance with high adsorption activity, namely potassium fluoromagnesiumate powder. The substance is then granulated using a composite comprising hydrogel powder, bentonite, ethanol, and water in combination with a rotary granulator, and calcined to increase strength and porosity. Finally, fluorination is used to further remove non-volatile impurities, thereby increasing the porosity and purity of the adsorbent. Ultimately, an adsorbent with a large specific surface area, high compressive strength, and high porosity is obtained. The adsorbent has a good adsorption effect when adsorbing uranium hexafluoride.

Description

Technical Field

[0001] The present invention relates to the technical field of spent fuel dry post-processing, and in particular to a preparation method and application of a granular potassium fluoromagnesiumate adsorbent. Background Art

[0002] Fluorination volatilization technology has broad application prospects in spent fuel reprocessing. It eliminates the generation of high-level radioactive liquid waste, reducing the complex waste treatment process and the risk of nuclear criticality. The volatile products exist as multi-component gaseous fluorides, with adsorption being the primary recovery target. However, the adsorbents used in these methods present various challenges, as detailed below:

[0003] Patent CN 119236869 discloses a method for preparing porous sodium fluoride adsorbent particles. The method uses sodium fluoride powder and sodium carboxymethyl cellulose powder as a binder and pore-forming agent to form a primary adhesive mixture. Sodium carbonate and 40% hydrofluoric acid are then reacted to form an auxiliary mixture. The primary and auxiliary mixtures are then mixed to form a colloidal adsorbent mixture. The mixture is then dried, ball-milled, screened, pressed, air-dried, and sintered to form 10×6 mm φ sodium fluoride adsorbent particles with a specific surface area of ​​up to 2.4 m². 2 / g, but sodium fluoride still shows powdering phenomenon after several cycles of adsorption, and its thermal stability is poor.

[0004] Patent CN 118302241B mentions that by adding a specific modifier, NiCl2·6H2O, the porosity and chemical adsorption activity of sodium fluoride are optimized, increasing the adsorption efficiency of hydrogen fluoride to over 98% and reducing the adsorption efficiency of chlorine trifluoride to approximately 3%. This demonstrates a specific adsorption effect for hydrogen fluoride, but does not state whether it has an excellent adsorption effect on spent fuel fluorination products.

[0005] Patent CN 115501866 A mentions a hydrogen fluoride adsorbent and its preparation and application method. It uses a large amount of skeleton materials and mesoporous materials, up to 30%, including polystyrene, mesoporous carbon and other materials that are easily ablated by fluorine gas reactions. It is not suitable for absorbing uranium hexafluoride (UF6) under the conditions of fluorination and volatilization of pure fluorine gas.

[0006] Patent CN 107337180 A mentions a filler for purifying fluorine gas, its preparation method, and application. While the filler achieves a certain purification effect on fluorine gas, the adsorbent prepared solely by mixing, granulating, and calcining hydrogen fluoride suffers from a contradiction between granulation strength and adsorption capacity, and the pores formed by hydrogen fluoride escape are not ideal.

[0007] Therefore, how to obtain an adsorbent with a large specific surface area, high compressive strength, high porosity and good uranium hexafluoride adsorption effect has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0008] The present invention provides a preparation method and application of a granular potassium fluoromagnesiumate adsorbent provided in an embodiment of the present invention, in which anhydrous potassium fluoride and anhydrous magnesium fluoride are used to prepare a high adsorption active point substance, i.e., potassium fluoromagnesiumate powder. Then, a complex including hydrogel powder, bentonite, ethanol and water is granulated in combination with a rotary granulator, and the strength and porosity are improved by calcination. Finally, the voids and purity of the adsorbent are further removed by fluorination and impurity removal, and an adsorbent with large specific surface area, high compressive strength and high porosity is finally obtained. The adsorbent has a good adsorption effect when adsorbing uranium hexafluoride.

[0009] In a first aspect, the present invention provides a method for preparing a granular potassium fluoromagnesiumate adsorbent, comprising:

[0010] Preparation of potassium fluoromagnesiumate powder and a composite; wherein the raw materials for preparing the potassium fluoromagnesiumate powder include the following components: anhydrous magnesium fluoride, anhydrous potassium fluoride and a solvent dispersant; the raw materials for preparing the composite include the following components: hydrogel powder, bentonite, ethanol and water;

[0011] placing the potassium fluoromagnesiumate powder on a rotating disk of a rotary disk granulator, and spraying the complex onto the potassium fluoromagnesiumate powder to obtain a mixture;

[0012] The mixture is sieved through a sieve to remove unformed powder and retain spherical particles;

[0013] After the spherical particles are dried in the shade, they are calcined at 600° C. for 3-5 hours to obtain semi-finished particles;

[0014] The semi-finished product particles are reacted at a temperature of 300-500° C. for 2-4 hours in an environment where a fluorine-argon mixed gas is introduced to obtain a granular potassium fluoromagnesiumate adsorbent.

[0015] In some embodiments, the step of preparing potassium fluoromagnesiumate powder comprises:

[0016] Mixing and grinding anhydrous potassium fluoride and anhydrous magnesium fluoride in a molar ratio of 1-1.5:1 to obtain a grind;

[0017] The ground material is placed in a reactor, and a solvent dispersant is added to the reactor at a filling degree of 60%-65%; after closing the reactor, the reactor is placed in an oven, heated at 150° C.-180° C. for 1-7 days, and cooled to obtain a white powder;

[0018] The white powder was washed multiple times with ethanol and deionized water, dried in air at room temperature, and then dried at 225° C. for 3-5 hours to obtain potassium fluoromagnesiumate powder.

[0019] In some embodiments, the solvent dispersant includes at least two of hydrofluoric acid, aqueous phenol solution, nitric acid, and tetrahydrofuran.

[0020] In some embodiments, the step of preparing the complex comprises:

[0021] The hydrogel powder, bentonite, ethanol and water were mixed in a volume ratio of 1:1:2:6 to obtain a composite.

[0022] In some embodiments, the volume ratio of F2 to Ar in the fluorine-argon mixed gas is 1:1.

[0023] In some embodiments, the specific surface area of ​​the granular potassium fluoromagnesiumate adsorbent is greater than 15 m 2 / g.

[0024] In some embodiments, the pore volume of the granular potassium fluoromagnesiumate adsorbent is ≥ 0.0003 cm 3 / g.

[0025] In some embodiments, the compressive strength of the granular potassium fluoromagnesiumate adsorbent is ≥3.0 MPa / m 2 .

[0026] In some embodiments, the granular potassium fluoromagnesiumate adsorbent has an adsorption rate of uranium hexafluoride exceeding 95%, and a desorption rate of 100% at 350°C.

[0027] In a second aspect, the present invention provides a use of a granular potassium fluoromagnesiumate adsorbent obtained by the preparation method in the adsorption of uranium hexafluoride, molybdenum hexafluoride and hydrogen fluoride.

[0028] The present invention provides a preparation method and application of a granular potassium fluoromagnesiumate adsorbent. In this method, anhydrous potassium fluoride and anhydrous magnesium fluoride are used to prepare a high adsorption active point substance, namely potassium fluoromagnesiumate powder. Then, a complex including hydrogel powder, bentonite, ethanol and water is granulated in combination with a rotary granulator, and the strength and porosity are improved by calcination. Finally, fluorination is used to further remove non-volatile impurities to improve the voids and purity of the adsorbent, ultimately obtaining an adsorbent with a large specific surface area, high compressive strength and high porosity. The adsorbent has a good adsorption effect when adsorbing uranium hexafluoride. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A flow chart illustrating a method for preparing a granular potassium fluoromagnesiumate adsorbent according to some embodiments is shown. DETAILED DESCRIPTION

[0030] In order to better understand the above technical solution, the technical solution of this application is described in detail below through specific implementation methods.

[0031] In order to solve the above-mentioned technical problems, the present application embodiment provides a preparation method and application of a granular potassium fluoromagnesiumate adsorbent, in which anhydrous potassium fluoride and anhydrous magnesium fluoride are used to prepare a high adsorption active point material, i.e., potassium fluoromagnesiumate powder. Then, a complex including hydrogel powder, bentonite, ethanol and water is granulated in combination with a rotary granulator, and the strength and porosity are improved by calcination. Finally, the voids and purity of the adsorbent are further removed by fluorination and impurity removal, and an adsorbent with large specific surface area, high compressive strength and high porosity is finally obtained. The adsorbent has a good adsorption effect when adsorbing uranium hexafluoride.

[0032] Figure 1 A flow chart illustrating a method for preparing a granular potassium fluoromagnesiumate adsorbent according to some embodiments is shown. The method includes: S100-S600.

[0033] S100, preparing potassium fluoromagnesiumate powder; wherein the raw materials for preparing the potassium fluoromagnesiumate powder include the following components: anhydrous magnesium fluoride, anhydrous potassium fluoride and a solvent dispersant.

[0034] In some embodiments, the step of preparing potassium fluoromagnesium oxide (KMgF3) powder comprises:

[0035] Anhydrous potassium fluoride (MgF2) and anhydrous magnesium fluoride (KF) are mixed and ground in a molar ratio of 1-1.5:1 to obtain a grind. In one example, the anhydrous magnesium fluoride and the anhydrous potassium fluoride are mixed and ground in an agate mortar.

[0036] In the examples of this application, when preparing potassium fluoromagnesiumate powder, anhydrous potassium fluoride (KF) is usually required in excess for the following reasons: 1. To promote reaction kinetics, specifically, The formation depends on and Ordered arrangement of octahedra (perovskite structure). Excess Provide more free ,accelerate The lattice reconstruction of α increases the reaction rate and conversion rate. Can promote the reaction to generate 2. Inhibit the generation of impurities. Specifically, if Insufficient, non-target products may be generated (such as or magnesium-rich phase), destroying the uniqueness of the perovskite structure. 3. Optimizing product purity and crystallinity. Specifically, excess KF can act as a mineralizer to promote The growth of grains improves crystallinity and phase purity. Experiments show that : The best effect can be achieved by controlling the molar ratio of KF to 1:1. The excess KF after the reaction can be removed by washing with water or ethanol ( Insoluble in water, easily soluble), simplifying the purification steps.

[0037] The ground material is placed in a reactor, and a solvent dispersant is added to the reactor at a filling degree of 60%-65%. After the reactor is closed, the reactor is placed in an oven and heated at 150° C.-180° C. for 1-7 days, and a white powder is obtained after cooling.

[0038] In one example, the grind is placed in a Teflon-lined stainless steel autoclave.

[0039] In some embodiments, the solvent dispersant includes at least two of hydrofluoric acid, aqueous phenol solution, nitric acid and tetrahydrofuran. In the embodiments of the present application, the solvent dispersant is used for dissolving and dispersing.

[0040] The white powder was washed multiple times with ethanol and deionized water, dried in air at room temperature, and then dried at 225° C. for 3-5 hours to obtain potassium fluoromagnesiumate powder.

[0041] S200, preparing a composite; wherein the raw materials for preparing the composite include the following components: hydrogel powder, bentonite, ethanol and water.

[0042] In some embodiments, the step of preparing the composite comprises: mixing hydrogel powder, bentonite, ethanol and water in a volume ratio of 1:1:2:6 to obtain the composite.

[0043] In the embodiments of the present application, the hydrogel powder swells upon contact with water. Subsequent calcination increases the internal microchannels and pore volume of the potassium fluoromagnesiumate powder. Furthermore, any remaining hydrogel powder is eventually etched away by the fluorine gas in the fluorine-argon gas mixture, ensuring the purity of the adsorbent. Bentonite acts as a binder. Water is used to adjust viscosity. Ethanol not only effectively dilutes the bentonite but also accelerates its volatilization rate during drying. The volume ratio of hydrogel powder, bentonite, ethanol, and water of 1:1:2:6 is a result of comprehensive practice in terms of spray viscosity and granulation effect during actual granulation. Excessive amounts of hydrogel and bentonite result in an unsuitable spray viscosity, while too little results in a loss of expansion and bonding. Excessive amounts of ethanol result in a rapid volatilization rate, resulting in a rough granule surface, which is why water is used for mixing.

[0044] S300, placing the potassium fluoromagnesiumate powder on a rotating disk of a rotary disk granulator, and spraying the complex onto the potassium fluoromagnesiumate powder to obtain a mixture.

[0045] In one example, the rotating disc has an inclination of 45°. After potassium fluoride magnesiumate powder is placed on a rotating disc with an inclination of 45°, a certain speed is set to start a rotary disc granulator. The rotary disc rotates continuously, and the potassium fluoride magnesiumate powder on the rotating disc rotates accordingly. During this process, the composite is sprayed onto the potassium fluoride magnesiumate powder. When the potassium fluoride magnesiumate powder gradually adheres to spherical particles of a certain size, the rotary disc granulator is controlled to stop running. At this time, the mixture in the rotating disc includes unformed powder and spherical particles. The mixture on the rotating disc is transferred to a screen.

[0046] S400, sieving the mixture through a sieve to remove unformed powder and retain spherical particles.

[0047] S500: After the spherical particles are dried in the shade, they are calcined at 600° C. for 3-5 hours to obtain semi-finished particles.

[0048] In one example, the spherical particles are dried in the shade, placed in a muffle furnace, and calcined at 600° C. for 3-5 hours to obtain semi-finished particles.

[0049] S600, reacting the semi-finished product particles at a temperature of 300-500° C. for 2-4 hours in an environment where a fluorine-argon mixed gas is introduced to obtain a granular potassium fluoromagnesiumate adsorbent.

[0050] In the embodiment of the present application, in an environment where a fluorine-argon mixed gas is introduced, after reacting at a temperature of 300-500°C for 2-4 hours, the non-volatile impurities remaining in the semi-finished particles can be removed, and channels are formed inside to obtain a granular potassium fluoromagnesiumate adsorbent with better purity and greater porosity.

[0051] In one example, the semi-finished product particles are placed in a muffle furnace, a fluorine-argon mixed gas is introduced, and the mixture is reacted at a temperature of 300-500° C. for 2-4 hours to obtain a granular potassium fluoromagnesiumate adsorbent.

[0052] In some embodiments, the volume ratio of F2 to Ar in the fluorine-argon mixed gas is 1:1.

[0053] In the embodiments of the present application, the granular potassium fluoromagnesiumate adsorbent has excellent thermal stability. When testing the compressive strength of the adsorbent, the adsorbent still has a high compressive strength after undergoing high-temperature calcination at 600°C and then cooling to room temperature, and undergoing multiple high and low temperature cycles, thus avoiding pulverization.

[0054] In the embodiment of the present application, the specific surface area of ​​the granular potassium fluoromagnesiumate adsorbent is higher than 15m 2 / g. The pore volume of the granular potassium fluoride magnesium oxide adsorbent is ≥0.0003cm 3 / g. The compressive strength of the granular potassium fluoride magnesium oxide adsorbent is ≥3.0Mpa / m 2 .

[0055] The adsorption rate of uranium hexafluoride by the granular potassium fluoromagnesiumate adsorbent in the embodiment of the present application reaches more than 95%, and the desorption rate is 100% at 350°C.

[0056] In an embodiment of the present application, a method for preparing a granular potassium fluoromagnesiumate adsorbent is provided for use in the adsorption of uranium hexafluoride, molybdenum hexafluoride and hydrogen fluoride.

[0057] In the embodiments of the present application, the granular potassium fluoromagnesiumate adsorbent is not only used for the absorption and capture of uranium hexafluoride, but is also suitable for the absorption and capture of molybdenum hexafluoride and hydrogen fluoride, and has strong adaptability.

[0058] Example 1

[0059] Anhydrous magnesium fluoride and anhydrous potassium fluoride were weighed in a molar ratio of anhydrous magnesium fluoride to anhydrous potassium fluoride = 1:1. Hydrofluoric acid and tetrahydrofuran were mixed in a volume ratio of hydrofluoric acid to tetrahydrofuran = 2:1 and used as a solvent dispersant.

[0060] Anhydrous magnesium fluoride and anhydrous potassium fluoride were mixed and ground in an agate mortar to obtain a ground product. The ground product was placed in a stainless steel reactor lined with polytetrafluoroethylene. A solvent dispersant was added to the reactor to a fill level of 60%, and the reactor was sealed. After sealing the reactor, the reactor was placed in an oven and heated at 150°C for 5 days. After cooling, a white powder was obtained. The white powder was washed with anhydrous ethanol and deionized water, dried in air at room temperature, and then oven-dried at 225°C for 5 hours to obtain potassium fluoromagnesiumate powder.

[0061] Potassium fluoromagnesium oxide powder was placed on a rotating disc with a 45° inclination. The rotary disc granulator was set to a certain speed and started. As the disc rotated, a composite consisting of hydrogel powder, bentonite, ethanol, and water in a volume ratio of 1:1:2:6 was sprayed onto the potassium fluoromagnesium oxide powder. When the potassium fluoromagnesium oxide powder gradually coalesced into spherical particles of a certain size, it was transferred to a sieve and sieved to remove the formed powder, retaining the spherical particles. After air drying, the spherical particles were calcined in a muffle furnace at 600°C for 3 hours to obtain semi-finished granules. The semi-finished granules were then placed in a muffle furnace and introduced with a fluorine-argon mixture (F2:Ar, volume ratio 1:1) for 4 hours at 300°C to obtain granular potassium fluoromagnesium oxide adsorbent.

[0062] The physical properties of the granular potassium fluoromagnesiumate adsorbent in Example 1 were tested, and the test results are shown in Table 1 below:

[0063] Table 1

[0064]

[0065] The adsorption performance of uranium hexafluoride was tested using the granular potassium fluoromagnesiumate adsorbent. The adsorption rate was above 95%, and 100% desorption was possible at 350°C.

[0066] Example 2

[0067] Anhydrous magnesium fluoride and anhydrous potassium fluoride were weighed in a molar ratio of anhydrous magnesium fluoride to anhydrous potassium fluoride = 1.15:1. Hydrofluoric acid and phenol aqueous solution were mixed in a volume ratio of hydrofluoric acid to phenol aqueous solution = 2:1 to serve as a solvent dispersant.

[0068] Anhydrous magnesium fluoride and anhydrous potassium fluoride were mixed and ground in an agate mortar to obtain a ground product. The ground product was placed in a stainless steel reactor lined with polytetrafluoroethylene. A solvent dispersant was added to the reactor to a fill level of 63%, and the reactor was sealed. After sealing the reactor, the reactor was placed in an oven and heated at 160°C for 4 days. After cooling, a white powder was obtained. The white powder was washed with anhydrous ethanol and deionized water, dried in air at room temperature, and then oven-dried at 225°C for 5 hours to obtain potassium fluoromagnesiumate powder.

[0069] Potassium fluoromagnesium oxide powder was placed on a rotating disc with a 53° inclination. The rotary disc granulator was set to a certain speed and started. As the disc rotated, a composite consisting of hydrogel powder, bentonite, ethanol, and water in a volume ratio of 1:1:2:6 was sprayed onto the potassium fluoromagnesium oxide powder. When the potassium fluoromagnesium oxide powder gradually coalesced into spherical particles of a certain size, it was transferred to a sieve and sieved to remove the formed powder, retaining the spherical particles. After air drying, the spherical particles were placed in a muffle furnace and calcined at 600°C for 4 hours to obtain semi-finished granules. The semi-finished granules were then placed in a muffle furnace and introduced with a fluorine-argon mixture (F2:Ar, volume ratio 1:1) at 400°C for 3 hours to obtain granular potassium fluoromagnesium oxide adsorbent.

[0070] The physical properties of the granular potassium fluoromagnesiumate adsorbent in Example 2 were tested, and the test results are shown in Table 2 below:

[0071] Table 2

[0072]

[0073] The adsorption performance of uranium hexafluoride was tested using the granular potassium fluoromagnesiumate adsorbent. The adsorption rate was above 95%, and 100% desorption was possible at 350°C.

[0074] Example 3

[0075] Anhydrous magnesium fluoride and anhydrous potassium fluoride were weighed in a molar ratio of anhydrous magnesium fluoride to anhydrous potassium fluoride = 1.5:1. Hydrofluoric acid and nitric acid were mixed in a volume ratio of hydrofluoric acid to nitric acid = 2:1 and used as a solvent dispersant.

[0076] Anhydrous magnesium fluoride and anhydrous potassium fluoride were mixed and ground in an agate mortar to obtain a ground product. The ground product was placed in a stainless steel reactor lined with polytetrafluoroethylene. A solvent dispersant was added to the reactor to a fill level of 65%, and the reactor was sealed. After sealing the reactor, the reactor was placed in an oven and heated at 180°C for 3 days. After cooling, a white powder was obtained. The white powder was washed with anhydrous ethanol and deionized water, dried in air at room temperature, and then oven-dried at 225°C for 5 hours to obtain potassium fluoromagnesiumate powder.

[0077] Potassium fluoromagnesium oxide powder was placed on a rotating disc with a 60° inclination. The rotary disc granulator was set to a certain speed and started. As the disc rotated, a composite consisting of hydrogel powder, bentonite, ethanol, and water in a volume ratio of 1:1:2:6 was sprayed onto the potassium fluoromagnesium oxide powder. When the potassium fluoromagnesium oxide powder gradually coalesced into spherical particles of a certain size, it was transferred to a sieve and sieved to remove the formed powder, retaining the spherical particles. After air drying, the spherical particles were placed in a muffle furnace and calcined at 600°C for 5 hours to obtain semi-finished granules. The semi-finished granules were then placed in a muffle furnace and introduced with a fluorine-argon mixture (F2:Ar, volume ratio 1:1). The reaction was continued at 500°C for 2 hours to obtain granular potassium fluoromagnesium oxide adsorbent.

[0078] The physical properties of the granular potassium fluoromagnesiumate adsorbent in Example 3 were tested, and the test results are shown in Table 3 below:

[0079] Table 3

[0080]

[0081] The adsorption performance of uranium hexafluoride was tested using the granular potassium fluoromagnesiumate adsorbent. The adsorption rate was above 95%, and 100% desorption was possible at 350°C.

[0082] In summary, the present invention provides a preparation method and application of a granular potassium fluoromagnesiumate adsorbent, in which anhydrous potassium fluoride and anhydrous magnesium fluoride are used to prepare a high adsorption active point material, i.e., potassium fluoromagnesiumate powder. Then, a complex including hydrogel powder, bentonite, ethanol and water is granulated in combination with a rotary granulator, and the strength and porosity are improved by calcination. Finally, the voids and purity of the adsorbent are further removed by fluorination and impurity removal, and an adsorbent with large specific surface area, high compressive strength and high porosity is finally obtained, which has a good adsorption effect when adsorbing uranium hexafluoride.

[0083] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed. The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application. The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application. These improvements and variations should also be regarded as the scope of protection of the present application.

Claims

1. A method for preparing a granular potassium fluoromagnesiumate adsorbent, characterized in that: include: Preparation of potassium fluoromagnesiumate powder and a composite; wherein the raw materials for preparing the potassium fluoromagnesiumate powder include the following components: Anhydrous magnesium fluoride, anhydrous potassium fluoride and solvent dispersant; the raw materials for preparing the composite include the following components: hydrogel powder, bentonite, ethanol and water; The steps of preparing potassium fluoromagnesiumate powder include: mixing and grinding anhydrous potassium fluoride and anhydrous magnesium fluoride in a molar ratio of 1-1.5:1 to obtain a ground product; placing the ground product in a reactor and adding a solvent dispersant to the reactor at a filling degree of 60%-65%; after sealing the reactor, placing the reactor in an oven, heating at 150° C.-180° C. for 1-7 days, and cooling to obtain a white powder; washing the white powder with ethanol and deionized water multiple times, drying in air at room temperature, and then drying at 225° C. for 3-5 hours to obtain potassium fluoromagnesiumate powder; placing the potassium fluoromagnesiumate powder on a rotating disk of a rotary disk granulator, and spraying the complex onto the potassium fluoromagnesiumate powder to obtain a mixture; The mixture is sieved through a sieve to remove unformed powder and retain spherical particles; After the spherical particles are dried in the shade, they are calcined at 600° C. for 3-5 hours to obtain semi-finished particles; The semi-finished product particles are reacted at a temperature of 300-500° C. for 2-4 hours in an environment where a fluorine-argon mixed gas is introduced to obtain a granular potassium fluoromagnesiumate adsorbent.

2. The method according to claim 1, characterized in that The solvent dispersant includes at least two of hydrofluoric acid, phenol aqueous solution, nitric acid and tetrahydrofuran.

3. The method according to claim 1, characterized in that The steps of preparing the complex include: The hydrogel powder, bentonite, ethanol and water were mixed in a volume ratio of 1:1:2:6 to obtain a composite.

4. The method according to claim 1, wherein The volume ratio of F2 to Ar in the fluorine-argon mixed gas is 1:

1.

5. The method according to claim 1, wherein The specific surface area of ​​the granular potassium fluoromagnesiumate adsorbent is higher than 15m 2 / g.

6. The method according to claim 1, characterized in that The pore volume of the granular potassium fluoromagnesiumate adsorbent is ≥0.0003cm 3 / g.

7. The method according to claim 1, characterized in that The compressive strength of the granular potassium fluoromagnesiumate adsorbent is ≥3.0Mpa / m 2 .

8. The method according to claim 1, characterized in that The adsorption rate of the granular potassium fluoromagnesiumate adsorbent for uranium hexafluoride reaches more than 95%, and the desorption rate is 100% at 350°C.

9. Use of a granular potassium fluoromagnesiumate adsorbent obtained by the preparation method according to any one of claims 1 to 8 in the adsorption of uranium hexafluoride, molybdenum hexafluoride and hydrogen fluoride.

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