Preparation method and application of potassium nickel ferrocyanide template adsorbent

Abstract

The embodiment of the invention provides a preparation method and application of a nickel potassium ferrocyanide template adsorbent. The method comprises the following steps: providing a cesium ferrocyanide solution; performing first mixing on the cesium ferrocyanide solution and a nickel source to obtain a cesium nickel ferrocyanide precursor; and carrying out second mixing on the cesium nickel ferrocyanide precursor and a potassium salt solution to obtain the potassium nickel ferrocyanide template adsorbent. The potassium nickel ferrocyanide template adsorbent prepared by the method disclosed by the invention has relatively good selective adsorption capacity on cesium ions in a cesium-containing solution, and is particularly suitable for adsorbing Cs < + > in a high-salt solution.

Description

Technical Field

[0001] This application relates to the field of radioactive waste treatment technology, and in particular to a method for preparing and applying a nickel potassium ferrocyanide template adsorbent. Background Technology

[0002] High-level radioactive waste is generated from the nuclear fuel cycle (uranium conversion and enrichment, nuclear fuel element production, spent fuel processing), nuclear power plant operation, decontamination and decommissioning of nuclear facilities, and the application of radioactive isotopes. 137Cs is not only a high-heat fission product nuclide with a long half-life (T1 / 2 = 30 years) in radioactive waste, but it is also a major source of beta and gamma rays. The separation of high-level radioactive waste begins with the removal of long-lived alpha radionuclides and 99Tc. If 137Cs can be removed before final disposal, it is possible not only to transform the high-level waste into low- or intermediate-level waste, achieving volume reduction and downgrading, and shortening the storage life, but also to simplify disposal procedures and save on treatment costs through cement solidification and shallow ground treatment.

[0003] For emergency treatment of radioactive wastewater, simple and rapid processes are required, with adsorption removal being the preferred technology. However, cesium removal remains a technical challenge, primarily due to the complex composition of high-level radioactive wastewater and seawater, which contains large amounts of Cs. + Like ions (Na) + K + (etc.), the selectivity and adsorption capacity of the adsorbents are still difficult to meet the requirements, therefore, there is an urgent need to propose a Cs... + Adsorbent.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the Invention

[0005] This application provides a nickel potassium ferrocyanide template adsorbent and its application to solve or alleviate one or more of the technical problems mentioned above.

[0006] A first aspect of this application provides a method for preparing a nickel potassium ferrocyanide template adsorbent, comprising the following steps: Provide cesium ferrocyanide solution; The cesium ferrocyanide solution is first mixed with a nickel source to obtain a nickel cesium ferrocyanide precursor; The nickel cesium ferrocyanide precursor is mixed with a potassium salt solution in a second mixing process to obtain a nickel potassium ferrocyanide template adsorbent.

[0007] The method in this embodiment involves providing a cesium ferrocyanide solution; firstly mixing the cesium ferrocyanide solution with a nickel source to obtain a nickel cesium ferrocyanide precursor; and secondly mixing the nickel cesium ferrocyanide precursor with a potassium salt solution to obtain a nickel potassium ferrocyanide template adsorbent, thereby obtaining nickel potassium ferrocyanide with good cesium adsorption capacity. This process introduces cesium vacancies to obtain a nickel potassium ferrocyanide template adsorbent with cesium vacancies. Specifically, cesium ions in the nickel cesium ferrocyanide precursor pre-occupy adsorption sites; then, after mixing the nickel cesium ferrocyanide precursor with the potassium salt solution, the cesium ions are eluted, leaving template vacancies. Since the size and shape of the aforementioned template vacancies are essentially consistent with the size and shape of cesium ions, and based on the steric hindrance effect in adsorption separation, only molecules or ions of suitable size and shape can easily diffuse into the adsorbent to undergo adsorption or exchange reactions, while other molecules or ions are blocked. This results in the nickel potassium ferrocyanide obtained in this application exhibiting good selective adsorption capacity for cesium ions in cesium-containing solutions. In summary, this application introduces cesium and then elutes it to form nickel potassium ferrocyanide with cesium ion template vacancies. The cesium ion vacancies present in this nickel potassium ferrocyanide have a good adsorption effect on cesium ions in cesium-containing solutions, making the nickel potassium ferrocyanide template adsorbent of this application particularly suitable for adsorption of Cs in high-salt solutions. + Adsorption.

[0008] According to embodiments of this application, the cesium ferrocyanide solution is formed in the following manner: A third mixture of ferrocyanide, cesium source, and solvent is performed to obtain cesium ferrocyanide, wherein the solvent includes water.

[0009] According to embodiments of this application, the ferrocyanide includes at least one of barium ferrocyanide and calcium ferrocyanide.

[0010] According to embodiments of this application, the cesium source includes at least one of cesium carbonate and cesium sulfate. According to an embodiment of this application, the molar ratio of the ferrocyanide to the cesium source is 1:(1-5).

[0011] According to an embodiment of this application, after the first mixing is performed and before obtaining the nickel cesium ferrocyanide, the process further includes: The first mixture was then filtered and washed sequentially.

[0012] According to embodiments of this application, the nickel source includes at least one of nickel nitrate and nickel chloride.

[0013] According to an embodiment of this application, the molar ratio of cesium ferrocyanide to nickel source is 1:(0.5-5).

[0014] According to an embodiment of this application, the first mixing time is 1h-3h.

[0015] According to embodiments of this application, after the second mixing is performed and before obtaining the nickel potassium ferrocyanide template adsorbent, the process further includes: The second mixture was then filtered, washed, and dried sequentially.

[0016] According to an embodiment of this application, the second mixing time is 10 min to 60 min.

[0017] According to an embodiment of this application, the temperature of the second mixing is 40°C-90°C.

[0018] According to embodiments of this application, the potassium salt in the potassium salt solution includes at least one of potassium nitrate, potassium chloride, and potassium sulfate.

[0019] According to an embodiment of this application, the potassium ion concentration in the potassium salt solution is 2 mol / L-5 mol / L.

[0020] A second aspect of this application provides the application of a nickel potassium ferrocyanide template adsorbent prepared by the method described in the first aspect in the adsorption of cesium ions.

[0021] The nickel potassium ferrocyanide obtained in this application is obtained by a template method. There are template vacancies in the nickel potassium ferrocyanide that are similar in size and shape to cesium ions, which makes the nickel potassium ferrocyanide obtained in this application have good selective adsorption capacity for cesium ions in cesium-containing solutions. Attached Figure Description

[0022] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0023] Figure 1 This is a schematic diagram of the process of the nickel potassium ferrocyanide template adsorbent provided in the embodiments of this application; Figure 2 It is a nickel potassium ferrocyanide template adsorbent; Figure 3 This is a comparison chart of the saturated adsorption capacity of the template adsorbent in Example 1 and the non-template adsorbent in Comparative Example 1 at different ion concentrations. Detailed Implementation

[0024] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings. In the drawings, for clarity, the dimensions of layers, regions, and elements, as well as their relative dimensions, may be exaggerated. Throughout, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0027] Nickel potassium ferrocyanide due to its affinity for Cs + Due to its specific adsorption properties, ferrocyanide is widely used in the adsorption and removal of Cs-137. The preparation method of metal ferrocyanide is relatively simple, and the raw material solution is inexpensive and readily available; therefore, there is currently a considerable amount of research on ferrocyanide. Studies have shown that ferrocyanide exhibits good adsorption performance for cesium under high acid conditions. However, in practical applications, especially in high-salt solutions, due to insufficient selectivity, the adsorption sites of nickel potassium ferrocyanide are occupied by other coexisting ions such as K+. + Na+ Ca 2+ The presence of isocations reduces its dependence on Cs. + Due to the limited adsorption capacity, problems arise such as frequent adsorbent replacements and large volumes of radioactive waste requiring treatment.

[0028] Accordingly, a first aspect of this application provides a method for preparing a nickel potassium ferrocyanide template adsorbent. (See reference...) Figure 1 This includes the following steps: S100: Provides cesium ferrocyanide solution In this step, the cesium ferrocyanide solution serves as the cesium source for the subsequent preparation of the nickel cesium ferrocyanide precursor.

[0029] In some embodiments, the cesium ferrocyanide solution is formed by a third mixing of ferrocyanide, a cesium source, and a solvent to obtain cesium ferrocyanide, wherein the solvent includes water. During this process, ferrocyanide ions exhibit a very high affinity for cesium ions, thereby yielding cesium ferrocyanide.

[0030] In some embodiments, the ferrocyanide provides ferrocyanide ions for the preparation of cesium ferrocyanide. The selection is based on the fact that the cations in the ferrocyanide readily react with the anions in the cesium source to form precipitates, thus separating them from cesium ferrocyanide. For example, heavy metal elements such as Ba salts readily form precipitates such as barium sulfate or barium carbonate, thereby achieving the separation and acquisition of the target product, cesium ferrocyanide.

[0031] Optionally, the ferrocyanide is at least one of barium ferrocyanide and calcium ferrocyanide.

[0032] In some embodiments, the cesium source provides cesium ions for the preparation of cesium ferrocyanide, and is selected based on the fact that the anionic portion reacts with the ferrocyanide cation to form a precipitate, thereby enabling rapid separation and removal.

[0033] Furthermore, the cesium source includes at least one of cesium carbonate and cesium sulfate.

[0034] In some embodiments, the molar ratio of the ferrocyanide to the cesium source is 1:(1-5), for example, 1:1, 1:2, 1:3, 1:4, 1:5, etc. This ensures that the ferrocyanide and the cesium source react sufficiently to obtain cesium ferrocyanide.

[0035] As a specific example, the ferrocyanide is barium ferrocyanide, the cesium source is cesium carbonate, and the solvent is water. In the formation of cesium ferrocyanide, barium ferrocyanide, cesium carbonate, and water are mixed and stirred to react and obtain cesium ferrocyanide. The specific reaction process is as follows: Ba2Fe(CN)6+2Cs2CO3→ Cs4[Fe(CN)6] + 2 BaCO3↓ In this process, cesium carbonate and barium ferrous hydride react to form barium carbonate precipitate and Cs4[Fe(CN)6]. Cs4[Fe(CN)6] is present in the solution, while barium carbonate is removed by filtration as a precipitate, thus improving the purity of the subsequently obtained K2Ni[Fe(CN)6].

[0036] S200: The cesium ferrocyanide solution is first mixed with a nickel source to obtain a nickel cesium ferrocyanide precursor. In this step, a cesium ferrocyanide solution is first mixed with a nickel source. During this first mixing process, cesium ferrocyanide and nickel ions undergo rapid nucleation, ion intercalation, and crystallization ripening to ultimately obtain nickel cesium ferrocyanide. Specifically, the rapid nucleation stage forms an amorphous nickel ferrocyanide precursor; the ion intercalation stage involves the released cesium ions intercalating into the cavities of the forming nickel ferrocyanide framework to stabilize the structure and balance the charge; during the crystallization ripening process, a clean nickel cesium ferrocyanide precursor with uniform cesium ion intercalation is formed, in which cesium ions initially occupy certain adsorption sites.

[0037] In some embodiments, the nickel source is used to provide nickel ions, including at least one of nickel nitrate and cesium chloride.

[0038] In some embodiments, the molar ratio of cesium ferrocyanide to the nickel source is 1:(0.5-5), for example, 1:0.5, 1:2, 1:3, 1:5, etc. Therefore, by controlling the molar ratio of cesium ferrocyanide to the nickel source within the aforementioned range, sufficient reaction between the cesium ferrocyanide and the nickel source can be achieved to obtain nickel cesium ferrocyanide.

[0039] In other embodiments, ferrocyanide can also be used to calculate the amount of nickel source. Optionally, the molar ratio of ferrocyanide to nickel source is 1:(1-3), for example, 1:1, 1:2, 1:3, etc.

[0040] In some embodiments, the first mixing can react a nickel source with cesium ferrocyanide to form a nickel ferrocyanide cesium precursor. This process involves first replacing cesium ions with nickel ions to form nickel ferrocyanide, and then inserting cesium ions into the nickel ferrocyanide to obtain the nickel ferrocyanide cesium precursor.

[0041] Optionally, the first mixing time is 1-3 hours, such as 1 hour, 2 hours, 3 hours, etc.

[0042] In some embodiments, after the first mixing and before obtaining the nickel cesium ferrocyanide, the method further includes filtering and washing the product obtained from the first mixing. Filtration can be performed by centrifugation. This can improve the purity of the obtained nickel cesium ferrocyanide.

[0043] As a specific example, nickel nitrate is used as the nickel source. Cesium ferrocyanide is reacted with nickel nitrate by stirring to form nickel cesium ferrocyanide. The specific reaction is as follows: Cs4[Fe(CN)6]+Ni(NO3)2→Cs2Ni[Fe(CN)6]↓+2CsNO3 S300: The nickel cesium ferrocyanide precursor is mixed with a potassium source for a second time to obtain a nickel ferrocyanide potassium template adsorbent. In this step, nickel cesium ferrocyanide is mixed with a potassium salt solution to obtain nickel potassium ferrocyanide. Specifically, during the second mixing process, the difference in affinity between potassium ions, cesium ions, and nickel ferrocyanide ions causes potassium ions to replace cesium ions in the potassium salt solution, thereby converting nickel cesium ferrocyanide into nickel potassium ferrocyanide. Since cesium particles in nickel cesium ferrocyanide pre-occupy adsorption sites, after cesium ions are eluted, template vacancies are left. The size and shape of these template vacancies are essentially consistent with the size and shape of the cesium ions, thus enabling the nickel potassium ferrocyanide template adsorbent obtained in this application to have good selective adsorption capacity for cesium ions in cesium-containing solutions. This good selective adsorption capacity is based on the steric hindrance effect in adsorption separation; only molecules or ions of suitable size and shape can easily diffuse into the adsorbent to undergo adsorption or exchange reactions, while other molecules or ions are blocked. Therefore, the cesium ion vacancies present in nickel potassium ferrocyanide have a good adsorption effect on cesium ions in cesium-containing solutions.

[0044] In some embodiments, the second mixing can elute cesium ions, leaving template vacancies, to obtain nickel potassium ferrocyanide with good selective adsorption capacity for cesium. Optionally, the second mixing time is 10 min-60 min, for example 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, etc.

[0045] Optionally, the temperature of the second mixing is 40℃-90℃, for example, 40℃, 60℃, 70℃, 90℃, etc. Thus, controlling the temperature of the second mixing within the aforementioned range can promote the substitution of cesium ions by potassium ions in the potassium salt solution.

[0046] In some embodiments, the potassium salt is the potassium source for the preparation of nickel potassium ferrocyanide. Optionally, the potassium salt includes at least one of potassium nitrate and potassium chloride.

[0047] In some embodiments, the potassium ion concentration in the potassium salt solution is 2 mol / L-5 mol / L, such as 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, etc. Therefore, using a higher concentration of potassium salt solution helps maintain a higher concentration gradient, thereby promoting the rate and efficiency of the cesium ion substitution reaction.

[0048] In some embodiments, after the second mixing is performed and before obtaining the nickel potassium ferrocyanide template adsorbent, the mixture further includes: sequentially filtering, washing, and drying the first mixture.

[0049] Optionally, the dried product can be recycled through step S300, and the recycling process can be adjusted according to actual needs. For example, it can be recycled 3-5 times. In this way, cesium ferrocyanide can be converted into potassium nickel ferrocyanide more completely.

[0050] As a specific example, the potassium salt solution is a potassium nitrate solution. The nickel-cesium ferrocyanide precursor is then mixed a second time with the potassium nitrate solution to obtain a nickel-potassium ferrocyanide template adsorbent. A physical image of the template adsorbent is shown below. Figure 2 The chemical reactions in this process are as follows: Cs2Ni[Fe(CN)6] +KNO3→K2Ni[Fe(CN)6]↓+ CsNO3 In some embodiments, atomic absorption spectrometry can be used to test the cesium content of the obtained nickel potassium ferrocyanide. When the mass fraction of cesium in the nickel potassium ferrocyanide is less than 1%, the synthesis of the nickel potassium ferrocyanide template adsorbent is completed.

[0051] The method in this embodiment involves providing a cesium ferrocyanide solution; firstly mixing the cesium ferrocyanide solution with a nickel source to obtain a nickel cesium ferrocyanide precursor; and secondly mixing the nickel cesium ferrocyanide precursor with a potassium salt solution to obtain a nickel potassium ferrocyanide template adsorbent, thereby obtaining nickel potassium ferrocyanide with good cesium adsorption capacity. This process introduces cesium vacancies to obtain a nickel potassium ferrocyanide template adsorbent with cesium vacancies. Specifically, cesium ions in the nickel cesium ferrocyanide precursor pre-occupy adsorption sites; then, after mixing the nickel cesium ferrocyanide precursor with the potassium salt solution, the cesium ions are eluted, leaving template vacancies. Since the size and shape of the aforementioned template vacancies are essentially consistent with the size and shape of cesium ions, and based on the steric hindrance effect in adsorption separation, only molecules or ions of suitable size and shape can easily diffuse into the adsorbent to undergo adsorption or exchange reactions, while other molecules or ions are blocked. This results in the nickel potassium ferrocyanide obtained in this application exhibiting good selective adsorption capacity for cesium ions in cesium-containing solutions. In summary, this application introduces cesium and then elutes it to form nickel potassium ferrocyanide with cesium ion template vacancies. The cesium ion vacancies present in this nickel potassium ferrocyanide have a good adsorption effect on cesium ions in cesium-containing solutions, making the nickel potassium ferrocyanide template adsorbent of this application particularly suitable for adsorption of Cs in high-salt solutions. + Adsorption.

[0052] A second aspect of this application provides the application of the nickel potassium ferrocyanide template adsorbent prepared by the preparation method described in the first aspect in the adsorption of cesium ions.

[0053] The nickel potassium ferrocyanide obtained in this application is obtained by a template method. There are template vacancies in the nickel potassium ferrocyanide that are similar in size and shape to cesium ions, which makes the nickel potassium ferrocyanide obtained in this application have good selective adsorption capacity for cesium ions in cesium-containing solutions.

[0054] In some embodiments, the nickel potassium ferrocyanide of this application is particularly suitable for the adsorption of cesium ions in high-salt solutions, thereby improving problems such as frequent replacement of adsorbents and large volumes of radioactive waste.

[0055] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. It should be understood that these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0056] Example 1 Cesium ferrocyanide was prepared by mixing barium ferrocyanide (Ba2Fe(CN)6) and cesium carbonate (Cs2CO3) in water at a molar ratio of 1:3 and stirring. Then, nickel nitrate (Ni(NO3)2) was added to the solution in an amount equal to that of barium ferrocyanide (Ba2Fe(CN)6), and the mixture was stirred for 2 hours to produce nickel cesium ferrocyanide. The precipitate was collected by centrifugation or filtration and washed to obtain the nickel cesium ferrocyanide precursor (Cs2Ni[Fe(CN)6]).

[0057] At a temperature of 60℃, (Cs2Ni[Fe(CN)6]) was dissolved in a 3 mol / L potassium nitrate (KNO3) solution, stirred thoroughly for 30 min, centrifuged to collect the precipitate and continued to react with ammonium nitrate solution. This process was repeated 5 times to complete the transformation of Cs2Ni[Fe(CN)6] to K2Ni[Fe(CN)6], thus obtaining the K2Ni[Fe(CN)6] template adsorbent.

[0058] Comparative Example 1 368.4 g of potassium ferrocyanide and 365.4 g of nickel nitrate were dissolved in water, and the mixture was stirred continuously to form a microcrystalline precipitate. The precipitate was filtered and then washed with deionized water while filtering. The collected precipitate was dried at 80°C for 12 hours to obtain untemplated potassium ferrocyanide. The reaction equation is as follows: K4Fe(CN)6+ Ni(NO3)2→K2Ni[Fe(CN)6] ↓ + 2 KNO3 Test case Adsorption tests were conducted on the K2Ni[Fe(CN)6] template adsorbents obtained in Example 1 and Comparative Example 1. The experimental process was as follows: First, set the concentrations of NaCl, KCl, and CaCl2 in the solution to 1 mol / L, and Cs... + At a concentration of 1000 mg / L, two adsorbents at 5 g / L were used for adsorption, and the residual Cs in the solution after adsorption was detected. + The concentrations of NaCl, KCl, and CaCl₂ were then increased to 2 mol / L and 5 mol / L, respectively, and the adsorption capacity was calculated using Cs. + At a concentration of 1000 mg / L, adsorption was performed using 5 g / L of each of the two adsorbents. The saturated adsorption capacity of each was calculated using Equation 1 below, and the results are shown in [Figure 1]. Figure 3 .

[0059] Saturated adsorption capacity = (initial Cs) + Total amount - Cs remaining after adsorption + Total amount) / Adsorbent dosage... (Equation 1) Figure 3 This is a comparison of the saturated adsorption capacity of the template adsorbent of Example 1 and the non-template adsorbent of Comparative Example 1 at different ion concentrations. The horizontal axis represents the coexisting ion content, which refers to the content of each cation. The vertical axis, saturated adsorption capacity, refers to the adsorption capacity after complete adsorption by the adsorbent, calculated using Equation 1. The figure shows that the nickel potassium ferrocyanide template adsorbent prepared by the method of this application has a better adsorption effect on cesium ions compared to the non-template nickel potassium ferrocyanide adsorbent of Comparative Example 1. With NaCl, KCl, and CaCl2 contents of 1 mol / L, 2 mol / L, and 5 mol / L, respectively, the nickel potassium ferrocyanide template adsorbent of this application exhibits good adsorption effects. Furthermore, the nickel potassium ferrocyanide template adsorbent of this application is particularly suitable for adsorbing Cs ions in high-salt solutions. + Adsorption.

[0060] It should also be noted that the terms "some embodiments," "other embodiments," and "embodiments" used in this application refer to specific features, structures, or characteristics described in connection with those embodiments, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0061] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0062] It should also be noted that the above are merely preferred embodiments of this application and do not limit the scope of patent protection of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A method for preparing a nickel potassium ferrocyanide template adsorbent, characterized in that, Includes the following steps: Provide cesium ferrocyanide solution; The cesium ferrocyanide solution is first mixed with a nickel source to obtain a nickel cesium ferrocyanide precursor; The nickel cesium ferrocyanide precursor is mixed with a potassium salt solution in a second mixing process to obtain a nickel potassium ferrocyanide template adsorbent.

2. The preparation method according to claim 1, characterized in that, The cesium ferrocyanide solution is formed by the following methods: A third mixture of ferrocyanide, cesium source, and solvent is performed to obtain cesium ferrocyanide, wherein the solvent includes water.

3. The preparation method according to claim 2, characterized in that, The ferrocyanide includes at least one of barium ferrocyanide and calcium ferrocyanide; And / or, the cesium source includes at least one of cesium carbonate and cesium sulfate; And / or, the molar ratio of the ferrocyanide to the cesium source is 1:(1-5).

4. The preparation method according to claim 1, characterized in that, After the first mixing is performed, and before obtaining the nickel cesium ferrocyanide, the process further includes: The first mixture was then filtered and washed sequentially.

5. The preparation method according to claim 1 or 4, characterized in that, The nickel source includes at least one of nickel nitrate and nickel chloride; And / or, the molar ratio of the cesium ferrocyanide to the nickel source is 1:(0.5-5); And / or, the first mixing time is 1h-3h.

6. The preparation method according to claim 1, characterized in that, After the second mixing is performed, and before obtaining the nickel potassium ferrocyanide template adsorbent, the following steps are also included: The second mixture was then filtered, washed, and dried sequentially.

7. The preparation method according to claim 1 or 6, characterized in that, The second mixture satisfies at least one of the following conditions: The time is 10-60 minutes; The temperature ranges from 40℃ to 90℃.

8. The preparation method according to claim 1 or 6, characterized in that, The potassium salt in the potassium salt solution includes at least one of potassium nitrate, potassium chloride, and potassium sulfate.

9. The preparation method according to claim 1 or 6, characterized in that, The potassium ion concentration in the potassium salt solution is 2 mol / L-5 mol / L.

10. The application of the nickel potassium ferrocyanide template adsorbent prepared by the preparation method according to any one of claims 1-9 in the adsorption of cesium ions.

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