A one-step method for in-situ preparation of high-performance flake-like composite adsorption material and a preparation method and application thereof

Abstract

This invention provides a one-step in-situ preparation method for high-performance oatmeal-like composite adsorbent materials, along with its application, belonging to the field of liquid resource development and rare metal recovery technology. The preparation method includes the following steps: dissolving ferrous cyanide and sodium alginate in water to obtain solution A; dissolving a metal salt in water to obtain solution B; adding solution A dropwise to solution B to initiate a cross-linking reaction and then separating and washing to obtain the oatmeal-like composite adsorbent material. This invention also provides an application of the oatmeal-like composite adsorbent material in the separation and enrichment of cesium in radioactive wastewater. The preparation method of this invention greatly simplifies the process flow, avoiding the technical difficulties of complex preparation processes, easy powder agglomeration, and cumbersome composite processes inherent in traditional powder adsorbents. Furthermore, the prepared composite adsorbent material exhibits high adsorption capacity, adsorption rate, and cycle stability, making it easy to achieve continuous industrial operation.

Description

Technical Field

[0001] This invention belongs to the field of liquid resource development and rare metal recycling technology, and particularly relates to a one-step in-situ preparation method for high-performance oatmeal-like composite adsorbent materials, its preparation method and application. Background Technology

[0002] Cesium, as a strategic rare metal, occupies an irreplaceable and crucial position in high-end manufacturing and new energy fields. Due to its unique physicochemical properties, cesium has become a core material for key technologies such as atomic clocks, photomultiplier tubes, and nuclear reactor coolants. Meanwhile, its application demand in cutting-edge fields such as quantum communication and high-precision navigation is continuously increasing, leading to a growing market dependence on cesium resources. However, global cesium resources are not only extremely scarce but also geographically unevenly distributed, severely restricting the sustainable development of related high-end industries. Alleviating cesium resource shortages has become a significant technological challenge globally. Against this backdrop, cesium resources found in geothermal waters, with their unique resource attributes, have gradually become a research hotspot for global cesium resource development and utilization. Compared with traditional solid mineral deposit mining methods, geothermal cesium extraction has significant advantages such as sustainable resource utilization and minimal disturbance to the ecological environment, providing a new technological path to overcome the global cesium resource shortage.

[0003] Located in the core area of ​​the Mediterranean-Himalayan geothermal belt, Tibet experiences exceptionally intense geothermal activity. Its geothermal system possesses a complex resource characteristic of integrating water, heat, and minerals, and is particularly rich in rare metals such as lithium, rubidium, and cesium. The enrichment of cesium is especially prominent, with cesium content reaching over 20 mg / L in many geothermal bodies, giving it extremely high industrial development value and providing a high-quality resource foundation for my country's self-sufficiency in cesium resources.

[0004] In the geothermal cesium resource extraction technology system, adsorption has become one of the most promising cesium extraction technologies for industrial application due to its core advantages such as simple operation, high selectivity, low energy consumption, and strong applicability. In recent years, researchers have developed a variety of adsorbent materials for cesium adsorption, including zeolites, ammonium molybdenum phosphate (AMP), clay, metal sulfides, and Prussian blue analogues (PB). Among them, Prussian blue analogues (PB), with their unique cage-like crystal structure and ion channels that are highly matched to the size of cesium ions, exhibit adsorption selectivity and adsorption capacity far exceeding those of other materials, and are recognized as the most promising cesium adsorbent material for current applications.

[0005] Although Prussian blue analogues (PB) adsorbents possess significant advantages in cesium adsorption performance, existing PB-type adsorbents still suffer from problems such as complex preparation processes, difficulties in large-scale production, and insufficient stability in practical geothermal environments, making it difficult to meet the needs of industrial applications of cesium extraction from geothermal water. Therefore, developing a cesium adsorbent with a simple preparation process, excellent adsorption performance, and strong environmental stability is of great practical significance and industrial value for promoting the efficient development and utilization of cesium resources in geothermal water, and has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a one-step in-situ preparation method for high-performance oatmeal-like composite adsorbents, along with its preparation method and application. This method solves the problems of complex preparation processes, easy powder agglomeration, and low adsorption efficiency of existing cesium adsorbents, enabling efficient and green extraction of cesium resources from liquid resources.

[0007] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of the present invention: This invention provides a one-step in-situ preparation method for high-performance oatmeal-like composite adsorbent materials, comprising the following steps: (1) Dissolve ferrous cyanide and sodium alginate in water to obtain solution A; (2) Dissolve the metal salt in water to obtain solution B; (3) The solution A is added dropwise to the solution B to carry out a cross-linking reaction and then separated and washed to obtain the cereal-like composite adsorbent material.

[0008] Further, the ferrocyanide mentioned in step (1) includes potassium ferrocyanide or potassium ferricyanide.

[0009] Beneficial effects: In this invention, ferrous cyanide (potassium ferrocyanide or potassium ferricyanide) can react with metal salt solutions to generate Prussian blue analogues.

[0010] Further, the mass ratio of ferrous cyanide and sodium alginate in step (1) is 1:4 to 4:1; The mass ratio of sodium alginate to water is 1:99 to 1:19.

[0011] Beneficial effects: The present invention sets the mass ratio of ferrous cyanide and sodium alginate to 1:4 to 4:1 to control the proportion of the core material in the composite adsorbent. The higher the proportion of the core material, the better the adsorption effect of the composite adsorbent. However, if the proportion of the core material is increased, it will cause the core material to overflow and cause solution pollution. The present invention sets the mass ratio of sodium alginate and water to 1:99 to 1:19 to control the morphology of the composite adsorbent. If the proportion of sodium alginate in the system is too high, the viscosity of the system will be too high, and the composite adsorbent will not easily form an ideal morphology. Conversely, the composite adsorbent will not form a shape.

[0012] Furthermore, the metal salt mentioned in step (2) includes one of copper salt, zinc salt, nickel salt and manganese salt or a combination of two or more of them in any proportion.

[0013] Beneficial effects: In this application, copper salt, zinc salt, nickel salt and manganese salt are used as raw material metal salts. These are common Prussian blue analogues and the adsorbents generated by the reaction with ferrous cyanide have good adsorption effects on cesium ions. Furthermore, it has been verified that other metal salts have unsatisfactory adsorption effects on cesium ions and are more expensive.

[0014] Furthermore, the metal salt mentioned in step (2) has a mass percentage of 2%-5% in the water; The molar ratio of the ferrous cyanide in step (1) to the metal salt in step (2) is 1:4 to 4:1, which makes the reaction more complete.

[0015] Furthermore, the dripping speed in step (3) is 2 drops / s. A faster dripping speed will affect the molding morphology, while a slower speed will affect the processing efficiency. The crosslinking reaction was carried out at room temperature for 3 hours. The separation method is solid-liquid separation, that is, using a mesh screen to filter and separate the reaction liquid after the cross-linking reaction.

[0016] The second technical solution of the present invention: The present invention also provides a cereal-like composite adsorbent material prepared by the one-step in-situ preparation method of the high-performance cereal-like composite adsorbent material.

[0017] The third technical solution of the present invention: The present invention also provides an application of the oatmeal-like composite adsorbent material in the process of separating and enriching cesium in radioactive wastewater.

[0018] Furthermore, the radioactive wastewater includes any one of the following: salt lake brine, geothermal water, underground brine, well and mine brine, marine brine, oilfield water, and seafloor hydrothermal vents.

[0019] Furthermore, the method of application includes adsorption column and fixed / moving adsorption bed operation.

[0020] The beneficial effects of this invention compared to the prior art are as follows: This invention employs a one-step in-situ preparation method for oat-like composite adsorbent materials, effectively solving the problems of powdered adsorbents such as easy agglomeration, difficulty in molding, poor flowability, poor stability, difficulty in recycling, and difficulty in large-scale production. The integrated molding and preparation of the composite adsorbent material in this invention significantly shortens the process preparation time, reduces environmental pollution, and is suitable for large-scale production.

[0021] The one-step in-situ preparation of oat-like composite adsorbents of this invention exhibits excellent selectivity for cesium ions, high adsorption capacity, adsorption rate, and cycling stability. The prepared high-performance oat-like cesium composite adsorbent can achieve an adsorption capacity of 213.18 mg / g for cesium ions and reaches adsorption equilibrium within 25 min. It is suitable for large-scale preparation and can be applied to the separation and extraction of cesium resources from liquid resources. Furthermore, the oat-like composite adsorbents of this invention are easy to implement in continuous industrial operation, resulting in significant economic and environmental benefits. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a photograph of the oat-like composite adsorbent material prepared in Example 1 of the present invention. Figure 2 Figure 1 shows a magnified image of the oat-like composite adsorbent material prepared in Example 1 of the present invention under a polarized light microscope. Figure 2 shows an overall view of the oat-like composite adsorbent material, Figure 3 shows a magnified view of a part of the oat-like composite adsorbent material, and Figure 4 shows a detailed view of the surface of the oat-like composite adsorbent material. Figure 3 Figure 1 shows the adsorption performance of the cereal-like composite adsorbent material prepared in Example 1 of this invention. Figure 1(a) is an adsorption isotherm diagram, Figure 2(b) is an adsorption kinetic diagram, and Figure 3(c) is an adsorption cycle stability diagram. Detailed Implementation

[0024] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0025] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0026] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0027] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0028] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0029] All raw materials used in the embodiments of this invention can be purchased commercially, and the methods described are conventional methods unless otherwise specified.

[0030] The room temperature described in the following embodiments of the present invention is 23±2 ℃.

[0031] Example 1 A one-step in-situ preparation method for high-performance oatmeal-like composite adsorbent materials includes the following steps: (1) Dissolve 0.01 mol potassium ferrocyanide and 2 g sodium alginate in 98 g deionized water and stir at room temperature until the solution is clear and homogeneous to obtain solution A.

[0032] (2) Dissolve 0.02 mol of copper sulfate in 100 g of deionized water and stir at room temperature until the solution is clear and homogeneous to obtain solution B.

[0033] (3) Solution A was slowly added to solution B at a dropping rate of 2 drops / s, and the cross-linking reaction was carried out at room temperature for 3 h until the shape became oatmeal-like. The solution and solid were then separated by filtration through a mesh screen. The solid was then washed with deionized water until the solution became clear, yielding the oatmeal-like composite adsorbent material. A physical image of the oatmeal-like composite adsorbent material is shown below. Figure 1 As shown, through Figure 1 It can be seen that the oat-like composite adsorbent material prepared by the preparation method of the present invention has a uniform morphology.

[0034] A magnified image of the oat-like composite adsorbent material prepared in Example 1 under a polarized light microscope is shown below. Figure 2 As shown, through Figure 2 As can be seen, the composite adsorbent exhibits a distinct cereal-like appearance, with regular Prussian blue-based adsorbent uniformly loaded on its surface, further demonstrating the successful preparation of the composite adsorbent.

[0035] The cereal-like composite adsorbent material prepared in Example 1 was applied to geothermal water to separate and extract cesium resources from the geothermal water, and its adsorption performance was tested. The results are as follows: Figure 3 As shown, through Figure 3 It can be seen that the oat-like composite adsorbent prepared in Example 1 has an adsorption capacity of 213.18 mg / L for cesium ions and reaches adsorption equilibrium within 25 min. The adsorption cycle stability of the oat-like composite adsorbent was tested, and the results are as follows: Figure 3 As shown in Figure (c), the adsorbent exhibits excellent cycling stability, maintaining an adsorption rate of over 80% for cesium ions even after 10 cycles.

[0036] Example 2 A one-step in-situ preparation method for high-performance oatmeal-like composite adsorbent materials differs from Example 1 in that potassium ferrocyanide is replaced with potassium ferricyanide in equal amounts. The remaining raw materials and preparation methods are the same as in Example 1.

[0037] The cereal-like composite adsorbent material prepared in Example 2 has a uniform morphology.

[0038] The cereal-like composite adsorbent material prepared in Example 2 was applied to underground brine to separate and extract cesium resources from the underground brine, and the adsorption performance was tested. The results showed that the cereal-like composite adsorbent material prepared in Example 2 had an adsorption capacity of 208.89 mg / L for cesium ions and reached adsorption equilibrium within 25 min.

[0039] Example 3 A one-step in-situ preparation method for high-performance cereal-like composite adsorbent materials differs from Example 1 in that copper sulfate is replaced with zinc sulfate in equal amounts. The remaining raw materials and preparation methods are the same as in Example 1.

[0040] The cereal-like composite adsorbent material prepared in Example 3 has a uniform morphology.

[0041] The oat-like composite adsorbent material prepared in Example 3 was applied to sea brine to separate and extract cesium resources from the sea brine, and the adsorption performance was tested. The results showed that the oat-like composite adsorbent material prepared in Example 3 had an adsorption capacity of 210.32 mg / L for cesium ions and reached adsorption equilibrium within 25 min.

[0042] Example 4 A one-step in-situ preparation method for high-performance oatmeal-like composite adsorbent materials includes the following steps: (1) Dissolve 0.01 mol potassium ferricyanide and 2 g sodium alginate in 98 g deionized water and stir at room temperature until the solution is clear and homogeneous to obtain solution A.

[0043] (2) Dissolve 0.02 mol of copper sulfate and zinc sulfate (the molar ratio of copper sulfate and zinc sulfate is 1:1) in 100 g of deionized water and stir at room temperature until the solution is clear and homogeneous to obtain solution B.

[0044] (3) The above solution A was slowly added to solution B at a dropping rate of 2 drops / s, and the cross-linking reaction was carried out at room temperature for 3 h until the shape was oatmeal-like. The solution and solid were then separated by filtration with a gauze screen. The solid was then washed with deionized water until the solution was clear, and the oatmeal-like composite adsorbent material was obtained. The oatmeal-like composite adsorbent material had a uniform morphology.

[0045] The cereal-like composite adsorbent material prepared in Example 4 was applied to underground brine to separate and extract cesium resources from the underground brine, and the adsorption performance was tested. The results showed that the cereal-like composite adsorbent material prepared in Example 4 had an adsorption capacity of 209.52 mg / L for cesium ions and reached adsorption equilibrium within 25 min.

[0046] Example 5 A one-step in-situ preparation method for high-performance oatmeal-like composite adsorbent materials includes the following steps: (1) Dissolve 0.01 mol potassium ferrocyanide and 2 g sodium alginate in 98 g deionized water and stir at room temperature until the solution is clear and homogeneous to obtain solution A.

[0047] (2) Dissolve 0.02 mol of copper sulfate and zinc sulfate (the molar ratio of copper sulfate and zinc sulfate is 1:1) in 100 g of deionized water and stir at room temperature until the solution is clear and homogeneous to obtain solution B.

[0048] (3) The above solution A was slowly added to solution B at a dropping rate of 2 drops / s, and the cross-linking reaction was carried out at room temperature for 3 h until the shape was oatmeal-like. The solution and solid were then separated by filtration with a gauze screen. The solid was then washed with deionized water until the solution was clear, and the oatmeal-like composite adsorbent material was obtained. The oatmeal-like composite adsorbent material had a uniform morphology.

[0049] The oat-like composite adsorbent material prepared in Example 5 was applied to seawater brine to separate and extract cesium resources from the brine. Adsorption performance was tested, and the results showed that the oat-like composite adsorbent material prepared in Example 5 had an adsorption capacity of 207.98 mg / L for cesium ions and reached adsorption equilibrium within 25 min.

[0050] Comparative Example 1 A method for in-situ preparation of high-performance oatmeal-like composite adsorbent material in one step differs from Example 1 in that: Step (1): Dissolve 0.01 mol potassium ferrocyanide and 0.2 g sodium alginate in 49 g deionized water and stir at room temperature until the solution is clear and homogeneous to obtain solution A, i.e., the mass ratio of potassium ferrocyanide to sodium alginate is 3.89:8; The remaining raw materials and preparation methods are the same as in Example 1.

[0051] The experiment showed that reducing the amount of water in Comparative Example 1 resulted in excessively high solution viscosity, making it impossible to form a uniform, cereal-like consistency during the later molding process. This demonstrates that increasing the mass ratio of sodium alginate to water prevents the composite material from being molded.

[0052] Comparative Example 2 A method for one-step in-situ preparation of high-performance oatmeal-like composite adsorbent materials, which differs from Example 1 in that: Step (1): Dissolve 0.01 mol potassium ferrocyanide and 0.1 g sodium alginate in 98 g deionized water, and stir at room temperature until the solution is clear and homogeneous to obtain solution A; The remaining raw materials and preparation methods are the same as in Example 1.

[0053] The experiment showed that in Comparative Example 2, reducing the amount of sodium alginate resulted in an excessively low solution viscosity, making it impossible to form during the later stages of molding. This demonstrates that reducing the mass ratio of sodium alginate to water prevents the composite material from being molded.

[0054] Comparative Example 3 A method for one-step in-situ preparation of high-performance oatmeal-like composite adsorbent material, which differs from Example 1 in that: Step (1): Dissolve 0.02 mol potassium ferrocyanide and 0.2 g sodium alginate in 98 g deionized water, and stir at room temperature until the solution is clear and homogeneous to obtain solution A; (2) Dissolve 0.04 mol of copper sulfate in 100 g of deionized water and stir at room temperature until the solution is clear and homogeneous to obtain solution B.

[0055] The remaining raw materials and preparation methods are the same as in Example 1.

[0056] The cereal-like composite adsorbent prepared in Comparative Example 3 was applied to geothermal water for the separation and extraction of cesium resources. Adsorption performance was tested, and the composite adsorbent showed an adsorption capacity of 210.22 mg / L for cesium ions, reaching adsorption equilibrium within 25 minutes. However, due to the increased dosage of ferrous cyanide and metal salt, core adsorbent leakage occurred in the adsorption solution. This indicates that increasing the dosage of ferrous cyanide and metal salt significantly reduces the stability of the composite adsorbent.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle 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 one-step in-situ preparation method for high-performance oatmeal-like composite adsorbent materials, characterized in that, Includes the following steps: (1) Dissolve ferrous cyanide and sodium alginate in water to obtain solution A; (2) Dissolve the metal salt in water to obtain solution B; (3) The solution A is added dropwise to the solution B to carry out a cross-linking reaction and then separated and washed to obtain the cereal-like composite adsorbent material.

2. The method for one-step in-situ preparation of high-performance cereal-like composite adsorbent materials according to claim 1, characterized in that, The ferrocyanide mentioned in step (1) includes potassium ferrocyanide or potassium ferricyanide.

3. The method for one-step in-situ preparation of high-performance cereal-like composite adsorbent materials according to claim 1, characterized in that, The mass ratio of ferrous cyanide and sodium alginate in step (1) is 1:4 to 4:1; The mass ratio of sodium alginate to water is 1:99 to 1:

19.

4. The method for one-step in-situ preparation of high-performance cereal-like composite adsorbent materials according to claim 1, characterized in that, The metal salt mentioned in step (2) includes one of copper salt, zinc salt, nickel salt and manganese salt or a combination of two or more in any proportion.

5. The method for one-step in-situ preparation of high-performance cereal-like composite adsorbent materials according to claim 1, characterized in that, The metal salt mentioned in step (2) has a mass percentage of 2%-5% in the water; The molar ratio of the ferrous cyanide in step (1) to the metal salt in step (2) is 1:4 to 4:

1.

6. The method for one-step in-situ preparation of high-performance cereal-like composite adsorbent materials according to claim 1, characterized in that, The dripping rate in step (3) is 2 drops / s; The cross-linking reaction took 3 hours. The separation method involves using a mesh screen to filter and separate the reaction liquid after the cross-linking reaction.

7. A cereal-like composite adsorbent prepared by the one-step in-situ preparation method of high-performance cereal-like composite adsorbent as described in any one of claims 1 to 6.

8. The application of the cereal-like composite adsorbent material as described in claim 7 in the process of separating and enriching cesium in radioactive wastewater.

9. The application according to claim 8, characterized in that, The radioactive wastewater includes any one of the following: salt lake brine, geothermal water, underground brine, well and mine brine, marine brine, oilfield water, and seafloor hydrothermal vents.

10. The application according to claim 8, characterized in that, The methods used in this application include adsorption column and fixed / moving adsorption bed operation.

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