A method for promoting formation of spherical titanium phosphate-based adsorbent material by mechanical-chemical activation and adsorbent material prepared thereby

Abstract

The application discloses a method for promoting formation of spherical titanyl phosphate-based adsorbing material by mechanical chemical activation and an adsorbing material prepared by the method, and belongs to the technical field of inorganic adsorbing material preparation. The application is aimed at the problems of low solid-phase reaction activity of titanium dioxide, long element diffusion distance and difficulty in forming a uniform spherical structure, and titanium dioxide, hydrated ammonium phosphate and ammonium fluoride are subjected to mechanical activation treatment, so that raw material particles are refined and surface activity is improved, then a solid-phase reaction is carried out, and after washing and drying, the spherical titanyl phosphate-based adsorbing material is obtained. The mechanical activation can promote formation of a Ti-O-P skeleton and improve material structure uniformity, the obtained adsorbing material has strong adsorbing capacity for Sr 2+ , and has stable Sr 2+ adsorbing performance in a wide pH range, and can be used for separation and recovery of strontium ions in a complex salt-containing system. The method is simple, solvent usage is small, easy to scale up, and has a good industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the field of water pollutant treatment technology, specifically relating to a method for promoting the formation of spherical titanium phosphate-based adsorbent materials through mechanochemical activation and the adsorbent materials prepared therefrom. Background Technology

[0002] Currently, strontium ions are present in various systems, including strontium-containing wastewater, salt lake brine, chlor-alkali mud leachate, and nuclear industry wastewater. As an alkaline earth metal element with high resource value, the efficient separation and recovery of strontium is not only of significant resource utilization value but also crucial for reducing environmental pollution risks. Current methods for strontium ion separation mainly include chemical precipitation, solvent extraction, membrane separation, and adsorption. Chemical precipitation typically requires the addition of large amounts of precipitant, easily generating new solid waste; solvent extraction, while highly efficient, suffers from high organic solvent consumption and complex processes; membrane separation is hampered by membrane fouling and high operating costs. In contrast, adsorption, with its advantages of simple process, low energy consumption, and reusable materials, has become an important research direction for strontium ion separation and recovery.

[0003] Phosphate-based inorganic ion exchange materials have attracted widespread attention due to their structural stability, strong radiation resistance, and excellent ion exchange performance. Among them, titanium phosphate materials contain both a Ti-OP framework and surface phosphate groups, which provide ion exchange sites, thereby adsorbing various metal ions. Studies have shown that titanium phosphate materials have good adsorption capacity for various divalent metal ions, especially exhibiting high selectivity and adsorption capacity for strontium ions. Furthermore, titanium phosphate materials possess good chemical and thermal stability, maintaining a stable structure even in acidic or high-salinity environments, thus showing broad application prospects in wastewater treatment and nuclear waste treatment. However, existing methods for preparing titanium phosphate adsorbents still have certain limitations, and the preparation process and structural control methods restrict further improvement of material performance.

[0004] Currently, methods for preparing titanium phosphate-based adsorbents include liquid-phase precipitation, hydrothermal methods, and solid-phase synthesis. In existing technologies, titanium phosphate-based adsorbents are mainly prepared using liquid-phase reaction methods. For example, Chinese patent CN103626145B discloses titanium phosphate nanomaterials, their preparation methods, and applications. This patent prepares titanium phosphate materials by reacting titanium-containing compounds with phosphorus-containing compounds in a solution system. Chinese patent CN112169748B discloses an adsorbent, its preparation method, and applications. This patent obtains titanium phosphate adsorbents through a liquid-phase reaction and heat treatment process involving a titanium source and a phosphate system. However, both of these methods typically rely on a liquid-phase medium to achieve the dissolution, migration, and crystal formation of reactants, resulting in problems such as high solvent consumption, complex post-processing, and difficulties in continuous preparation.

[0005] While solid-phase synthesis can reduce solvent usage, the high structural stability of titanium dioxide means that the reaction between the titanium and phosphorus sources relies primarily on diffusion at the solid particle interface. This leads to issues such as insufficient reactivity, long element diffusion distances, and high reaction temperatures. Furthermore, high-temperature solid-phase treatment can easily cause particle sintering and grain growth, reducing the material's specific surface area and limiting the exposure of adsorption active sites. In addition, existing strontium ion adsorbents exhibit varying adsorption performance under different pH conditions; therefore, improving the adsorption stability of titanium phosphate materials over a wide pH range remains crucial.

[0006] In recent years, mechanochemical methods have been used to improve the reactivity of solid materials, promoting particle refinement and surface activation through mechanical impact, shearing, and friction. However, existing mechanochemical techniques are mainly used for material crushing, mixing, or simple activation. The focus here is on utilizing mechanical energy to induce a solid-state transformation reaction between titanium and phosphorus sources, and further modulating the structure of titanium phosphate and its Sr content. 2+ Research on the selection of adsorption properties is still limited.

[0007] Therefore, there is an urgent need to develop a method for preparing novel titanium phosphate-based adsorbent materials by promoting solid-phase reactions through mechanochemical activation. This method aims to improve the efficiency of solid-phase reactions by inducing reactant activation through mechanical energy, thereby obtaining titanium phosphate-based adsorbent materials with uniform structure and good selective adsorption performance of strontium ions over a wide pH range. Summary of the Invention

[0008] To address the problems existing in the prior art, this invention provides a method for promoting the formation of spherical titanium phosphate-based adsorbents through mechanochemical activation, and the adsorbents prepared therefrom. This method utilizes mechanical energy to induce a solid-phase transformation reaction between a titanium source and a phosphorus source, thereby controlling the titanium phosphate structure to obtain spherical titanium phosphate-based adsorbents. The obtained spherical titanium phosphate-based adsorbents can effectively adsorb Sr over a wide pH range. 2+ Selective adsorption.

[0009] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for promoting the formation of spherical titanium phosphate-based adsorbent materials through mechanochemical activation includes the following steps: S01, Mechanical activation: Titanium dioxide, ammonium hydrated phosphate, and ammonium fluoride are added to a mechanical crushing and mixing equipment for mechanical activation treatment to obtain a mixture; S02, Solid-phase reaction: The mixture is added to a heating device to carry out a solid-phase reaction, and then washed and dried to obtain spherical titanium phosphate-based adsorbent material.

[0010] Preferably, in step S01, the molar ratio of titanium dioxide, ammonium hydrate, and ammonium fluoride is controlled to be 1:2-6:0.1-0.4.

[0011] Preferably, in step S01, the mechanical crushing and mixing equipment is one of a ball mill or a high-speed solid crusher.

[0012] More preferably, in step S01, the mechanical pulverizing and mixing equipment is one of a planetary ball mill, a vibratory ball mill, a stirred ball mill, a drum ball mill, or a high-speed solid pulverizer.

[0013] Preferably, in step S01, during the mechanical activation treatment, when the mechanical pulverizing and mixing equipment used is a ball mill, the mechanical activation treatment is ball milling treatment, the mass ratio of the mixed material to the grinding media is 1:9-11, the ball milling adopts an alternating forward and reverse rotation method, the forward rotation speed is 600-1000 rpm, the reverse rotation speed is 600-1000 rpm, and the ball milling treatment time is 1-4 hours; when the mechanical pulverizing and mixing equipment used is a high-speed solid pulverizer, the mechanical activation treatment is high-speed pulverizing treatment, the high-speed pulverizing speed is 12000-15000 rpm, and the high-speed pulverizing treatment time is 40-80 minutes.

[0014] More preferably, in step S01, during the mechanical activation treatment, when the mechanical pulverizing and mixing equipment used is a ball mill, the mechanical activation treatment is ball milling treatment, the mass ratio of the mixed material to the grinding media is 1:9-11, the ball milling adopts an alternating forward and reverse method, the forward rotation speed is 600-1000 rpm, the rotation time is 0.5-2h, the reverse rotation speed is 600-1000 rpm, the rotation time is 0.5-2h, the ball milling media is zirconia balls, and the zirconia ball particle size ratio is φ10mm:φ6mm:φ3mm=15-25%:35-45%:35-45%; when the mechanical pulverizing and mixing equipment used is a high-speed solid pulverizer, the mechanical activation treatment is high-speed pulverizing treatment, the high-speed pulverizing speed is 12000-15000 rpm, and the high-speed pulverizing treatment time is 40-80min.

[0015] Preferably, in step S02, the heating device is a reaction vessel equipped with polytetrafluoroethylene.

[0016] Preferably, in step S02, the reaction temperature in the solid-phase reaction is 120-150℃ and the reaction time is 24-48h.

[0017] Furthermore, in step S02, the solid-phase reaction is carried out in a closed environment provided by a reaction vessel equipped with polytetrafluoroethylene.

[0018] Preferably, in step S02, the washing method is to first wash with deionized water until neutral, and then wash with ethanol.

[0019] More preferably, in step S02, the washing method is to first wash with deionized water until neutral, and then wash with ethanol 1-2 times. After each washing, the precipitate is separated by centrifugation at a speed of 5000-8000 rpm for 2-4 min.

[0020] Preferably, in step S02, the drying temperature is 60-80℃ and the drying time is 4-6h.

[0021] Furthermore, the obtained spherical titanium phosphate-based adsorbent material has a near-spherical particle structure with a particle size of 20-80 nm.

[0022] An adsorbent material prepared by the aforementioned method.

[0023] An adsorbent material prepared by the aforementioned method selectively adsorbs Sr in a strontium-containing solution. 2+ The application includes the following steps: the adsorbent material is added to a strontium-containing solution for adsorption, and solid-liquid separation is performed after adsorption is completed.

[0024] Preferably, the strontium-containing solution is one of industrial wastewater, saline waste liquid, or simulated solution; The strontium-containing solution includes Sr 2+ and competing ions, said competing ions including Ca 2+ Mg 2+ One or a combination thereof; The amount of the adsorbent material added to the strontium-containing solution is 0.5-2 g / L.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention utilizes mechanochemical activation treatment to refine the particles, uniformly mix, and activate the surfaces of solid raw materials such as titanium dioxide, ammonium hydrate, and ammonium fluoride under mechanical action. This increases the contact between reactants and shortens the solid-phase diffusion distance. Because mechanochemical activation can increase the surface energy of solid raw materials and reduce the reaction diffusion resistance, it can promote the solid-phase transformation reaction at lower temperatures and promote the formation of the Ti-OP framework structure. Compared with direct mixing without mechanical activation treatment, mechanical activation can effectively improve the structural properties of the prepared titanium phosphate material.

[0026] (2) This invention utilizes a mechanochemical solid-phase synthesis method, which reduces dependence on liquid media, simplifies the preparation process, and improves the greenness of the preparation process. Traditional methods for preparing titanium phosphate materials via liquid-phase precipitation and hydrothermal methods typically require large amounts of water or organic solvents as reaction media and involve multiple steps such as precursor dissolution, precipitation, filtration, and washing, easily generating phosphorus-containing waste liquid and washing waste liquid. This invention uses direct mechanical activation of solid raw materials and forms titanium phosphate materials through a solid-phase conversion reaction, avoiding the problem of large amounts of solvent participating in the reaction in traditional liquid-phase systems and reducing subsequent waste liquid treatment processes. Furthermore, the mechanized pulverizing and mixing equipment used in this invention includes ball milling equipment and solid pulverizing and mixing equipment, which are highly adaptable and facilitate process scale-up according to production conditions.

[0027] (3) This invention achieves a uniform spherical structure in the prepared titanium phosphate material through the synergistic regulation of mechanical activation and ammonium fluoride, which is beneficial to improving adsorption performance. In this invention, the mechanochemical activation process not only achieves raw material mixing but also improves the surface activity of particles; ammonium fluoride can regulate the formation of crystal nuclei and the crystal growth process during the reaction, thereby promoting the formation of a uniform spherical structure. The titanium phosphate material prepared by this invention is composed of a large number of near-spherical nanoparticles with a particle size of about 20-80 nm. The particles are relatively uniformly distributed and have a certain porosity between them. The spherical nanostructure can increase the contact area between the material and the solution, which is beneficial to the exposure of adsorption sites and improves the mass transfer efficiency of target ions.

[0028] (4) The titanium phosphate adsorbent prepared in this invention has a positive effect on Sr 2+ It exhibits good selective adsorption performance, maintaining high adsorption capacity even in the presence of competing ions. Furthermore, the prepared titanium phosphate adsorbent material possesses a stable Ti-OP framework structure and abundant phosphate adsorption sites, enabling the adsorption of Sr through ion exchange, surface coordination, and electrostatic interactions. 2+ Adsorption, in the presence of Ca 2+ Mg 2+ Adsorption experiments were conducted in a simulated mixed salt system of competing ions. The titanium phosphate adsorbent prepared in this invention showed adsorption of Sr... 2+Its removal capacity is 5.2 times that of titanium phosphate adsorbents that have not undergone mechanochemical activation treatment.

[0029] (5) The titanium phosphate material prepared by this invention has a wide applicable pH range, which can meet the application requirements of complex aquatic environments. Adsorption experiments under different pH conditions show that the titanium phosphate material prepared by this invention has Sr content in the pH range of 4-10. 2+ Adsorption capacity. The titanium phosphate material prepared in this invention exhibits optimal adsorption performance at pH=8, with an adsorption capacity reaching 66.2 mg / g. This indicates that the titanium phosphate material prepared in this invention possesses good structural stability and adsorption adaptability under different acidic and alkaline environments, and can be used for the selective removal of strontium ions in complex salt-containing systems.

[0030] (6) The preparation method of the present invention has good process adaptability and application value. It improves the traditional solid-phase reaction kinetics through mechanical activation, while avoiding the use of large amounts of solvents and complex post-processing in traditional liquid-phase synthesis methods. Moreover, the raw materials are widely available, the process steps are simple, and the mechanical activation equipment can be selected from ball mills or solid pulverizing and mixing equipment according to actual production needs, which has the potential for further large-scale application. Attached Figure Description

[0031] Figure 1 X-ray diffraction patterns of titanium phosphate materials prepared in Comparative Example 1 and Example 1; In the picture, Figure 1 (a) is the X-ray diffraction pattern of the titanium phosphate material prepared in Comparative Example 1; Figure 1 (b) is the X-ray diffraction pattern of the titanium phosphate material prepared in Example 1; Figure 2 Scanning electron microscope (SEM) images of the titanium phosphate material prepared in Example 1 at different scales; In the picture, Figure 2 (a) is a scanning electron microscope image of the titanium phosphate material prepared in Example 1 at a scale bar of 10 μm; Figure 2 (b) is a scanning electron microscope image of the titanium phosphate material prepared in Example 1 at a scale bar of 100 nm; Figure 3 The energy spectrum and elemental distribution of the titanium phosphate material prepared in Example 1 are shown below. In the picture, Figure 3 (a) is the energy spectrum of the titanium phosphate material prepared in Example 1; Figure 3 (b) is a carbon element distribution diagram of the titanium phosphate material prepared in Example 1; Figure 3 (c) is a nitrogen element distribution diagram of the titanium phosphate material prepared in Example 1; Figure 3 (d) is the O element distribution diagram of the titanium phosphate material prepared in Example 1; Figure 3(e) is the F element distribution diagram of the titanium phosphate material prepared in Example 1; Figure 3 (f) is the P element distribution diagram of the titanium phosphate material prepared in Example 1; Figure 3 (g) is the Ti element distribution diagram of the titanium phosphate material prepared in Example 1; Figure 4 The image shows the X-ray photoelectron spectrum of the titanium phosphate material prepared in Example 1. Detailed Implementation

[0032] The present invention will now be described in detail with reference to embodiments and accompanying drawings, but the scope of protection of the present invention is not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified by the manufacturer, are all commercially available conventional products.

[0033] Embodiments of the present invention provide a method for promoting the formation of spherical titanium phosphate-based adsorbent materials through mechanochemical activation, comprising the following steps: S01, Mechanical activation: Titanium dioxide, ammonium hydrated phosphate, and ammonium fluoride are added to a mechanical crushing and mixing equipment for mechanical activation treatment to obtain a mixture; S02, Solid-phase reaction: The mixture is added to a heating device to carry out a solid-phase reaction, and then washed and dried to obtain spherical titanium phosphate-based adsorbent material.

[0034] Preferably, in step S01, the molar ratio of titanium dioxide, ammonium hydrate, and ammonium fluoride is controlled to be 1:2-6:0.1-0.4 (preferably 1:2-6:0.1-0.3).

[0035] Preferably, in step S01, the mechanical crushing and mixing equipment is one of a ball mill or a high-speed solid crusher.

[0036] More preferably, in step S01, the mechanical pulverizing and mixing equipment is one of a planetary ball mill, a vibratory ball mill, a stirred ball mill, a drum ball mill, or a high-speed solid pulverizer.

[0037] Preferably, in step S01, during the mechanical activation treatment, when the mechanical pulverizing and mixing equipment used is a ball mill, the mechanical activation treatment is ball milling treatment, the mass ratio of the mixed material to the grinding media is 1:9-11, the ball milling adopts an alternating forward and reverse rotation method, the forward rotation speed is 600-1000 rpm, the reverse rotation speed is 600-1000 rpm, and the ball milling treatment time is 1-4 hours; when the mechanical pulverizing and mixing equipment used is a high-speed solid pulverizer, the mechanical activation treatment is high-speed pulverizing treatment, the high-speed pulverizing speed is 12000-15000 rpm, and the high-speed pulverizing treatment time is 40-80 minutes.

[0038] More preferably, in step S01, during the mechanical activation treatment, when the mechanical pulverizing and mixing equipment used is a ball mill, the mechanical activation treatment is ball milling treatment, the mass ratio of the mixed material to the grinding media is 1:9-11, the ball milling adopts an alternating forward and reverse method, the forward rotation speed is 600-1000 rpm, the rotation time is 0.5-2h, the reverse rotation speed is 600-1000 rpm, the rotation time is 0.5-2h, the ball milling media is zirconia balls, and the zirconia ball particle size ratio is φ10mm:φ6mm:φ3mm=15-25%:35-45%:35-45%; when the mechanical pulverizing and mixing equipment used is a high-speed solid pulverizer, the mechanical activation treatment is high-speed pulverizing treatment, the high-speed pulverizing speed is 12000-15000 rpm, and the high-speed pulverizing treatment time is 40-80min.

[0039] Preferably, in step S02, the heating device is a reaction vessel equipped with polytetrafluoroethylene.

[0040] Preferably, in step S02, the reaction temperature in the solid-phase reaction is 120-150℃ and the reaction time is 24-48h.

[0041] Furthermore, in step S02, the solid-phase reaction is carried out in a closed environment provided by a reaction vessel equipped with polytetrafluoroethylene.

[0042] Preferably, in step S02, the washing method is to first wash with deionized water until neutral, and then wash with ethanol.

[0043] More preferably, in step S02, the washing method is to first wash with deionized water until neutral, and then wash with ethanol 1-2 times. After each washing, the precipitate is separated by centrifugation at a speed of 5000-8000 rpm for 2-4 min.

[0044] Preferably, in step S02, the drying temperature is 60-80℃ and the drying time is 4-6h.

[0045] Furthermore, the obtained spherical titanium phosphate-based adsorbent material has a near-spherical particle structure with a particle size of 20-80 nm.

[0046] An embodiment of the present invention also provides an adsorbent material prepared by the method described above.

[0047] Embodiments of the present invention also provide an adsorbent material prepared by the method for selective adsorption of Sr in a strontium-containing solution. 2+ The application includes the following steps: the adsorbent material is added to a strontium-containing solution for adsorption, and solid-liquid separation is performed after adsorption is completed; Preferably, the strontium-containing solution is one of industrial wastewater, saline waste liquid, or simulated solution.

[0048] Preferably, the strontium-containing solution includes Sr 2+ and competing ions, said competing ions including Ca 2+ Mg 2+ One or a combination thereof.

[0049] Preferably, the amount of the adsorbent material added to the strontium-containing solution is 0.5-2 g / L.

[0050] The titanium dioxide used in the subsequent examples and comparative examples was micron-sized titanium dioxide with analytical purity.

[0051] Example 1 (1) 12.5 mmol titanium dioxide, 25 mmol ammonium hydrate and 1.25 mmol ammonium fluoride were mixed in a ball mill. The grinding media was zirconium oxide. The mass ratio of the mixture to the grinding media was 1:10. The ratio of grinding balls φ10mm:φ6mm:φ3mm was 20%:40%:40%. The ball mill rotated at 600 rpm for 1 hour in the forward direction and at 600 rpm for 1 hour in the reverse direction to obtain the mixture. (2) The mixture was transferred to a heating device for reaction at a temperature of 120°C for 24 hours. After the reaction was completed, it was washed with deionized water until neutral and then washed with ethanol once. After each washing, the precipitate was separated by centrifugation at a speed of 5000 rpm for 2 minutes. Then it was transferred to an oven and dried at a temperature of 60°C for 4 hours to obtain titanium phosphate material. The heating device is a reaction vessel equipped with polytetrafluoroethylene, which can provide a closed reaction space during the reaction.

[0052] Example 2 (1) 12.5 mmol titanium dioxide, 25 mmol ammonium phosphate hydrate and 1.25 mmol ammonium fluoride were added to a high-speed solid pulverizer for mechanochemical activation treatment. The pulverization speed in the mechanochemical activation treatment was 12000 rpm and the pulverization time was 60 min to obtain a mixture. (2) The mixture was transferred to a heating device for reaction at a temperature of 120°C for 24 hours. After the reaction was completed, it was washed with deionized water until neutral and then washed with ethanol once. After each washing, the precipitate was separated by centrifugation at a speed of 5000 rpm for 2 minutes. Then it was transferred to an oven and dried at a temperature of 60°C for 4 hours to obtain titanium phosphate material. The heating device is a reaction vessel equipped with polytetrafluoroethylene, which can provide a closed reaction space during the reaction.

[0053] Example 3 (1) 12.5 mmol titanium dioxide, 75 mmol ammonium hydrate and 3.75 mmol ammonium fluoride were mixed in a ball mill. The grinding media was zirconium oxide. The mass ratio of the mixture to the grinding media was 1:10. The ratio of grinding balls φ10mm:φ6mm:φ3mm was 20%:40%:40%. The ball mill rotated at 1000 rpm for 1 hour in the forward direction and at 1000 rpm for 1 hour in the reverse direction to obtain the mixture. (2) The mixture was transferred to a heating device for reaction at a temperature of 150°C for 48 hours. After the reaction was completed, it was washed with deionized water until neutral and then washed with ethanol once. After each washing, the precipitate was separated by centrifugation at a speed of 8000 rpm for 4 minutes. Then it was transferred to an oven and dried at a temperature of 80°C for 6 hours to obtain titanium phosphate material. The heating device is a reaction vessel equipped with polytetrafluoroethylene, which can provide a closed reaction space during the reaction.

[0054] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no mechanical chemical activation treatment was performed in step (1). Instead, 12.5 mmol of titanium dioxide, 25 mmol of ammonium hydrate and 1.25 mmol of ammonium fluoride were added to the heating device (polytetrafluoroethylene reactor), and mechanically stirred at a stirring rate of 100 rpm for 5 min. Then, the reaction, washing and drying were carried out according to step (2).

[0055] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that ammonium fluoride is not added in step (1), while other operating methods and reaction conditions remain unchanged.

[0056] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the washing with ethanol once is omitted in step (2), while other operation methods and reaction conditions remain unchanged.

[0057] Application Example 1 100 mg of the titanium phosphate material prepared in Example 1 was added to 100 mL of pure strontium solution (strontium chloride hexahydrate solution), wherein Sr 2+ =1865ppm, after static adsorption for 0.5h at room temperature and pH=4, 6, 8, 10, centrifugation was performed and the supernatant was collected. Sr was measured by ICP. 2+ The adsorption capacity was calculated based on the concentration changes. The calculated adsorption capacity results are shown in Table 1.

[0058] Application Example 2 Take 100 mg of each of the titanium phosphate materials prepared in Example 1 and Comparative Examples 1-3 and add them to 100 mL of a mixed solution. The mixed solution contains Ca... 2+ =188.7ppm, Mg 2+ =84.9ppm, Sr 2+ =114.1ppm, pH=8.32; after static adsorption at room temperature for 0.5h, centrifugation was performed and the supernatant was collected. Ca2+ was measured using ICP. 2+ Mg 2+ 、Sr 2+ Concentration changes, adsorption of titanium phosphate materials prepared in Example 1 and Comparative Examples 1-3 in the mixed solution (Ca after adsorption) 2+ Mg 2+ 、Sr 2+ The results of the concentration changes are shown in Table 2.

[0059] Table 1. Adsorption capacity of titanium phosphate material prepared in Example 1 at different pH values.

[0060] Table 2. Adsorption of titanium phosphate materials prepared in Example 1 and Comparative Examples 1-3 in the mixed solution.

[0061] Table 1 shows that the titanium phosphate material prepared in Example 1 exhibits good strontium ion adsorption performance at pH values ​​of 4, 6, 8, and 10. The adsorption capacity reaches its maximum at pH value of 8. This indicates that the titanium phosphate material prepared in Example 1 has a wide applicable pH range and can meet the requirements for strontium ion adsorption under complex aquatic conditions. 2+ The adsorption and separation requirements were also explained; it was further demonstrated that the mechanochemical solid-phase synthesis method of Example 1 can effectively solve the problems of insufficient reactivity, difficulty in structural control, and limited adsorption performance of traditional titanium phosphate materials during the preparation process.

[0062] Comparing the adsorption conditions of Example 1 and Comparative Example 1 in Table 2, it can be seen that the difference between Comparative Example 1 and Example 1 is that Comparative Example 1 did not undergo mechanochemical activation treatment; it only used direct mixing of raw materials. All other preparation conditions were the same as in Example 1. Compared with Comparative Example 1, the titanium phosphate material prepared in Example 1 showed better adsorption of Sr... 2+ The adsorption capacity of this material is 5.2 times that of the titanium phosphate material prepared in the same proportion. This indicates that mechanochemical activation treatment can improve the adsorption capacity of the material for Sr. 2+The adsorption capacity is enhanced, and the non-selective adsorption of competing ions is reduced. This is because during the mechanochemical activation process, the raw material particles are broken, refined, and recombine under mechanical action, which increases the contact degree between titanium dioxide, hydrated ammonium phosphate, and ammonium fluoride. At the same time, it increases the active sites on the particle surface, shortens the diffusion distance in the solid-phase reaction process, thereby promoting the formation of the Ti-OP framework structure and facilitating the formation of titanium phosphate materials.

[0063] Comparing the adsorption conditions of Example 1 and Comparative Example 2 in Table 2, it can be seen that the difference between Comparative Example 2 and Example 1 is that ammonium fluoride was not added during the preparation process of Comparative Example 2, while all other preparation conditions remained the same. After adding ammonium fluoride, the prepared titanium phosphate material exhibited higher Sr content. 2+ Adsorption capacity and better selection of adsorption performance. This indicates that ammonium fluoride not only participates in the reaction system composition in the preparation of this invention, but also regulates the formation process of titanium phosphate material, which is beneficial to promoting the formation of titanium phosphate crystal structure and improving the particle morphology of titanium phosphate material, thereby improving the adsorption performance of titanium phosphate material.

[0064] Comparing the adsorption conditions of Example 1 and Comparative Example 3 in Table 2, it can be seen that the difference between Comparative Example 3 and Example 1 is that the titanium phosphate material prepared in Comparative Example 3 was only washed with deionized water, without further washing with ethanol, while the other preparation conditions remained the same. This indicates that ethanol washing treatment can improve the pore structure and surface state of the titanium phosphate material, and enhance the adsorption capacity of the titanium phosphate material for Sr. 2+ Selective adsorption performance. Ethanol washing can further remove residues on the material surface, reduce pore blockage, increase the effective specific surface area of ​​titanium phosphate, and promote the exposure of adsorption active sites, thereby improving the selective adsorption performance of titanium phosphate.

[0065] Figure 1 The images show the X-ray diffraction patterns of the titanium phosphate materials prepared in Comparative Example 1 and Example 1. Figure 1 (a) is the X-ray diffraction pattern of the titanium phosphate material prepared in Comparative Example 1, i.e., the X-ray diffraction pattern of the titanium phosphate material without mechanochemical treatment. Figure 1 (a) It can be seen that the components in the titanium phosphate material prepared in Comparative Example 1 still maintain the original crystal structure, and the number of diffraction peaks is large and the peak shape is sharp. Figure 1 (b) is the X-ray diffraction pattern of the titanium phosphate material prepared in Example 1, i.e., the X-ray diffraction pattern of the titanium phosphate material after mechanochemical ball milling. Figure 1 (b) and Figure 1(a) After comparison, it was found that the diffraction peaks in the X-ray diffraction pattern of the titanium phosphate material prepared in Example 1 changed significantly compared with the X-ray diffraction pattern of the titanium phosphate material prepared in Comparative Example 1. The intensity of some diffraction peaks decreased, indicating that the ball milling process not only achieved uniform mixing of raw materials, but also improved the surface activity of particles through continuous mechanical impact, friction and shearing, providing favorable conditions for subsequent solid-phase transformation.

[0066] Figure 2 This is a scanning electron microscope (SEM) image of the titanium phosphate material prepared in Example 1. Figure 2 (a) It can be seen that the titanium phosphate material prepared in Example 1 exhibits a uniform powder morphology, and no obvious large-size particle aggregation was observed, indicating that mechanochemical activation and subsequent solid-phase transformation processes are beneficial to improving the uniformity of raw material mixing. Figure 2 (b) Further observation reveals that the titanium phosphate material prepared in Example 1 is mainly composed of near-spherical or ellipsoidal nanoparticles with relatively clear particle edges and a relatively uniform size distribution. The particle size is approximately 20-80 nm, indicating that the titanium phosphate material prepared in Example 1 is a spherical titanium phosphate material. Simultaneously, there are certain interstitial structures between the particles, forming a relatively loose particle packing morphology. This spherical nanoparticle structure can increase the contact area between the material and the solution, which is beneficial for ion diffusion and the exposure of adsorption active sites during the adsorption process.

[0067] Figure 3 The energy dispersive spectroscopy (EDS) spectrum and elemental distribution diagram of the titanium phosphate material prepared in Example 1 are shown. The EDS results indicate the presence of Ti, O, P, N, F, and C elements in the sample. Ti, O, and P are the main constituent elements of the titanium phosphate framework; N originates from the ammonium phosphate system, which is beneficial for the formation of ammonium-type titanium phosphate structures; and F originates from ammonium fluoride additives. Figure 3 (b)- Figure 3 The elemental distribution diagram (g) shows that Ti, O, and P elements are uniformly distributed within the test area, with no obvious enrichment regions. This indicates that the titanium and phosphorus sources achieved good mixing during the mechanochemical activation process, promoting the formation of a uniform titanium phosphate structure. Meanwhile, N and F elements are dispersed, indicating their participation in the structure regulation process during material formation. In summary, the titanium phosphate material prepared in Example 1 has a relatively uniform elemental composition and structural distribution.

[0068] Figure 4 The image shows the X-ray photoelectron spectrum of the titanium phosphate material prepared in Example 1. Figure 4It can be seen that characteristic signal peaks corresponding to Ti, O, P, N, and F elements were detected on the surface of the titanium phosphate material sample prepared in Example 1. Among them, the Ti element signal indicates that titanium element exists in the structure of titanium phosphate material; the P element signal indicates the formation of phosphate structure; the O element signal comes from Ti-O bond and oxygen element in phosphate group; the N element signal is related to ammonium ion in ammonium type titanium phosphate structure; the F element signal may come from the residue of ammonium fluoride added component in the material formation process or participate in the regulation.

[0069] comprehensive Figure 1-4 The results corroborate each other, further demonstrating that spherical titanium phosphate materials containing elements such as Ti, P, and O can be formed through mechanochemical activation and solid-phase transformation processes.

[0070] The specific embodiments described above provide a further detailed explanation of the present invention; however, these descriptions should not be construed as limiting the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for promoting the formation of spherical titanium phosphate-based adsorbent materials through mechanochemical activation, characterized in that, Includes the following steps: S01, Mechanical activation: Titanium dioxide, ammonium hydrated phosphate, and ammonium fluoride are added to a mechanical crushing and mixing equipment for mechanical activation treatment to obtain a mixture; S02, Solid-phase reaction: The mixture is added to a heating device to carry out a solid-phase reaction, and then washed and dried to obtain spherical titanium phosphate-based adsorbent material; In step S01, the molar ratio of titanium dioxide, ammonium hydrate, and ammonium fluoride is controlled to be 1:2-6:0.1-0.

4.

2. The method for promoting the formation of spherical titanium phosphate-based adsorbent materials by mechanochemical activation according to claim 1, characterized in that, In step S01, the mechanical crushing and mixing equipment is either a ball mill or a high-speed solid crusher.

3. The method for promoting the formation of spherical titanium phosphate-based adsorbent materials by mechanochemical activation according to claim 2, characterized in that, In step S01, during the mechanical activation treatment, when the mechanical pulverizing and mixing equipment used is a ball mill, the mechanical activation treatment is ball milling treatment, the mass ratio of the mixed material to the grinding media is 1:9-11, the ball milling adopts an alternating forward and reverse rotation method, the forward rotation speed is 600-1000 rpm, the reverse rotation speed is 600-1000 rpm, and the ball milling treatment time is 1-4 hours; when the mechanical pulverizing and mixing equipment used is a high-speed solid pulverizer, the mechanical activation treatment is high-speed pulverizing treatment, the high-speed pulverizing speed is 12000-15000 rpm, and the high-speed pulverizing treatment time is 40-80 minutes.

4. The method for promoting the formation of spherical titanium phosphate-based adsorbent materials by mechanochemical activation according to claim 1, characterized in that, In step S02, the heating device is a reaction vessel equipped with polytetrafluoroethylene.

5. The method for promoting the formation of spherical titanium phosphate-based adsorbent materials by mechanochemical activation according to claim 1, characterized in that, In step S02, the solid-phase reaction is carried out at a temperature of 120-150℃ for 24-48 hours.

6. The method for promoting the formation of spherical titanium phosphate-based adsorbent materials by mechanochemical activation according to claim 1, characterized in that, In step S02, the washing method is to first wash with deionized water until neutral, and then wash with ethanol.

7. The method for promoting the formation of spherical titanium phosphate-based adsorbent materials by mechanochemical activation according to claim 1, characterized in that, In step S02, during the drying process, the drying temperature is 60-80℃ and the drying time is 4-6 hours.

8. An adsorbent material prepared by the method according to any one of claims 1-7.

9. An adsorbent material prepared by the method according to any one of claims 1-7 selectively adsorbs Sr in a strontium-containing solution. 2+ The application of this is characterized by, Includes the following steps: The adsorbent material is added to a strontium-containing solution for adsorption, and solid-liquid separation is performed after adsorption is complete.

10. The adsorbent material according to claim 9 selectively adsorbs Sr in a strontium-containing solution. 2+ The application of this is characterized by, The strontium-containing solution is one of the following: industrial wastewater, saline waste liquid, or simulated solution; The strontium-containing solution includes Sr 2+ and competing ions, said competing ions including Ca 2+ Mg 2+ One or a combination thereof; The amount of the adsorbent material added to the strontium-containing solution is 0.5-2 g / L.

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