A sodium ion adsorbent material with high stability, its preparation method and application

Abstract

This invention discloses a highly stable sodium ion adsorbent material, its preparation method, and its applications. The material is a K₂O-SiO₂-Al₂O₃-based crystal-glass composite material, comprising, by mass percentage of oxides: 30-60 wt% SiO₂, 1-11 wt% Al₂O₃, 0-25 wt% TiO₂, 0-20 wt% ZrO₂, and 30-60 wt% K₂O. After heat treatment, the material forms a crystal-glass composite structure with a crystallinity of 5%-30%. This material maintains its ability to adsorb sodium ions from reinforced salts. + While increasing adsorption capacity, it also reduces K + It improves the migration rate in the residual glass phase, inhibits precipitation and fogging under humid and hot conditions, reduces leaching and enhances the pH rise of the salt, and improves the stability of high-temperature salt bath use.

Description

Technical Field

[0001] This invention belongs to the field of inorganic functional materials and glass chemical strengthening technology, specifically relating to a sodium ion adsorption material with high stability, its preparation method and application. Background Technology

[0002] In the chemical strengthening process of Na₂O-containing glasses or microcrystalline glasses, KNO₃ molten salt is often used for K₂O strengthening. + -Na + Ion exchange. As continuous production proceeds, the sodium in the glass... + The continuous introduction of sodium into the molten salt causes the sodium content in the molten salt to rise. + Accumulation weakens the driving force of subsequent ion exchange, affecting the strengthening depth, surface compressive stress, and batch stability.

[0003] To restore and maintain the properties of enhanced molten salt, it is necessary to create a system capable of adsorbing Na in high-temperature molten salt. + Functional materials. While existing K2O-SiO2-Al2O3-based sodium-absorbing materials can provide a certain amount of sodium... + While the material exhibits good exchange capacity, increasing the K₂O content to enhance adsorption capacity can lead to new failure mechanisms: potassium salt precipitation and fogging occur on the surface under humid and hot conditions, and K₂O precipitation occurs in aqueous media or reinforced molten salts. + Leaching, accompanied by an increase in pH, leads to the risk of corrosion of the glass substrate and a decrease in the stability of the material's appearance.

[0004] The publicly disclosed crystallization ion sieve technology (CN 118270978 B) mainly focuses on the structural stability of Na-based or Na-K-based ion sieves in high-temperature salt baths, low TGA weight loss, and Li + The continuous adsorption of impurity ions, along with the underlying technology of increasing the content of specific nepheline crystal phases and suppressing high-temperature instability, is employed. This is particularly relevant for KNO3-enhanced salts containing Na... + There is still a lack of solutions to the complex contradictions of accumulation, and the tendency of high-K adsorbent materials to precipitate, fog, leach, and increase alkali in humid and hot environments. Summary of the Invention

[0005] The purpose of this invention is to provide a sodium ion adsorbent material with high stability. This invention, by controlling the composition and heat treatment process, enables the material to form a crystal-glass composite structure in which the crystalline phases KAlSiO4, or KAlSi3O8 and KAlSiO4, coexist with the residual glass phase. This controls the crystallinity within a specific window, thereby achieving a balance between sodium and water absorption. + Adsorption capacity, wet heat appearance stability, leaching stability, and enhanced salt pH stability.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a highly stable sodium ion adsorbent material, comprising, by mass percentage of oxides, 30-60 wt% SiO2, 1-11 wt% Al2O3, 0-25 wt% TiO2, 0-20 wt% ZrO2, and 30-60 wt% K2O, wherein TiO2 and ZrO2 are not simultaneously 0, and 6 wt% ≤ Al2O3 + TiO2 + ZrO2 ≤ 30 wt%, m SiO2 / m (Al2O3+TiO2+ZrO2) =1.2-7, m K2O / m SiO2 =0.5-2.0, the crystallinity of the adsorbent material is 5%-30%, and the crystal phase includes KAlSiO4, or KAlSi3O8 and KAlSiO4.

[0007] Furthermore, m SiO2 / m (Al2O3+TiO2+ZrO2) =1.2-7; in some embodiments, m SiO2 / m (Al2O3+TiO2+ZrO2） The ratio is 1.2 or 1.5 or 2 or 2.5 or 3 or 3.5 or 4 or 4.5 or 5 or 5.5 or 6 or 6.5 or 7 or any value between the two aforementioned values.

[0008] Furthermore, m K2O / m SiO2 =0.5-2.0. In some embodiments, m K2O / m SiO2 The ratio is 0.5 or 0.6 or 0.7 or 0.8 or 0.9 or 1 or 1.1 or 1.2 or 1.3 or 1.4 or 1.5 or 1.6 or 1.7 or 1.8 or 1.9 or 2 or any value between the two aforementioned values.

[0009] Furthermore, the mass loss rate of the adsorbent material after soaking in deionized water at 95°C for 2 hours is 0.05%-0.45%.

[0010] The pH of the leachate obtained after soaking the adsorbent material in deionized water at 95°C for 2 hours is 7.5-9.15.

[0011] This invention also provides a method for preparing the above-mentioned material, comprising: Step S1: Weigh the raw materials according to the formula: SiO2 30-60wt%, Al2O3 1-11wt%, TiO2 0-25wt%, ZrO2 0-20wt%, K2O 30-60wt%, with TiO2 and ZrO2 not both 0, and 6wt%≤Al2O3+TiO2+ZrO2≤30wt%, m SiO2 / m (Al2O3+TiO2+ZrO2) =1.2-7, m K2O / mSiO2=0.5-2.0, mixed uniformly; in some embodiments, the SiO2 content is 30wt% or 31wt% or 32wt% or 33wt% or 34wt% or 35wt% or 36wt% or 37wt% or 38wt% or 39wt% or 40wt% or 41wt% or 42wt% or 43wt% or 44wt% or 45wt% or 46wt% or 47wt% or 48wt% or 49wt% or 50wt% or 51wt% or 52wt% or 53wt% or 54wt% or 55wt% or 56wt% or 57wt% or 58wt% or 59wt% or 60wt% or any value between the two aforementioned values. The Al2O3 content is 1wt% or 2wt% or 3wt% or 4wt% or 5wt% or 6wt% or 7wt% or 8wt% or 9wt% or 10wt% or 11wt% or any value between the two aforementioned values. The K2O content is 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, or any value between the two aforementioned values. The TiO2 content is 0 or 1 wt%, or 2 wt%, or 3 wt%, or 4 wt%, or 5 wt%, or 6 wt%, or 7 wt%, or 8 wt%, or 9 wt%, or 10 wt%, or 11 wt%, or 12 wt%, or 13 wt%, or 14 wt%, or 15 wt%, or 16 wt%, or 17 wt%, or 18 wt%, or 19 wt%, or 20 wt%, or 21 wt%, or 22 wt%, or 23 wt%, or 24 wt%, or 25 wt%, or any value between the two aforementioned values. The ZrO2 content is 0 or 1 wt%, or 2 wt%, or 3 wt%, or 4 wt%, or 5 wt%, or 6 wt%, or 7 wt%, or 8 wt%, or 9 wt%, or 10 wt%, or 11 wt%, or 12 wt%, or 13 wt%, or 14 wt%, or 15 wt%, or 16 wt%, or 17 wt%, or 18 wt%, or 19 wt%, or 20 wt%, or any value between the two aforementioned values. The sum of the mass fractions of Al2O3, TiO2, and ZrO2 is 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt%, or any value between the two aforementioned values.

[0012] Step S2: Add the mixed raw materials into the melting furnace and melt them at 1200-1600℃ for 2-8 hours to form a uniform glass melt; Step S3: Prepare thin sheets with a thickness of 0.2-1.0 mm by rolling the molten glass, or prepare particles with a diameter of 0.1-10 mm by water quenching; Step S4: Perform one-step or two-step crystallization on the shaped body obtained in step S3 to prepare a sodium ion adsorbent material with a certain degree of crystallinity. The crystallization temperature of the one-step method is 480-700℃ and the holding time is 0.5-10h. The first crystallization temperature of the two-step method is 450-550℃ and the holding time is 0.5-4h, and the second crystallization temperature is 560-700℃ and the holding time is 0.5-4h.

[0013] After heat treatment, the material forms a crystal-glass composite structure in which glass phase and crystalline phase coexist, with a crystallinity of 5-30%, preferably 5-25%; the crystalline phase includes KAlSiO4, or KAlSi3O8 and KAlSiO4.

[0014] Preferably, the TiO2 and / or ZrO2 are used as nucleating agents, with a total content of 2-29 wt%, more preferably 3-20 wt%. The TiO2 and / or ZrO2, combined with the heat treatment process, induce the formation of fine potassium-containing crystalline phases within the material, while retaining a certain proportion of continuous glassy phase.

[0015] This invention also provides the above-mentioned material for adsorbing Na in reinforced molten salt. + , Regulation and enhancement of molten salt Na + Content and methods for manufacturing chemically strengthened glass.

[0016] Composition description of the sodium-absorbing material of this invention: SiO2 is the primary network formant in the material of this invention, used to construct a continuous silicon-oxygen framework and provide basic formability and durability. When the SiO2 content is too low, the network polymerization degree is insufficient, and K... + High mobility easily leads to leaching, pH increase, and low-temperature precipitation; excessive SiO2 content will result in insufficient effective ion exchange channels, which is detrimental to Na+. + Adsorption. Therefore, this invention uses SiO2 content and m K2O / m SiO2 The dual constraints achieve a comprehensive balance. Meanwhile, the SiO2 content in this invention is 30-60 wt%, preferably 35-55 wt%.

[0017] Al₂O₃ is an intermediate oxide; after entering the network, it forms [AlO₄] structural units, increasing the degree of cross-linking of the framework and enhancing the chemical durability of the material. An appropriate amount of Al₂O₃ can also increase K₂O₃ content. +Coordination binding in local structures reduces the free migration of K + The proportion of Al2O3 is important to suppress pH rise after immersion and low-temperature precipitation. However, a higher Al2O3 content is not always better. When the Al2O3 content is too high, the proportion of [AlO4] structural units in the system is too large, leading to excessive cross-linking of the glass network. This increases the high-temperature viscosity of the melt and the tendency for crystallization near the liquidus line, resulting in narrower windows for melt clarification, discharge, and roll forming or water quenching. During roll forming of thin sheets, discontinuous discharge, thickness fluctuations, streaks, bubble inclusions, edge cracking, or localized devitrification are likely to occur, making it difficult to obtain uniformly shaped bodies of 0.2 mm-1.0 mm. Excessive Al2O3 content also reduces the amount of Na available in the residual glass phase. + -K + The continuity of the effective migration channels for exchange increases the difficulty of controlling crystallinity and grain size in subsequent crystallization processes. Therefore, this invention controls the Al2O3 content at 1-11 wt%, preferably 2-10 wt%, to ensure good framework stability and K2 content. + A balance is achieved between binding effect, melt forming ability and sodium absorption capacity.

[0018] K2O is a material that allows Na to exert its effects. + The key source of adsorption function. K + It can react with Na in the enhanced molten salt + An exchange occurs, thus achieving sodium removal. However, if the K₂O concentration is too high, the K₂O in the amorphous phase will... + Increased migration can easily lead to leaching, increased pH, and surface salt precipitation; conversely, excessively low K₂O content weakens adsorption capacity. Therefore, the K₂O content in this invention is 30-60 wt%, preferably 35-55 wt%. This invention does not simply reduce K₂O, but rather reduces it by introducing TiO₂ and / or ZrO₂ and performing controlled heat treatment. + Effective migration rate.

[0019] In this invention, TiO2 and ZrO2 primarily function as nucleation sites and regulate the microstructure. TiO2 and / or ZrO2 provide nucleation centers, and with one or two-step crystallization processes, potassium-containing crystalline phases such as KAlSiO4, KAlSi3O8, or KAlSiO4 precipitate within the material. Unlike the fully crystallized route with high crystalline phase content, this invention emphasizes the formation of a crystal-glass composite structure where "crystalline phase + glassy phase" coexist: the crystalline phase serves to confine some of the potassium... + To improve stability; the glassy phase is used to retain ion migration and exchange channels, thereby maintaining Na+. + Adsorption capacity. Therefore, the TiO2 content in this invention is 0-25 wt%, preferably 2-20 wt%. The ZrO2 content in this invention is 0-20 wt%, preferably 0.2-15 wt%.

[0020] In the system of this invention, SiO2 provides the basic network framework and influences ion diffusion channels; after Al2O3 enters the network, it can improve the degree of crosslinking and enhance K. + Local confinement; TiO2 and ZrO2 act as nucleating agents to promote controlled nucleation and grain refinement. Through the synergistic design of formulation and heat treatment, the material forms a microstructure in which crystalline phase and residual glass phase coexist.

[0021] When the crystallinity is too low, K + It still mainly exists in the amorphous phase in a relatively easily migratable state, and is prone to surface enrichment and precipitation in humid and hot environments. It is also more easily leached in aqueous media or molten salts, leading to an increase in pH. When the crystallinity is too high, it can participate in Na+... + -K + The reduced effective exchange channels decrease the sodium adsorption efficiency of the material. Therefore, controlling the crystallinity within a window of 5%-30%, preferably 5%-25%, is a key technical point of this invention. In some embodiments, the crystallinity of the highly stable sodium ion adsorbent material is 5% or 6% or 7% or 8% or 9% or 10% or 11% or 12% or 13% or 14% or 15% or 16% or 17% or 18% or 19% or 20% or 21% or 22% or 23% or 24% or 25% or 26% or 27% or 28% or 29% or 30%, or any value between the aforementioned two values.

[0022] The aforementioned application of highly stable sodium ion adsorbent materials is for adsorbing sodium ions in glass chemically strengthened molten salts.

[0023] Furthermore, the application of the highly stable sodium ion adsorbent material is specifically described as follows: 0.01wt%-10wt% of the material by mass of molten salt is placed in a NaNO3-KNO3 mixed salt bath with a NaNO3 mass fraction of 0.3wt%-5wt%, and kept at 350℃-550℃ for 0.5 h-24 h.

[0024] A method for manufacturing chemically strengthened glass includes the step of adding the aforementioned highly stable sodium ion adsorbent material to a salt bath.

[0025] This invention achieves its effect through the synergistic effect of the following three key designs: Composite structure of crystalline and amorphous phases: This invention uses controlled heat treatment to form a crystal-glass composite structure with a crystallinity of 5%-30%, i.e., an amorphous glass phase as the main component, with KAlSiO4, or KAlSi3O8 and potassium-containing KAlSiO4 crystalline phases dispersed within it. The function of this structure does not rely on the crystalline phase directly to generate Na+. + Instead of exchange, Na is retained in the amorphous phase. + -K +The efficient migration channels required for ion exchange enhance the Na+ in molten salts. + Able to exchange with K in the material + Ion exchange occurs, thereby achieving the removal of Na+. + Adsorption; simultaneously, the appropriate amount of potassium-containing crystalline phase precipitated can bind part of the K. + or K near the stable crystal-glass interface + , reduce K + Excessive migration and leaching tendency in the amorphous phase improves the material's hydrothermal stability, immersion stability, and enhanced salt pH stability. However, when crystallinity is too high (>30%), the proportion of the crystalline phase is too large, reducing the available Na in the continuous amorphous phase. + -K + Reduced exchange channels limit ion migration, decreasing the material's sodium uptake efficiency. Low crystallinity (<5%, almost amorphous): Under high temperature and humidity environments, precipitation or fogging may occur. This is due to: 1. K + From "anchored" to "free": In an ideal structure, K + It should be confined to lattice or network modification sites. However, in its near-amorphous state, [AlO4] - The number of tetraligands decreased, and a large amount of K... + 1. The K2O molecules lose their corresponding negative charge centers to balance, becoming free K2O. 2. High temperature and humidity trigger "salt frost": Water vapor in the air reacts with this free K2O to generate strongly alkaline KOH, which migrates to the surface and then reacts with CO2 to form white K2CO3 crystals. 3. "Fogging" becomes permanent corrosion: The initial precipitation may only be a foggy white film; as the alkaline KOH solution continues to erode, the already fragile pure amorphous SiO2 framework is dissolved, leaving an opaque, porous silicate gel layer, becoming an unremovable fog. A crystallinity of 5%-30% ensures both good sodium ion adsorption performance and stability under high temperature and humidity conditions.

[0026] 2. Chemical durability under controlled composition: K₂O / SiO₂ mass ratio = 0.5-2.0; K₂O provides exchangeable potassium ions; SiO₂ forms a stable network framework. A moderate ratio avoids excessive K₂O (poor water resistance) or excessive SiO₂ (insufficient ion exchange sites); the total mass fraction of Al₂O₃ + TiO₂ + ZrO₂ is controlled at 6-30 wt%, with Al… 3+ Partially replaces Si 4+ This generates negatively charged sites to bind K. + and exchange Na + TiO2 and ZrO2 are recognized network reinforcing agents that can significantly improve the chemical stability of materials in acidic, alkaline or high-salt environments and prevent the skeleton from disintegrating.

[0027] 3. Optimized framework strength: The mass ratio of SiO2 / (Al2O3+TiO2+ZrO2) is controlled between 1.2 and 7, which ensures sufficient bonding strength (avoiding a loose structure due to an excessively low ratio) while preventing ion diffusion from being hindered by an excessively high ratio. The high bond strength of Ti and Zr can enhance the rigidity of the local structure and suppress structural rearrangement in long-term cycling.

[0028] The synergistic effect of the amorphous phase providing exchange function, the crystalline phase binding the K⁺ portion and stabilizing the microstructure, and the Ti / Zr enhancing chemical durability allows the material to resist structural degradation and chemical dissolution during repeated adsorption-desorption of sodium ions. This achieves a comprehensive balance in terms of adsorption capacity, pH stability, and damp-heat appearance stability. This invention has the following beneficial effects: (1) Controlled partial crystallization induced by TiO2 and / or ZrO2, resulting in partial K + Being confined to a stable position near the crystalline phase or grain boundary reduces K. + Migration rate in the residual glass phase; (2) By controlling the crystallinity window, rather than blindly increasing the crystal phase content, the Na content was balanced. + Adsorption capacity and wet heat / leaching stability; (3) It can effectively inhibit surface precipitation and fogging under conditions of 55℃ and 95%RH, and can reduce the risk of pH increase after immersion in water at 95℃ and use of enhanced salt. (4) Applicable to online control of molten salt in KNO3 system, which can reduce Na + The cumulative effect has a negative impact on subsequent ion exchange enhancement. Attached Figure Description

[0029] Figure 1 The image shows the XRD pattern of the sodium-absorbing material prepared in Example 1 of this invention. Figure 2 The XRD pattern of the product obtained in Comparative Example 1 of this invention; Figure 3 Here is a photograph of the sodium-absorbing material prepared in Example 1 of this invention; Figure 4 Here is a photograph of the sodium-absorbing material prepared in Comparative Example 1 of this invention. Figure 5 This is a photograph of the sodium-absorbing material prepared in Comparative Example 3 of the present invention. Figure 6 This is a photograph of the sodium-absorbing material prepared in Comparative Example 7 of the present invention. Detailed Implementation

[0030] The relevant test methods for the sodium-absorbing material of this invention are described below: 1. Crystallinity test: After the sample is crushed, XRD test is performed. The Rietveld refinement method is used to calculate the crystal phase content, and the crystallinity is characterized by the ratio of the total crystal phase to the total sample volume.

[0031] 2. Sodium ion adsorption efficiency: Weigh out m0 of adsorbent and add it to a NaNO3-KNO3 mixed salt bath. After maintaining the temperature at 350℃-550℃ for t hours, measure the Na ion adsorption efficiency in the salt bath. + Reduction Δm Na The adsorption efficiency is defined as Δm. Na / m0, the unit is g / kg.

[0032] 3. Water immersion mass loss rate: The sample was immersed in deionized water at 95℃ for 2 h, dried, and the mass loss rate was measured.

[0033] 4. pH of the leachate: The pH of the solution obtained from the above immersion experiment was tested to evaluate the leaching tendency of the alkali metals in the sample.

[0034] 5. Enhanced salt pH: Take the molten salt after using the adsorbent, prepare a solution with deionized water at a fixed mass, and measure the pH to evaluate the tendency of the sample to increase alkali in the enhanced molten salt environment.

[0035] 6. Damp-heat stability: Store the sample at 55℃ and 95%RH for 240 h and observe whether there is visible precipitation and fogging on the surface; preferably, further evaluation is carried out at 85℃ / 85%RH for 72 h-240 h.

[0036] The following examples are used to further illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the examples and comparative examples all adopt the following general preparation process: raw materials are weighed and mixed according to the formulations listed in Tables 1-1 to 1-3, Tables 2-1 to 2-2, and Tables 3-4, melted at 1450°C for 4 hours, clarified, and then rolled into thin sheets of about 0.2-1.0 mm or water-quenched into particles of 0.1-10 mm; subsequently, annealing heat treatment is performed to induce crystallization. In both examples and comparative examples, sodium ions are absorbed at 480°C for 8 hours, and the sodium ion content of the molten salt is tested to calculate the sodium ion absorption efficiency, wherein the amount of adsorbent material added is 4 wt% of the mass of the molten salt.

[0037] Note: The " / " in the crystallization conditions column of the table indicates that the sample deviates from the scope defined in this invention, resulting in abnormal melt viscosity, discontinuous discharge, difficulty in roll forming, or defects such as local devitrification and cracking. Therefore, it cannot form a uniformly shaped body that meets the requirements of subsequent crystallization treatment, XRD characterization, and adsorption / leaching performance testing. Such samples do not meet the conditions for crystallization treatment and therefore did not undergo crystallization treatment or related performance tests. Their crystallization conditions, crystal phase, crystallinity, and performance indicators are not of evaluative significance.

[0038] Example 1

[0039] Sodium ion adsorbent material was prepared according to the following steps: Step 1: Weigh the raw materials according to the formula: 45.69wt% SiO2, 6.42wt% Al2O3, 2.35wt% TiO2, 3.11wt% ZrO2, and 42.43wt% K2O. Mix them evenly and put them into the melting furnace. Melt them at 1200-1600℃ for 2-8 hours to form a uniform glass melt. Step 2: The molten glass is rolled into thin sheets with a thickness of 0.2-1.0 mm. Step 3: The shaped body obtained in Step 2 is subjected to two-step crystallization. The first crystallization temperature is 520℃ and the holding time is 4h. The second crystallization temperature is 650℃ and the holding time is 1h to obtain the final product. The obtained product is characterized and tested.

[0040] Example 2-15 The difference from Example 1 is the raw material composition, or the raw material composition and crystallization conditions. The raw material composition, crystallization conditions, product crystal phase, crystallinity and response test results of Examples 2-15 are shown in Tables 1-1 to 1-3.

[0041] Comparative Examples 1-10 The difference from Example 1 is the raw material composition, or the raw material composition and crystallization conditions. The raw material composition, crystallization conditions, product crystal phase, crystallinity and response test results of Comparative Examples 1-10 are shown in Tables 2-1 to 2-2.

[0042] Examples 16-20 Examples 16 and 18-20 differ from Example 1 in their raw material composition, or raw material composition and crystallization conditions. Example 17 differs from Example 1 in its raw material composition, crystallization conditions, and morphology in step 2. The raw material composition, crystallization conditions, product crystal phase, crystallinity, and response test results of Examples 16-20 are shown in Table 3.

[0043] Comparative Examples 11-15 The difference from Example 1 is the raw material composition, or the raw material composition and crystallization conditions. The raw material composition, crystallization conditions, product crystal phase, crystallinity and response test results of Comparative Examples 11-15 are shown in Table 4.

[0044] Table 1-1

[0045] Table 1-2

[0046] Table 1-3

[0047] Table 2-1

[0048] Table 2-2

[0049] Table 3

[0050] Table 4

[0051] The XRD test results of the product obtained in Example 1 are as follows: Figure 1 As shown, by Figure 1 It can be seen that the product obtained in Example 1 contains crystalline phases, namely KAlSiO4 and KAlSi3O8. Figure 2 The image shown is the XRD pattern of the product obtained in Comparative Example 1 of this invention. Figure 2 It is evident that the product obtained in Comparative Example 1 does not contain a crystalline phase. Figure 3 This is a photograph of the sodium-absorbing material prepared in Example 1 of the present invention. Figure 4 This is a picture of the sodium-absorbing material prepared in Comparative Example 1. Figure 5 This is a photograph of the sodium-absorbing material prepared in Comparative Example 3. Figure 6 This is a photograph of the sodium-absorbing material prepared in Comparative Example 7. Figures 3-6 It is evident that the sodium-absorbing material prepared using the technical solution of this invention can be well molded, while the sodium-absorbing materials prepared in Comparative Examples 1, 3, and 7 cannot be well molded.

[0052] Comparative Examples 1-15 do not meet the technical solution of this invention; they either cannot be molded or have poor high-temperature and high-humidity stability. Comparative Example 15, in particular, is a comparative formulation with increased Al2O3 content, raising it to 12.70 wt%, exceeding the upper limit set by this invention. Although m SiO2 / m (Al2O3+TiO2+ZrO2) and m K2O / m SiO2 While still within the specified limits, the viscosity of the molten glass increased significantly after melting, resulting in discontinuous discharge and large fluctuations in sheet thickness during rolling. This made it difficult to obtain uniformly shaped bodies that met the requirements of subsequent crystallization and adsorption tests. Consequently, the sodium ion absorption efficiency, immersion mass loss rate, leachate pH, and strengthening salt pH could not be stably evaluated. This comparative example illustrates that excessive Al2O3 significantly impairs the melt forming and subsequent preparation stability of the material, failing to achieve the comprehensive balance of adsorption capacity, structural stability, and industrial formability as described in this invention.

Claims

1. A sodium ion adsorbent material with high stability, characterized in that, Based on the mass percentage of oxides, it includes 30-60 wt% SiO2, 1-11 wt% Al2O3, 0-25 wt% TiO2, 0-20 wt% ZrO2, and 30-60 wt% K2O, wherein TiO2 and ZrO2 are not simultaneously 0, and 6 wt% ≤ Al2O3 + TiO2 + ZrO2 ≤ 30 wt%, m SiO2 / m (Al2O3+TiO2+ZrO2) =1.2-7, m K2O / m SiO2 =0.5-2.0, the crystallinity of the adsorbent material is 5%-30%, and the crystal phase includes KAlSiO4, or KAlSi3O8 and KAlSiO4.

2. The sodium ion adsorbent material with high stability according to claim 1, characterized in that, The mass loss rate of the material after immersion in deionized water at 95°C for 2 hours was 0.05%-0.45%.

3. The sodium ion adsorbent material with high stability according to claim 1 or 2, characterized in that, The pH of the leachate obtained after soaking the material in deionized water at 95°C for 2 hours is 7.5-9.

15.

4. A method for preparing the highly stable sodium ion adsorbent material as described in claim 1 or 2, characterized in that, Includes the following steps: Step 1: Weigh and mix the ingredients according to the recipe; Step 2: Melt the mixed raw materials at 1200℃-1600℃ to form a uniform glass melt; Step 3: Roll press the molten glass into thin sheets with a thickness of 0.2 mm to 1.0 mm, or quench the molten glass in water to form particles with a particle size of 0.1 mm to 10 mm; Step 4: Heat treat the molded body obtained in Step 3 to form a crystal-glass composite structure with a crystallinity of 5%-30%, and obtain the final product.

5. The method for preparing a highly stable sodium ion adsorbent material according to claim 4, characterized in that, The heat treatment in step 4 can be performed using a one-step or two-step method: the crystallization temperature of the one-step method is 480-700℃, and the holding time is 0.5-10h; the first crystallization temperature of the two-step method is 450-550℃, the holding time is 0.5-4h, and the second crystallization temperature is 560-700℃, the holding time is 0.5-4h.

6. The application of the highly stable sodium ion adsorbent material according to claim 1 or 2, characterized in that, Used to adsorb sodium ions.

7. The application of the highly stable sodium ion adsorbent material according to claim 6, characterized in that, Used to adsorb sodium ions in glass chemical strengthening molten salt.

8. The application of the highly stable sodium ion adsorbent material according to claim 7, characterized in that, Specific application method: Place 0.01wt%-10wt% of the material by mass of molten salt in a NaNO3-KNO3 mixed salt bath with a NaNO3 mass fraction of 0.3wt%-5wt%, and keep it at 350℃-550℃ for 0.5 h-24 h.

9. A method for manufacturing chemically strengthened glass, characterized in that, include: The process of adding the highly stable sodium ion adsorbent material as described in claim 1 or 2 to a salt bath.

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