Ion sieve and application thereof, and regeneration method of failed ion sieve

Abstract

The invention relates to the technical field of ion sieves, and discloses an ion sieve and application thereof, and a regeneration method of a failed ion sieve. Based on the total weight of the ion sieve, the ion sieve contains 38-65 wt% of SiO2, 4-30 wt% of Al2O3, 27-45 wt% of alkali metal oxide, 0.5-5 wt% of rare earth metal oxide and a glass network regulator with the mass content of x, wherein 0 < x < = 5 wt%; on the basis of the total weight of the ion sieve, the total mass content of SiO2 and Al2O3 in the ion sieve is defined as y, and x / y = 0.007-0.08. The ion sieve provided by the invention can keep structural stability for a long time in a glass-reinforced molten salt bath, has a good lithium absorption effect, and is very suitable for being applied to the glass-reinforced molten salt bath.

Description

Technical Field

[0001] This invention relates to the field of ion sieve technology, specifically to ion sieves and their applications, and a method for regenerating a failed ion sieve. Background Technology

[0002] In the chemical strengthening process of glass, molten salt baths play a central role as ion exchange media.

[0003] When lithium-containing aluminosilicate glass or microcrystalline glass is immersed in high-temperature molten salt, the alkali metal ions with smaller ionic radii (such as Li) in the glass... + Na + It will react with larger alkali metal ions (Na+) in the molten salt. + K + An exchange reaction occurs, which forms a compressive stress layer on the glass surface, significantly improving the glass's mechanical strength and impact resistance.

[0004] However, as the chemical strengthening process continues, small-radius ions are continuously released from the glass and accumulate in the molten salt, causing molten salt "poisoning," which is mainly manifested as: reduced ion exchange efficiency; uncontrolled changes in glass dimensions; and deterioration of glass surface quality. If effective purification measures are not taken, not only will the product qualification rate drop significantly, but frequent replacement of molten salt will also be required, significantly increasing production costs and the burden of waste salt disposal.

[0005] To maintain the activity of the salt bath, a relatively mature method in industrial production is to directly add powdered phosphate (such as Na3PO4) to the "poisoned" molten salt, allowing the phosphate ions to react with impurity ions (such as Li3PO4). + The reaction produces precipitates, which reduces the impurity content in the molten salt and extends its service life. However, the precipitates can make the molten salt cloudy and cause uneven heating at the bottom of the pressure furnace, resulting in unstable stress states in the same batch of tempered glass. To ensure the quality of the tempered glass, it is necessary to continuously clean the precipitates at the bottom of the furnace and replace the salt bath, which not only reduces efficiency but also increases production costs.

[0006] Ion sieve products have a good absorption effect on impurity ions in molten salts and can avoid a series of problems that occur when using phosphates.

[0007] However, conventional ion sieves will exhibit significant crystallization under prolonged high-temperature salt bath conditions. After crystallization, the ion sieves will be less effective at absorbing impurity ions from the molten salt, and may even release impurity ions into the molten salt, contaminating it and affecting the surface quality of the tempered glass. Furthermore, the crystallized ion sieves will have reduced strength and become brittle, making them difficult to collect and reuse. Additionally, fine fragments of the ion sieves entering the molten salt can easily adhere to the glass surface, reducing the glass yield. Summary of the Invention

[0008] The purpose of this invention is to overcome the problems of crystallization in high-temperature molten salt baths and difficulty in regenerating existing ion sieves.

[0009] To achieve the above objectives, a first aspect of the present invention provides an ion sieve, wherein, based on the total weight of the ion sieve, the ion sieve contains 38-65 wt% SiO2, 4-30 wt% Al2O3, 27-45 wt% alkali metal oxides, 0.5-5 wt% rare earth metal oxides, and a glass network modifier with a mass content of x; wherein 0 < x ≤ 5 wt%; Based on the total weight of the ion sieve, the total mass content of SiO2 and Al2O3 in the ion sieve is defined as y, x / y=0.007-0.08; The molar ratio of alkali metal oxides (calculated as metal elements) to oxides (calculated as Si elements) in the ion sieve is 0.8-1.9:1.

[0010] A second aspect of the present invention provides the application of the ion sieve described in the first aspect in glass chemical strengthening molten salts, wherein the application is performed by a method comprising the following steps: The ion sieve and the glass to be strengthened are mixed in molten salt at 380-530℃ for 8-12 hours to obtain the strengthened glass and the failed ion sieve. The failed ion sieve has an amorphous structure.

[0011] A third aspect of the present invention provides a method for regenerating a failed ion sieve, the method comprising: mixing the failed ion sieve with an alkaline solution to obtain a regenerated ion sieve; The failed ion sieve is the failed ion sieve described in the second aspect above; The regenerated ion sieve is the ion sieve described in the first aspect above.

[0012] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects: (1) The ion sieve provided by the present invention has a high-temperature resistant structure composed of SiO2-Al2O3 and a network channel adapted to lithium ions, which is conducive to the efficient ion exchange between mobile alkali metal ions in the framework and target impurity ions in molten salt. In addition, by introducing rare earth components, the electric field strength on the surface of the pores can be controlled, further increasing the adsorption characteristics for specific impurity ions, making it very suitable for stable and efficient lithium ion adsorption in molten salt environment.

[0013] (2) The ion sieve provided by this invention, through the specific combination of components, and the ratio of the mass content of the glass network regulator to the total mass content of SiO2 and Al2O3 in the ion sieve satisfying 0.007-0.08, and the molar ratio of alkali metal oxides (calculated as metal elements) to oxides (calculated as Si elements) satisfying 0.8-1.9:1, forms a stable amorphous network. This network works synergistically in molten salt. The introduction of the glass network regulator, by controlling the viscosity and stability of the glass network structure, suppresses the tendency for crystallization in the molten salt environment. When the ion sieve is applied to glass-strengthening molten salt, its structure still maintains good stability, and no significant crystallization phenomenon occurs, thus weakening the lithium adsorption effect.

[0014] (3) After the ion sieve material of the present invention fails in the application of glass-strengthened molten salt, its amorphous structure allows it to be recycled by alkaline washing, and it still has high strength after alkaline corrosion, which can maintain the stability of the next cycle. Attached Figure Description

[0015] Figure 1 These are the XRD patterns of the ion sieve provided in this embodiment of the invention before and after use (applied to glass strengthening molten salt); Figure 2 The XRD patterns of the ion sieve provided in the comparative example of this invention are before and after use (applied to glass strengthening molten salt). Detailed Implementation

[0016] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0017] As previously stated, a first aspect of the present invention provides an ion sieve, wherein, based on the total weight of the ion sieve, the ion sieve contains 38-65 wt% SiO2, 4-30 wt% Al2O3, 27-45 wt% alkali metal oxides, 0.5-5 wt% rare earth metal oxides, and a glass network modifier with a mass content of x; wherein 0 < x ≤ 5 wt%; Based on the total weight of the ion sieve, the total mass content of SiO2 and Al2O3 in the ion sieve is defined as y, x / y=0.007-0.08; The molar ratio of alkali metal oxides (calculated as metal elements) to oxides (calculated as Si elements) in the ion sieve is 0.8-1.9:1.

[0018] The ion sieve provided by this invention achieves stable, efficient, and regenerable lithium-ion adsorption in a molten salt environment through precise control of component ratios. A stable amorphous network is formed by the specific combination of components, improving resistance to crystallization. The ion sieve, in molten salt, works synergistically by introducing a glass network regulator. By controlling the viscosity and stability of the glass network structure, the kinetic potential energy of the network is enhanced, thereby suppressing the tendency to crystallize in the molten salt environment and achieving efficient and selective lithium adsorption. Furthermore, after the ion sieve material fails in glass-reinforced molten salt, its amorphous structure allows for recycling through alkali washing, and it retains high strength after alkali corrosion, maintaining stability for subsequent cycles.

[0019] In a preferred embodiment, the glass network modifier is selected from at least one of B2O3, ZnO, and Sb2O3. The inventors of this invention have discovered that, in this preferred embodiment, ZnO can act as a network intermediate in the ion sieve network structure, forming [ZnO4], strengthening the network, and also reducing the thermal expansion coefficient of the ion sieve, improving chemical stability, and contributing to inhibiting crystallization. B2O3 can reduce the thermal expansion coefficient of the ion sieve, improve chemical and thermal stability, and simultaneously act as a flux in the ion sieve preparation process, accelerating the melting and clarification of raw materials. Sb2O3, as a melting aid in the ion sieve preparation process, can help lower the melting point, accelerate the melting rate, and play a role in defoaming, clarification, and impurity removal.

[0020] In a preferred embodiment, the glass network conditioner includes at least ZnO, and the mass ratio of the rare earth metal oxide to ZnO in the ion sieve is ≥2:1. The inventors of this invention have discovered that, in this preferred embodiment, ZnO typically uses zinc-oxygen octahedrons [ZnO6] as the network outer oxide. When there is sufficient free oxygen in the ion sieve, zinc-oxygen tetrahedra [ZnO4] can be formed and enter the glass network structure, stabilizing the structure. Furthermore, [ZnO4] has a larger size than [SiO4] and [AlO4], forming more spacious pores or cavities, which is beneficial for ion diffusion, resulting in better lithium adsorption performance of the ion sieve.

[0021] Preferably, the molar ratio of alkali metal oxides (based on metal element) to oxides (based on Si element) in the ion sieve is 0.9-1.9:1. In this preferred configuration, it is more advantageous for appropriate Si-O-Si and Si-O-Al to form a stable, high-temperature resistant network structure, suppressing the precipitation and growth of crystalline phases, while ensuring good lithium removal performance during use and reducing the tendency of the ion sieve to crystallize.

[0022] Preferably, the alkali metal oxide includes at least one of Na₂O and K₂O. In this preferred embodiment, Na₂O or K₂O can reduce viscosity, thus acting as a flux; and can also replenish the molten salt with the necessary Na ions while removing impurities. + / K + In the ion sieve, the alkali metal oxide is further preferably Na₂O, which is used for impurity removal in chemically strengthened molten salts. + With impurities Li in molten salt + Because the radius difference is relatively small, the exchange rate is faster.

[0023] Preferably, the rare earth metal oxide is La2O3 and / or CeO2. In this preferred case, La2O3 or CeO2 exists as an external network in the ion sieve structure. Due to its high field strength and large radius, it is extremely difficult for it to migrate in the ion sieve network structure, severely hindering the diffusion of other ions, thus strongly suppressing crystal nucleation from a kinetic perspective. Furthermore, they can significantly improve the softening temperature, hardness, and thermal shock resistance of the ion sieve material, enabling it to maintain shape stability when used in high-temperature molten salts and reducing the risk of thermal deformation. The rare earth metal oxide is further preferably La2O3, La... 3+ It exists stably in the network structure in the form of +3 valence. It breaks the uniformity of the network by forming "aggregates", increases viscosity, and kinetically hinders atomic migration and crystal growth.

[0024] In a preferred embodiment, based on the total weight of the ion sieve, the ion sieve contains 0-4 wt% B₂O₃, 0.30-2.5 wt% ZnO, and 0-3 wt% Sb₂O₃. This preferred embodiment improves the thermal stability of the ion sieve, reduces its crystallization tendency, avoids weakening its lithium removal efficiency, and is also beneficial to the preparation of the ion sieve.

[0025] Preferably, based on the total weight of the ion sieve, the total mass content of B2O3, ZnO, and Sb2O3 in the ion sieve is ≤2.5wt%. In this preferred embodiment, the glass network modifier component can more effectively regulate the glass network structure, creating more active sites with high selectivity for lithium ions while maintaining the stable structure of the ion sieve.

[0026] According to a preferred embodiment, the ion sieve is a sheet-like ion sieve with a thickness of 0.3~0.8 mm, more preferably 0.4~0.6 mm. In this preferred embodiment, due to the larger specific surface area of ​​the ion sieve, its lithium adsorption efficiency in glass strengthening molten salts is higher.

[0027] The present invention does not impose any particular requirements on the preparation method of the ion sieve. Those skilled in the art can select a method based on the technical means available in the art. For example, the preparation method of the ion sieve includes the following steps: (i) A silicon source, an aluminum source, an alkali metal source, a rare earth metal source, and an M source are stirred and mixed to obtain a mixture; wherein the M source is selected from at least one of a boron source, a zinc source, and an antimony source; (ii) The mixture is subjected to melting and molding processes in sequence to obtain the ion sieve.

[0028] In some embodiments, the silicon source is selected from at least one of silica sand, sandstone, and quartz, preferably silica sand, in which the SiO2 purity is higher.

[0029] In some embodiments, the aluminum source is selected from at least one of alumina, aluminum hydroxide, and aluminum carbonate.

[0030] In some embodiments, the alkali metal source is selected from sodium and / or potassium sources. The sodium source is selected from at least one of sodium carbonate, sodium hydroxide, sodium bicarbonate, and sodium nitrate, preferably sodium carbonate; the potassium source is selected from at least one of potassium carbonate, potassium hydroxide, potassium bicarbonate, and potassium nitrate, preferably potassium carbonate. In this preferred embodiment, the gas generated by high-temperature decomposition helps with defoaming and clarification; the carbon oxides generated by carbonate decomposition are non-polluting.

[0031] In some embodiments, the rare earth metal source is at least one of lanthanum oxide and cerium oxide.

[0032] In some embodiments, the boron source is selected from at least one of boric acid and boric anhydride.

[0033] In some embodiments, the zinc source is selected from at least one of zinc oxide and zinc carbonate.

[0034] In some embodiments, the antimony source is selected from antimony oxide.

[0035] In some embodiments, the melting treatment conditions include: a temperature of 1250-1650°C, preferably 1300-1500°C; and a time of 2-6 hours, preferably 3-4 hours.

[0036] In some embodiments, the melting process is carried out in a vessel made of platinum or platinum-rhodium alloy, which is beneficial for the clarification and homogenization of the melt produced by the melting process and for its resistance to chemical corrosion.

[0037] In some embodiments, the forming method includes: rolling or drawing the melt into sheet-like ion sieves by external force, or quenching the melt in water to obtain granular ion sieves.

[0038] As previously stated, the second aspect of the present invention provides the application of the ion sieve described in the first aspect in glass chemical strengthening molten salt, wherein the application is performed by a method comprising the following steps: The ion sieve and the glass to be strengthened are mixed in molten salt at 380-530℃ for 8-12 hours to obtain the strengthened glass and the failed ion sieve. The failed ion sieve has an amorphous structure.

[0039] The ion sieve provided by this invention can be applied to all applications requiring reduction of Li in chemically fortified molten salts. + The field of ion concentration includes, but is not limited to, applications in the chemical strengthening of lithium aluminum silicon system glass or microcrystalline glass; and the ion sieve provided by the present invention can enter the molten salt simultaneously with the glass, improving the glass strengthening effect without changing the optical properties of the glass.

[0040] It should be noted that in this invention, ppm refers to parts per million (ppm) of mass concentration.

[0041] As mentioned above, a third aspect of the present invention provides a method for regenerating a failed ion sieve, the method comprising: mixing the failed ion sieve with an alkaline solution to obtain a regenerated ion sieve; The failed ion sieve is the failed ion sieve described in the second aspect above; The regenerated ion sieve is the ion sieve described in the first aspect above.

[0042] Preferably, the failed ion screen is in granular or flake form, more preferably in flake form with a thickness of <1 mm, and even more preferably in flake form with a thickness of 0.3-0.6 mm. The inventors of this invention have discovered that, in this preferred embodiment, on the one hand, the regenerated ion screen has a large specific surface area, resulting in good lithium adsorption performance during use; on the other hand, the regenerated ion screen has good strength to maintain stability during use.

[0043] In a preferred embodiment, the alkaline solution is a NaOH solution and / or a KOH solution.

[0044] Preferably, the mass concentration of the alkaline solution is ≥5 wt%, more preferably 20-70 wt%, and even more preferably 30-50 wt%. The inventors of this invention have discovered that under these preferred conditions, good reaction efficiency is maintained while ensuring that the failed ion sieve is not excessively corroded, thus preventing a reduction in strength and affecting its reusability.

[0045] Preferably, the mass ratio of the alkaline solution to the degraded ion sieve is ≥3:1, more preferably (4-10):1, and even more preferably (6-8):1. The inventors of this invention have discovered that, under this preferred condition, both high reaction efficiency and high utilization rate of the alkaline solution are maintained.

[0046] In a preferred embodiment, the conditions for the mixing process include: a temperature of 50-200°C, more preferably 80-170°C, and even more preferably 95-130°C; and a time of 0.5-20 h, more preferably 4-12 h, and even more preferably 6-10 h.

[0047] According to a preferred embodiment, in order to accelerate the reaction rate between the alkaline solution and the failed ion sieve, devices such as oscillation, bubbling, circulating spraying, and ultrasonic generators can be added.

[0048] In some embodiments, the regeneration method further includes: filtering the material obtained from the mixing process to obtain the solid and the filtrate, and washing and drying the solid in sequence to obtain the regenerated ion sieve.

[0049] In this invention, the filtrate can be reused as an alkaline solution. Considering that the hydroxide ion concentration in the filtrate gradually decreases with repeated use, the hydroxide ion concentration can be increased by directly adding NaOH and / or KOH solids to the filtrate, thereby improving the regeneration rate.

[0050] The regenerated ion screen described in this invention, after being used in a pressurization plant until its second failure, can still be recycled and reused a second time according to the steps in the above-described regeneration method. This regeneration method can repeatedly regenerate the same batch of failed lithium-ion screens multiple times until the strength and performance of the failed lithium-ion screens no longer meet the requirements of the pressurization plant.

[0051] The present invention will be described in detail below through examples. Unless otherwise specified, the instruments, reagents, and materials involved in the following examples are all conventional instruments, reagents, and materials, which can be obtained through legitimate commercial channels. Unless otherwise stated, all reagents used are commercially available analytical grade products.

[0052] Raw materials for preparing ion sieves: Silicon source: silica sand.

[0053] Aluminum source: aluminum oxide.

[0054] Alkali metal source: Sodium source, sodium carbonate.

[0055] Rare earth metal sources: lanthanum oxide or cerium oxide.

[0056] Boron source: boric acid.

[0057] Zinc source: Zinc oxide.

[0058] Antimony source: antimony oxide.

[0059] Glass to be strengthened: Commercial lithium aluminum silicon microcrystalline glass, with dimensions of 150×70×0.5mm.

[0060] The contents of each component in the ion sieves designed and prepared in the following preparation examples and comparative examples are shown in Table 1.

[0061] Table 1

[0062] Continued from Table 1

[0063] Note: "x / y" refers to the ratio of the total mass content of Sb2O3, ZnO and B2O3 in the ion sieve to the total mass content of SiO2 and Al2O3 in the ion sieve.

[0064] Preparation Example 1 (i) The silicon source, aluminum source, alkali metal source, rare earth metal source and M source are stirred and mixed to obtain a mixture; the M source is selected from boron source, zinc source and antimony source; (ii) The mixture is melted in a platinum-rhodium alloy vessel (temperature 1400℃, time 3h) to obtain a melt; the melt is then shaped (pressed into a sheet with a thickness of about 0.5mm) to obtain an ion sieve; The composition and phase (XRD test) of the ion sieve obtained in this preparation example are shown in Table 1.

[0065] Unless otherwise specified, Preparation Examples 2-4 and Comparative Preparation Examples 1-3 were carried out using a method similar to that of Preparation Example 1, except that the formulation of the mixture in step (i) was different, resulting in an ion sieve. The composition and phase composition of the ion sieves obtained in the above preparation examples are shown in Table 1.

[0066] Example 1 This embodiment illustrates the application of the ion sieves prepared in the aforementioned preparation examples and comparative preparation examples to glass chemical strengthening molten salts, referring to the formulations in Table 2. Specifically: 30g of ion sieve, the glass to be strengthened, and 5kg of molten salt (containing Li) were added. + A mixed molten salt of sodium nitrate and potassium nitrate (with a mass ratio of 2:3) was contacted and mixed at 530°C for 8 hours to obtain strengthened glass and failed ion sieves. Unless otherwise specified, Examples 2-4 and Comparative Examples 1-3 were carried out using methods similar to those in Example 1, the differences being the type of ion sieve and the amount of Li in the molten salt. + The concentrations are shown in Table 2.

[0067] XRD was used to test whether the failed ion sieves in the above examples crystallized, and the results are shown in Table 2.

[0068] Table 2

[0069] Continued from Table 2

[0070] Note: "4h reaction ratio" refers to the ratio of the mass percentage of ion sieves in the molten salt after 4 hours of contact mixing to the change in the mass fraction of lithium nitrate before and after 4 hours of contact mixing in the molten salt; "8h reaction ratio" refers to the ratio of the mass percentage of ion sieves in the molten salt after 8 hours of contact mixing to the change in the mass fraction of lithium nitrate before and after 8 hours of contact mixing in the molten salt.

[0071] Test case 1. Regeneration method for failed ion sieves: Take 200g of the failed ion sieves (sheet-shaped) obtained from each of the aforementioned examples and place them in 1L of NaOH solution with a mass concentration of 40% for mixing treatment (with an ultrasonic generator, fully soaked under ultrasonic conditions at 100℃ for 8h), wash and dry to obtain regenerated ion sieves; filter the NaOH solution after mixing treatment and collect the filtrate.

[0072] Lithium adsorption effect test of regenerated ion sieve: Following the steps in Example 1 above, the regenerated ion sieve was applied to glass strengthening molten salt, and the results are shown in Table 3.

[0073] Table 3

[0074] Note: "4h reaction ratio" refers to the ratio of the mass percentage of regenerated ion sieve in the molten salt after 4 hours of contact mixing to the change in the mass fraction of lithium nitrate before and after 4 hours of contact mixing in the molten salt. "8h reaction ratio" refers to the ratio of the mass percentage of regenerated ion sieves in the molten salt after 8 hours of contact mixing to the change in the mass fraction of lithium nitrate before and after 8 hours of contact mixing in the molten salt.

[0075] 2. The XRD patterns of the ion sieves prepared in the above embodiments and comparative examples before and after use (applied in glass strengthening molten salt) were tested using an X-ray diffractometer. The results are as follows: Figure 1 and Figure 2 As shown: pass Figure 1 and Figure 2It can be seen that the XRD patterns of the ion sieves prepared in the examples before and after use only show the peaks, indicating that they are all amorphous. The comparative ion sieves are amorphous when not in use, but obvious crystallization peaks appear in the XRD patterns after use, indicating that crystals precipitate after use of the comparative ion sieves, and the greater the intensity of the crystallization peaks, the more crystals precipitate.

[0076] The results above show that the ion sieve provided by this invention not only has good lithium adsorption efficiency, but also does not crystallize after being applied to glass strengthening molten salt, and still maintains good lithium adsorption efficiency after alkaline washing and recovery. In contrast, the ion sieve provided in the comparative example has poor lithium adsorption performance and the risk of crystallization after use, and cannot be recycled through alkaline washing.

[0077] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An ion sieve, characterized in that, Based on the total weight of the ion sieve, the ion sieve contains 38-65 wt% SiO2, 4-30 wt% Al2O3, 27-45 wt% alkali metal oxides, 0.5-5 wt% rare earth metal oxides, and a glass network modifier with a mass content of x; wherein 0 < x ≤ 5 wt%; Based on the total weight of the ion sieve, the total mass content of SiO2 and Al2O3 in the ion sieve is defined as y, x / y=0.007-0.08; The molar ratio of alkali metal oxides (calculated as metal elements) to oxides (calculated as Si elements) in the ion sieve is 0.8-1.9:

1.

2. The ion sieve according to claim 1, characterized in that, The glass network modifier is selected from at least one of B2O3, ZnO, and Sb2O3.

3. The ion sieve according to claim 1, characterized in that, The glass network conditioner includes at least ZnO, and the mass ratio of the rare earth metal oxides and ZnO in the ion sieve is ≥2:

1.

4. The ion sieve according to claim 1, characterized in that, The molar ratio of alkali metal oxides (calculated as metal elements) to oxides (calculated as Si elements) in the ion sieve is 0.9-1.9:

1.

5. The ion sieve according to any one of claims 1-4, characterized in that, The alkali metal oxide includes at least one of Na2O and K2O.

6. The ion sieve according to any one of claims 1-4, characterized in that, The rare earth metal oxide is La2O3 and / or CeO2.

7. The ion sieve according to any one of claims 1-4, characterized in that, Based on the total weight of the ion sieve, the ion sieve contains 0-4 wt% B2O3, 0.30-2.5 wt% ZnO, and 0-3 wt% Sb2O3.

8. The ion sieve according to claim 7, characterized in that, Based on the total weight of the ion sieve, the total mass content of B2O3, ZnO, and Sb2O3 in the ion sieve is ≤2.5wt%.

9. The application of the ion sieve according to any one of claims 1-8 in glass chemical strengthening molten salt, characterized in that, The application is performed using a method that includes the following steps: The ion sieve and the glass to be strengthened are mixed in molten salt at 380-530℃ for 8-12 hours to obtain the strengthened glass and the failed ion sieve. The failed ion sieve has an amorphous structure.

10. A method for regenerating a failed ion sieve, characterized in that, The method includes: mixing a failed ion sieve with an alkaline solution to obtain a regenerated ion sieve; The failed ion sieve is the failed ion sieve according to claim 9; The regenerated ion sieve is the ion sieve described in any one of claims 1-8.

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