A method for preparing a cesium feldspar glass ceramic solidification body by cryogenic in-situ microwave mineralization of cesium-exchanged NaY zeolite

Abstract

The application belongs to the technical field of radioactive waste treatment, and discloses a kind of low-temperature in-situ microwave mineralization cesium exchanged NaY zeolite preparation cesium garnet glass ceramic solidified body and method thereof, the application includes the following steps: S1, Cs+ exchanged NaY zeolite powder is mixed with lead boron glass precursor powder according to proportion, is ground by wet method, drying, and homogeneous precursor mixed powder is obtained;S2, the mixed powder obtained in S1 is cold pressed into shape, and green body is obtained;S3, the green body obtained in S2 is placed in microwave sintering furnace, heated to 500~800 ℃ under air atmosphere and kept warm, and then naturally cooled, and cesium garnet-based glass ceramic solidified body is obtained.The application utilizes the structural affinity of zeolite and cesium garnet, under the synergistic effect of lead boron glass fluxing and microwave volume heating, realizes the in-situ reconstruction conversion of zeolite to cesium garnet crystal phase at a temperature significantly lower than the conventional process.The obtained solidified body has a dual barrier structure of cesium lattice cesium fixation and lead boron glass matrix physical encapsulation, and has the characteristics of high density.

Description

Technical Field

[0001] This invention belongs to the field of radioactive waste treatment technology, and particularly relates to a method for preparing cesium garnet glass-ceramic solidified bodies by low-temperature in-situ microwave mineralization of cesium exchange NaY zeolite. Background Technology

[0002] Radioactive cesium, especially 137 Cesium (Cs) is characterized by its long half-life, high environmental mobility, and prolonged radiation hazard, making it one of the key radionuclides requiring control in the treatment of radioactively contaminated water and secondary solid waste. In engineering practice, adsorption and ion exchange methods are commonly used to remove cesium ions from the liquid phase and transfer them to adsorbents such as zeolites, thus forming cesium-containing secondary solid waste. This type of waste requires further stabilization treatment before storage, transportation, and final disposal to reduce the risk of radionuclide leaching and migration.

[0003] Cesium garnet (CsAlSi₂O₆) is considered an ideal host crystal phase for long-term cesium fixation, as its three-dimensional aluminosilicate framework can stably accommodate cesium ions within its crystal structure. Existing cesium garnet-based solidified bodies are typically prepared using methods such as high-temperature reaction sintering, melt crystallization, or spark plasma sintering, with sintering temperatures often approaching or exceeding 1000 °C. Excessively high processing temperatures not only consume significant energy but also easily lead to cesium volatilization and increase the burden on exhaust gas control.

[0004] NaY zeolite belongs to the FAU type aluminosilicate and already contains the Al-Si framework units required for the formation of cesium garnet, theoretically making it suitable as a precursor for low-temperature in-situ mineralization. However, it is difficult to achieve framework reconstruction, matrix densification, and cesium volatilization suppression simultaneously at relatively low temperatures by relying solely on heat treatment.

[0005] Low-melting-point glass additives can promote particle contact, interfacial diffusion, and densification through transient liquid phase. PbO-B2O3 glass, with its low softening temperature, strong glass-forming ability, and tunable viscosity and network structure, is suitable for promoting the conversion of cesium exchange NaY zeolite to cesium garnet at relatively low temperatures, forming a continuous encapsulated matrix. Meanwhile, microwave heating offers advantages such as volumetric heating and short thermal history, which helps reduce cesium volatilization and promote mineralization and densification.

[0006] Therefore, developing a method for in-situ conversion of cesium-exchanged NaY zeolite into cesium garnet glass-ceramic solids at 700 °C and below is of great significance for the safe disposal of secondary radioactive waste containing cesium zeolite. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a method for preparing cesium garnet glass-ceramic solidified bodies by low-temperature in-situ microwave mineralization of cesium-exchanged NaY zeolite. This method utilizes the synergistic effect of microwave volumetric heating and lead-boron glass fluxing to in-situ transform Cs-exchanged NaY zeolite into the cesium garnet (CsAlSi2O6) main crystalline phase at a temperature significantly lower than that of conventional processes. This cesium garnet is then uniformly dispersed within a dense lead-boron glass matrix, forming a dual-barrier structure of "lattice-fixed cesium + glass encapsulation." The resulting solidified body exhibits high density, excellent cesium volatilization suppression, and superior chemical stability.

[0008] This invention is implemented as follows: a method for preparing cesium garnet glass-ceramic solidified bodies by low-temperature in-situ microwave mineralization of cesium exchange NaY zeolite, comprising:

[0009] Step 1: Mix cesium ion-exchanged NaY zeolite powder with lead borosilicate glass precursor powder to obtain homogeneous precursor mixed powder.

[0010] Step 2: The homogeneous precursor mixture powder is cold-pressed to obtain a green body;

[0011] Step 3: Place the green body in a microwave sintering furnace, heat it to 500~800 ℃ in an air atmosphere and keep it at that temperature. After keeping it at that temperature, let it cool naturally to room temperature to obtain a cesium garnet-based glass ceramic solidified body.

[0012] Furthermore, the method for preparing the cesium ion-exchanged NaY zeolite powder includes:

[0013] NaY zeolite powder was dispersed in an aqueous solution of cesium chloride containing cesium ions, and the mixture was kept at 25 °C and shaken for 12 h. After filtration, washing, and drying, the cesium ion-exchanged NaY zeolite powder was obtained.

[0014] Furthermore, the concentration of cesium ions in the cesium chloride aqueous solution is 5 g / L.

[0015] Furthermore, the lead boron glass precursor powder is a mixed powder of lead dioxide and boron trioxide, wherein the molar ratio of lead dioxide to boron trioxide is 60:40.

[0016] Furthermore, the mixing mass ratio of the cesium ion-exchanged NaY zeolite powder to the lead borosilicate glass precursor powder is 40~80:60~20.

[0017] Furthermore, the mixing is carried out by wet grinding, and the wet grinding is followed by drying; the pressure of cold pressing is 150~250 MPa; the heating rate is 15~25 ℃ / min, and the holding time is 30~60 min.

[0018] Another objective of this invention is to provide a cesium garnet-based glass-ceramic solidified body, which is obtained by cold pressing, microwave sintering in air atmosphere, and natural cooling of a homogeneous precursor mixture powder containing cesium ion-exchanged NaY zeolite powder and lead borosilicate glass precursor powder. The microwave sintering temperature is 500~800 °C.

[0019] Furthermore, the cesium ion-exchanged NaY zeolite powder is obtained by exchanging NaY zeolite powder with a cesium chloride aqueous solution containing cesium ions. The concentration of cesium ions in the cesium chloride aqueous solution is 5 g / L, the temperature of the exchange treatment is 25°C, and the time of the exchange treatment is 12 h.

[0020] Furthermore, the lead boron glass precursor powder is a mixed powder of lead dioxide and boron trioxide, wherein the molar ratio of lead dioxide to boron trioxide is 60:40.

[0021] Furthermore, in the homogeneous precursor mixed powder, the mass ratio of the cesium ion-exchanged NaY zeolite powder to the lead borosilicate glass precursor powder is 40~80:60~20; the pressure of the cold pressing is 150~250 MPa; the heating rate of the microwave sintering is 15~25 ℃ / min, and the holding time is 30~60 min.

[0022] Another object of the present invention is to provide a system for preparing cesium garnet glass-ceramic solidified bodies using low-temperature in-situ microwave mineralization of cesium-exchange NaY zeolite, which implements the above-described method for preparing cesium garnet glass-ceramic solidified bodies using low-temperature in-situ microwave mineralization of cesium-exchange NaY zeolite. The system comprises:

[0023] The mixing module is used to mix Cs+-exchanged NaY zeolite powder with lead borosilicate glass precursor powder at a predetermined mass ratio, followed by wet grinding and drying to obtain a homogeneous precursor mixed powder.

[0024] The cold pressing module is used to cold press the obtained homogeneous precursor mixed powder to obtain a green body;

[0025] The heating module is used to place the obtained green body in a microwave sintering furnace, heat it to 500~800 ℃ in an air atmosphere and keep it at that temperature, and then let it cool naturally to room temperature to obtain the cesium garnet-based glass ceramic solidified body.

[0026] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0027] This invention utilizes the structural similarity between FAU-type zeolite and cesium garnet (ANA-type) zeolite, using Cs-exchanged NaY zeolite as a reactive precursor. Under the synergistic effect of lead borosilicate glass flux and microwave volumetric heating, in-situ reconstruction and transformation of the zeolite framework into the cesium garnet crystal phase can be achieved in the low-temperature range of 500–800 °C. This significantly reduces the synthesis temperature of traditional cesium garnet ceramics and effectively suppresses cesium volatilization loss. Examples show that after sintering at 700 °C, the apparent Cs retention rate can reach over 99%.

[0028] This invention, by controlling the ratio of zeolite to the glass precursor and the sintering temperature, results in a cured body that possesses both a highly crystalline cesium garnet phase and a continuous, dense lead-boron glass matrix. The cesium garnet lattice provides the first layer of cesium immobilization barrier, while the glass matrix provides the second layer of physical encapsulation barrier; their synergistic effect endows the cured body with excellent chemical stability. Examples show that after static leaching in deionized water at 90 °C for 42 days, the normalized Cs leaching rate of the optimal formulation sample is extremely low.

[0029] This invention employs microwave sintering technology, which utilizes its volumetric heating and rapid thermal response characteristics to significantly shorten the high-temperature processing time, reduce energy consumption, and avoid the problems of sample cracking and abnormal grain growth caused by thermal gradients in conventional resistance furnace heating. The resulting solidified body has a uniform and dense microstructure.

[0030] The process of this invention is simple, the raw materials are readily available, and there is no need for complex pretreatment or expensive sintering equipment. It is easy to achieve industrial-scale production and is suitable for the safe solidification treatment of cesium-containing zeolite secondary waste generated during the operation of nuclear facilities and post-accident processing.

[0031] This invention combines cesium ion-exchanged NaY zeolite with a lead-boron glass precursor and employs a low-temperature in-situ microwave mineralization process to achieve rapid generation of the cesium garnet crystalline phase and densification of the glass-ceramic at 500–800℃. Compared to traditional high-temperature sintering methods, this invention significantly reduces processing temperature and energy consumption, shortens the curing cycle, and minimizes cesium volatilization loss under high-temperature conditions. Simultaneously, microwave volumetric heating promotes uniform nucleation and growth of cesium garnet and stable cesium entry into the crystal lattice, thereby improving the structural uniformity, chemical stability, and leaching resistance of the cured body. This method is simple, efficient, energy-saving, safe, and provides excellent cesium consolidation, achieving outstanding substantive features and significant progress.

[0032] The expected benefits and commercial value of the technical solution of this invention after transformation are as follows:

[0033] This invention targets applications in nuclear facility operation, radioactive waste treatment, accident-contaminated water purification, and cesium-containing adsorbent reprocessing. It directly converts cesium-exchanged NaY zeolite secondary solid waste generated during adsorption or ion exchange processes into cesium garnet-based glass-ceramic solidified bodies. Compared to traditional high-temperature ceramic sintering, melt crystallization, or plasma sintering processes, this invention achieves in-situ formation of the cesium garnet crystal phase and densification of the solidified body at 700 °C and below, reducing processing temperature and heat treatment burden, thus reducing energy consumption, equipment temperature resistance requirements, and tail gas control costs associated with cesium volatilization. The process flow is relatively short, mainly including mixing, cold pressing, and microwave sintering steps. The raw material source is clear, and the operating conditions are controllable, facilitating integration with existing radioactive waste pretreatment, molding, and sintering equipment. The resulting solidified body possesses a dual-barrier structure combining cesium garnet lattice confinement and glass matrix encapsulation, reducing the risk of cesium leaching during storage, transportation, and final disposal, demonstrating promising engineering conversion prospects and environmental safety value.

[0034] The technical solution of this invention fills a technological gap in the industry both domestically and internationally:

[0035] Existing stabilization technologies for cesium-containing secondary waste mainly focus on high-temperature ceramicization, vitrification, geopolymer solidification, or direct sintering of adsorbents. Traditional cesium garnet-based solids typically require processing temperatures close to or higher than 1000 °C to achieve aluminosilicate framework reconstruction and target crystalline phase formation. For cesium-containing adsorbents like cesium-exchanged NaY zeolite with an FAU-type framework, a complete technical solution is still lacking that can simultaneously achieve in-situ zeolite framework reconstruction, cesium garnet crystalline phase formation, continuous glass matrix encapsulation, and solidification of the solidified body at lower temperatures. This invention utilizes the structural characteristic of Cs-exchanged NaY zeolite containing Al-Si framework units, introduces a PbO–B2O3 lead boron glass precursor as a low-temperature fluxing phase, and combines it with microwave volumetric heating to achieve low-temperature in-situ mineralization transformation of cesium-exchanged zeolite into a cesium garnet-based glass-ceramic solid. Therefore, this invention provides a new technical path for low-temperature crystalline phase solidification and glass-ceramic dual-barrier construction of cesium-containing zeolite secondary waste.

[0036] The technical solution of this invention solves a technical problem that people have long desired to solve but have been unable to achieve:

[0037] Cesium-containing zeolite adsorbents can effectively remove cesium ions from water, but the zeolite itself remains cesium-containing secondary radioactive waste. This type of waste faces three mutually restrictive technical challenges: first, the zeolite framework is difficult to fully reconstruct into a cesium garnet crystal phase under low-temperature conditions; second, lowering the treatment temperature often leads to insufficient densification of the solidified body and decreased leaching stability; and third, increasing the sintering temperature may increase cesium volatilization losses and the burden on tail gas treatment. This invention utilizes a lead-boron glass flux phase to form a reactive liquid phase at a lower temperature, promoting interparticle contact, interfacial diffusion, and the reconstruction of the FAU-type zeolite framework into a cesium garnet crystal phase. Simultaneously, the volumetric heating and rapid thermal response characteristics of microwave heating help shorten the heat treatment cycle and promote overall mineralization. Therefore, this invention achieves a balance between cesium garnet crystal phase formation, solidified body densification, cesium retention, and anti-leaching properties at a lower sintering temperature, solving the technical challenge of simultaneously achieving low-temperature treatment, cesium crystal phase consolidation, and glass encapsulation.

[0038] The technical solution of this invention overcomes technical bias:

[0039] It is generally believed in the art that the formation of the cesium garnet crystal phase requires a long solid-state reaction at a high temperature or a high-temperature melting and crystallization process. Meanwhile, zeolite materials are prone to dehydration, structural collapse, or the formation of other aluminosilicate impurities during heating, making it difficult to directly transform into a stable cesium garnet solidified phase at lower temperatures. Therefore, existing technologies often tend to employ high-temperature sintering, molten glass solidification, or high-energy external field-assisted sintering methods, and rarely use cesium-exchanged NaY zeolite directly as a low-temperature in-situ mineralization precursor. This invention breaks through the above understanding by utilizing the structural correlation between NaY zeolite and cesium garnet on the aluminosilicate framework, and by forming a transient liquid phase at low temperature using PbO–B2O3 lead borosilicate glass, promoting zeolite framework reconstruction and cesium garnet crystal phase nucleation and growth. The results show that without the addition of a lead-boron glass precursor, microwave treatment of cesium-exchanged NaY zeolite alone is insufficient to form a distinct cesium garnet crystal phase. However, with the introduction of the lead-boron glass precursor, cesium garnet-based glass-ceramic solidified bodies can be prepared within the temperature range of 500–800 °C. This indicates that the present invention does not simply lower the sintering temperature, but rather overcomes the technical biases of difficulty in forming cesium garnet at low temperatures, difficulty in densifying the solidified body, and easy migration and release of cesium through a synergistic mechanism of "zeolite reactive precursor + low-temperature fluxing of lead-boron glass + microwave volumetric heating". Attached Figure Description

[0040] Figure 1 This is a flowchart of a method for preparing cesium garnet glass-ceramic solidified bodies by low-temperature in-situ microwave mineralization of cesium exchange NaY zeolite, provided in an embodiment of the present invention.

[0041] Figure 2 This is a structural block diagram of the low-temperature in-situ microwave mineralization cesium exchange NaY zeolite system for preparing cesium garnet glass-ceramic solidified bodies, provided in an embodiment of the present invention.

[0042] Figure 3 This is a schematic diagram of the preparation process of the cesium garnet-based glass-ceramic solidified body provided in the embodiments of the present invention.

[0043] Figure 4 The XRD patterns and relative crystallinity of Examples 1-5 and Comparative Example 1 provided in this invention at different sintering temperatures are shown in the figures. (a) XRD phase analysis of the sample sintered at 700 °C; (b) XRD phase analysis of the sample sintered at 600 °C; (c) XRD phase analysis of the sample sintered at 500 °C; (d) Comparison of the relative crystallinity of the samples at different sintering temperatures.

[0044] Figure 5 This is the Rietveld refined spectrum and cesium garnet crystal structure model of the representative sample in Example 2 provided by the present invention.

[0045] Figure 6 These are the infrared spectra of Examples 1-5 provided in this invention; (a) Fourier transform infrared spectra of NaY zeolite before and after adsorption and of CGZ100-700 samples; (b) Fourier transform infrared spectra of CGZ samples with different ratios under sintering conditions at 700 ℃; (c) Fourier transform infrared spectra of CGZ samples with different ratios under sintering conditions at 600 ℃; (d) Fourier transform infrared spectra of CGZ samples with different ratios under sintering conditions at 500 ℃.

[0046] Figure 7 These are the bulk density and volume shrinkage rate of Examples 1-5 provided in this invention.

[0047] Figure 8 These are scanning electron microscope (SEM) morphology images and energy dispersive X-ray spectroscopy (EDS) elemental distribution maps of representative samples in Example 2 provided by the present invention.

[0048] Figure 9 These are evidence diagrams showing how the lead boron glass precursor provided in this embodiment of the invention promotes the formation of low-temperature cesium garnet crystal phase; (a) XRD phase analysis of CGZ samples with different ratios at 700 ℃; (b) XRD phase analysis of CGZ samples with different ratios at 600 ℃; (c) XRD phase analysis of CGZ samples with different ratios at 500 ℃; (d) Comparison of the relative crystallinity of each CGZ sample at different temperatures.

[0049] Figure 10 This is an evidence diagram showing the stable formation of the cesium garnet lattice structure provided in the embodiments of the present invention.

[0050] Figure 11These are the evidence diagrams of zeolite framework reconstruction and glass phase participation in the reaction provided in the embodiments of the present invention; (a) FTIR spectral analysis of NaY zeolite before and after adsorption and CGZ100-700 samples; (b) FTIR spectral analysis of CGZ samples with different ratios at 700 ℃; (c) FTIR spectral analysis of CGZ samples with different ratios at 600 ℃; (d) FTIR spectral analysis of CGZ samples with different ratios at 500 ℃.

[0051] Figure 12 This is an evidence diagram of the densification effect of the cured body provided in the embodiments of the present invention.

[0052] Figure 13 These are evidence diagrams showing the advantages of the microwave low-temperature mineralization process provided in the embodiments of the present invention; (a) the change of normalized cumulative leaching amount of Cs in different CGZ solidified bodies over time; (b) the change of normalized leaching rate of Cs in different CGZ solidified bodies over time; (c) the change of normalized cumulative leaching amount of Pb in different CGZ solidified bodies over time. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0054] like Figure 1 As shown in the embodiment of the present invention, a method for preparing cesium garnet glass-ceramic solidified bodies by low-temperature in-situ microwave mineralization of cesium exchange NaY zeolite includes the following steps:

[0055] S101, cesium ion-exchanged NaY zeolite powder is mixed with lead borosilicate glass precursor powder to obtain homogeneous precursor mixed powder.

[0056] S102, the homogeneous precursor mixed powder is cold-pressed to form a green body;

[0057] S103, the green body is placed in a microwave sintering furnace, heated to 500~800 ℃ in an air atmosphere and held at that temperature, and then naturally cooled to room temperature to obtain a cesium garnet-based glass ceramic solidified body.

[0058] The method for preparing cesium ion-exchanged NaY zeolite powder provided in this embodiment of the invention includes:

[0059] NaY zeolite powder was dispersed in an aqueous solution of cesium chloride containing cesium ions, and the mixture was kept at 25 °C and shaken for 12 h. After filtration, washing, and drying, the cesium ion-exchanged NaY zeolite powder was obtained.

[0060] The concentration of cesium ions in the cesium chloride aqueous solution provided in this embodiment of the invention is 5 g / L.

[0061] The lead-boron glass precursor powder provided in this embodiment of the invention is a mixed powder of lead dioxide and boron trioxide, wherein the molar ratio of lead dioxide to boron trioxide is 60:40.

[0062] The mixing mass ratio of cesium ion-exchanged NaY zeolite powder to the lead borosilicate glass precursor powder provided in this embodiment of the invention is 40~80:60~20.

[0063] The mixture provided in this embodiment of the invention is produced by wet grinding, followed by drying; the pressure of cold pressing is 150~250 MPa; the heating rate is 15~25 ℃ / min; and the holding time is 30~60 min.

[0064] The present invention provides a cesium garnet-based glass-ceramic solidified body, which is obtained by cold pressing, microwave sintering in air atmosphere and natural cooling of a homogeneous precursor mixture powder containing cesium ion-exchanged NaY zeolite powder and lead borosilicate glass precursor powder. The microwave sintering temperature is 500~800 ℃.

[0065] The cesium ion-exchanged NaY zeolite powder provided in this embodiment of the invention is obtained by exchanging NaY zeolite powder with a cesium chloride aqueous solution containing cesium ions. The concentration of cesium ions in the cesium chloride aqueous solution is 5 g / L, the temperature of the exchange treatment is 25 °C, and the time of the exchange treatment is 12 h.

[0066] The lead-boron glass precursor powder provided in this embodiment of the invention is a mixed powder of lead dioxide and boron trioxide, wherein the molar ratio of lead dioxide to boron trioxide is 60:40.

[0067] In the homogeneous precursor mixed powder provided in this embodiment of the invention, the mass ratio of the cesium ion-exchanged NaY zeolite powder to the lead borosilicate glass precursor powder is 40~80:60~20; the pressure of the cold pressing is 150~250 MPa; the heating rate of the microwave sintering is 15~25 ℃ / min, and the holding time is 30~60 min.

[0068] This invention provides a method for preparing cesium garnet glass-ceramic solidified bodies by low-temperature in-situ microwave mineralization of cesium exchange NaY zeolite, comprising the following steps:

[0069] S1, Cs + The exchanged NaY zeolite powder and lead borosilicate glass precursor powder are mixed at a predetermined mass ratio, and then wet-milled and dried to obtain a homogeneous precursor mixed powder.

[0070] S2. The homogeneous precursor mixture powder obtained in S1 is cold-pressed to form a green body;

[0071] S3. Place the green body obtained in S2 in a microwave sintering furnace, heat it to 500~800 ℃ in an air atmosphere and keep it at that temperature, and then let it cool naturally to room temperature to obtain the cesium garnet-based glass ceramic solidified body.

[0072] The Cs described in S1 provided in this embodiment of the invention + The preparation method of exchanged NaY zeolite powder is as follows: NaY zeolite powder is dispersed in a Cs-containing medium. + The Cs chloride solution was prepared by constant temperature shaking at 25 °C for 12 h in a 5 g / L aqueous solution of cesium chloride, followed by filtration, washing, and drying to obtain the Cs. + Exchanged NaY zeolite powder.

[0073] The lead boron glass precursor provided in S1 of this embodiment is a mixed powder of lead dioxide (PbO) and boron trioxide (B2O3), wherein the molar ratio of PbO to B2O3 is 60:40.

[0074] The Cs described in S1 provided in this embodiment of the invention + The mass ratio of the exchanged NaY zeolite powder to the lead borosilicate glass precursor powder is (40~80):(60~20).

[0075] The pressure for cold pressing in S2 provided in this embodiment of the invention is 150~250 MPa.

[0076] The heating rate in S3 provided in this embodiment of the invention is 15~25 ℃ / min, and the holding time is 30~60 min.

[0077] like Figure 2 As shown in the embodiment of the present invention, a low-temperature in-situ microwave mineralization system for preparing cesium garnet glass-ceramic solidified bodies from cesium exchange NaY zeolite includes:

[0078] The mixing module is used to mix Cs+-exchanged NaY zeolite powder with lead borosilicate glass precursor powder at a predetermined mass ratio, followed by wet grinding and drying to obtain a homogeneous precursor mixed powder.

[0079] The cold pressing module is used to cold press the obtained homogeneous precursor mixed powder to obtain a green body;

[0080] The heating module is used to place the obtained green body in a microwave sintering furnace, heat it to 500~800 ℃ in an air atmosphere and keep it at that temperature, and then let it cool naturally to room temperature to obtain the cesium garnet-based glass ceramic solidified body.

[0081] Another object of the present invention is to provide a computer device, the computer device including a memory and a processor, the memory storing a computer program, the computer program being executed by the processor causing the processor to perform the steps of the method for preparing cesium garnet glass-ceramic solidified body by low-temperature in-situ microwave mineralization of cesium exchange NaY zeolite.

[0082] Example 1 (CGZ40-700)

[0083] Figure 3 A method for preparing a cesium garnet-based glass-ceramic solidified body includes the following steps:

[0084] S1, Weigh 0.40 g Cs + Exchanged NaY zeolite powder (CZ) and 0.60 g of lead borosilicate glass precursor powder (BP6, PbO to B2O3 molar ratio 60:40) were placed in an agate mortar, and 5 mL of anhydrous ethanol was added as a dispersion medium for wet grinding. Grinding continued until the ethanol was completely evaporated, resulting in a homogeneous precursor mixture powder.

[0085] S2. The mixed powder obtained in S1 is cold-pressed into discs (diameter 12.5 mm, thickness about 0.3~0.6 mm) under a pressure of 200 MPa.

[0086] S3. Place the green body obtained in S2 in an alumina crucible, put it in a microwave muffle furnace, heat it to 700 ℃ at 20 ℃ / min in an air atmosphere, hold it for 40 min, and then cool it naturally to room temperature to obtain a cesium garnet-based glass ceramic solidified body (CGZ40-700).

[0087] Example 2 (CGZ60-700)

[0088] The preparation method is the same as in Example 1, except that Cs in S1 + The exchanged NaY zeolite powder weighed 0.60 g, and the lead borosilicate glass precursor powder weighed 0.40 g.

[0089] Example 3 (CGZ809700)

[0090] The preparation method is the same as in Example 1, except that Cs in S1 + The exchanged NaY zeolite powder weighed 0.80 g, and the lead borosilicate glass precursor powder weighed 0.20 g.

[0091] Example 4 (CGZ60-600)

[0092] The preparation method is the same as in Example 2, except that the target temperature for microwave sintering in S3 is 600 °C.

[0093] Example 5 (CGZ60-500)

[0094] The preparation method is the same as in Example 2, except that the target temperature for microwave sintering in S3 is 500 °C.

[0095] Comparative Example 1 (CGZ100-700)

[0096] The preparation method is the same as in Example 1, except that only 1.00 g of Cs is used in S1. + The NaY zeolite powder was exchanged without the addition of lead borosilicate glass precursor powder.

[0097] The structure and properties of the cured bodies obtained in the above embodiments and comparative examples were characterized.

[0098] 1. Phase and Structure Analysis

[0099] X-ray diffraction (XRD) was used to identify the phase composition of the sample. For example... Figure 4 As shown, samples from Examples 1-3 (700 °C) and Example 4 (600 °C) all exhibited typical cesium garnet-type CsAlSi2O6 characteristic diffraction peaks, indicating that the zeolite precursor had been successfully transformed into the target crystalline phase. In Example 5 (500 °C), the cesium garnet main peak was still clearly visible in samples with low zeolite content (such as CGZ40-500), while residual FAU zeolite peaks appeared in samples with high zeolite content (CGZ80-500), indicating that the transformation was incomplete when the glass phase was insufficient at low temperatures. Comparative Example 1 (without glass) still mainly consisted of the FAU zeolite phase after treatment at 700 °C, confirming that the lead borosilicate glass precursor is indispensable for promoting low-temperature mineralization.

[0100] To further confirm this, Rietveld refinement was performed on samples from Examples 2, 4, and 5, as well as samples with different proportions. For example... Figure 5 As shown, all diffraction patterns can be well fitted using the tetragonal cesium garnet structural model (space group I41 / acd), with cell parameters a≈c≈13.66 Å. The refinement results indicate that the cesium garnet lattice remains highly robust under different temperatures and stoichiometry, and the structural evolution is mainly reflected in the relative contributions of the crystalline phase formation and the amorphous matrix.

[0101] 2. Infrared spectroscopy analysis

[0102] The local structure of the sample was analyzed using Fourier transform infrared spectroscopy (FT-IR). For example... Figure 6 As shown, the original NaY and CZ precursors exhibit typical FAU skeletal vibrational fingerprints. After adding the glass precursor and sintering, the FAU characteristic peaks are significantly suppressed, replaced by a peak at ~1383 cm⁻¹. -1 The BO stretching vibration peak of the [BO3] group, 1240-804 cm⁻¹ -1The presence of broad composite peaks of borate network and Si-OT framework vibrations within the range, as well as low wavenumber framework vibration peaks, indicates that the zeolite framework has been reconstructed and has undergone interfacial reactions with the glass phase to form new reactive structures.

[0103] 3. Densification behavior

[0104] The volume density of the sample was determined using the Archimedes' method of water displacement, and the volume shrinkage rate was calculated. Figure 7 As shown, the density of all glass-containing samples was significantly higher than that of Comparative Example 1 (approximately 2.01 g·cm³). -3 Example 2 (CGZ60) achieved a good balance between densification and waste loading at 600-700 °C, with a volume shrinkage rate of up to 58%. Examples 1 (CGZ40) and 2 achieved a high degree of densification at 500-600 °C, indicating that the glass enrichment formulation can be effectively sintered at lower temperatures.

[0105] 4. Microstructure and elemental distribution

[0106] The microstructure of representative samples was observed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Figure 8 As shown, Example 2 (CGZ60-700) exhibits the most uniform and dense microstructure, with dark cesium garnet grains rich in Cs, Si, and Al uniformly dispersed in a continuous glass matrix. EDS point and surface scan results show that Cs is co-located with Si and Al, while Pb is enriched in the surrounding continuous matrix, which directly verifies the dual-barrier structure of "lattice-fixed cesium + glass encapsulation".

[0107] (1) Expansion of zeolite types:

[0108] The above embodiments all use NaY zeolite (SiO2 / Al2O3 molar ratio of 4.5~5) as the cesium source support. However, the low-temperature in-situ microwave mineralization strategy proposed in this invention can also be applied to other zeolite types with similar Si / Al ratios. Under the technical concept of this invention, the Si / Al ratio of the selected zeolite should preferably be controlled at around 4~5 to meet the stoichiometric requirements of cesium garnet (CsAlSi2O6) and ensure the structural affinity of the zeolite framework to the cesium garnet crystal phase transformation, for example, but not limited to:

[0109] Other zeolites with a FAU-type framework, such as NaX-type zeolites, but their silica-to-alumina ratio must be controlled to be no less than 4. Zeolites with low silica-to-alumina ratios (such as 13X-type zeolites, where the SiO2 / Al2O3 molar ratio is usually 2-3) are prone to generating impurities such as albite during subsequent microwave mineralization, which affects the purity of cesium garnet and the overall performance of the solidified body, and therefore should be avoided.

[0110] β-zeolite (*BEA type): Varieties with a silica-alumina ratio in the range of 4 to 5 can be obtained by controlling the synthesis conditions. Its twelve-membered ring three-dimensional channel structure and high specific surface area are expected to provide cesium loading characteristics and mineralization behavior different from NaY zeolite.

[0111] ZSM-5 zeolite (MFI type): Although ZSM-5 with a high silica-alumina ratio has a unique ten-membered ring cross-channel structure, it is necessary to adjust the silica-alumina ratio to a suitable range through post-processing methods such as dealuminization and aluminization supplementation to ensure the full formation of cesium garnet crystal phase during subsequent mineralization.

[0112] Among the aforementioned alternative zeolite types, controlling the silica-alumina ratio is a key factor in ensuring the low-temperature in-situ mineralization conversion rate and phase purity of cesium garnet. The specific zeolite to be selected can be determined comprehensively based on factors such as the actual radioactive waste treatment process, source, and economic feasibility.

[0113] (2) Optimization of lead borosilicate glass precursor formulation:

[0114] In the above embodiments, a lead borosilicate glass composition of 60 mol% PbO–40 mol% B2O3 (BP6) was selected as the fluxing additive. Under the technical concept of this invention, the composition of the lead borosilicate glass precursor can be further optimized, for example:

[0115] Adjusting the molar ratio of PbO to B2O3: This can be further finely controlled within the range of 40–80 mol% PbO to balance the softening temperature, viscosity, degree of network polymerization, and reactivity with zeolite precursors of the glass.

[0116] Introducing a third component oxide: Small amounts of alumina (Al2O3), zinc oxide (ZnO), silicon dioxide (SiO2), titanium dioxide (TiO2), or zirconium oxide (ZrO2) can be added to the lead borosilicate glass precursor to adjust the chemical stability and mechanical properties of the glass network, further improve the leaching resistance and mechanical strength of the cured body, and make it more adaptable to different geological treatment environments and long-term safety evaluation requirements.

[0117] By optimizing the lead boron glass precursor formulation, the physical encapsulation ability, interfacial reactivity, and chemical durability of the glass matrix can be directionally controlled, thereby further improving the overall performance of the cesium garnet glass-ceramic cured body.

[0118] (3) Precise control of microwave sintering parameters:

[0119] The above embodiments use a fixed heating rate (20 ℃ / min), holding time (40 min), and microwave power. However, all process parameters in the microwave sintering process can be optimized and adjusted according to actual conditions, mainly including:

[0120] Microwave power: It should be controlled within the range of 500~1500 W, and adjusted according to the charge amount and target sintering temperature. Too low a power may result in insufficient heating rate, affecting the softening of the glass phase and the mass transfer effect of the liquid phase; too high a power may cause local overheating, leading to excessive volatilization of cesium or cracking of the solidified body.

[0121] Heating rate: can be adjusted within the range of 5~20 ℃ / min to optimize the matching relationship between the crystal phase transformation process and the liquid phase formation rate. A slower heating rate is beneficial for the full dehydration of the zeolite precursor and the uniform softening of the glass phase, while a faster heating rate helps to shorten the process cycle and improve production efficiency;

[0122] Holding time: should be no less than 30 minutes to ensure sufficient reconstruction and transformation of the zeolite framework into the cesium garnet crystal phase and densification of the matrix. The holding time can be appropriately extended according to the charge amount and the target crystal phase conversion rate, for example, within the range of 30~120 minutes;

[0123] Segmented heating program: Multiple heating-holding programs can be designed to control the progress of different stages in a specific temperature range, such as the zeolite dehydration stage (approximately 100~300 ℃), the glass softening and liquid phase formation stage (approximately 350~500 ℃), and the cesium garnet nucleation and crystal growth stage (approximately 500~700 ℃), thereby achieving more precise structural control.

[0124] By finely optimizing the above microwave sintering parameters, the volatilization loss of cesium can be further reduced, the chemical durability of the solidified body can be improved, and energy utilization efficiency can be optimized, while ensuring the crystallinity of cesium garnet and the density of the solidified body.

[0125] (4) Process integration and automation:

[0126] From an industrial application perspective, the various process steps involved in this invention can be integrated and automated, including but not limited to:

[0127] C s+ Unit operations such as exchange pretreatment, wet mixing and grinding, drying, cold pressing and microwave sintering are integrated into a continuous or semi-continuous production process.

[0128] An automated control system is used to precisely control and monitor key process variables such as raw material ratio, grinding process parameters, molding pressure and holding time, and microwave sintering program.

[0129] For radioactive operating environments, an integrated equipment combining shielding protection and remote operation is designed to reduce the impact of human factors on product quality and ensure the safety of operators.

[0130] Through process integration and automation, production efficiency can be significantly improved, production costs reduced, and product quality consistency guaranteed, thereby promoting the large-scale application of the low-temperature in-situ microwave mineralization and solidification method of this invention in the field of radioactive waste treatment.

[0131] To verify the technical effectiveness of the present invention in preparing cesium garnet glass-ceramic solidified bodies by low-temperature in-situ microwave mineralization of cesium exchange NaY zeolite, the inventors systematically characterized the material from aspects such as phase transformation, local structure evolution, densification behavior, elemental distribution, and comparative analysis.

[0132] First, X-ray diffraction results showed that, with the addition of a lead-boron glass precursor, cesium-exchanged NaY zeolite could form a cesium garnet-type CsAlSi2O6 crystal phase after microwave sintering at 500–800 °C. Specifically, at 600–700 °C, no obvious FAU-type zeolite residual characteristic peaks were observed in the samples containing the lead-boron glass precursor, indicating that cesium-exchanged NaY zeolite can undergo framework reconstruction and transform into the cesium garnet crystal phase at lower temperatures. In contrast, the comparative sample without the lead-boron glass precursor mainly retained the FAU-type zeolite phase after microwave treatment at 700 °C, without forming a distinct cesium garnet main crystal phase. These results demonstrate that the lead-boron glass precursor plays a key role in fluxing and promoting interfacial reactions during low-temperature mineralization.

[0133] Secondly, Rietveld refinement results show that the diffraction patterns of representative solidified samples can be well fitted using a tetragonal cesium garnet structure model, indicating that the obtained crystal phase has a stable cesium garnet crystal structure. FT-IR spectroscopy further shows that after microwave sintering, the characteristic vibrational peaks of the FAU framework of the original NaY zeolite and cesium-exchanged NaY zeolite are significantly weakened or disappear, while absorption peaks related to the vibrations of the borate network and Si-OT framework appear, indicating that the zeolite framework has been reconstructed under the action of the reactive liquid phase formed by the softening of lead borosilicate glass and has undergone interfacial reactions with the glass phase.

[0134] Furthermore, the bulk density and volume shrinkage rate tests showed that the bulk density of the sample with the added lead borosilicate glass precursor was significantly higher than that of the comparative sample without the precursor, indicating that lead borosilicate glass can promote particle rearrangement, pore filling, and matrix densification during microwave sintering. Representative samples achieved a good balance between cesium garnet crystal phase formation, waste loading, and densification within the temperature range of 600–700 °C, demonstrating that this invention can obtain a relatively dense glass-ceramic solidified body at a lower temperature than that used in traditional cesium garnet ceramic preparation.

[0135] Furthermore, SEM-EDS analysis showed that Cs in the representative cured body was mainly co-located with Si and Al, indicating that Cs was mainly distributed in the aluminosilicate crystalline phase region; Pb was mainly distributed in the continuous glass matrix, forming an encapsulation effect on the cesium garnet crystalline phase. This result directly proves that the cured body obtained in this invention possesses a dual-barrier structure of "cesium garnet lattice solidification + lead borosilicate glass matrix encapsulation". This dual-barrier structure helps reduce the leaching and migration risk of Cs during storage and disposal.

[0136] Furthermore, the results of different zeolite-to-lead borosilicate glass precursor ratios, different microwave sintering temperatures, and comparative samples in the examples show that the degree of cesium garnet formation, the densification degree of the solidified body, and the continuity of the glass matrix are jointly regulated by the ratio and temperature. When the cesium-exchanged NaY zeolite content is too high or the sintering temperature is too low, insufficient glass phase or insufficient liquid phase reaction may lead to zeolite residues and structural inhomogeneity. When the ratio of cesium-exchanged NaY zeolite to lead borosilicate glass precursor is appropriate and sintering is carried out in the range of 600–700℃, better cesium garnet formation and matrix encapsulation effects can be obtained. The above results indicate that the present invention does not simply employ microwave heating, but achieves low-temperature in-situ mineralization and glass-ceramic two-phase solidification through the synergistic effect of the reactive cesium-exchanged NaY zeolite precursor, low-temperature softening of lead borosilicate glass, and microwave volumetric heating.

[0137] Based on the above experimental results, it can be confirmed that the present invention has at least the following technical effects: First, it achieves low-temperature in-situ conversion of cesium-exchanged NaY zeolite into cesium garnet-based glass-ceramic solidified bodies within the temperature range of 500–800 °C; second, it promotes low-temperature liquid phase formation, interfacial diffusion, and densification of the solidified body through lead boron glass precursors; third, it forms a dual-barrier structure with the synergistic effect of cesium garnet lattice solidification and lead boron glass matrix encapsulation; fourth, compared with the comparative example without lead boron glass precursors, it significantly improves the cesium garnet crystal phase formation ability and the structural integrity of the solidified body; and fifth, it provides an feasible technical route for the low-temperature, short-process, and stabilization treatment of cesium-containing zeolite secondary radioactive waste.

[0138] Evidence related to the technical effects obtained in the embodiments of the present invention.

[0139] I. Evidence that lead borosilicate glass precursors promote the formation of low-temperature cesium garnet crystal phases

[0140] Figure 9 X-ray diffraction was used to analyze the phase composition of the solidified bodies obtained in Examples 1 to 5 and Comparative Example 1. The results showed that, with the addition of a lead borosilicate glass precursor, Examples 1 to 3 all exhibited characteristic diffraction peaks of cesium garnet-type CsAlSi2O6 after microwave sintering at 700 °C, and Example 4 also formed a distinct cesium garnet crystal phase after microwave sintering at 600 °C. In contrast, Comparative Example 1 only used Cs... +Replacing NaY zeolite powder with no lead borosilicate glass precursor resulted in the retention of the FAU-type zeolite phase after microwave treatment at 700℃, without the formation of a distinct cesium garnet main crystal phase. These results indicate that the lead borosilicate glass precursor is not a typical filler component, but rather a key fluxing component that promotes zeolite framework reconstruction and cesium garnet crystal phase formation at lower temperatures.

[0141] II. Evidence for the Synergistic Regulation of Mineralization Transformation by Sintering Temperature and Glass Phase Content

[0142] The results of the examples show that the degree of cesium garnet crystal formation is affected by both the microwave sintering temperature and the amount of lead borosilicate glass precursor added. When the sintering temperature is 600–700 °C, no obvious residual characteristic peaks of zeolite precursors were observed in the samples containing lead borosilicate glass precursors, indicating that a relatively complete zeolite-to-cesium garnet conversion can be achieved within this temperature range. When the sintering temperature is reduced to 500 °C, samples with low zeolite content can still form clear cesium garnet main peaks, while samples with high zeolite content show residual FAU zeolite peaks, indicating that if the glass phase is insufficient at lower temperatures, the interfacial reaction and liquid-phase assisted mass transfer are insufficient, leading to incomplete mineralization conversion. These results demonstrate that the present invention controls Cs... + By changing the mass ratio of NaY zeolite to lead borosilicate glass precursor and the microwave sintering temperature, the formation rate of cesium garnet and the structure of the solidified body can be effectively controlled.

[0143] III. Evidence for the Stable Formation of the Cesium Garnet Lattice Structure

[0144] Figure 10 Rietveld refinement analysis was performed on representative sample examples. The results showed that the XRD patterns of all representative samples could be well fitted using the tetragonal cesium garnet structure model, with a space group of I41 / acd and cell parameters a≈c≈13.66 Å. This indicates that the obtained cesium garnet lattice maintains a stable crystal structure under different sintering temperatures and formulations. Combined with the XRD dispersion background, it is clear that the obtained solidified body is not a single-phase ceramic, but a glass-ceramic solidified body composed of both the cesium garnet crystalline phase and the residual glass phase. This structure provides the phase basis for the subsequent formation of a dual barrier of "lattice-solidified cesium + glass encapsulation".

[0145] IV. Evidence for Zeolite Framework Reconstruction and Glass Phase Participation in Reactions

[0146] Figure 11 Fourier transform infrared spectroscopy was used to analyze the original NaY zeolite and Cs. + Local structural analysis was performed on the exchanged NaY zeolite and sintered samples. The results showed that the original NaY zeolite and Cs... +Exchange-modified NaY zeolite exhibits typical FAU-type zeolite framework vibration characteristics. After microwave sintering assisted by a lead-boron glass precursor, the characteristic absorption peaks of the FAU-type zeolite significantly weakened or disappeared, while composite absorption peaks related to the borate network, Si-OT framework vibrations, and low-wavenumber framework vibrations appeared. This result indicates that during microwave sintering, the zeolite precursor underwent framework reconstruction and interfacial reactions with the lead-boron glass phase, forming a new coexisting structure of aluminosilicate crystalline phase and glass matrix.

[0147] V. Evidence of the densification effect of the cured body

[0148] Figure 7 Bulk density and volume shrinkage rate were tested on the samples from the examples. The results showed that the bulk density of all samples with added lead borosilicate glass precursors was significantly higher than that of Comparative Example 1 without the lead borosilicate glass precursor, indicating that lead borosilicate glass can promote particle rearrangement, pore filling, and matrix densification during microwave sintering. The CGZ60 system corresponding to Example 2 achieved a good balance between densification and waste loading at 600–700℃, with a volume shrinkage rate of approximately 58%. This result demonstrates that the liquid phase formed by the low-temperature softening of lead borosilicate glass can effectively promote sintering shrinkage and structural densification of the solidified body, thereby improving the overall integrity of the solidified body.

[0149] VI. Evidence for the formation of the double-barrier structure

[0150] Figure 8 The microstructure and elemental distribution of representative samples were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that the CGZ60-700 sample obtained in Example 2 possessed a relatively uniform and dense microstructure, with cesium garnet grains dispersed within a continuous glass matrix. EDS point and surface scan results revealed a significant spatial co-location relationship between Cs, Si, and Al elements, while Pb was mainly enriched in the surrounding continuous matrix. This elemental distribution indicates that Cs primarily enters the aluminosilicate crystal phase region and is constrained by the cesium garnet lattice, while Pb mainly exists within the glass matrix, providing continuous encapsulation. This demonstrates that the cured body obtained in this invention forms a dual-barrier structure with the synergistic effect of cesium garnet lattice confinement and lead-boron glass matrix encapsulation.

[0151] VII. Evidence of cesium retention and lead stability

[0152] Representative samples were subjected to microwave digestion and inductively coupled plasma mass spectrometry (ICP-MS). The results showed that under microwave sintering conditions at 700 °C, neither Cs nor Pb experienced significant loss in the solidified body, with an apparent Cs retention rate exceeding 99%. This demonstrates that the low-temperature microwave mineralization process employed in this invention can effectively reduce the volatilization loss of Cs during heat treatment while simultaneously forming the cesium garnet crystal phase and glass-ceramic structure, and maintain the relative stability of the Pb component in the solidified body. This evidence further supports the technical effectiveness of this invention in low-temperature cesium solidification and reducing the burden of exhaust gas treatment.

[0153]

[0154] 8. Evidence regarding leaching resistance and long-term treatment safety

[0155] Figure 12 A static leaching test was conducted on a representative solidified body using deionized water at 90 °C. The results showed that the optimized formulation sample maintained a low Cs release level after 42 days of leaching, indicating that the cesium garnet crystalline phase and the glass matrix synergistically inhibited Cs release into the aqueous phase. XRD analysis after leaching showed that the sample retained characteristic diffraction peaks of cesium garnet, and no obvious new crystalline corrosion products were detected. SEM-EDS analysis after leaching showed that only localized alteration occurred on the sample surface, and the internal structure remained relatively dense and intact, without large-area cracking, peeling, or structural collapse. These results demonstrate that the solidified body obtained in this invention exhibits good structural stability and leaching resistance under water contact conditions, and can reduce the risk of radioactive Cs migration during storage and disposal.

[0156] IX. Evidence of the advantages of microwave cryogenic mineralization process

[0157] Figure 13 The example uses a microwave sintering temperature range of 500–800 °C, and Cs can be achieved by holding at that temperature for 30–60 min. + The invention facilitates the conversion of NaY zeolite into a cesium garnet-based glass-ceramic solid. Compared to typical cesium garnet or glass-ceramic preparation routes that require temperatures close to or above 1000 °C, this invention significantly reduces the processing temperature and shortens the high-temperature heat treatment time. Combined with comparative results, it is evident that microwave treatment alone is insufficient to complete cesium garnet mineralization at low temperatures; a synergistic effect exists between the low-temperature fluxing of lead-boron glass and microwave volumetric heating. This evidence suggests that the technical effect of this invention does not derive from conventional heated sintering, but rather from a low-temperature in-situ mineralization mechanism resulting from the coupling of "reactive zeolite precursor, low-temperature liquid phase of lead-boron glass, and microwave heating."

[0158] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0159] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing cesium garnet glass-ceramic solidified bodies by low-temperature in-situ microwave mineralization of cesium exchange NaY zeolite, characterized in that, Includes the following steps: Step 1: Mix cesium ion-exchanged NaY zeolite powder with lead borosilicate glass precursor powder to obtain homogeneous precursor mixed powder. Step 2: The homogeneous precursor mixture powder is cold-pressed to obtain a green body; Step 3: Place the green body in a microwave sintering furnace, heat it to 500~800 ℃ in an air atmosphere and keep it at that temperature. After keeping it at that temperature, let it cool naturally to room temperature to obtain a cesium garnet-based glass ceramic solidified body.

2. The method as described in claim 1, characterized in that, The method for preparing the cesium ion-exchanged NaY zeolite powder includes: NaY zeolite powder was dispersed in an aqueous solution of cesium chloride containing cesium ions, and the mixture was kept at a constant temperature and shaken at 25 °C for 12 h. After filtration, washing, and drying, the cesium ion-exchanged NaY zeolite powder was obtained.

3. The method as described in claim 2, characterized in that, The concentration of cesium ions in the cesium chloride aqueous solution is 5 g / L.

4. The method as described in claim 1, characterized in that, The lead boron glass precursor powder is a mixture of lead dioxide and boron trioxide, with a molar ratio of lead dioxide to boron trioxide of 60:

40.

5. The method as described in claim 1, characterized in that, The mass ratio of the cesium ion-exchanged NaY zeolite powder to the lead borosilicate glass precursor powder is 40~80:60~20.

6. The method as described in claim 1, characterized in that, The mixing process employs wet grinding, followed by drying; the cold pressing pressure is 150~250 MPa; the heating rate is 15~25 ℃ / min; and the holding time is 30~60 min.

7. A cesium garnet-based glass-ceramic cured body, characterized in that, The cesium garnet-based glass-ceramic solidified body is prepared by cold pressing, microwave sintering in air atmosphere, and natural cooling of a homogeneous precursor mixture powder containing cesium ion-exchanged NaY zeolite powder and lead borosilicate glass precursor powder. The microwave sintering temperature is 500~800 ℃.

8. The cesium garnet-based glass-ceramic cured body as described in claim 7, characterized in that, The cesium ion-exchanged NaY zeolite powder was obtained by exchanging NaY zeolite powder with a cesium chloride aqueous solution containing cesium ions. The concentration of cesium ions in the cesium chloride aqueous solution was 5 g / L, the exchange treatment temperature was 25 °C, and the exchange treatment time was 12 h.

9. The cesium garnet-based glass-ceramic cured body as described in claim 7, characterized in that, The lead boron glass precursor powder is a mixture of lead dioxide and boron trioxide, with a molar ratio of lead dioxide to boron trioxide of 60:

40.

10. The cesium garnet-based glass-ceramic cured body as described in claim 7, characterized in that, In the homogeneous precursor mixed powder, the mass ratio of the cesium ion-exchanged NaY zeolite powder to the lead borosilicate glass precursor powder is 40~80:60~20; the pressure of the cold pressing is 150~250 MPa; the heating rate of the microwave sintering is 15~25 ℃ / min, and the holding time is 30~60 min.

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