Method for preparing Li2TiO3 tritium breeding microspheres and rich phase structure by centrifugal granulation batch

Abstract

The present application relates to the technical field of preparation of tritium breeder, in particular to a method for batch preparation of Li2TiO3 tritium breeding microspheres and rich phase structure by centrifugal granulation, comprising the following steps: S1, Li2TiO3 ceramic powder is pretreated by spray granulation, then sprayed with a solution of xanthan gum for granulation, and sieved to obtain a green body; S2, the green body is added into a centrifugal granulator, and a second binder solution is sprayed at the same time, so that Li2TiO3 microsphere seeds with a preset diameter are generated by centrifugal granulation; S3, then the second binder solution is sprayed while lithium-containing ceramic powder is added for granulation and bonding; S4, the process of S3 is repeated until ceramic microsphere green bodies with the required diameter are obtained; S5, then deionized water is sprayed in the granulator and continues to roll for 3-8 min; S6, the ceramic microspheres obtained in S5 are dried at constant temperature and humidity, degummed, and sintered. The method can realize batch preparation of high-lithium-content tritium breeding microspheres with single-phase structure or multi-phase structure.

Description

Technical Field

[0001] This invention relates to the field of tritium proliferation agent preparation technology, and in particular to a method for the mass preparation of Li2TiO3 tritium proliferation microspheres and rich phase structures by centrifugation granulation. Background Technology

[0002] With the gradual depletion of fossil fuels, energy and environmental pollution issues have been a major global concern. Currently, nuclear fusion energy, due to its environmentally friendly, clean, safe, and sustainable advantages, is being actively explored by researchers worldwide. Among these, the deuterium-tritium nuclear reaction is considered the most ideal and reliable route. Deuterium is abundant in seawater and easily extracted; however, tritium is scarce in nature and must be obtained through a violent reaction between neutrons and lithium atoms under high temperature and pressure. Solid-state lithium ceramics, with their excellent chemical stability, high safety, and absence of magnetohydrodynamic effects, are currently considered the most ideal tritium breeder material.

[0003] Ideal tritium breeding materials should possess high lithium density, high thermal conductivity, high mechanical strength, low tritium retention, good compatibility with structural materials, and excellent radiation resistance. Currently, solid tritium breeding materials that meet these requirements mainly include Li₂O, Li₂TiO₃, Li₄SiO₄, Li₂ZrO₃, and LiAlO₂. Furthermore, solid tritium breeders in the cladding are typically designed as spherical structures. Spherical structures offer advantages such as (1) facilitating tritium diffusion and release; (2) ease of filling complex spherical beds and recovering residual lithium; (3) benefiting high lithium density; and (4) reducing thermal stress concentration and preventing blockage of tritium release channels. Currently, improving the tritium breeding ratio by increasing lithium content has become a major research focus in cladding. Integrating the advantages of single-phase ceramics can significantly increase lithium density, but current research mainly focuses on multiphase powders, which cannot meet the actual needs of cladding spherical beds. This invention can effectively overcome this difficulty, enabling the mass production of multiphase ceramics and providing a favorable guarantee for tritium raw materials.

[0004] Current literature reports that wet molding and melt spraying techniques can be used for small-scale preparation of tritium-breeding agent ceramic microspheres. The wet process involves ball milling a mixture of ceramic powder, binder, and deionized water to obtain a ceramic slurry, which is then dripped into silicone oil or liquid nitrogen, where surface tension acts to form ceramic microspheres. Melt spraying requires melting the ceramic powder into a liquid state at high temperatures, which is then sprayed onto a cold airflow to form ceramic microspheres. However, these methods suffer from high costs, low lithium content, poor sphericity, and difficulty in large-scale production, thus failing to meet practical application requirements.

[0005] Moreover, the existing methods for preparing multiphase ceramic microspheres usually involve ball milling and mixing two powders and then preparing biphase ceramic microspheres by wet processing. However, the structure of multiphase microspheres is difficult to control, and the production efficiency is still low, which cannot meet the actual needs. Summary of the Invention

[0006] The technical problem this invention aims to solve is to provide a method for the mass production of Li₂TiO₃ tritium-cultured microspheres and their enriched phase structure using centrifugal granulation. The obtained Li₂TiO₃ tritium-cultured microspheres exhibit good sphericity, high lithium content, and excellent mechanical properties, meeting the practical requirements for future nuclear fusion reactors. This invention achieves the mass production of Li₂TiO₃ tritium-cultured microspheres using centrifugal granulation. This method is a simple and easy technology for the mass production of tritium-cultured ceramic microspheres, and it easily increases the lithium content of the tritium-cultured agent, enabling the production of multiphase structure ceramic microspheres. This method allows for the mass production of high-lithium-content tritium-cultured microspheres, which will provide a favorable guarantee for the supply of tritium fuel.

[0007] The inventors of this invention discovered that although centrifugal granulation technology has related applications in other fields such as zirconium oxide, it has not been reported in the preparation of Li2TiO3 tritium-grown microspheres. After extensive experimentation, the inventors found that conventional centrifugal granulation methods could not be successfully applied to the preparation of Li2TiO3 tritium-grown microspheres, and it was impossible to prepare Li2TiO3 tritium-grown microspheres with high sphericity and high lithium content. The inventors speculate that the reason may be that the combination of binder and powder type has a very important impact on product performance. Different functional groups, electronegativity, pH and other physical properties of powder or binder will affect the bonding force between powder and binder, thereby affecting the amount of lithium powder added later, and affecting sphericity and strength. The surface area of ​​Li2TiO3 ceramic powder in this field is too large, making it prone to agglomeration. When a binder is sprayed, it easily causes a large amount of particle agglomeration, rather than the layer-by-layer growth as in this invention. Through further extensive research, the inventors discovered that by using a combination of specific types of binders and specific steps, especially 1. using spray granulation pretreatment, the flowability and bulk density of the powder can be improved, and the collision between particles can be increased during centrifugal granulation; 2. using specific types and concentrations of binders can improve the plasticity and binding force of the powder, allowing the powder to slowly grow layer by layer on the surface of the green sphere. This enabled the successful mass production of Li2TiO3 tritium-growing microspheres by centrifugal granulation, leading to this invention.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] A method for the mass production of Li₂TiO₃ tritium-rich microspheres and their enriched phase structure by centrifugal granulation includes the following steps:

[0010] S1. Li2TiO3 ceramic powder is pretreated by spray granulation, then sprayed with Tianqing gum solution for granulation, and sieved to obtain spherical blanks; the spray granulation pretreatment includes a first binder solution containing 0.1-0.5 wt% PVA (i.e., polyvinyl alcohol) and 0.1-0.3 wt% dispersant; the concentration of Tianqing gum in the Tianqing gum solution is 1-5 wt%.

[0011] S2. Add the pellet to a centrifugal granulator and spray the second binder solution at the same time. Generate Li2TiO3 microsphere seeds of a preset diameter by centrifugal granulation.

[0012] S3. Using Li2TiO3 microsphere seeds as the base material, lithium-containing ceramic powder is added while spraying the second binder solution to granulate and bind the material.

[0013] The second binder solution contains a second binder concentration of 0.1-0.5 wt%, preferably 0.2-0.4 wt%, and the second binder is at least two of hydroxypropyl methylcellulose, glycerin, tannin, and ethanol.

[0014] S4. Then repeat the process of S3 until the desired diameter of Li2TiO3 ceramic microsphere preform is obtained.

[0015] S5. Spray the ceramic microsphere preform obtained in S4 with deionized water in a granulator and continue rolling for 3-8 minutes to obtain dense ceramic microspheres.

[0016] S6. The ceramic microspheres obtained in S5 are dried under constant temperature and humidity, debinded, and sintered to obtain Li2TiO3 tritium-proliferating ceramic microspheres.

[0017] In S1 to S4, the centrifugal rotation speed of the centrifugal granulator is 30-50 rpm, and the granulation plane tilt angle is 30-45°; in S5, the centrifugal rotation speed of the granulator is 10-25 rpm, and the granulation plane tilt angle is 10-25°.

[0018] In S1 of this invention, a first binder solution containing PVA and a dispersant is used for spray granulation pretreatment. This can obtain powder with high solid content, improve the powder's flowability and bulk density, prevent the powder from being suspended in the centrifuge, and facilitate the obtaining of spherical blanks with high dispersibility and good flowability. However, if the first binder solution does not contain a dispersant, the solid content of the ceramic slurry cannot be increased, resulting in hollow or elliptical particles after spray granulation.

[0019] This invention involves spraying a PVA solution after pretreatment for spray granulation. This fully utilizes the multiple hydroxyl functional groups in PVA, which can effectively bond with lithium titanate powder and improve the powder's plasticity, making it easier to form spherical seeds. If PVA solution is not used for granulation, and only PVA is used for spray granulation pretreatment, the plasticity of the powder cannot be improved.

[0020] This invention first uses high speed and high tilt angle for granulation, and then rolls at low speed and low tilt angle after the required size is reached, which helps to improve the compactness of the ceramic microsphere structure.

[0021] Preferably, in S1, the dispersant is at least one of ammonium citrate, polyacrylic acid, and sodium tripolyphosphate.

[0022] Those skilled in the art can prepare ceramic powder raw materials (such as Li₂TiO₃, Li₄SiO₄, LiAlO₂, Li₂ZrO₃) using any existing method. For example, the Li₂TiO₃ ceramic powder is prepared by ball milling and a solid-state reaction at 700-800℃. In some embodiments, the Li₂TiO₃ ceramic powder is prepared by mixing Li₂CO₃ and TiO₂, then adding water and ball milling, followed by a solid-state reaction at 700-800℃.

[0023] Preferably, in S1, the conditions for the spray granulation pretreatment include: the solid content of the spray-formed ceramic slurry is 30-55 wt%, the spraying method is centrifugal granulation, and the slurry is continuously stirred during the spraying process. This preferred scheme is more conducive to improving the quality and yield of microspheres. Under the same conditions, a low solid content can cause the spheres to collapse and stick together; too much powder or too high a solid content can easily cause abnormal growth of the spheres, resulting in a loose internal structure.

[0024] Those skilled in the art can select the amount of Tianqing gum solution to be added according to the granulation requirements. For example, the amount of Tianqing gum solution added relative to Li2TiO3 ceramic powder is controlled to be 0.5-1wt%.

[0025] Preferably, in S1, the particle size of the spherical blank is 80-90 mesh.

[0026] Preferably, in S2, the diameter of the Li2TiO3 microsphere seeds is 0.2-0.4 mm.

[0027] Preferably, the second binder comprises four components: hydroxypropyl methylcellulose, glycerol, tannin gum, and ethanol, with a weight ratio of 1:1-2:3-5:0.5-2. This preferred embodiment utilizes a specific binder combination to adjust the plasticity, wettability, and adhesion of the powder, achieving optimal matching with the ceramic powder in terms of plasticity and adhesion. The resulting bond is quite strong, facilitating the preparation of ceramic microspheres with a dense internal structure and high sphericity.

[0028] In this invention, the spraying amount of the second binder solution is only sufficient to wet the spherical blank and facilitate adhesion of other materials to increase its diameter. Preferably, in steps S2-S4, the spraying amount of the second binder solution is 1-3 mL / min. Under this preferred embodiment, the moisture content of the ceramic microspheres in the centrifuge can be better controlled, which is beneficial for the uniform adhesion of powder particles to the surface of the spherical blank.

[0029] Those skilled in the art can select the amount of preform added according to their needs, as long as it is beneficial to the subsequent preparation of a product with the desired diameter. Preferably, the amount of preform added is less than 100g. Adding too much preform will prolong the time to obtain the desired diameter.

[0030] Preferably, in S3, the lithium-containing ceramic powder includes at least one of Li2TiO3, Li4SiO4, Li2ZrO3, and LiAlO2.

[0031] In S3, preferably, the centrifugal dispersion refers to dispersing the spheres coated with the second binder using a 30-50 mesh sieve during the centrifugal granulation process.

[0032] The phase-rich structure described in this invention includes a single-phase structure or a multiphase structure.

[0033] Preferably, the method further includes: in S3 and S4, selecting the type of lithium-containing ceramic powder added in each step according to the desired layer structure of the microspheres, and obtaining multiphase structure ceramic microspheres when the types of lithium-containing ceramic powder added in each step are different.

[0034] More preferably, the second binder solution in step S3 further includes polyethylene glycol, with a mass ratio of polyethylene glycol to the second binder of 1-2:1. This preferred embodiment is more conducive to preparing ceramic microspheres with a dense internal structure, rather than preventing stratification due to differences in the powder composition.

[0035] More preferably, the multiphase ceramic microspheres include any one of Li2TiO3-Li4SiO4, Li2TiO3-Li2ZrO3, Li2TiO3-LiAlO2, and Li2TiO3-Li4SiO4-Li2ZrO3.

[0036] In this invention, preferably, the amount of lithium-containing ceramic powder added is 3-50 g / min, more preferably 3-30 g / min. Those skilled in the art can determine the addition amount based on the density of the lithium-containing ceramic powder; the lower the density, the less powder should be added. Preferably, the density of the Li4SiO4 powder is as low as 2.39 g / cm³. 3 The addition rate is 3-5 g / min, and the addition rate of Li2ZrO3 powder is 5-20 g / min.

[0037] Preferably, in step S6, the constant temperature and humidity drying time is 5-10 hours, the temperature is preferably the same as the ambient temperature (e.g., 20-30℃), and the humidity is 5%-10%.

[0038] In some preferred embodiments, the constant temperature and humidity drying conditions in S6 include: a temperature of 20°C, a humidity of 10%, and a time of 5-10 hours.

[0039] In step S5, preferably, the adhesive removal process includes: heating from room temperature to 450-550℃ at a heating rate of 0.5-2℃ / min, and holding at that temperature for 2-4 hours. Under this preferred embodiment, slowly heating the Li2TiO3 ceramic microsphere preform to remove the adhesive helps eliminate organic matter from the ceramic microsphere preform and prevents internal cracking.

[0040] In step S5, preferably, the sintering conditions include a temperature of 1000-1130℃ and a time of 2-4 hours. Preferably, the centrifugal granulator of the present invention is coated with a uniformly thick polyurethane coating, which helps to reduce friction between the pellets and the inner wall of the centrifuge, resulting in smooth and dense ceramic pellets.

[0041] This invention enables the preparation of Li2TiO3 tritium-breviated ceramic microspheres with a diameter of 0.2-10 mm.

[0042] The beneficial effects of the above-described technical solution of the present invention are as follows:

[0043] In the above scheme, a spherical preform with high bulk density, good sphericity, and good flowability is first prepared by spray granulation pretreatment. Then, Li2TiO3 tritium-grown microspheres and multiphase ceramic microspheres are prepared by centrifugal granulation technology under appropriate process parameters using a suitable binder. Finally, Li2TiO3 tritium-grown ceramic microspheres and multiphase ceramic microspheres with high sphericity, high lithium content, high density, and excellent mechanical properties are obtained by debinding and sintering.

[0044] This invention has the following advantages:

[0045] 1. The present invention provides a method for the mass production of Li2TiO3 tritium-proliferating microspheres and rich-phase structures by centrifugal granulation. Pre-treatment of the powder with spray granulation technology is beneficial to obtaining Li2TiO3 tritium-proliferating microsphere seeds with high sphericity, which can be further used to prepare Li2TiO3 tritium-proliferating ceramic microspheres with excellent performance.

[0046] 2. The centrifugal granulation method used in this invention is a simple and easily mass-produced technique for ceramic microspheres. This method can prepare not only single-phase ceramic microspheres but also multi-phase ceramic microspheres, which will facilitate the acquisition of tritium breeding agents with high lithium density and improve tritium productivity.

[0047] 3. By using different binders in different steps, this invention can improve the plasticity of the powder, thereby increasing the density and sphericity of the ceramic microspheres.

[0048] 4. This invention is mainly based on the use of a specific binder to wet the powder, which can reduce the specific surface area of ​​the powder. Under the action of centrifugal force and binding force, tritium-breeding ceramic microspheres are prepared. The equipment used is simple, easy to operate, low in cost, and easy to mass-produce, making it suitable for widespread use in this field. Attached Figure Description

[0049] Figure 1 is SEM image of Li2TiO3 powder after spray granulation pretreatment;

[0050] Figure 2 This is a SEM image of Li2TiO3 tritium propagation agent microspheres after centrifugation and granulation;

[0051] Figure 3 These are SEM images of Li2TiO3 tritium-infused ceramic microspheres after centrifugation and granulation.

[0052] Figure 4 SEM images of Li2TiO3-Li4SiO4 biphase tritium-breeding ceramic microspheres prepared in batches using centrifugal granulation method;

[0053] Figure 5 SEM image of Li2TiO3 tritium proliferator microspheres prepared in Comparative Example 1 without spray granulation pretreatment;

[0054] Figure 6 This is a SEM image of the Li2TiO3 tritium proliferator microspheres prepared by centrifugation at a speed of 55 r / min in Comparative Example 5. Detailed Implementation

[0055] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0056] Example 1

[0057] A method for batch preparation of Li₂TiO₃ tritium-rich microspheres and their enriched phase structure by centrifugal granulation includes the following steps:

[0058] (1) Mix Li2CO3 and TiO2 in a 1:1 molar ratio, add 1.5 times the amount of deionized water and ball mill for 2 hours, dry, sinter at 750℃ and keep warm for 2 hours to obtain Li2TiO3 ceramic powder.

[0059] 500g of Li₂TiO₃ ceramic powder was pretreated by spray granulation. The SEM image of the resulting powder is shown below. Figure 1 The process involves spraying 50g of Tianqing gum solution for granulation, followed by sieving through an 80-mesh sieve to obtain highly fluid spherical preforms. The spray granulation pretreatment includes spraying a first binder solution containing 0.3wt% PVA and 0.2wt% dispersant. The Tianqing gum solution contains 2wt% Tianqing gum. Centrifugal granulation is used, with the slurry continuously stirred during the spraying process. The powder formed by the spray granulation pretreatment has a solid content of 45wt%. The dispersant is polyacrylic acid.

[0060] (2) The pellets and the second binder solution are added to a centrifugal granulator by adding pellets and spraying a second binder solution on one side. The centrifugal granulator has a uniformly thick polyurethane coating inside. Through centrifugal rolling, Li2TiO3 microsphere seeds with a diameter of 0.3 mm and a certain strength are generated. Their SEM images are as follows: Figure 2 As shown; the second binder solution is prepared from hydroxypropyl methylcellulose, glycerol, tannin gum, ethanol, and deionized water, with a total mass concentration of 0.3 wt% for hydroxypropyl methylcellulose, glycerol, tannin gum, and ethanol; the weight ratio of hydroxypropyl methylcellulose, glycerol, tannin gum, and ethanol is 1:1:3:0.5. The spraying rate of the second binder solution is 2 mL / min, and the amount of pellet added is 100 g.

[0061] (3) Using Li2TiO3 microsphere seeds as the base material, Li2TiO3 ceramic powder (the amount of ceramic powder added is 10g / min) is added while spraying the second binder solution to granulate and bind. The mixture is then centrifuged and dispersed through a 30-mesh sieve to obtain new ceramic seeds as the base material for the next step.

[0062] (4) Then repeat the process of (3) until a Li2TiO3 ceramic microsphere blank with a diameter of 1 mm is obtained;

[0063] (5) Spray the ceramic microsphere blank obtained in S4 with deionized water in a granulator and continue rolling for 5 minutes to obtain dense ceramic microspheres.

[0064] (6) Then, constant temperature and humidity drying was performed (temperature 20℃, humidity 10%, time 6h). The temperature was increased from room temperature to 500℃ at a rate of 1℃ / min, and the mixture was kept at this temperature for 2h to remove the binder. Finally, it was sintered at 1100℃ for 2h to obtain single-phase Li2TiO3 tritium-infused microspheres. Figure 3 As shown.

[0065] In steps (1) to (4), the centrifugal granulator used has a centrifugal rotation speed of 40 rpm and a granulation plane tilt angle of 35°; in step (5), the centrifugal granulator used has a centrifugal rotation speed of 20 rpm and a granulation plane tilt angle of 20°.

[0066] The performance test data of the obtained Li2TiO3 tritium-proliferated microspheres are shown in Table 1 below: sphericity (tested by measuring the major and minor axis diameters of the ceramic spheres through SEM images, with the ratio of the minor axis to the major axis as the sphericity), lithium content (inductively coupled plasma atomic emission spectrometry), strength (results from force-displacement curves measured by a universal testing machine), and density (determined according to Archimedes' displacement method).

[0067] Example 2

[0068] The method was carried out according to Example 1, except that Li4SiO4 was added instead of Li2TiO3 ceramic powder in the continued granulation and bonding in step (3), and polyethylene glycol was also added to the second binder solution used in step (3), with a mass ratio of polyethylene glycol to the total amount of the second binder of 1:1; two-phase Li2TiO3-Li4SiO4 ceramic microspheres were obtained, and their SEM images are shown below. Figure 4 As shown. The final optical image of the obtained Li2TiO3-Li4SiO4 dual-phase tritium-breeding ceramic microspheres is shown below. Figure 4 As shown. From Figure 4 As can be seen, the internal bonding of the two-phase tritium breeder ceramic is tight, and no layered structure is observed.

[0069] Example 3

[0070] The method is the same as in Example 1, except that there are two types of second binders in the second binder solution, unlike the four types in Example 1. Specifically, this example uses hydroxypropyl methylcellulose and glycerin in a mass ratio of 1:1.

[0071] Example 4

[0072] The method is the same as in Example 1, except that there are two types of second adhesives in the second adhesive solution, unlike the four types in Example 1. Specifically, this example uses hydroxypropyl methylcellulose and ethanol in a mass ratio of 1:1.

[0073] Example 5

[0074] The method was carried out in accordance with Example 1, except that the concentration of the second adhesive in the second adhesive solution was 0.5 wt%.

[0075] Example 6

[0076] The method was carried out in accordance with Example 1, except that the amount of ceramic powder added in step (3) was 50 g / min.

[0077] Comparative Example 1

[0078] The method described in Example 1 is followed, except that spray granulation pretreatment is not used; instead, the subsequent step of spraying the second binder solution is performed directly. This method fails to obtain satisfactory seeds; the seeds obtained under this method are not dense enough internally and have low density, thus failing to meet the requirements. Figure 5 As shown.

[0079] Comparative Example 2

[0080] The method was carried out according to Example 1, except that the first binder was PVA, not Tianqing gum. Its centrifugal granulation process could not obtain seeds with high sphericity.

[0081] Comparative Example 3

[0082] The method was carried out in accordance with Example 1, except that the second binder was a single binder, hydroxypropyl methylcellulose, instead of the four binder combinations in Example 1. The hydroxypropyl methylcellulose alone resulted in poor sphericity and surface finish of the binder microspheres.

[0083] Comparative Example 4

[0084] The method was carried out according to Example 1, except that the weight ratio of the second binder to water in the second binder solution was 0.8%:1. The sphericity of the ceramic microspheres was not high enough.

[0085] Comparative Example 5

[0086] The method is the same as in Example 1, except that the centrifugal granulator rotates at a speed of 55 rpm. The surface of the ceramic microspheres is uneven, such as... Figure 6 As shown.

[0087] Table 1

[0088]

[0089]

[0090] As can be seen from the above embodiments and comparative examples, only by using the specific binder and specific method of the present invention can the mass production of Li2TiO3 tritium-breeding ceramic microspheres be successfully achieved by centrifugal granulation.

[0091] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for the mass production of Li₂TiO₃ tritium-rich microspheres and their enriched phase structure by centrifugal granulation, characterized in that, Includes the following steps: S1. Li2TiO3 ceramic powder is pretreated by spray granulation, then sprayed with Tianqing gum solution for granulation, and sieved to obtain spherical blanks; the spray granulation pretreatment includes a first binder solution containing 0.1-0.5 wt% PVA and 0.1-0.3 wt% dispersant; the dispersant is at least one of ammonium citrate, polyacrylic acid, and sodium tripolyphosphate; the concentration of Tianqing gum in the Tianqing gum solution is 1-5 wt%. S2. Add the pellet to a centrifugal granulator and spray the second binder solution at the same time. Generate Li2TiO3 microsphere seeds of a preset diameter by centrifugal granulation. S3. Using Li2TiO3 microsphere seeds as the base material, lithium-containing ceramic powder is added while spraying the second binder solution to granulate and bind the material. The second binder solution contains a second binder concentration of 0.1-0.5 wt%, and the second binder includes four types: hydroxypropyl methylcellulose, glycerin, tannin gum, and ethanol, with a weight ratio of 1:1-2:3-5:0.5-2. S4. Then repeat the process of S3 until the desired diameter of Li2TiO3 ceramic microsphere preform is obtained. S5. Spray the ceramic microsphere preform obtained in S4 with deionized water in a granulator and continue rolling for 3-8 minutes to obtain dense ceramic microspheres. S6. The ceramic microspheres obtained in S5 are dried under constant temperature and humidity, debinded, and sintered to obtain Li2TiO3 tritium-proliferating ceramic microspheres. In S1 to S4, the centrifugal rotation speed of the centrifugal granulator is 30-50 rpm, and the granulation plane tilt angle is 30-45°; in S5, the centrifugal rotation speed of the granulator is 10-25 rpm, and the granulation plane tilt angle is 10-25°.

2. The method according to claim 1, characterized in that, In S1, the conditions for the spray granulation pretreatment include: the solid content of the ceramic slurry is 30-55 wt%, the spraying method is centrifugal granulation, and the slurry is continuously stirred during the spraying process.

3. The method according to claim 1, characterized in that, In S1, the particle size of the spherical preform is 80-90 mesh; and / or, in S2, the diameter of the Li2TiO3 microsphere seeds is 0.2-0.4 mm.

4. The method according to claim 1, characterized in that, In S2-S4, the spraying rate of the second adhesive solution is 1-3 mL / min.

5. The method according to claim 1, characterized in that, In S3, the lithium-containing ceramic powder includes at least one of Li2TiO3, Li4SiO4, Li2ZrO3, and LiAlO2, and the amount of lithium-containing ceramic powder added is 3-30 g / min.

6. The method according to claim 1, characterized in that, The method further includes: in S3 and S4, selecting the type of lithium-containing ceramic powder added in each step according to the layer structure of the desired microspheres, and obtaining multiphase structure ceramic microspheres when the types of lithium-containing ceramic powder added in each step are different.

7. The method according to claim 6, characterized in that, The multiphase ceramic microspheres include any one of Li2TiO3-Li4SiO4, Li2TiO3-Li2ZrO3, Li2TiO3-LiAlO2, and Li2TiO3-Li4SiO4-Li2ZrO3.

8. The method according to claim 6 or 7, characterized in that, The second adhesive solution in S3 also includes polyethylene glycol, and the mass ratio of polyethylene glycol to the second adhesive is 1-2:

1.

9. The method according to claim 1, characterized in that, The constant temperature and humidity drying conditions in S6 include: temperature of 20℃, humidity of 10%, and time of 5-10h. In S6, the process of removing the adhesive includes: heating from room temperature to 450-550℃ at a heating rate of 0.5-2℃ / min and holding at that temperature for 2-4 hours; the sintering conditions include: a temperature of 1000-1130℃ and a time of 2-4 hours.

Images