Preparation method of zirconium oxide microspheres
Through the combination of sol-gel technology and spray granulation equipment, the problem of insufficient particle size and density of existing zirconia microspheres is solved, and high-performance zirconia microspheres are prepared, achieving both small size and high performance.
Patent Information
- Application Number
- CN202411352609.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2025-05-13
AI Technical Summary
The limit size of existing zirconia microspheres is 0.05mm, and smaller size zirconia microspheres cannot be prepared. At the same time, the zirconia spheres prepared by traditional processes have defects such as many internal pores and non-density, which cannot meet the needs.
Using sol-gel technology combined with spray granulation equipment, the pH, specific gravity and viscosity index of the dissolving solution is monitored, and organic solvents are selected to obtain a stable sol system. After spraying into balls, drying, washing and sintering are carried out to prepare zirconia microspheres with small particle size, dense internal and poreless zirconia microspheres.
The zirconia microspheres with particle sizes of 0.01 to 0.05 mm were prepared, which had high hardness, large density, small grains, low sintering temperature and no single-clinical zirconia, which improved the performance and application value of zirconia microspheres.
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Figure CN119976952A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of inorganic non-metallic materials, and specifically is a method for preparing zirconium oxide microspheres by combining sol-gel technology with spray granulation equipment. Background Art
[0002] The preparation methods of nano-zirconia generally include physical methods and chemical methods. The physical methods mainly include spray pyrolysis, sputtering, plasma technology, etc., and the chemical methods mainly include gas phase methods (such as gas phase evaporation, chemical vapor synthesis, chemical vapor deposition, and low-temperature gas phase hydrolysis, etc.), liquid phase methods (such as coprecipitation, sol-gel, microemulsion, hydrothermal synthesis, etc.), solid phase methods, solvent thermal methods, etc. Among them, the preparation of nano-zirconia with high dispersion, narrow particle size distribution, no agglomeration and single phase composition has always been a research difficulty in the field of zirconia synthesis.
[0003] Zirconia balls have the characteristics of high strength, high toughness, high rigidity, good wear resistance, high temperature resistance, corrosion resistance, non-magnetic conductivity, and electrical insulation at room temperature. At 600°C, the strength and hardness of zirconia ceramic balls remain almost unchanged, and their density is 6.00g / cm 3 The thermal expansion rate is close to that of metals, and it can be used in conjunction with metals, and is suitable for bearings, seals, etc. High-purity zirconium oxide microbeads (TZP Ceramics beads) are the most ideal grinding media, and are now widely used in the ultra-fine grinding and dispersion of materials in non-metallic minerals, coatings, inks, paints, dyes, titanium dioxide, pesticides, magnetic materials and other industries.
[0004] At present, zirconia microspheres used in the MLCC (Multilayer Ceramic Capacitor) field are mainly imported, and the maximum particle size of existing zirconia microspheres is 0.05mm, and it is impossible to prepare zirconia microspheres of smaller sizes. At the same time, zirconia balls prepared by traditional processes often have defects such as many internal pores and lack of density, which cannot meet the needs. Summary of the invention
[0005] The technical problem to be solved by the present invention is to provide a method for preparing zirconium oxide microspheres. The sol-gel technology is combined with a spray granulation device to prepare zirconium oxide microspheres with a small particle size (average particle size ≤ 0.031 mm). Moreover, the zirconium oxide microspheres prepared by the method also have the advantages of internal density, no pores, high hardness, high density, small grains, low sintering temperature, etc., and XRD testing shows that there is no monoclinic zirconium oxide in the zirconium oxide microspheres.
[0006] In order to solve the above technical problems, the present invention provides a method for preparing zirconium oxide microspheres, comprising the following steps:
[0007] (1) mixing a water-soluble zirconium salt, a water-soluble yttrium salt, and deionized water in a molar ratio of 1:(0.05-0.08):(80-110), and stirring until the water-soluble zirconium salt and the water-soluble yttrium salt are completely dissolved to obtain a solution A;
[0008] (2) slowly adding ammonia water with a volume concentration of 3 to 10% to the solution A of step (1) to form a precipitate, filtering out the precipitate, and washing it with anhydrous ethanol for 4 to 7 times, and then repeatedly adding anhydrous ethanol to the precipitate for 4 to 7 times, stirring and beating, and filtering to obtain a precipitated product;
[0009] (3) preparing a mixed solution of a water-soluble zirconium salt and a water-soluble yttrium salt according to the method of step (1) as solution B; adding the precipitated product obtained in step (2) to solution B and heating it to 65-75° C. for dissolution, and monitoring the pH of the solution to be 1.8-2, the specific gravity to be 1.1-1.2, and the viscosity to be 400-500 mPa.s, to obtain solution C;
[0010] (4) adding an organic solvent to solution C and stirring to obtain sol D;
[0011] (5) using a spray granulator to spray sol D into balls and then drying them, the inlet temperature of the spray granulator being 170 to 200° C. and the frequency of the atomizing disk being 20 to 30 Hz, to obtain the first balls after drying;
[0012] (6) adding the first ball prepared in step (5) into ammonia water having a volume concentration of 10 to 15%, and washing the ball repeatedly for 3 to 5 times using a planetary ball mill at a rotation speed of 100 to 150 r / min, and then placing the washed first ball in an oven at 150 to 180° C. to dry the first ball to obtain a dried second ball;
[0013] (7) Debinding and sintering: The second ball of step (6) is debinded and sintered, the debinding temperature is 500-750°C, the debinding time is 20-50 hours, the sintering temperature is 1100-1200°C, and the sintering time is 10-20 hours. After sintering, zirconia microspheres with a particle size of 0.01-0.05 mm can be obtained.
[0014] Preferably, the water-soluble zirconium salt described in step (1) is any one of zirconium nitrate, zirconium sulfate or zirconium oxychloride, or a mixture of two or more thereof; the water-soluble yttrium salt is any one of yttrium nitrate, yttrium acetate or yttrium chloride, or a mixture of two or more thereof; the molar ratio of the total amount of the water-soluble zirconium salt and the water-soluble yttrium salt to deionized water is 1:(70-130); the amount of the water-soluble yttrium salt added is added in a ratio of 5-8% of the yttrium oxide formed after sintering to the total weight of the zirconium oxide and yttrium oxide after sintering.
[0015] Preferably, the amount of ammonia water added in step (2) is such that the pH value of solution A is maintained at 7 to 9; the volume of anhydrous ethanol added each time in step (2) is 7 to 10 times the volume of the precipitate; and the duration of each stirring and beating in step (2) is 10 to 15 minutes.
[0016] Preferably, the amount of each component of solution B added in step (3) is 1 / 2 of the amount of the corresponding component of solution A added.
[0017] Preferably, the organic solvent described in step (4) is any one of propylene alcohol, isopropanol, polyvinyl alcohol or polyethylene glycol, or a mixture of two or more thereof; the amount of the organic solvent added in step (4) is 1 / 60 to 1 / 40 of the weight of solution C.
[0018] Preferably, the drying temperature in step (5) is 130-150°C.
[0019] Compared with the prior art, this application has the following beneficial effects:
[0020] 1. Sol-gel technology is used to monitor the pH, specific gravity and viscosity of the solution and select organic solvents to obtain a stable sol system. The sol has good stability and can meet the long-term storage requirements of the sol;
[0021] 2. The first ball can be prepared by combining with the spray granulator. The first ball of the required size can be obtained by adjusting the inlet temperature, feed speed and rotation speed of the atomizing disk of the spray granulator, and the particle size of the first ball can be regulated. The faster the rotation speed of the atomizing disk, the smaller the particle size of the first ball, which is more conducive to the preparation of small-sized first balls;
[0022] 3. With the help of the debinding sintering step of the second ball, the sintering of the second ball can be achieved at 1100°C to 1200°C, and after sintering, 0.01 to 0.05 mm zirconia microspheres are obtained, and the surface grain size of the zirconia microspheres is uniform and there are no defects such as pores;
[0023] 4. Through the XRD test of zirconia microspheres, it can be seen that the crystal phases of the zirconia microspheres obtained after sintering are all tetragonal phase and cubic phase, and there is no monoclinic phase, which can ensure that the zirconia microspheres have good anti-aging performance, extended service life, and effectively reduced risk of introducing impurities during use. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 This is a SEM image of the zirconia microspheres prepared in Example 1 at a scale of 20 μm.
[0025] Figure 2 This is a SEM image of the zirconia microspheres prepared in Example 1 at a scale of 5 μm.
[0026] Figure 3 This is the XRD spectrum of the zirconia microspheres prepared in Example 1.
[0027] Figure 4 This is the XRD spectrum of the zirconia microspheres prepared in Example 2.
[0028] Figure 5 This is the XRD spectrum of the zirconia microspheres prepared in Example 3. DETAILED DESCRIPTION
[0029] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.
[0030] Example 1
[0031] A method for preparing zirconium oxide microspheres comprises the following steps:
[0032] Zirconium oxychloride, yttrium chloride and deionized water are mixed at a molar ratio of 1:0.06:80, and stirred until the zirconium oxychloride and yttrium chloride are completely dissolved to obtain a solution A; the molar ratio of the total amount of zirconium oxychloride and yttrium chloride to deionized water is 1:75.47;
[0033] Slowly drop ammonia water with a volume concentration of 5% into solution A until solution A fully reacts, the amount of ammonia water added is such that the pH value of solution A is maintained at 7.0, a precipitate is formed, the precipitate is filtered out by filter press, and washed with anhydrous ethanol 5 times, anhydrous ethanol is repeatedly added to the precipitate 5 times, stirred and beaten, and filtered by filter press to obtain a precipitate product after washing with chlorine, the volume of anhydrous ethanol added each time is 8 times the volume of the precipitate, and the duration of each stirring and beating is 10 minutes;
[0034] Preparation of solution B:
[0035] Zirconium oxychloride, yttrium chloride and deionized water are mixed at a molar ratio of 1:0.06:80, and stirred until zirconium oxychloride and yttrium chloride are completely dissolved, as solution B, wherein the amount of each component of solution B added is 1 / 2 of the amount of each corresponding component of solution A;
[0036] The precipitated product after chlorine washing is slowly added to solution B and heated to 70° C. in a water bath for dissolution, and the pH of the dissolved solution is monitored to be 1.8-2, the specific gravity is 1.1-1.2, and the viscosity is 400-500 mPa.s, to obtain solution C;
[0037] Add polyvinyl alcohol to solution C and stir, wherein the amount of polyvinyl alcohol added is 1 / 50 of the weight of solution C, to obtain sol D;
[0038] The sol D was sprayed into balls by a spray granulator and then dried. The drying temperature was 130°C (dried in an oven), the inlet temperature of the spray granulator was 200°C, and the frequency of the atomizing disk was 20 Hz, to obtain the first balls after drying;
[0039] The first ball was added into ammonia water with a volume concentration of 12%, and the ball was repeatedly washed 4 times using a planetary ball mill, the rotation speed of the planetary ball mill was 100r / min, and then the washed first ball was placed in an oven at 160°C for drying to obtain a dried second ball;
[0040] The second ball is debinded and sintered, the debinding temperature is 600°C, the debinding time is 35h, the sintering temperature is 1200°C, and the sintering time is 11h. After sintering, ultra-small zirconia microspheres can be obtained;
[0041] In Example 1, the amount of yttrium chloride added is such that the yttrium oxide formed after sintering accounts for 5.2% of the total weight of zirconium oxide and yttrium oxide after sintering.
[0042] Depend on Figure 1 , Figure 2 It can be seen that the sphericity of the prepared zirconia microspheres is good, and the grains are evenly distributed, without pores and obvious defects. The average grain size is measured to be 153nm by the grain testing software; Figure 3 It can be seen that the crystal phases of the zirconia microspheres sintered at 1200°C are all tetragonal and cubic, and there is no monoclinic phase.
[0043] Table 1 shows the particle size distribution of the zirconia microspheres prepared in Example 1. From the data in the table, it can be seen that the particle size of the zirconia microspheres prepared in Example 1 is less than 0.05 mm, the particle size distribution in the range of 0.02 to 0.04 mm accounts for 75%, and the average particle size is 0.031 mm.
[0044] Table 1 Particle size distribution of zirconia microspheres prepared in Example 1
[0045] Serial number Particle size / mm Proportion / % 1 0～0.01 3 2 0.01～0.02 16 3 0.02～0.03 38 4 0.03～0.04 37 5 0.04～0.05 6
[0046] Example 2
[0047] A method for preparing zirconium oxide microspheres comprises the following steps:
[0048] A mixture of zirconium nitrate and zirconium oxychloride, a mixture of yttrium nitrate and yttrium chloride and deionized water are mixed at a molar ratio of 1:0.07:100, and stirred until the mixture of zirconium nitrate and zirconium oxychloride and the mixture of yttrium nitrate and yttrium chloride are completely dissolved to obtain a solution A; in the mixture of zirconium nitrate and zirconium oxychloride, the molar ratio of zirconium nitrate to zirconium oxychloride is 1:0.5; in the mixture of yttrium nitrate and yttrium chloride, the molar ratio of yttrium nitrate to yttrium chloride is 1:1; the molar ratio of the total amount of the mixture of zirconium nitrate and zirconium oxychloride and the mixture of yttrium nitrate and yttrium chloride to deionized water is 1:93.46;
[0049] Slowly drop ammonia water with a volume concentration of 3% into solution A until solution A fully reacts, the amount of ammonia water added is such that the pH value of solution A is maintained at 7.8, a precipitate is formed, the precipitate is filtered out by filter press, and washed with anhydrous ethanol 7 times, anhydrous ethanol is repeatedly added to the precipitate 4 times and stirred and beaten, and filtered by filter press to obtain a precipitate product after washing with chlorine, the volume of anhydrous ethanol added each time is 7 times the volume of the precipitate, and the duration of each stirring and beating is 15 minutes;
[0050] Preparation of solution B:
[0051] A mixture of zirconium nitrate and zirconium oxychloride, a mixture of yttrium nitrate and yttrium chloride, and deionized water are mixed at a molar ratio of 1:0.07:100, and stirred until the mixture of zirconium nitrate and zirconium oxychloride, and the mixture of yttrium nitrate and yttrium chloride are completely dissolved, as solution B, wherein the addition amount of each component of solution B is 1 / 2 of the addition amount of each corresponding component of solution A;
[0052] The precipitated product after chlorine washing is slowly added to solution B and heated to 75° C. in a water bath for dissolution, and the pH of the dissolved solution is monitored to be 1.8-2, the specific gravity is 1.1-1.2, and the viscosity is 400-500 mPa.s, to obtain solution C;
[0053] Add a mixture of allyl alcohol and isopropyl alcohol to solution C and stir; in the mixture of allyl alcohol and isopropyl alcohol, the weight ratio of allyl alcohol to isopropyl alcohol is 1:1; the amount of the mixture of allyl alcohol and isopropyl alcohol added is 1 / 40 of the weight of solution C, to obtain sol D;
[0054] Sol D was sprayed into balls by a spray granulator and then dried. The drying temperature was 150°C (dried in an oven), the inlet temperature of the spray granulator was 170°C, and the frequency of the atomizing disk was 22 Hz, to obtain the first balls after drying;
[0055] The first ball is added into ammonia water with a volume concentration of 10%, and the ball is repeatedly washed three times using a planetary ball mill, the rotation speed of the planetary ball mill is 120r / min, and then the washed first ball is placed in an oven at 180°C for drying to obtain a dried second ball;
[0056] The second ball is debinded and sintered, the debinding temperature is 500°C, the debinding time is 50h, the sintering temperature is 1100°C, and the sintering time is 19h. After sintering, ultra-small zirconia microspheres can be obtained;
[0057] In Example 2, the amount of the mixture of yttrium nitrate and yttrium chloride added is such that the yttrium oxide formed after sintering accounts for 6.03% of the total weight of the zirconium oxide and yttrium oxide after sintering.
[0058] pass Figure 4 It can be seen that the crystal phases of the sintered zirconium oxide microspheres are all tetragonal and cubic phases, and there is no monoclinic phase. Therefore, by adopting this method, when the sintering temperature is only 1100°C, the crystal phase transformation from monoclinic phase to tetragonal phase and cubic phase can be achieved, which is impossible to achieve with other existing processes.
[0059] Table 2 shows the particle size distribution of the zirconia microspheres prepared in Example 2. From the data in the table, it can be seen that the particle size of the zirconia microspheres prepared in Example 2 is less than 0.05 mm, the particle size distribution in the range of 0.02 to 0.04 mm accounts for 68%, and the average particle size is 0.028 mm.
[0060] Table 2 Particle size distribution of zirconia microspheres prepared in Example 2
[0061] Serial number Particle size / mm Proportion / % 1 0～0.01 6 2 0.01～0.02 19 3 0.02～0.03 33 4 0.03～0.04 35 5 0.04～0.05 7
[0062] Example 3
[0063] A method for preparing zirconium oxide microspheres comprises the following steps:
[0064] The mixture of zirconium sulfate and zirconium oxychloride, yttrium acetate and deionized water are mixed at a molar ratio of 1:0.065:110, and stirred until the mixture of zirconium sulfate and zirconium oxychloride and yttrium acetate are completely dissolved to obtain a solution A, wherein the molar ratio of zirconium sulfate to zirconium oxychloride in the mixture of zirconium sulfate and zirconium oxychloride is 1:1; the molar ratio of the total amount of the mixture of zirconium sulfate and zirconium oxychloride and yttrium acetate to deionized water is 1:103.29;
[0065] Slowly drop ammonia water with a volume concentration of 10% into solution A until solution A fully reacts, the amount of ammonia water added is such that the pH value of solution A is maintained at 9, a precipitate is formed, the precipitate is filtered out by filter press, and washed with anhydrous ethanol 4 times, anhydrous ethanol is repeatedly added to the precipitate 7 times, stirred and beaten, and filtered by filter press to obtain a precipitate product after washing with chlorine, the volume of anhydrous ethanol added each time is 10 times the volume of the precipitate, and the duration of each stirring and beating is 10 minutes;
[0066] Preparation of solution B:
[0067] A mixture of zirconium sulfate and zirconium oxychloride, yttrium acetate and deionized water are mixed at a molar ratio of 1:0.065:110, and stirred until the mixture of zirconium sulfate and zirconium oxychloride and yttrium acetate are completely dissolved, as solution B, wherein the amount of each component of solution B added is 1 / 2 of the amount of each corresponding component of solution A added;
[0068] The precipitated product after chlorine washing is slowly added to solution B and heated to 65° C. in a water bath for dissolution, and the pH of the dissolved solution is monitored to be 1.8-2, the specific gravity is 1.1-1.2, and the viscosity is 400-500 mPa.s, to obtain solution C;
[0069] Add polyethylene glycol to solution C and stir, wherein the amount of polyethylene glycol added is 1 / 60 of the weight of solution C, to obtain sol D;
[0070] The sol D was sprayed into balls by a spray granulator and then dried. The drying temperature was 140°C (dried in an oven), the inlet temperature of the spray granulator was 180°C, and the frequency of the atomizing disk was 30 Hz, to obtain the first balls after drying;
[0071] The first ball is added into ammonia water with a volume concentration of 15%, and the ball is repeatedly washed 5 times using a planetary ball mill, and the rotation speed of the planetary ball mill is 150r / min. Then, the washed first ball is placed in an oven at 150°C for drying to obtain a dried second ball;
[0072] The second ball is debinded and sintered, the debinding temperature is 750°C, the debinding time is 20h, the sintering temperature is 1150°C, and the sintering time is 16h. After sintering, ultra-small zirconia microspheres can be obtained;
[0073] In Example 3, the amount of yttrium acetate added is such that the yttrium oxide formed after sintering accounts for 5.6% of the total weight of zirconium oxide and yttrium oxide after sintering.
[0074] pass Figure 5 It can be seen that the crystal phases of the zirconia microspheres sintered at 1150°C are all tetragonal and cubic, and there is no monoclinic phase.
[0075] Table 3 shows the particle size distribution of the zirconia microspheres prepared in Example 3. From the data in the table, it can be seen that the particle size of the zirconia microspheres prepared in Example 3 is less than 0.05 mm, the particle size distribution in the range of 0.02 to 0.04 mm accounts for 65%, and the average particle size is 0.025 mm.
[0076] Table 3 Particle size distribution of zirconia microspheres prepared in Example 3
[0077] Serial number Particle size / mm Proportion / % 1 0～0.01 2 2 0.01～0.02 28 3 0.02～0.03 34 4 0.03～0.04 31 5 0.04～0.05 5
[0078] The random test results of the Vickers hardness of the zirconia microspheres prepared in Examples 1-3 are shown in Table 4. From the data in the table, it can be seen that the hardness of the zirconia microspheres prepared in Examples 1-3 is relatively high, and the average value of the Vickers hardness can reach a maximum of 1345.7 HV.
[0079] Table 4 Vickers hardness of zirconia microspheres prepared in Examples 1-3
[0080]
[0081] The random test data of the density of the zirconia microspheres prepared in Examples 1-3 are shown in Table 5. From the data in the table, it can be seen that the density of the zirconia microspheres prepared in Examples 1-3 is relatively high, and the average density is ≥6.06 g / cm 3 .
[0082] Table 5 Density of zirconia microspheres prepared in Examples 1-3
[0083]
[0084] In summary, the preparation method of zirconium oxide microspheres of the present invention mainly adopts sol-gel technology, monitors the pH, specific gravity and viscosity index of the dissolved solution, selects an organic solvent to obtain a stable sol system, combines a spray granulator, and completes the preparation of ultra-small size zirconium oxide microspheres by debinding sintering. It can be seen from different embodiments that by changing process parameters, such as solution ratio, pH, amount of organic solvent added, sintering temperature, etc., zirconium oxide microspheres can be obtained, indicating that the method of the present invention has good applicability. According to this method, zirconium oxide microspheres with dense interior, no pores, high hardness, large density, small grains and low sintering temperature can be obtained. Through the SEM image, it can be seen that the prepared zirconium oxide microspheres have uniform grain size and no abnormally grown grains. Through the XRD spectrum, it can be seen that the prepared zirconium oxide microspheres have no monoclinic zirconium oxide after sintering at 1100°C.
[0085] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, slight adjustments to the raw material ratios can be made without departing from the principles of the present invention, and these should also be considered to fall within the scope of protection of the present invention.
Claims
1. A method for preparing zirconium oxide microspheres, characterized in that: The following steps are involved: (1) mixing a water-soluble zirconium salt, a water-soluble yttrium salt, and deionized water in a molar ratio of 1:(0.05-0.08):(80-110), and stirring until the water-soluble zirconium salt and the water-soluble yttrium salt are completely dissolved to obtain a solution A; (2) slowly adding ammonia water with a volume concentration of 3 to 10% to the solution A of step (1) to form a precipitate, filtering out the precipitate, and washing it with anhydrous ethanol for 4 to 7 times, and then repeatedly adding anhydrous ethanol to the precipitate for 4 to 7 times, stirring and beating, and filtering to obtain a precipitated product; (3) preparing a mixed solution of a water-soluble zirconium salt and a water-soluble yttrium salt according to the method of step (1) as solution B; adding the precipitated product obtained in step (2) to solution B and heating it to 65-75° C. for dissolution, and monitoring the pH of the solution to be 1.8-2, the specific gravity to be 1.1-1.2, and the viscosity to be 400-500 mPa.s, to obtain solution C; (4) adding an organic solvent to solution C and stirring to obtain sol D; (5) using a spray granulator to spray sol D into balls and then drying them, the inlet temperature of the spray granulator being 170 to 200° C. and the frequency of the atomizing disk being 20 to 30 Hz, to obtain the first balls after drying; (6) adding the first ball prepared in step (5) into ammonia water having a volume concentration of 10 to 15%, and washing the ball repeatedly for 3 to 5 times using a planetary ball mill at a rotation speed of 100 to 150 r / min, and then placing the washed first ball in an oven at 150 to 180° C. to dry the first ball to obtain a dried second ball; (7) Debinding and sintering: The second ball of step (6) is debinded and sintered, the debinding temperature is 500-750°C, the debinding time is 20-50 hours, the sintering temperature is 1100-1200°C, and the sintering time is 10-20 hours. After sintering, zirconia microspheres with a particle size of 0.01-0.05 mm can be obtained.
2. The method for preparing zirconium oxide microspheres according to claim 1, characterized in that: The water-soluble zirconium salt described in step (1) is any one of zirconium nitrate, zirconium sulfate or zirconium oxychloride, or a mixture of two or more thereof; the water-soluble yttrium salt is any one of yttrium nitrate, yttrium acetate or yttrium chloride, or a mixture of two or more thereof.
3. A method for preparing zirconium oxide microspheres according to claim 1 or 2, characterized in that: The amount of ammonia water added in step (2) is such that the pH value of solution A is maintained at 7 to 9.
4. The method for preparing zirconium oxide microspheres according to claim 3, characterized in that: The volume of anhydrous ethanol added each time in step (2) is 7 to 10 times the volume of the precipitate.
5. The method for preparing zirconium oxide microspheres according to claim 4, characterized in that: The duration of each stirring and beating in step (2) is 10 to 15 minutes.
6. A method for preparing zirconium oxide microspheres according to claim 1 or 2, characterized in that: The amount of each component added to solution B in step (3) is 1 / 2 of the amount of the corresponding component added to solution A.
7. A method for preparing zirconium oxide microspheres according to claim 1 or 2, characterized in that: The organic solvent described in step (4) is any one of propylene alcohol, isopropyl alcohol, polyvinyl alcohol or polyethylene glycol, or a mixture of two or more thereof.
8. The method for preparing zirconium oxide microspheres according to claim 7, characterized in that: The amount of the organic solvent added in step (4) is 1 / 60 to 1 / 40 of the weight of solution C.
9. The method for preparing zirconium oxide microspheres according to claim 1, characterized in that: The drying temperature in step (5) is 130-150°C.