Method for preparing nanometer yttrium oxide powder by solid phase grinding

Abstract

The application discloses a method for preparing nano yttrium oxide powder by solid phase grinding, wherein low-melting-point yttrium salt is dispersed by using molten dispersant, and yttrium element is uniformly dispersed on the dispersant matrix by vacuum heating and decomposition, so that yttrium precursor powder with high dispersity and without agglomeration can be obtained, and finally nano yttrium oxide powder can be obtained through calcination process. The particle size of the prepared yttrium oxide nano powder is 50-650nm, the specific surface area is 10-200m 2 / g, and the prepared yttrium oxide nano powder can be applied in the fields of electronic ceramic materials, fluorescent materials and other functional ceramics.

Description

Technical fields:

[0001] This invention relates to a method for preparing nano-yttrium oxide powder by solid-phase grinding. Background technology:

[0002] Yttrium oxide is an important rare earth oxide that can be used in optical glass, electronic ceramic materials, fluorescent materials and other fields. It can also be used to manufacture thin film capacitors and special refractory materials, as well as magnetic bubble materials for high-pressure mercury lamps, lasers, storage elements and so on.

[0003] There are many methods for preparing yttrium oxide, including precipitation, hydrothermal, sol-gel, and spray pyrolysis. (1) Precipitation is one of the most commonly used methods in industry. Usually, the inorganic salt of yttrium is dissolved in water, and a precipitant is added to precipitate yttrium ions from the solution. The precipitate is collected, washed, and then calcined to obtain yttrium oxide powder. Precipitation has the advantages of simple process and low cost, but the yttrium oxide powder prepared has disadvantages such as large secondary particle size, poor particle size dispersion, serious agglomeration, and poor sintering activity. (2) The hydrothermal method for preparing yttrium oxide is divided into hydrothermal hydrolysis and hydrothermal precipitation. The hydrothermal precipitation method used in industrial production usually adopts a high-temperature and high-pressure reactor. By heating and pressurizing the aqueous solution containing yttrium source and precipitant, after a long reaction time of precipitation-dissolution-recrystallization, a reaction precipitate is obtained. After washing and drying, nano-yttrium oxide powder is obtained. The powder material prepared by hydrothermal precipitation has good crystal form, high purity, small secondary particle size, and less agglomeration, and has good sintering activity. However, hydrothermal precipitation has high equipment requirements and disadvantages such as difficult control of process parameters and long production cycle. (3) Sol-gel method is also a common method for preparing yttrium oxide. This method usually involves adding a complexing agent to an aqueous solution containing yttrium to form a sol solution under certain conditions. After a long period of gelation, a yttrium precursor gel is obtained, and then yttrium oxide powder is obtained after calcination. The advantages of this method are that the prepared powder has good crystal form, small secondary particle size and narrow particle size distribution, and high activity. The disadvantages are that the sol gelation process has a long cycle, agglomeration during drying leading to a large shrinkage rate, and complex operation. (4) Spray pyrolysis involves spraying a solution of yttrium-containing metal salts at high speed into a high-temperature air atmosphere in the form of atomized droplets. This immediately causes the solvent to evaporate and the yttrium salts to thermally decompose. Subsequently, due to supersaturation, a solid phase precipitates, thus directly obtaining yttrium oxide nanoparticles. Spray pyrolysis has the advantages of simple preparation, convenient operation, and good controllability in preparing nanoparticles. However, due to the high thermal decomposition temperature of yttrium salts and their corrosiveness to equipment, the requirements for spray pyrolysis equipment are high, making industrialization still difficult. Summary of the Invention:

[0004] The purpose of this invention is to provide a method for preparing nano-yttrium oxide powder by solid-phase grinding.

[0005] This invention is achieved through the following technical solutions:

[0006] A method for preparing nano-yttrium oxide powder by solid-phase grinding, the method comprising the following steps:

[0007] (1) A low-melting-point yttrium salt and a low-melting-point dispersant are mixed in a clean mortar at a mass ratio of 2 to 4:1 and ground and dispersed at 50 to 70°C to obtain a colloidal mixture in which the yttrium salt and the dispersant are uniformly mixed; the low-melting-point yttrium salt is selected from yttrium nitrate hexahydrate and yttrium acetate hydrate, and the low-melting-point dispersant is poloxamer F127 or polyoxypropylene polyoxyethylene copolymer P123;

[0008] (2) The colloidal mixture obtained in step (1) is quickly transferred to a vacuum drying oven and heated in a vacuum of 0.1 to 10 Pa to the decomposition temperature of yttrium salt, 180 to 240°C, preferably 200 to 240°C, and kept at the temperature for 1 to 2 hours. The colloidal mixture decomposes to obtain yttrium precursor powder.

[0009] (3) The precursor powder of yttrium was heat-treated at 600℃~900℃ in air atmosphere to obtain yttrium oxide nanopowder.

[0010] Preferably, the mass ratio of yttrium salt to dispersant in step (1) is 2.5:1.

[0011] Preferably, step (3) specifically involves: transferring the yttrium precursor powder into a muffle furnace, heating it to 400°C at a rate of 5°C / min in an air atmosphere, holding it at that temperature for 1 to 2 hours, and then heating it to 600°C to 900°C at a rate of 1 to 5°C / min, holding it at that temperature for 1 to 3 hours.

[0012] More preferably, step (3) specifically involves: transferring the yttrium precursor powder into a muffle furnace, heating it to 400°C at a rate of 5°C / min in an air atmosphere, holding it at that temperature for 1 to 2 hours, and then heating it to 650°C to 850°C at a rate of 5°C / min, holding it at that temperature for 2 to 3 hours.

[0013] The solid-phase grinding method employed in this invention involves grinding a low-melting-point yttrium salt with a low-melting-point dispersant in a solid state, ensuring the yttrium salt is uniformly dispersed in the molten dispersant. The resulting yttrium salt-mixed dispersant is then vacuum-heated and calcined to obtain nano-yttrium oxide powder. The key to this method lies in the molten dispersion of the low-melting-point yttrium salt. By using grinding to moltenly disperse metallic yttrium ions in a specific dispersant, the particle shape and size of yttrium oxide can be more easily controlled. Furthermore, this method is simple to operate, uses readily available raw materials, and is suitable for industrial production.

[0014] The beneficial effects of this invention are:

[0015] 1. This invention utilizes a molten dispersant to disperse low-melting-point yttrium salts, and then decomposes them by vacuum heating to uniformly disperse the yttrium element on the dispersant matrix, thereby obtaining highly dispersed, non-agglomerated yttrium precursor powder. Finally, nano-yttrium oxide powder is obtained through a calcination process.

[0016] 2. The yttrium oxide nanoparticles prepared by this invention have a particle size of 50–650 nm and a specific surface area of ​​10–200 m². 2 / g, which can be applied to electronic ceramic materials, fluorescent materials and other functional ceramics. Attached image description:

[0017] Figure 1 This is a scanning electron microscope image of yttrium oxide prepared in Example 1 of the present invention. Detailed implementation method:

[0018] The following is a further description of the invention, but not a limitation thereof.

[0019] Example 1: A method for preparing nano-yttrium oxide through solid-phase grinding

[0020] Includes the following steps:

[0021] (1) Weigh 19.15g of yttrium nitrate hexahydrate and 7.66g of poloxamer F127 at room temperature and normal pressure, mix them in an agate mortar, heat in a ventilated drying oven at 60℃ for 20min, take it out and grind it quickly until the yttrium nitrate hexahydrate particles and poloxamer F127 powder are mixed evenly into a white viscous colloidal mixture.

[0022] (2) The colloidal mixture was quickly transferred into a vacuum drying oven, and the vacuum degree in the vacuum drying oven was kept at 1 Pa and the temperature at 200 °C for 1 h to obtain a light yellow yttrium precursor powder.

[0023] (3) The light yellow yttrium precursor powder is heated to 400°C at a rate of 5°C / min in air atmosphere and held for 1 hour. Then it is heated to 750°C at a rate of 5°C / min and held for 2 hours. Then it is cooled to room temperature in the furnace and taken out to obtain nano yttrium oxide powder.

[0024] The yttrium oxide powder prepared in this embodiment was subjected to performance testing. The particle size, measured by laser dynamic light scattering method, was D. 50 =0.127μm, the specific surface area of ​​the powder calculated by the BET method is 142.21m². 2 / g, scanning electron microscope ( Figure 1 It is shown to be spherical with a diameter of 521.74 nm.

[0025] Example 2: A method for preparing nano-yttrium oxide through solid-phase grinding

[0026] Includes the following steps:

[0027] (1) At room temperature and normal pressure, weigh 12.77g of yttrium nitrate hexahydrate and 4.26g of polyoxypropylene polyoxyethylene copolymer P123 and mix them in an agate mortar. Heat in a ventilated drying oven at 60℃ for 20min. After taking it out, grind it quickly until the yttrium nitrate hexahydrate particles and polyoxypropylene polyoxyethylene copolymer P123 powder are mixed evenly into a white viscous colloidal mixture.

[0028] (2) The colloidal mixture was quickly transferred into a vacuum drying oven, and the vacuum degree in the vacuum drying oven was kept at 1 Pa and the temperature at 200 °C for 1 h to obtain a light yellow yttrium precursor powder.

[0029] (3) The light yellow yttrium precursor powder is heated to 400°C at a rate of 5°C / min in air atmosphere and held for 1 hour. Then it is heated to 700°C at a rate of 5°C / min and held for 2 hours. Then it is cooled to room temperature in the furnace and taken out to obtain nano yttrium oxide powder.

[0030] The yttrium oxide powder prepared in this embodiment was subjected to performance testing. The particle size, measured by laser dynamic light scattering, was D. 50 =0.167μm, the specific surface area of ​​the powder calculated by the BET method is 45.94m². 2 / g, scanning electron microscopy shows that it is spherical with a diameter of about 640nm.

[0031] Example 3: A method for preparing nano-yttrium oxide through solid-phase grinding

[0032] Includes the following steps:

[0033] (1) At room temperature and normal pressure, weigh 13.3g of yttrium acetate hydrate and 5.32g of poloxamer F127 and mix them in an agate mortar. Heat in a ventilated drying oven at 60℃ for 20min. After taking it out, grind it quickly until the yttrium acetate hydrate particles and poloxamer F127 powder are mixed evenly into a white viscous colloidal mixture.

[0034] (2) The colloidal mixture was quickly transferred into a vacuum drying oven, and the vacuum degree in the vacuum drying oven was kept at 1 Pa and the temperature at 240 °C for 1 h to obtain a light yellow yttrium precursor powder.

[0035] (3) The light yellow yttrium precursor powder is heated to 400°C at a rate of 5°C / min in air atmosphere and held for 1 hour. Then it is heated to 650°C at a rate of 5°C / min and held for 2 hours. Then it is cooled to room temperature in the furnace and taken out to obtain nano yttrium oxide powder.

[0036] The yttrium oxide powder prepared in this embodiment was subjected to performance testing. The particle size, measured by laser dynamic light scattering, was D. 50 =0.104μm, the specific surface area of ​​the powder calculated by the BET method is 64.08m². 2 / g, scanning electron microscopy shows that it is spherical with a diameter of 358.57nm.

[0037] Example 4: A method for preparing nano-yttrium oxide through solid-phase grinding

[0038] Includes the following steps:

[0039] (1) At room temperature and normal pressure, weigh 26.6g of yttrium acetate hydrate and 6.65g of polyoxypropylene polyoxyethylene copolymer P123 and mix them in an agate mortar. Heat in a ventilated drying oven at 60℃ for 40min. After taking it out, grind it quickly until the yttrium acetate hydrate particles and polyoxypropylene polyoxyethylene copolymer P123 powder are mixed evenly into a white viscous colloidal mixture.

[0040] (2) The colloidal mixture was quickly transferred into a vacuum drying oven, and the vacuum degree in the vacuum drying oven was kept at 1 Pa and the temperature at 240 °C for 1 h to obtain a light yellow yttrium precursor powder.

[0041] (3) The light yellow yttrium precursor powder is heated to 400°C at a rate of 5°C / min in air atmosphere and held for 1 hour. Then it is heated to 850°C at a rate of 5°C / min and held for 3 hours. Then it is cooled to room temperature in the furnace and taken out to obtain nano yttrium oxide powder.

[0042] The yttrium oxide powder prepared in this embodiment was subjected to performance testing. The particle size, measured by laser dynamic light scattering, was D. 50 =0.429μm, the specific surface area of ​​the powder calculated by the BET method is 21.08m². 2 / g, scanning electron microscopy shows that it is spherical with a diameter of about 600nm.

[0043] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope 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 preparing nano-yttrium oxide powder by solid-phase grinding, characterized in that, The method includes the following steps: (1) A low-melting-point yttrium salt and a low-melting-point dispersant are mixed in a clean mortar at a mass ratio of 2 to 4:1 and ground and dispersed at 50 to 70°C to obtain a colloidal mixture in which the yttrium salt and the dispersant are uniformly mixed; the low-melting-point yttrium salt is selected from yttrium nitrate hexahydrate and yttrium acetate hydrate, and the low-melting-point dispersant is poloxamer F127 or polyoxypropylene polyoxyethylene copolymer P123; (2) The colloidal mixture obtained in step (1) is quickly transferred to a vacuum drying oven and heated to the decomposition temperature of yttrium salt, 180-240°C, in a vacuum of 0.1-10 Pa and kept at that temperature for 1-2 hours. The colloidal mixture decomposes to obtain yttrium precursor powder. (3) The precursor powder of yttrium was heat-treated at 600℃~900℃ in air atmosphere to obtain yttrium oxide nanopowder.

2. The method according to claim 1, characterized in that, The mass ratio of yttrium salt to dispersant in step (1) is 2.5:

1.

3. The method according to claim 1, characterized in that, The temperature for step (2) is 200-240℃.

4. The method according to claim 1, characterized in that, Step (3) involves transferring the yttrium precursor powder into a muffle furnace, heating it to 400°C at a rate of 5°C / min in an air atmosphere, holding it at that temperature for 1 to 2 hours, and then heating it to 600°C to 900°C at a rate of 1 to 5°C / min, holding it at that temperature for 1 to 3 hours.

5. The method according to claim 4, characterized in that, Step (3) involves transferring the yttrium precursor powder into a muffle furnace, heating it to 400°C at a rate of 5°C / min in an air atmosphere, holding it at that temperature for 1 to 2 hours, and then heating it to 650°C to 850°C at a rate of 5°C / min and holding it at that temperature for 2 to 3 hours.

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