Process for preparing yttrium oxide material

Abstract

The invention discloses a process for preparing an yttrium oxide material. The process comprises the following steps: preparing materials; putting a metal yttrium guide wire into the reaction container, feeding through a wire feeding device, and connecting an electric storage capacitor with an internal yttrium wire outside the reaction container; filling gas; filling argon and oxygen into the reaction container; electric explosion; the electric storage capacitor discharges, and the metal yttrium conducting wire is heated till electric explosion; forming an electric arc; the electric storage capacitor continuously discharges in the powder particles and the medium atmosphere after electric explosion, so that the electric storage capacitor breaks down the medium between the two electrodes to form an electric arc; cooling is performed; enabling the metal vapor and the plasma which move at a high speed to violently collide with a surrounding medium and then rapidly cool to form yttrium oxide particles; performing grading; pulsating airflow is introduced for stirring, so that powder stripping is promoted. According to the method, the particle size can be effectively controlled by adjusting parameters such as capacitance and voltage, the technological process is simple, chemicals are not needed, the method is a green powder preparation method, and the prepared yttrium oxide product is higher in purity and more uniform in particle size distribution.

Description

Technical Field

[0001] The present invention belongs to the technical field of yttrium oxide preparation, and particularly relates to a process for preparing yttrium oxide materials. Background Art

[0002] Yttrium oxide is a white powdery rare earth oxide, which has wide applications in industrial and high-tech fields such as luminescent materials, laser materials, high-temperature superconducting materials, precision ceramic materials, and catalyst materials. The purity and particle size distribution of yttrium oxide have a significant impact on the performance and value of the product.

[0003] However, traditional yttrium oxide products have relatively low purity, wide particle size distribution, and large differences in particle size; moreover, the process for preparing yttrium oxide is relatively complex, with high costs, and some processes even require the use of chemicals, which are prone to pollution. Therefore, the present invention designs a process for preparing yttrium oxide materials to solve the above problems.

[0004] It should be noted that the above introduction to the technical background is only for the convenience of clearly and completely explaining the technical solution of the present invention and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the present invention. Summary of the Invention

[0005] To overcome the deficiencies in the above prior art, the purpose of the present invention is to provide a process for preparing yttrium oxide materials.

[0006] To achieve the above purpose and other related purposes, the technical solution provided by the present invention is: a process for preparing yttrium oxide materials, and the steps of the process include:

[0007] Step 1: Material preparation; prepare a vacuum-sealed reaction vessel, place the corresponding metal yttrium wire inside the reaction vessel, feed the metal yttrium wire through a wire feeding device, and connect a storage capacitor outside the reaction vessel to the metal yttrium wire inside the reaction vessel;

[0008] Step 2: Fill with gas; fill argon and oxygen inside the reaction vessel;

[0009] Step 3: Perform electroexplosion; discharge the storage capacitor, heat the metal yttrium wire through the current until electroexplosion occurs; the metal yttrium wire melts and vaporizes under the action of high-power continuous heating, the conductor breaks into droplets and generates plasma, the plasma forms a pinch effect under the current channel, causing the vapor to expand and generate internal high pressure, and the conductor forms an explosion;

[0010] Step 4: Discharge to form an arc; the storage capacitor continues to discharge in the powder particles and dielectric atmosphere after the electro-explosion of the yttrium metal wire, causing it to break down the dielectric between the two electrodes and form an arc;

[0011] Step 5: Cooling; the high-speed moving metal vapor and plasma in the reaction vessel are rapidly cooled after intense collision with the surrounding medium, forming yttrium oxide particles to obtain primary oxide powder;

[0012] Step 6: Classification; introduce pulsating air flow into the reaction vessel for agitation, promote powder separation and then conduct classification, recovery and packaging. The periodic air flow impact can break the adsorption force between particles and promote uniform dispersion.

[0013] Further, in the said Step 1, the diameter of the yttrium metal wire is 0.5 - 2 mm. In this solution, the yttrium metal wire with a small diameter of 0.5 - 2 mm is adopted, which can accelerate the contact between yttrium metal and oxygen, making the oxidation reaction more efficient and uniform.

[0014] Further, the wire feeding speed of the wire feeding device for the yttrium metal wire is 1 - 10 cm / min. In this solution, the wire feeding speed of 1 - 10 cm / min can achieve continuous feeding of the yttrium metal wire, avoid the intermittent pause of batch process, and is suitable for industrial production.

[0015] Further, in the said Step 1, it also includes electrolytic polishing treatment on the surface of the yttrium metal wire before feeding, so that the surface roughness Ra of the yttrium metal wire ≤ 0.1 μm. In this solution, the electrolytic polishing treatment on the surface of the yttrium metal wire can significantly improve the reaction controllability, product purity and performance consistency, eliminate surface defects and improve oxidation uniformity.

[0016] Further, in the said Step 2, it also includes filling a reaction gas of 60% argon and 40% oxygen into the sealed reaction vessel. In this solution, filling a mixed gas of argon (Ar) and oxygen (O 2 ) in the reaction vessel can reduce the surface energy of particles, reduce particle contact, avoid agglomeration of nano yttrium oxide at high temperature; it can play a role in balancing oxidation and protection, and can improve the purity of the obtained yttrium oxide.

[0017] Further, the reaction vessel is a tube furnace. In this solution, the annular heating element and quartz tube design of the tube furnace can ensure uniform temperature distribution in the reaction zone, avoid uneven decomposition of the precursor and particle sintering and coarsening caused by local overheating.

[0018] Further, in the said Step 3, the voltage of the storage capacitor is 5 - 20 kV, and the current density is 10 7 -10 8 A / cm2 In this solution, the storage capacitor is set with a voltage of 5 - 20 kV, which can prevent particle agglomeration and ensure the uniformity of the nano - powder; setting a high - current density can generate instantaneous high temperature, causing the explosion of the yttrium metal wire and instantaneously oxidizing to generate Y 2 O 3 nano - powder.

[0019] Furthermore, in step three, the heating temperature is controlled at 800 - 1200 °C. In this solution, the high temperature of 800 °C - 1200 °C helps to obtain spherical or regular - shaped Y 2 O 3 particles and improve the dispersibility.

[0020] Furthermore, in step six, the frequency of introducing the pulsating air flow is 0.5 - 10 Hz. In this solution, the pulsating air flow provides periodic ventilation, which can refresh the oxygen concentration in the reaction zone, avoid local hypoxia caused by consumption during the explosion; promote gas - phase mixing, make the Y vapor fully contact with O 2 and reduce the generation of unreacted Y or sub - oxides.

[0021] Furthermore, in step one, the purity of the yttrium metal wire is ≥99.95%. In this solution, high - purity yttrium can avoid impurities that may form local hot spots, resulting in uneven distribution of explosion energy and a wider particle - size distribution.

[0022] Due to the application of the above - mentioned technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0023] The process for preparing yttrium oxide material designed by the present invention can effectively control the particle size by adjusting parameters such as capacitance and voltage. The process flow is simple, without the use of chemicals and without generating harmful substances. It is a green method for preparing powder. The prepared yttrium oxide product has higher purity and a more uniform particle - size distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the process flow for preparing yttrium oxide in the present invention;

[0025] Figure 2 It is a thermal - energy process diagram under high - explosion in the present invention;

[0026] Figure 3 It is a microscopic observation picture of yttrium oxide particles by the electro - conversion method in the present invention;

[0027] Figure 4 It is a schematic diagram of the particle - size distribution of yttrium oxide in the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0028] To make the above objects, features, and advantages of the present application more apparent and understandable, the following provides a detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings.

[0029] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application may be implemented in other ways different from those described herein. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0030] As shown in the present application document, unless the context clearly indicates otherwise, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0031] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0032] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings. This is only for the convenience of describing the present application and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as limiting the protection scope of the present application; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0033] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is merely for the convenience of distinguishing the corresponding components. Without additional declaration, these terms have no special meaning, and thus should not be construed as a limitation on the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some of the terms mentioned in the specification of this application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of this description. In addition, it is required to understand this application not only through the actual terms used, but also through the meaning implied by each term.

[0034] Example:

[0035] See the attached Figure 1 As shown, this example provides a process for preparing yttrium oxide material, and the steps of this process include:

[0036] Step 1: Material preparation; Prepare a vacuum-sealed reaction vessel, place the corresponding metal yttrium wire inside the reaction vessel, feed the metal yttrium wire through a wire feeding device, and connect a storage capacitor to the metal yttrium wire inside the reaction vessel outside the reaction vessel.

[0037] Specifically, the purity of the metal yttrium wire ≥ 99.95%. High-purity yttrium (≥ 99.95%) can control the impurity content at the ppm level, avoiding the formation of local hot spots by impurities in the low-purity yttrium wire, resulting in uneven distribution of explosion energy and broadening of the particle size distribution. High-purity yttrium can directly generate Y 2 O 3 nanopowders can obtain high-purity phases through calcination, saving energy.

[0038] Specifically, the diameter of the metal yttrium wire is 0.5 - 2 mm. In some embodiments, the diameter of the metal yttrium wire can be 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm; The metal yttrium wire uses a small-diameter yttrium wire with a diameter of 0.5 - 2 mm, which is equivalent to having a relatively high surface area / volume ratio, can accelerate the contact between metal yttrium and oxygen, and make the oxidation reaction more efficient and uniform.

[0039] Thin wires (such as 0.5 mm) are more likely to achieve complete vaporization-explosion under high-voltage pulsed current, generating nanoscale Y 2 O 3 particles (particle size 20 - 100 nm). During the explosion process, the pinch effect (Z-pinch) and plasma expansion can form high-purity and non-agglomerated nanometer powders. The smaller the diameter, the more concentrated the resistive heat, and the lower the explosion threshold current. Wires with a diameter ≤ 1 mm require relatively less explosion energy.

[0040] The design with a diameter of the yttrium metal wire ≥ 0.5 mm is to maintain its sufficient mechanical strength, and the design with a diameter of the yttrium metal wire ≤ 2 mm is to maintain its flexibility for operations such as winding, fixing, and conveying.

[0041] Specifically, the wire feeding speed of the yttrium metal wire by the wire feeding device is 1 - 10 cm / min. In some embodiments, the wire feeding speed is 1 cm / min, 3 cm / min, 5 cm / min, 6 cm / min, 8 cm / min, or 10 cm / min.

[0042] In the electro - explosion or plasma process, too fast wire feeding speed (> 10 cm / min) will lead to insufficient energy, resulting in incomplete vaporization of yttrium and residual metal particles; too slow wire feeding speed (< 1 cm / min) will lead to excessive energy, causing over - oxidation or particle coarsening; a wire feeding speed of 1 - 10 cm / min can ensure synchronous adjustment of the wire feeding speed and current / energy input. Setting the wire feeding speed at 1 - 10 cm / min can achieve continuous feeding of the yttrium metal wire, avoid intermittent pauses in batch processes, and is suitable for industrial production. In some embodiments of preparing nano - Y 2 O 3 by electro - explosion method, a wire feeding speed of 5 cm / min, combined with a 10 kA pulsed current, can ensure complete vaporization and form particles with a size of 50 - 100 nm.

[0043] Specifically, the reaction vessel is a tube furnace. The tube furnace can accurately introduce a mixed gas (such as: 60% Ar + 40% O 2 ), and adjust it in real - time through a flow meter to ensure the stoichiometric ratio of yttrium oxide (to avoid oxygen defects in Y 2 O 3-x ). The design of the annular heating element and quartz tube of the tube furnace can ensure a uniform temperature distribution in the reaction zone (±1 - 5 °C), avoiding local overheating resulting in uneven decomposition of the precursor, particle sintering and coarsening (nano - Y 2 O 3 agglomeration).

[0044] Specifically, before feeding by the feeding device, the surface of the yttrium metal wire needs to be electrolytically polished so that the surface roughness Ra of the yttrium metal wire ≤ 0.1 μm. Electrolytically polishing the surface of the yttrium metal wire can significantly improve reaction controllability, product purity, and performance consistency, eliminate surface defects, and improve oxidation uniformity.

[0045] Electrolytic polishing removes mechanical scratches, micro - cracks, and oxide layers on the surface of the wire through anodic dissolution, and an atomically flat surface (Ra ≤ 0.1 μm) can be obtained. A smooth surface can ensure a uniform contact area between oxygen and yttrium, avoiding non - stoichiometric products caused by differences in local oxidation rates (such as YO or Y 2 O 3-x)。The oxidation reaction equation is closer to the ideal state: 4Y + 3O 2 →2Y 2 O 3

[0046] Electropolishing treatment can reduce the hot spot effect (local overheating leading to grain coarsening or phase transformation) caused by surface defects.

[0047] Metal surface defects (such as micropores, inclusions) are prone to adsorb moisture, hydrocarbons or processing residues (such as lubricants), and generate impurities such as Y(OH) 3 , YC x etc. during high-temperature oxidation. Electropolishing can remove these pollution sources and leave only pure metal yttrium on the surface of the guide wire.

[0048] During the preparation of nano-Y 2 O 3 by the electro-explosion method, the surface roughness affects the current distribution. A guide wire with Ra ≤ 0.1 μm can avoid too high local current density, thereby reducing the residue of yttrium particles that are not completely vaporized, generating a more uniform plasma, and improving the particle size consistency of nano-Y 2 O 3 (such as: 50 ± 5 nm). It can also avoid surface defects from accelerating the fatigue fracture of the guide wire during high-temperature oxidation or electro-explosion.

[0049] The performance index data comparison of polished and unpolished yttrium guide wires is as shown in the following table, Table 1:

[0050]

[0051] Step 2: Fill with gas; Fill argon and oxygen inside the reaction vessel; Specifically, fill a reaction gas of 60% argon and 40% oxygen in the closed reaction vessel. Fill a mixed gas of argon (Ar) and oxygen (O 2 ) in the reaction vessel. The main purpose is to control the reaction environment; Argon can play an inert protection role, reduce the surface energy of particles, reduce particle contact, and avoid agglomeration of nano-yttrium oxide at high temperatures; Oxygen ensures the complete oxidation of metal yttrium and controls the lattice oxygen defects; Under the combined action of argon and oxygen, it can play a role in balancing oxidation and protection, and improve the purity of the obtained yttrium oxide. 60% argon can dilute the oxygen concentration and avoid deflagration during the rapid decomposition of the precursor. 40% oxygen ensures the integrity of the lattice, avoids amorphization caused by oxygen defects, and meets the preparation requirements of high-purity yttrium oxide.

[0052] Step 3: Perform electroexplosion; discharge the storage capacitor, heat the yttrium metal wire through the current until electroexplosion occurs; the yttrium metal wire melts and vaporizes under the action of continuous high-power heating, the conductor breaks into droplets and generates plasma, and the plasma forms a pinch effect under the current channel, causing the vapor to expand and generate internal high pressure, and the conductor forms an explosion; for the heat energy process diagram under high explosion, see the appendix Figure 2 as shown;

[0053] Specifically, the voltage of the storage capacitor is 5 - 20 kV, and the current density is 10 7 -10 8 A / cm 2 . Setting the voltage of the storage capacitor at 5 - 20 kV can prevent particle agglomeration and ensure the uniformity of the nano powder. Setting a high current density can generate instantaneous high temperature, cause the yttrium metal wire to explode, and instantaneously oxidize to generate Y 2 O 3 nano powder.

[0054] Specifically, the heating temperature is controlled at 800 - 1200 °C. The high temperature of 800 °C - 1200 °C helps to obtain spherical or regular-shaped Y 2 O 3 particles and improve the dispersibility. Above 800 °C, the residual carbon or organic adsorbates can be effectively removed, improving the product purity. Taking 800 °C as the lower limit can ensure the minimum energy requirements for oxidation and crystallization, and avoid incomplete reactions caused by low temperatures. Taking 1200 °C as the upper limit can prevent excessive sintering of particles due to too high temperatures; avoid phase transformation or volatilization loss of Y 2 O 3 at high temperatures above 1300 °C.

[0055] Step 4: Discharge to form an arc; the storage capacitor continues to discharge in the powder particles and dielectric atmosphere after the electroexplosion of the yttrium metal wire, causing it to break down the dielectric between the two electrodes and form an arc;

[0056] Step 5: Cooling; rapidly cool the high-speed moving metal vapor and plasma in the reaction vessel after intense collision with the surrounding medium to form yttrium oxide particles and obtain the primary oxide powder, see the appendix Figure 3 as shown.

[0057] Step 6: Classification; introduce a pulsating air flow into the reaction vessel to stir, promote the separation of the powder, and then perform classification, recovery, and packaging. The periodic air flow impact can break the adsorption force between particles and promote uniform dispersion.

[0058] Specifically, the frequency of the introduced pulsating gas flow is 0.5 - 10 Hz. In some embodiments, the frequency of the pulsating gas flow can be 0.5 Hz, 1 Hz, 2 Hz, 5 Hz, or 10 Hz. The pulsating gas flow provides periodic ventilation, which can refresh the oxygen concentration in the reaction zone and avoid local hypoxia caused by explosion consumption; it promotes gas-phase mixing, enabling sufficient contact between Y vapor and O 2 to reduce the generation of unreacted Y or suboxides (such as YO).

[0059] A frequency of 0.5–2 Hz is suitable for larger particles (micrometer scale), avoiding uneven deposition caused by excessive disturbance, which can extend the high-temperature residence time and improve crystallinity.

[0060] A frequency of 1–5 Hz can strip the particles deposited on the wall, reduce wall deposition, and improve the product recovery rate.

[0061] A frequency of 2–5 Hz optimizes the oxygen supply and reduces unreacted Y.

[0062] A frequency of 5 - 10 Hz is suitable for ultrafine nanoparticles (<100 nm), which can enhance the turbulent effect, disperse the nanoparticles, and inhibit agglomeration.

[0063] For the particle size distribution diagram of yttrium oxide, see the appendix Figure 4 as shown.

[0064] The technical solution of this embodiment is not limited to the preparation of yttrium oxide, and is also applicable to the preparation of materials such as alumina and zirconia.

[0065] The materials produced by the present invention have high purity, with a purity > 99.99%; the particle size distribution of the materials is more uniform, and the discharge can vaporize the entire metal wire simultaneously; the particle size of the materials can be controlled, by adjusting parameters such as capacitance, charging voltage, and the size of the explosive wire; the particle size can be effectively controlled (adjustable from 100 nm to 2 μm); the process flow is simple, suitable for continuous production; no chemicals are required, no harmful substances are produced, and there is no pollution, which is a green method for preparing powders; the energy conversion rate is high, and it is easy to convert electrical energy into heat energy relying on the resistance of the metal wire in the discharge circuit.

[0066] The process for preparing yttrium oxide materials designed by the present invention can effectively control the particle size by adjusting parameters such as capacitance and voltage. The process flow is simple, no chemicals are required, no harmful substances are produced, which is a green method for preparing powders. The prepared yttrium oxide products have higher purity and more uniform particle size distribution.

[0067] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it. However, the protection scope of the present invention cannot be limited by this. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A process for preparing yttrium oxide material, characterized in that: The process steps include: Step 1: material preparation; prepare a vacuum-sealed reaction container, put a corresponding metal yttrium guide wire into the reaction container, feed the metal yttrium guide wire through a wire feeding device, and connect the metal yttrium guide wire inside the reaction container with a storage capacitor outside the reaction container; Step 2: Filling gas: filling argon and oxygen into the reaction container; Step 3: Performing an electric explosion; discharging the storage capacitor and heating the metal yttrium wire through the current until an electric explosion occurs; Step 4: Discharging to form an arc; the storage capacitor continues to discharge in the powder particles and dielectric atmosphere after the metal yttrium wire is electrically exploded, so that it breaks through the dielectric between the two electrodes and forms an arc; Step 5: Cooling; causing the high-speed metal vapor and plasma in the reaction vessel to collide violently with the surrounding medium and then cool rapidly to form yttrium oxide particles to obtain primary oxide powder; Step six: classification; introducing pulsating airflow into the reaction container for stirring to promote powder peeling and then classification, recovery and packaging.

2. A process for preparing yttrium oxide material according to claim 1, characterized in that: In the step 1, the diameter of the metal yttrium guide wire is 0.5-2 mm.

3. A process for preparing yttrium oxide material according to claim 1, characterized in that: The wire feeding speed of the wire feeding device for the metal yttrium guide wire is 1-10cm / min.

4. A process for preparing yttrium oxide material according to claim 1, characterized in that: In the step one, it also includes electrolytic polishing the surface of the metal yttrium guide wire before feeding, so that the surface roughness Ra of the metal yttrium guide wire is ≤0.1μm.

5. A process for preparing yttrium oxide material according to claim 1, characterized in that: In the step 2, the process also includes filling the sealed reaction container with a reaction gas of 60% argon and 40% oxygen.

6. A process for preparing yttrium oxide material according to claim 1, characterized in that: The reaction vessel is a tubular furnace.

7. A process for preparing yttrium oxide material according to claim 1, characterized in that: In step 3, the voltage of the storage capacitor is 5-20 kV, and the current density is 10 7 -10 8 A / cm 2 .

8. A process for preparing yttrium oxide material according to claim 1, characterized in that: In the step three, the heating temperature is controlled at 800-1200°C.

9. A process for preparing yttrium oxide material according to claim 1, characterized in that: In step six, the frequency of the pulsating airflow introduced is 0.5-10 Hz.

10. A process for preparing yttrium oxide material according to claim 1, characterized in that: In the step 1, the purity of the metal yttrium guide wire is ≥99.95%.

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