A method and device for mass production of high-purity gallium oxide without solvent and catalyst

Abstract

The application discloses a method and device for batch production of high-purity gallium oxide without solvent and catalyst, and particularly relates to the technical field of semiconductor material preparation, and comprises the following steps: (a) placing metal gallium into a crucible, and forming liquid gallium by vacuumizing and heating treatment; (b) performing mechanical crushing treatment on the liquid gallium for multiple times to obtain micron to nanometer gallium particles; (c) performing grading separation on the gallium particles obtained in the step (b) to collect ultra-fine gallium particles; (d) sending the ultra-fine gallium particles into a reactor to perform multistage oxidation reaction with oxygen to generate Ga2O3 crystal grains in a polymorphic form; (e) performing high-temperature treatment on the Ga2O3 crystal grains in the polymorphic form to convert the Ga2O3 crystal grains into molten and stable state beta-Ga2O3 crystal grains; and (f) performing rapid cooling and solidification on the molten and stable state beta-Ga2O3 crystal grains to obtain beta-Ga2O3 powder or particles. The application lays a solid foundation for obtaining electronic-grade ultra-high-purity beta-Ga2O3 powder.

Description

Technical Field

[0001] This invention relates to the field of semiconductor material preparation technology, and in particular to a method and apparatus for mass production of high-purity gallium oxide without solvents and catalysts. Background Technology

[0002] Gallium oxide (Ga2O3), as an emerging ultrawide bandgap semiconductor material, has shown great application potential in power electronic devices, deep ultraviolet optoelectronic devices, and gas sensors. Its high-performance applications place stringent requirements on material purity, crystal quality, and preparation cost.

[0003] Currently, the mainstream preparation methods for high-purity gallium oxide powder or particles are still mainly wet chemical methods, such as the sol-gel method, hydrothermal method, and precursor synthesis method of metal-organic chemical vapor deposition (MOCVD). These methods generally have the following inherent drawbacks: Complex and lengthy process flow: They typically involve multiple steps such as dissolution, precipitation, filtration, washing, drying, and calcination, with production cycles lasting several days and low production efficiency. High risk of introducing impurities: The large-scale use of acid, alkali, salt solutions, organic solvents, and precipitants (catalysts) makes complete removal difficult, resulting in high levels of metallic and anionic impurities in the final product, making it difficult to meet electronic-grade purity requirements. Environmental pollution and cost issues: The use and subsequent treatment of large amounts of chemical reagents generate waste liquids and gases, imposing a heavy environmental burden, and the reagent costs are high. Difficulty in continuous production: The various processes are mostly intermittent operations, and the equipment is discrete, making it difficult to integrate into an automated, continuous production line.

[0004] For example, patent document CN120535005A proposes a method to improve the reaction rate of gallium oxide preparation from metallic gallium. This method employs a wet chemical route, mixing metallic gallium with water and adding a promoter (such as an oxidant or catalyst). Under the influence of an external physical field (such as an ultrasonic field or pressure field), the mixture reacts to generate gallium hydroxyl oxide powder, which is then thermally decomposed to obtain gallium oxide powder. Although this method improves the reaction rate through the synergistic effect of the promoter and the physical field, it still falls under the category of wet processes, requiring the use of water, chemical reagents, and an external energy field. After the reaction, multiple post-processing steps such as filtration, washing, and drying are still necessary, making it impossible to avoid the generation of waste liquid and reagent residues. This limits product purity and environmental friendliness, and makes it difficult to achieve continuous and closed-loop production throughout the entire process.

[0005] Another patent document, CN223243296U, discloses a heating device and system for calcining gallium oxide. This device is mainly used for the thermal decomposition of gallium hydroxyl oxide in an inert atmosphere. A rotatable containment component drives the movement of internal materials, improving heating uniformity and thus increasing the crystal purity of gallium oxide. While this design optimizes certain aspects, it is limited to the post-calcination processing stage and does not address the entire process of gallium oxide powder preparation. In particular, it fails to solve the pollution and efficiency problems in precursor preparation, still relying on intermediates synthesized using wet chemical methods. The overall process remains lengthy and discontinuous.

[0006] Therefore, there is an urgent need to develop a method and apparatus for the continuous and efficient production of high-purity gallium oxide powder without the need for solvents and catalysts. Summary of the Invention

[0007] To solve the aforementioned technical problems, this invention employs the basic principles of mechanochemistry, primarily utilizing physical mechanical energy to drive and complete the chemical conversion from metallic gallium to gallium oxide. The technical solution consists of two closely related parts: the preparation method and the specialized apparatus. Part 1: A method for mass production of high-purity gallium oxide without solvents and catalysts A method for mass production of high-purity gallium oxide without solvents and catalysts, the method being a continuous or semi-continuous dry process, comprising the following steps: S1: Vacuum melting and purification of gallium metal Solid gallium metal is placed in a specialized crucible (such as a tungsten crucible) and subjected to rigorous vacuum treatment: first, the system is evacuated to a high vacuum, and then an inert gas (such as argon or helium) is introduced for purging; this "vacuuming-inert gas purging" cycle can be repeated multiple times to thoroughly remove air, moisture, and other volatile impurities from the reaction chamber. Under vacuum or inert atmosphere protection, the crucible is heated using methods such as electromagnetic induction radiation heating, with the temperature controlled above the melting point of gallium metal, typically in the range of 50-150°C, so that the gallium metal is completely melted into a smoothly flowing liquid state.

[0008] S2: Stepwise atomization and microparticle formation of liquid gallium Molten gallium is introduced into an atomization chamber for multi-stage, cascaded mechanical fragmentation, aiming to obtain gallium particles ranging from micrometers to nanometers, and even approaching atomic scales. The first stage of fragmentation (coarse fragmentation) primarily employs inert gas atomization. A high-pressure inert gas stream impacts the liquid gallium stream, utilizing the shear and impact forces of the gas to initially break it into micrometer-sized droplets. The second and subsequent stages of fragmentation (fine fragmentation) utilize ultrasonic atomization technology to further refine the products from the coarse fragmentation. Different types of ultrasonic atomizers can be selected or combined as needed: Ultrasonic nozzle type: frequency approximately 100-200 kHz; Ultrasonic mesh type: frequency approximately 10-50 kHz; Ultrasonic cavitation type: frequency approximately 0.5-5 MHz, utilizing the cavitation effect to generate extremely high local energy for fragmentation; Ultrasonic pulse vibration type: frequency approximately 10-100 kHz; Surface acoustic wave (SAW) type: frequency approximately 10-200 MHz. Atomizers at each stage can be connected in parallel or series to integrate the liquid gallium, allowing it to undergo a progressive refinement process from "fine stream → micron-sized droplets → micro-nano-sized particles → nano-atomic-sized particles". The entire atomization environment needs to be maintained at a certain temperature to prevent gallium from solidifying.

[0009] S3: Separation and screening of ultrafine gallium particles: The mixture of gallium particles of varying sizes, formed after atomization, is introduced into a gravity separator (or particle classification device). The particles are automatically classified based on their gravitational differences: the finest gallium particles (targeting the nanometer scale) float and aggregate at the top of the separator, forming a uniform particle flow; larger and heavier droplets or particles settle to the bottom of the separator, re-aggregating into liquid gallium. The separator is equipped with a heating and insulation device to ensure the fluidity of the gallium liquid at the bottom for recycling. By controlling the outlet position and airflow, the ultrafine gallium particles at the top can be continuously and selectively exported for the next reaction stage.

[0010] S4: Gas-phase oxidation reaction and crystal formation: The separated ultrafine, highly active gallium particles are used as a precursor and continuously fed into a multi-temperature zone tubular reactor. The reactor can be designed as a single-chamber multi-temperature zone or a multi-chamber series structure, with the reaction temperature precisely controlled within the range of 400-1050℃. High-purity oxygen is introduced into the reactor as the reaction gas. The reactor can be designed as a rotary reactor and equipped with a particle purging gas path and a reaction extension structure to increase particle residence time, prevent wall deposition, and promote particle collision and complete reaction.

[0011] S5: Post-treatment for crystal stabilization: Primary polycrystalline gallium oxide grains are introduced into a post-processing device. Heat treatment is performed in a specific high-temperature range (e.g., 900℃ to 1250℃) to promote the growth of the thermodynamically stable β-Ga2O3 phase as the dominant phase, resulting in gallium oxide grains with uniform crystal structure and stable structure.

[0012] S6: Rapid cooling and collection of products The incandescent β-Ga₂O₃ grains are conveyed to a grain cooling device. A combination of cross-flow circulating water cooling and inert gas convection cooling is used to achieve rapid and uniform quenching, preventing excessive grain growth or phase transformation. The cooled high-purity β-Ga₂O₃ powder is collected at the end of the device.

[0013] Part Two: An apparatus for carrying out the above method This device is an integrated system, characterized in that it sequentially includes, and is connected to, via sealed pipelines, the following unit equipment along the material flow path: Vacuum melting equipment includes a sealed melting chamber, inside which is placed a high-temperature resistant crucible made of tungsten, tantalum or their alloys. The crucible is surrounded by an electromagnetic induction heating coil. The top of the chamber is provided with a sealable feeding port, a high vacuum interface and an inert gas injection interface. The bottom or side is provided with a liquid metal outlet and is equipped with a liquid level sensor and a temperature sensor. It is used to heat and melt solid gallium metal into high-purity liquid gallium under vacuum or inert atmosphere protection. A metal shredding device, sealed to the liquid metal outlet of the vacuum melting device, includes an atomizing chamber. At least two physical atomizing devices are integrated or connected in series within the atomizing chamber. Each of the at least two atomizing devices includes an inert gas atomizing nozzle and at least one ultrasonic atomizer. The ultrasonic atomizer can be selected from one or more of an ultrasonic nozzle atomizer, an ultrasonic cavitation atomizer, and an ultrasonic vibrating disc atomizer. An insulating heating jacket is provided outside the atomizing chamber to maintain the temperature inside the chamber above the melting point of gallium. The particle separation device is sealed to the outlet of the metal crushing device. It is a vertically or inclined separation chamber. The coarse particles are separated from the ultrafine particles by controlling the airflow speed and direction and using gravity. The bottom of the separation chamber is equipped with a heating device and a coarse particle collection and discharge outlet, and the top or upper part is equipped with an ultrafine particle outlet. The particle pretreatment equipment, which is sealed to the ultrafine particle outlet of the particle separation equipment, is a plasma generator. It includes a tubular discharge cavity made of quartz or high-purity alumina, and a plasma excitation source is coupled to the outside of the discharge cavity. The plasma excitation source is an inductively coupled plasma source or a microwave plasma source, which is used to generate high-temperature plasma in the discharge cavity, so that the passing ultrafine gallium particles are instantly evaporated and ionized, and transformed into highly active gaseous gallium species. An oxidation reaction device, sealed to the outlet of the particle pretreatment device, includes at least one tubular reaction chamber made of high-temperature resistant and oxidation-resistant quartz or alumina ceramic. The exterior of the reaction chamber is segmented along the axial direction with independently temperature-controlled heating modules, forming multiple temperature-adjustable reaction zones covering a temperature range of 400-1050℃. One or both ends of the reaction chamber are connected to a rotary drive mechanism, allowing the chamber to rotate around its axis. The inner wall of the feed end of the reaction chamber has annularly distributed inclined air holes for introducing oxygen to form a wall-purge airflow. The inner wall of the discharge end of the reaction chamber has a flow-blocking or guiding structure to prolong the material residence time. The post-processing equipment, which is sealed to the outlet of the oxidation reaction equipment, is a high-temperature heat treatment furnace. The furnace temperature can be precisely controlled within the range of 900℃ to 1250℃. It is used to receive gallium oxide grains from the oxidation reaction equipment and perform isothermal heat treatment to transform their crystal form into a single, stable β-Ga2O3. The grain cooling device is sealed to the outlet of the post-processing device and includes a cooling chamber. The outside of the cooling chamber is covered with a circulating cooling medium coil or jacket for indirect cooling. The top and bottom of the cooling chamber are also provided with inert gas injection distributors for introducing cooling inert gas into the chamber to form forced convection and achieve rapid and uniform quenching of the product. The bottom of the cooling chamber is connected to a powder collection container.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides a novel dry, solvent-free method for preparing gallium oxide, which fundamentally eliminates the dependence on acids, alkalis, solvents and catalysts in traditional wet chemical methods. This method completely eliminates the risk of introducing impurity ions due to the use of chemical reagents, while avoiding the generation of toxic and harmful waste liquids, realizing green and clean production, and laying a solid foundation for obtaining electronic-grade ultra-high purity β-Ga2O3 powder. 2. The technical solution of this invention achieves continuous and efficient conversion from metallic gallium to gallium oxide through the high integration of mechanical atomization, plasma activation, and multi-temperature zone oxygen control reaction. Through inert gas atomization and ultrasonic atomization technology of multiple frequencies, nanoscale highly active gallium precursors can be stably prepared. Combined with the rotary multi-temperature zone reactor design, the gas-solid mass transfer and reaction process are greatly enhanced, ensuring high conversion rate and uniformity of the product. Attached Figure Description

[0015] Figure 1 This is a complete process flow diagram of the method for mass production of gallium oxide described in this invention; Figure 2 This is a schematic diagram of the device structure of Embodiment A of the present invention; Figure 3This is a schematic diagram of the vacuum melting furnace structure in Embodiment A of the present invention; Figure 4 This is a schematic diagram of the metal shredding device according to Embodiment A of the present invention; Figure 5 This is a schematic diagram of the particle separation device according to Embodiment A of the present invention; Figure 6 This is a schematic diagram of the particle pretreatment equipment according to Embodiment A of the present invention; Figure 7 This is a schematic diagram of the oxidation reaction equipment structure of Embodiment A of the present invention; Figure 8 This is a schematic diagram of the post-processing device structure according to Embodiment A of the present invention; Figure 9 This is a schematic diagram of the grain cooling device structure according to Embodiment A of the present invention; Figure 10 This is a schematic diagram of the device structure in Embodiment B of the present invention; Figure 11 This is a schematic diagram of the vacuum melting furnace structure in Embodiment B of the present invention; Figure 12 This is a schematic diagram of the metal shredding device according to Embodiment B of the present invention; Figure 13 This is a schematic diagram of the particle separation device according to Embodiment B of the present invention; Figure 14 This is a schematic diagram of the particle pretreatment equipment according to Embodiment B of the present invention; Figure 15 This is a schematic diagram of the oxidation reaction equipment structure in Embodiment B of the present invention; Figure 16 This is a schematic diagram of the post-processing device structure according to Embodiment B of the present invention; Figure 17 This is a schematic diagram of the grain cooling device structure according to Embodiment B of the present invention;

[0016] Detailed Implementation

[0017] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0018] A method for mass production of high-purity gallium oxide without solvents and catalysts, such as Figure 1 As shown, the reaction gas used in this method (process) is oxygen; the inert gases are argon and helium.

[0019] In operation 101, metallic gallium is placed into a crucible and, through vacuuming and heating, forms liquid gallium. This includes single placement and continuous placement. Single placement: using one set of vacuum melting equipment; first, metallic gallium is manually placed into the crucible within the vacuum melting equipment, then the crucible lid is closed, and the crucible and lid are sealed. Continuous placement: using two sets of vacuum melting equipment, one as a backup or used alternately, to continuously and uninterruptedly supply molten gallium metal, achieving continuous and batch preparation of gallium oxide particles. The metallic gallium in the crucible is evacuated and heated to form liquid gallium, including: vacuum treatment and crucible induction melting. Vacuum treatment consists of: i) vacuuming and degassing purification, ii) introducing inert gas, and iii) repeating i) and ii) multiple times to remove air and impurities from the crucible. The vacuum degree is 10. -6 Pa-10 -9 Pa. Induction melting in a crucible involves using electromagnetic induction radiation heating to inductively heat gallium metal within the crucible, transforming it into a smoothly flowing liquid. The heating temperature exceeds the melting point of gallium: 29.67℃.

[0020] In operation 102, liquid gallium undergoes multiple fragmentation processes. These fragmentation processes utilize physical means or mechanical energy / force to repeatedly break down or fracture the liquid gallium metal, including: inert gas atomization, ultrasonic atomization, and pulsed (mechanical) vibration atomization. The inert gas atomization pressure range is 0.08-0.3 MPa. Ultrasonic atomizers include nozzle type, mesh type, cavitation type, vibration type, and surface acoustic wave (SAW) type. The ultrasonic nozzle type has a frequency of 100-200 kHz; the ultrasonic mesh type has a frequency of 10-50 kHz; the ultrasonic cavitation type has a frequency of 0.5-5 MHz; the ultrasonic vibration type has a frequency of 10-100 kHz; and the surface acoustic wave (SAW) type has a frequency of 10-200 MHz. A single atomizer or fragmenter is insufficient for achieving the miniaturization (nano-atomic scale) of liquid gallium. Using multiple atomizers or fragmenters, liquid gallium undergoes multiple fragmentation processes, gradually reducing its size from large to small, eventually forming numerous, fine (micro-nano-scale, nano-atomic-scale) gallium particles. These atomizing processors can be used individually or integrated (i.e., in parallel or series) to process the liquid gallium through a series of processes: micronization, micro-nanoization, and finally nano-atomicization. Simultaneously, the ambient temperature for the atomization process must be maintained above the melting point of metallic gallium (29.67°C) to prevent solidification. It is important to note that the operation of the ultrasonic atomization setup (ultrasonic transducer) is limited by the ambient temperature; the solution is to equip it with cooling facilities.

[0021] In operation 103, numerous tiny gallium particles, due to their own gravity / weight, rise with smaller particles floating in the upper part of the separator (particle separation device), while larger gallium particles / droplets fall and remain at the bottom of the separator, forming molten gallium. Simultaneously, the separator mitigates the impact of various fragmentation (mechanical) processes ("brute force"), allowing the ultrafine (nanoscale) gallium particles to settle, suspend, and rise, forming a stream of small, highly uniform gallium particles in the upper part of the separator; while larger, heavier gallium droplets fall and deposit at the bottom of the separator. The ultrafine (nanoscale) gallium particles in the upper part of the separator are separated and exported for subsequent processing; the molten gallium formed by larger gallium droplets deposited at the bottom of the separator is collected and reused. Meanwhile, the separator is heated and kept at a constant temperature to ensure smooth flow of the molten gallium at the bottom. The heating or insulation temperature at the bottom of the separator is maintained at 50-150 °C.

[0022] In operation 104, ultrafine gallium particles, as precursor materials, undergo multiple continuous reactions with reactant gases in the reactor to generate molten, polymorphic Ga2O3 crystals. The reactor, which is also an oxidation reaction device, includes a single reaction chamber / cavity or multiple reaction chambers / cavities. Each reaction chamber / cavity contains a single temperature zone or multiple temperature zones. The reaction temperature within the reaction chamber / cavity is 400-1050℃. Reactant gases introduced by the particle purging and reaction extension devices purge along the inner wall of the reaction chamber / cavity, removing gallium particles / ions and Ga2O3 crystals adhering to the inner wall and increasing the reaction opportunities between gallium particles / ions or Ga2O3 crystals and the reactant gases within the reaction chamber / cavity. A rotary motor is installed at the head or tail of the reactor to control its rotation, causing the gallium ions / particles or Ga2O3 crystals within the reaction chamber / cavity to continuously come into contact, rub, collide, and break apart, ensuring thorough mixing with the reactant gases, followed by reaction, fragmentation, and further reaction. Furthermore, the rotation of the reactor further reduces the adhesion of gallium ions / particles or Ga2O3 grains to the inner wall of the reaction chamber / cavity. Simultaneously, multiple reaction chambers / cavities are used, each with multiple reaction zones (temperature zones), to implement continuous reactions until polymorphic and isomeric Ga2O3 grains (α-Ga2O3, β-Ga2O3, γ-Ga2O3, δ-Ga2O3, ε-Ga2O3, and κ-Ga2O3) are completely generated.

[0023] In operation 105, the polymorphic Ga2O3 grains undergo subsequent processing to become molten, stable β-Ga2O3 grains. The subsequent processing is high-temperature treatment; the temperature range of the high-temperature treatment is 900-1250℃.

[0024] In operation 106, the molten, stable β-Ga₂O₃ grains undergo uniform cooling to become β-Ga₂O₃ powder or particles. The β-Ga₂O₃ powder or particles are then collected, sorted, and stored. Cooling temperature: less than 50°C.

[0025] Example A Reference Figure 2 This embodiment illustrates a specific implementation of the present invention. Its core technology lies in the combined technical route of inert gas primary atomization, ultrasonic vibration secondary atomization, microwave plasma pretreatment, and single-cavity multi-temperature zone reaction to achieve efficient and continuous preparation of gallium oxide.

[0026] The operating procedures and equipment are described in detail below: S1, Vacuum Melting and Purification Equipment: High-purity gallium metal blocks are placed in vacuum melting furnace A110 (see...) Figure 3 Vacuum melting equipment A110, which melts solid gallium metal into a smoothly flowing liquid, includes: a crucible A111, a heater A112, a heat shield / baffle A113, a crucible cover A114, a gallium metal level gauge A115, an inert gas inlet A116, a vacuum outlet A117, and a molten metal guide pipe A118. The crucible A111 is a semi-circular container made of high-temperature resistant and corrosion-resistant tungsten material. The heater A112 is a resistance or electromagnetic induction heater, ring-shaped, surrounding the crucible A111. The heat shield / baffle A113 is a cylindrical graphite plate located around the heater A112. The crucible cover A114 is a circular plate made of stainless steel with a Teflon coating, located on top of the crucible A111, and seals it to prevent contaminants or air from entering. The inert gas inlet tube (A116) and the vacuum outlet tube (A117) are made of PTFE. The gallium metal level gauge A115, the inert gas inlet tube (A116), and the vacuum outlet tube (A117) are all located above the crucible cover plate A114. The molten metal guide tube A118 is a tungsten tube, located at the center of the top of the crucible cover plate A114.

[0027] Procedure: First, place the high-purity gallium metal block in a tungsten crucible A111 and seal the crucible lid A114; then, evacuate the system to a high vacuum (10⁻⁶ m³ / h) through the vacuum tube A117. -6 -10 -9 The air is removed from the chamber by purging with an inert gas such as argon through inert gas tube A116. This "vacuuming-inert gas filling" cycle can be repeated multiple times to thoroughly remove air and volatile impurities from the chamber. Under vacuum or inert atmosphere protection, the heater A112 surrounding the crucible is activated for induction heating, raising the temperature to the gallium melting point (29.67°C). At temperatures above ℃, metallic gallium melts into a liquid state; during the process, gallium metal level gauge A115 monitors the liquid level, and finally the liquid gallium flows out smoothly through the tungsten guide tube A118 at the top and enters the subsequent atomization process.

[0028] S2, stepped atomization and microparticle formation Equipment: Molten liquid gallium is introduced into the metal shredding equipment A120 through the bottom guide tungsten tube A118 (see...) Figure 4 The metal fragmentation device A120, which breaks down liquid gallium into ultrafine gallium particles / droplets, includes: a fragmentation chamber A121, a fragmentation chamber heater A122, a fragmentation chamber cover A123, an inert gas atomizer A124, an ultrasonic vibrating spray plate A125, a piezoelectric ceramic transducer A126, a gallium metal level gauge A127, a gallium particle outlet A128, and a gallium metal liquid collector A129. The fragmentation chamber A121, also known as the atomization chamber, is cylindrical and made of high-temperature resistant and corrosion-resistant tungsten material. The fragmentation chamber heater A122 is a resistance or electromagnetic induction heater, ring-shaped, wound around the bottom of the fragmentation chamber A121. The fragmentation chamber cover A123 is located at the top of the fragmentation chamber A121 and seals it. The inert gas atomizer A124 is located at the center of the top of the fragmentation chamber and communicates with the molten metal guide pipe A118. The ultrasonic vibrating spray plate A125 is located at the center of the lower part of the fragmentation chamber A121. The piezoelectric ceramic transducer A126 is located at the bottom of the fragmentation chamber A121, driving the ultrasonic vibrating spray plate A125 to perform secondary atomization of the gallium metal liquid. The gallium metal level gauge A127 is located on top of the fragmentation chamber cover plate A123. The gallium particle outlet A128 is located on the upper side of the fragmentation chamber A121. The gallium metal liquid collector A129 is conical in shape, made of stainless steel, with a Teflon coating on the inner wall, and is located at the bottom of the fragmentation chamber A121.

[0029] Process: Molten gallium is injected into the sealed fragmentation chamber A121 via the guide tube A118, and the temperature is maintained by the heater A122 surrounding the bottom to prevent solidification. First, the liquid gallium flows through the inert gas atomizer A124 at the top, under high-pressure inert gas (0.08-0.3... Under shearing impact of MPa (100 MPa), the droplets are initially broken down into micron-sized droplets. These droplets then fall downwards onto the central ultrasonic vibrating spray disk A125, where high-frequency mechanical vibration is generated by the piezoelectric ceramic transducer A126 at the bottom, further refining the droplets to the nanoscale through secondary cavitation and fragmentation. Throughout the process, the liquid level is monitored by a gallium metal level gauge A127. The atomized ultrafine particles are discharged from the upper gallium particle outlet A128 with the airflow, while larger droplets that are not fully broken down settle to the bottom gallium metal liquid collector A129 for recycling.

[0030] S3. Particle classification and separation Equipment: The gas stream carrying gallium particles enters the particle separator A130 from the upper side outlet A128 of the atomizing chamber (see...) Figure 5 The particle separation device A130, also known as a separator, mitigates the impact of gallium particles or droplets and separates ultrafine gallium particles. It includes: a separation chamber A131, a separation chamber heater A132, a heat insulation plate A133, a gallium metal level gauge A134, a gallium particle inlet A135, a gallium particle outlet A136, and a gallium metal liquid collector A137. The separation chamber A131 is a cylindrical cavity made of tungsten material. The separation chamber heater A132 is a resistance or electromagnetic induction heater, ring-shaped, wound around the separation chamber A131. The heat insulation plate A133 is located around the periphery of the separation chamber heater A132. The gallium metal level gauge A134 is positioned above the separation chamber A131. The gallium particle inlet A135 is located in the center of the separation chamber A131. The gallium particle outlet A136 is located at the top center of the separation chamber A131. Gallium metal liquid collector A137 is conical in shape, made of stainless steel, with a Teflon coating on the inner wall, and is located at the tail of separation chamber A131.

[0031] Process: The airflow carrying gallium particles enters the separation chamber tangentially from the atomization chamber through the gallium particle inlet A135. Under the heat preservation of heater A132 (30-150℃), a stable thermal and flow field is formed within the chamber. The incoming particle group undergoes classification under the combined action of gravity and airflow: ultrafine (nanoscale) gallium particles, due to their light weight and high resistance, slowly float upward with the airflow and gradually accumulate in the upper part of the separation chamber, eventually being continuously discharged through the gallium particle outlet A136 at the top and entering subsequent processes. Larger and heavier gallium droplets or particles, however, sink downward under gravity and converge into liquid gallium at the tail of the separation chamber, which is collected by the gallium metal liquid collector A137 at the bottom and can be returned to the atomization system for reuse. During the separation process, the gallium metal liquid level gauge A134 monitors the liquid level in real time to ensure stable separation.

[0032] S4, Plasma High-Energy Activation Equipment: The particle pretreatment equipment A140 (see...) Figure 6 The system performs high-temperature, high-energy pretreatment on molten gallium particles, including: a discharge chamber / cavity A141, a waveguide A142, a microwave plasma generator A143, a high-temperature plasma zone A144, and a water-cooled cooling jacket A145. The discharge chamber / cavity A141 is a cylindrical cavity made of corrosion-resistant and high-temperature-resistant quartz material. The waveguide A142 is a rectangular tube; the microwave plasma generator A143 is connected to the waveguide A142. The high-temperature plasma zone A144 is a high-temperature, high-energy zone generated by the microwave plasma arc. The water-cooled cooling jacket A145, made of stainless steel and filled with circulating cooling water, is located around the discharge chamber / cavity A141.

[0033] Process: Ultrafine gallium particles, carried by a carrier gas, enter a quartz discharge chamber A141 through inlet A412. A microwave plasma generator A143 introduces microwave energy into the chamber through waveguide A142, exciting and maintaining a high-energy plasma arc A144, forming an extremely high-temperature activation region. As the gallium particles pass through this region, they are instantly heated, melted, and further dissociated into highly active gaseous or highly excited gallium ions, achieving a significant increase in energy and surface activity. Throughout the process, a water-circulating cooling jacket A145 surrounding the discharge chamber continuously operates, removing excess heat from the chamber walls and ensuring stable operation of the quartz chamber at high temperatures. The activated, highly active gallium ion stream is then transported to the subsequent oxidation reaction equipment through discharge chamber outlet A416.

[0034] S5, Multi-temperature zone oxidation reaction Equipment: The oxidation reaction equipment is A150 (see...) Figure 7 The system comprises: a single-temperature zone reaction chamber A151, a reaction chamber heater A152, a graphite heat insulation plate A153, a circulating cooling water jacket A154, a particle purging device A155, a reaction extension device A156, and a rotary motor A157. The single-temperature zone reaction chamber A151 is a cylindrical cavity made of high-temperature resistant and corrosion-resistant quartz or alumina material. The reaction chamber heater A152 is a resistance or electromagnetic induction heater, ring-shaped, wound around the single-temperature zone reaction chamber A151. The graphite heat insulation plate A153 is located around the reaction chamber heater A152. The circulating cooling water jacket A154 is located around the graphite heat insulation plate A153. The particle purging device A155 consists of multiple oblique holes, evenly distributed on the inner wall of the front end of the single-temperature zone reaction chamber A151; while the reaction extension device A156 consists of multiple oblique and straight holes, intersecting and evenly distributed on the inner wall of the rear end of the single-temperature zone reaction chamber A151. The rotary motor A157 is located at the tail of the single-temperature zone reaction chamber A151.

[0035] Process: A highly active gallium ion stream, activated by plasma, enters a single-temperature zone reaction chamber A151, made of quartz or alumina, from the front end of the reaction chamber. The reaction chamber is precisely controlled at an oxidation reaction temperature of 400-1050℃ by a heater A152 wrapped around it. Simultaneously, a rotary motor A157 drives the reaction chamber to slowly rotate around its axis, causing the materials inside to continuously tumble and mix. High-purity oxygen is blown tangentially along the inner wall through multiple inclined air holes in the particle purging device A155 at the front end, forming a wall-sweeping airflow that prevents gallium ions and products from depositing on the wall and enhances gas-solid contact. During the material's backward transport, the reaction extension device A156 at the rear end generates turbulence through cross-arranged inclined and straight holes, extending the residence time and ensuring that the oxidation reaction proceeds fully, ultimately generating polycrystalline Ga2O3 grains. The external graphite heat insulation plate A153 and the circulating cooling water jacket A154 ensure the stability of the reaction temperature and the safety of the equipment.

[0036] S6, Crystal stabilization treatment Equipment: The post-processing equipment A160 (see...) Figure 8 The system comprises: a post-treatment chamber A161, a post-treatment chamber heater A162, a graphite heat insulation plate A163, a circulating cooling water jacket A164, a particle purging device A165, and a residence time extension device A166. The post-treatment chamber A161 is a cylindrical cavity made of high-temperature resistant and corrosion-resistant quartz or alumina material. The post-treatment chamber heater A162 is a resistance or electromagnetic induction heater, ring-shaped, wound around the periphery of the post-treatment chamber A161. The graphite heat insulation plate A163 is located around the periphery of the post-treatment chamber heater A162. The circulating cooling water jacket A164 is located around the periphery of the graphite heat insulation plate A163. The particle purging device A165 consists of multiple oblique holes, evenly distributed on the inner wall of the front end of the post-treatment chamber A161; while the residence time extension device A166 consists of multiple oblique and straight holes, intersecting and evenly distributed on the inner wall of the rear end of the post-treatment chamber A161.

[0037] Process: Polycrystalline Ga2O3 grains from the oxidation reaction enter the post-processing chamber A161 through the inlet. The furnace temperature is precisely controlled within the range of 900-1250℃ by the annular heater A162. Isothermal heat treatment is performed at this high temperature to promote the growth of the thermodynamically stable β-Ga2O3 phase and make it the dominant crystal form. During the process, a small amount of oxygen or inert gas is introduced through the oblique holes of the particle purging device A165 on the front inner wall to prevent particle deposition and maintain airflow turbulence. The residence time extension device A166 at the tail end generates turbulence through a cross-channel structure, extending the particle residence time and ensuring sufficient and uniform crystal transformation. Finally, the uniformly shaped and structurally stable β-Ga2O3 grains are discharged from the outlet and enter the subsequent cooling process. The external graphite heat insulation plate A163 and the circulating cooling water jacket A164 ensure the stability of the thermal field and the safe operation of the equipment.

[0038] S7, Rapid Cooling and Product Collection Equipment: Incandescent β-Ga2O3 grains flow into grain cooling equipment A170 (see...) Figure 9The grain cooling device A170 includes: a cooling chamber A171, an inlet-outlet cross-circulation cooling water pipe A172, a cooling chamber shell A173, a top purging device A174, a bottom purging device A175, a cooling chamber inlet A176, a cooling chamber outlet A177, and a gallium oxide powder collector A178. The cooling chamber A171 is made of stainless steel with a smooth inner wall. The inlet-outlet cross-circulation cooling water pipe A172 consists of multiple straight pipes with intersecting inlets and outlets, welded to the outer wall of the cooling chamber A171. The cooling chamber shell A173 is located around the inlet-outlet cross-circulation cooling water pipe A172. The top of the cooling chamber A171 has a top purging device A174, and the bottom of the cooling chamber A171 has a bottom purging device A175. The cooling chamber inlet A176 is located at the center of the top of the cooling chamber A171. The cooling chamber outlet A177 is located at the bottom of the cooling chamber A171. The gallium oxide powder collector A178 is located at the tail of the cooling chamber A171 and is connected to the cooling chamber outlet A177.

[0039] Process: Incandescent β-Ga₂O₃ grains enter the stainless steel cooling chamber A171 through the inlet A176. Cooling water flows through the inlet-outlet cross-circulation cooling water pipe A172 welded to its outer wall, rapidly cooling the chamber through indirect heat exchange. Simultaneously, cooling inert gas is introduced into the chamber through the top purging device A174 and the bottom purging device A175, creating forced convection to further accelerate and homogenize the quenching process. The grains rapidly cool to below 50°C within the cooling chamber, solidifying into high-purity β-Ga₂O₃ powder, effectively preventing excessive grain growth or adverse phase transformations. The cooled powder falls under gravity through the bottom cooling chamber outlet A177, ultimately entering the connected gallium oxide powder collector A178 for collection and storage.

[0040] Example B Reference Figure 10 This embodiment demonstrates another preferred embodiment of the present invention, which employs a combination of ultrasonic nozzle atomization, ultrasonic cavitation atomization, inductive plasma pretreatment, and multi-cavity series reaction, making it suitable for production scenarios with higher requirements for production capacity and reaction uniformity.

[0041] The operating procedures and equipment are described in detail below: S1, Vacuum Melting and Purification Equipment: The vacuum melting equipment B110 (see...) Figure 11The system, which melts solid gallium metal into a smoothly flowing liquid, includes: a crucible B111, a heater B112, a heat shield / baffle B113, a crucible lid B114, a gallium metal level gauge B115, an inert gas inlet B116, a vacuum outlet B117, and a gallium metal liquid guide pipe B118. The crucible B111 is cylindrical and made of tungsten and tantalum. The heater B112 is an electromagnetic induction heater, ring-shaped, wrapped around the perimeter of the crucible B111. The heat shield / baffle B113 is a cylindrical graphite plate located around the heater B112. The crucible lid B114 is a circular plate made of stainless steel with a Teflon coating, located on top of the crucible B111, and seals it to prevent contaminants or air from entering. The gallium metal level gauge B115, the inert gas tube (inlet) B116, and the vacuum tube (outlet) B117 are all located above the crucible cover plate B114. The gallium metal liquid guide tube B118 is a tungsten tube located at the bottom of the crucible B111.

[0042] Procedure: A high-purity gallium metal block is placed into a cylindrical crucible B111 made of tungsten / tantalum, and covered with a stainless steel cover plate B114 with a Teflon coating and sealed. The system is evacuated to a high vacuum (10⁻⁶ m³ / h) through the top vacuum tube B117. -6 -10 -9 The air is then purged (Pa) and replaced with argon gas through inert gas tube B116; this "evacuation-purging" cycle can be repeated multiple times to thoroughly remove air and volatile impurities. Subsequently, the electromagnetic induction heater B112 surrounding the crucible is activated to heat the gallium metal to its melting point (29.67 Pa) under vacuum or inert atmosphere. The temperature is above ℃ to completely melt it into a liquid state. During the process, the liquid level is monitored by a gallium metal level gauge B115. Finally, the liquid gallium is smoothly discharged from the bottom of the crucible through a tungsten guide tube B118, entering the next atomization process. The entire process is carried out efficiently and cleanly under the protection of the heat insulation plate B113. S2, Composite Ultrasonic Atomization Equipment: Liquid gallium enters the metal shredding equipment B120 through a guide tube (see...) Figure 12The metal fragmentation device B120 breaks down liquid gallium into numerous fine or micro-sized gallium particles / droplets. It includes: a fragmentation chamber B121, a fragmentation chamber heater B122, a fragmentation chamber cover B123, an ultrasonic nozzle atomizer B124, an ultrasonic cavitation atomizer / transducer B125, a gallium metal level gauge B126, a gallium particle outlet B127, and a gallium metal liquid collector B128. The fragmentation chamber B121, also known as the atomization chamber, is made of tungsten and tantalum metal. The fragmentation chamber heater B122 is an electromagnetic induction heater, ring-shaped, wound around the bottom of the fragmentation chamber B121. The fragmentation chamber cover B123 is a circular plate made of stainless steel with a Teflon coating, located on top of the fragmentation chamber B121 and sealed to it. The ultrasonic nozzle atomizer B124 is located at the center above the fragmentation chamber B21 and is connected to the molten metal guide pipe B118. The ultrasonic cavitation atomizer / transducer B125 is located at the center of the bottom of the fragmentation chamber B121, further fragmenting the accumulated gallium molten metal. The gallium molten metal level gauge B126 is located above the fragmentation chamber cover plate B123. The gallium particle outlet B127 is located on the upper side of the fragmentation chamber B121. The gallium molten metal collector B128 is a cone made of stainless steel with a Teflon coating and is located at the bottom of the fragmentation chamber B121.

[0043] Process: Molten gallium is injected into a sealed fragmentation chamber B121 through a guide tube B118, while a bottom heater B122 maintains the temperature to prevent solidification. The liquid gallium first flows through the ultrasonic nozzle atomizer B124 at the top, where it is initially broken into micron-sized droplets under specific high-frequency vibrations (100-200kHz). The droplets then fall to the bottom of the chamber, where the accumulated melt is further fragmented by the ultrasonic cavitation atomizer / transducer B125 at the center, under the cavitation effect at a higher frequency (0.5-5 MHz), generating a large number of highly active nano-sized gallium particles. Throughout the process, the liquid level is monitored by a gallium metal level gauge B126. The ultrafine particles formed by atomization are discharged from the gallium particle outlet B127 at the top with the carrier gas, while larger droplets that are not sufficiently refined settle to the gallium metal liquid collector B128 at the bottom, which can be returned to the system for recycling.

[0044] S3. Particle classification and separation Equipment: The aerosol generated by atomization enters the particle separation equipment B130 (see...) Figure 13The particle separation device B130, which mitigates the impact of gallium particles or droplets and separates ultrafine gallium particles, includes: a separation chamber B131, a separation chamber heater B132, a heat insulation plate B133, a gallium metal level gauge B134, a gallium particle inlet B135, a gallium particle outlet B136, and a gallium metal liquid collector B137. The separation chamber B131 is cylindrical and made of tungsten and tantalum materials. The separation chamber heater B132 is annular and wrapped around the separation chamber B131. The heat insulation plate B133 is a cylindrical graphite material located around the periphery of the separation chamber heater B132. The gallium metal level gauge B134 is positioned above the separation chamber B131. The gallium particle inlet B135 is located in the center of the separation chamber B131. The gallium particle outlet B136 is located at the top center of the separation chamber B131. The accumulated gallium metal liquid collector B137 is a cone-shaped stainless steel material with a Teflon coating, located at the tail of the separation chamber B131.

[0045] Process: The aerosol generated by atomization enters tangentially into the cylindrical separation chamber B131 through the gallium particle inlet B135. Under the action of the surrounding heater B132, the chamber temperature is maintained within the range of 30-150℃, preventing metal solidification and maintaining a stable thermal field. Under the combined action of gravity and airflow, the entering particles undergo classification: ultrafine (nanoscale) gallium particles, being lightweight and subject to high resistance, slowly rise with the airflow and accumulate at the top of the separation chamber, ultimately being continuously discharged through the gallium particle outlet B136 at the top, entering the subsequent activation process. Larger and heavier droplets or particles settle to the bottom and converge into liquid gallium at the tail of the separation chamber, collected by the accumulated gallium metal liquid collector B137 at the bottom, which can be returned to the atomization system for reuse. During the process, the gallium metal liquid level gauge B134 monitors the liquid level in real time to ensure a stable and controllable separation process. S4, Inductively Coupled Plasma Pretreatment Equipment: Ultrafine gallium particles are fed into particle pretreatment equipment B140 (see...) Figure 14 The particle pretreatment device B140 performs inductive plasma pretreatment on molten gallium particles and includes: a plasma chamber / discharge chamber B141, a plasma coil / heater B142, a graphite heat shield B143, a circulating cooling water jacket B144, a plasma chamber inlet B145, and a plasma chamber outlet B146. The plasma chamber / discharge chamber B141 is cylindrical and made of quartz or alumina. The plasma coil / heater B142 is wound around the plasma chamber / discharge chamber B141. The graphite heat shield B143 is located around the plasma coil / heater B142. The circulating cooling water jacket B144 is located around the periphery of the graphite heat shield B143. The plasma chamber inlet B145 is located at the front end of the plasma chamber / discharge chamber B141. The plasma chamber outlet B146 is located at the rear end of the plasma chamber / discharge chamber B141.

[0046] Process: Ultrafine gallium particles, carried by a carrier gas, enter a discharge chamber B141 made of quartz or alumina through the plasma inlet B145. A high-frequency current is supplied to the plasma coil / heater B142 surrounding the chamber, exciting and maintaining a high-intensity inductively coupled plasma within the chamber, forming an extremely high-temperature, energy-dense activation region. As the gallium particles pass through this region, they are instantly heated, melted, and further dissociated into highly reactive gaseous gallium ions, resulting in a significant increase in surface energy and reactivity. Throughout the process, an external graphite heat shield B143 reduces heat loss, while a circulating cooling water jacket B144 ensures controlled chamber wall temperature and stable equipment operation. The fully activated, highly reactive gallium ion stream is then continuously transported from the plasma outlet B146 to the downstream oxidation reaction equipment.

[0047] S5, Multi-cavity series oxidation reaction Equipment: The activated material enters the oxidation reaction equipment B150 (see...) Figure 15 The oxidation reaction apparatus B150 includes: a multi-temperature zone electromagnetic induction reaction chamber B151, a #1 reaction chamber heater B152, a #2 reaction chamber heater B153, a #3 reaction chamber heater B154, a graphite heat insulation plate B155, a circulating cooling water jacket B156, a particle purging device B157, a reaction extension device B158, and a rotary motor B159. The multi-temperature zone electromagnetic induction reaction chamber B151 is made of high-temperature resistant and corrosion-resistant material. The #1 reaction chamber heater B152 is wound around the head of the multi-temperature zone electromagnetic induction reaction chamber B151; the #2 reaction chamber heater B153 is wound around the middle of the multi-temperature zone electromagnetic induction reaction chamber B151; and the #3 reaction chamber heater B154 is wound around the tail of the multi-temperature zone electromagnetic induction reaction chamber B151. The graphite heat insulation plate B155 is located around the periphery of the #1 reaction chamber heater B152, the #2 reaction chamber heater B153, and the #3 reaction chamber heater B154. The circulating cooling water jacket B156 is located around the graphite heat insulation plate B155. The particle purging device B157 is embedded in the inner wall of the tail end of the multi-temperature zone electromagnetic induction reaction chamber B151; while the reaction extension device B158 is embedded in the inner wall of the tail end of the multi-temperature zone electromagnetic induction reaction chamber B151. The rotary motor B159 is located at the tail end of the multi-temperature zone electromagnetic induction reaction chamber B151.

[0048] Process: A highly reactive gaseous gallium ion stream activated by plasma enters the multi-temperature zone electromagnetic induction reaction chamber B151 from the front end of the reaction chamber. This reaction chamber is independently and precisely temperature-controlled by heaters (#1 B152, #2 B153, #3 B154) arranged in sections along the axial direction, forming multiple controllable temperature gradient reaction zones (400-1050℃) to meet the thermodynamic requirements of different stages of the oxidation reaction. Driven by a rotary motor B159 at the tail end, the reaction chamber rotates slowly, causing continuous tumbling and mixing of the materials. High-purity oxygen is tangentially blown in through oblique holes in the particle purging device B157 embedded in the inner wall of the tail end, forming a wall-adhering airflow to prevent deposition and enhance gas-solid contact. Simultaneously, the reaction extension device B158 further extends the material residence time through turbulent flow in the channels, ensuring a sufficient and complete oxidation reaction, ultimately generating polycrystalline Ga2O3 grains. External graphite heat insulation plate B155 and circulating cooling water jacket B156 ensure thermal stability and safe operation of the equipment.

[0049] S6, Crystal stabilization treatment Equipment: Gallium oxide grains exiting the series reactors enter post-processing unit B160 (see...) Figure 16 The post-processing equipment B160 includes: a post-processing chamber B161, a post-processing chamber heater B162, a graphite heat insulation plate B163, a circulating cooling water jacket B164, a particle purging device B165, and a residence time extension device B166. The post-processing chamber B161 is a cylindrical cavity made of high-temperature resistant and corrosion-resistant quartz or alumina material. The post-processing chamber heater B162 is a resistance or electromagnetic induction heater, ring-shaped, wound around the post-processing chamber B161. The graphite heat insulation plate B163 is cylindrical and located around the post-processing chamber heater B162. The circulating cooling water jacket B164 is located around the graphite heat insulation plate B163. The particle purging setting B165 consists of multiple oblique holes, which are evenly distributed on the inner wall of the front end of the post-treatment chamber B161; while the residence time extension setting B166 consists of multiple oblique holes and straight holes, which are intersected and evenly distributed on the inner wall of the rear end of the post-treatment chamber B161.

[0050] Process: Polymorphic Ga2O3 grains from the tandem oxidation reaction enter the cylindrical post-processing chamber B161. The temperature inside the chamber is precisely controlled within the range of 900–1250℃ by the surrounding post-processing chamber heater B162, performing isothermal heat treatment to promote the growth of the thermodynamically stable β-Ga2O3 phase and make it the dominant crystal form. During this process, a small amount of oxygen or inert gas is blown in through the oblique holes of the particle purging device B165 on the front inner wall to prevent particle deposition and maintain airflow turbulence; the residence time extension device B166 at the tail end generates turbulence through cross-distributed oblique and straight holes, extending the particle residence time and ensuring sufficient and uniform crystal transformation. Finally, the uniformly shaped and structurally stable β-Ga2O3 grains are discharged from the outlet and enter the cooling process. The external graphite heat insulation plate B163 and the circulating cooling water jacket B164 ensure thermal stability and safe operation of the equipment. S7, Rapid Cooling and Product Collection Equipment: The grain cooling equipment B170 (see...) Figure 17 The system includes: a cooling chamber B171, an inlet-outlet cross-circulation cooling water pipe B172, a cooling chamber shell B173, a top purging device B174, a bottom purging device B175, a cooling chamber inlet B176, a cooling chamber outlet B177, and a gallium oxide powder collector B178. The cooling chamber B171 is made of stainless steel with a smooth inner wall. The inlet-outlet cross-circulation cooling water pipe B172 consists of multiple straight pipes with intersecting inlets and outlets, welded to the outer wall of the cooling chamber B171. The cooling chamber shell B173 is located around the inlet-outlet cross-circulation cooling water pipe B172. A top purging device B174 is located at the top of the cooling chamber B171, and a bottom purging device B175 is located at the bottom of the cooling chamber B171. The cooling chamber inlet B176 is located at the center of the top of the cooling chamber B171; the cooling chamber outlet B177 is located at the bottom of the cooling chamber B171. The gallium oxide powder collector B178 is located below the tail of the cooling chamber B171 and is connected to the cooling chamber outlet B177.

[0051] Process: Incandescent β-Ga₂O₃ grains enter the stainless steel cooling chamber B171 through the cooling chamber inlet B176. Cooling water flows through the inlet-outlet cross-circulation cooling water pipe B172 welded to the outer wall, efficiently cooling the chamber through indirect heat exchange. Simultaneously, cooling inert gases are introduced through the top purging device B174 and the bottom purging device B175, creating forced convection within the chamber to accelerate and homogenize the quenching process. The grains are rapidly cooled to below 50°C, solidifying into high-purity β-Ga₂O₃ powder, effectively preventing excessive grain growth or adverse phase transformations. The cooled powder falls under gravity through the bottom cooling chamber outlet B177, ultimately entering the gallium oxide powder collector B178 below for collection and storage, achieving continuous and closed-loop product recovery.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for mass production of high-purity gallium oxide without solvents and catalysts, characterized in that: Includes the following steps: (a) Placing metallic gallium into a crucible and subjecting it to vacuum and heating to form liquid gallium; (b) The liquid gallium is subjected to multiple mechanical crushing processes to obtain gallium particles ranging from micrometers to nanometers; (c) The gallium microparticles obtained in step (b) are graded and separated to collect ultrafine gallium particles; (d) The ultrafine gallium particles are fed into a reactor and undergo a multi-stage oxidation reaction with oxygen to generate polycrystalline Ga2O3 grains. (e) The polymorphic Ga2O3 grains are subjected to high-temperature treatment to transform them into molten, stable β-Ga2O3 grains; (f) The molten, stable β-Ga2O3 grains are rapidly cooled and solidified to obtain β-Ga2O3 powder or particles.

2. The method for mass production of high-purity gallium oxide without solvent and catalyst according to claim 1, characterized in that: In step (a), the vacuuming and heating treatment includes crucible vacuuming and induction melting. The crucible vacuuming includes: i) vacuuming, ii) injecting inert gas, and iii) repeating steps i) and ii) multiple times; the vacuum degree is 10. -6 Pa-10 -9 Pa; The induction melting is carried out using electromagnetic induction radiation heating, and the heating temperature is higher than the melting point of gallium, which is 29.67°C.

3. The method for mass production of high-purity gallium oxide without solvent and catalyst according to claim 1, characterized in that: In step (b), the multiple crushing processes include inert gas atomization and ultrasonic atomization. The pressure range of the inert gas atomization is 0.08-0.3 MPa, and the ultrasonic atomization is selected from at least one of nozzle type, mesh type, cavitation type, pulse vibration type or surface acoustic wave type.

4. The method for mass production of high-purity gallium oxide without solvent and catalyst according to claim 3, characterized in that: The frequency range of the ultrasonic atomizer is as follows: nozzle type 100-200 kHz, mesh type 10-50 kHz, cavitation type 0.5-5 MHz, pulse vibration type 10-100 kHz, surface acoustic wave type 10-200 MHz.

5. The method for mass production of high-purity gallium oxide without solvent and catalyst according to claim 1, characterized in that: In step (c), the separation is carried out in a heated separator, which utilizes the gravitational differences of the gallium particles themselves to achieve separation. The heating temperature of the separator is 30-150℃, and the separated ultrafine gallium particles are nanoscale.

6. The method for mass production of high-purity gallium oxide without solvent and catalyst according to claim 1, characterized in that: In step (d), the reactor includes a single reaction chamber or multiple reaction chambers; the reaction temperature in the reaction chamber is 400-1050℃, and the multiple reactions are achieved by introducing oxygen from different directions through multiple airflow channels, purging along the inner wall of the reaction chamber, and rotating the reactor to allow the materials in the reaction chamber to come into contact, rub, and collide with each other.

7. The method for mass production of high-purity gallium oxide without solvent and catalyst according to claim 1, characterized in that: In step (e), the temperature of the high-temperature treatment is 900-1250℃.

8. The method for mass production of high-purity gallium oxide without solvent and catalyst according to claim 1, characterized in that: In step (f), the rapid cooling is to cool the molten β-Ga2O3 grains to less than 50°C.

9. An apparatus for carrying out the method according to any one of claims 1 to 8, characterized in that, Along the material flow direction, the following are included in sequence: Vacuum melting equipment is used to heat and melt solid gallium metal into liquid gallium metal in an inert atmosphere or vacuum environment; The metal crushing equipment has its inlet connected to the outlet of the vacuum melting equipment via a guide pipe, and is used to crush the received liquid gallium metal into gallium metal particles; A particle separation device, the inlet of which is connected to the particle outlet of the metal crushing device, is used to separate ultrafine gallium particles from the metal gallium particles; The particle pretreatment equipment has its inlet connected to the ultrafine particle outlet of the particle separation equipment, and is used to convert the ultrafine gallium particles into highly active, molten gaseous gallium ions. An oxidation reaction device, the inlet of which is connected to the outlet of the particle pretreatment device, is used to react the gaseous gallium ions with the introduced oxygen-containing reactive gas to generate gallium oxide grains; The post-processing equipment, whose inlet is connected to the outlet of the oxidation reaction equipment, is used to perform high-temperature heat treatment on the gallium oxide grains to transform them into stable β-phase gallium oxide grains. A grain cooling device, the inlet of which is connected to the outlet of the post-processing device, is used to cool and solidify the β-phase gallium oxide grains into gallium oxide powder and collect it. The various devices are connected by sealed pipelines.

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