High-purity metal powder preparation equipment and process

Abstract

The invention discloses high-purity metal powder preparation equipment and process, and relates to the technical field of metal powder preparation, the high-purity metal powder preparation equipment comprises a furnace body, a heating device arranged in the furnace body, a crucible located in a heating area of the heating device, and a collecting device matched with the crucible and used for collecting powder; the crucible is used for melting a metal ingot in the crucible after being heated and generating metal steam, and the collecting device is configured to condense and collect the metal steam through airflow guidance. Compared with a traditional chemical method, a physical method of inert gas condensation is adopted, residues of impurity elements such as a reducing agent are avoided, chemical pollution is avoided, and the continuous feeding module is constructed through the feeding abdominal bin, the lifting supporting column, the valve plate and the vacuum pump. Rapid charging can be achieved under the condition that the high-temperature vacuum environment of the main furnace chamber is not damaged, and the invalid time caused by repeated vacuumizing and heating and cooling links in the traditional process is greatly shortened.

Description

Technical Field

[0001] This invention relates to the field of metal powder preparation technology, specifically to a high-purity metal powder preparation equipment and process. Background Technology

[0002] High-purity metal powders have a wide range of applications, including as alloy dopant, semiconductor dopant, soft magnetic materials, 3D printing substrates, conductive pastes, and active catalysts. They can be composited with various matrices such as plastics and ceramics, and have become an emerging material in modern technology.

[0003] Traditional chemical methods utilize reducing agents to reduce metal compounds, yielding metal powders with advantages such as fine particle size and high production capacity. However, this method results in significant residual impurities and environmental pollution; it also consumes a lot of energy, requiring heating to accelerate the reduction reaction. Furthermore, it necessitates a series of subsequent steps such as collection, sieving, and drying, making the process complex and resulting in lower product purity.

[0004] Traditional physical ball milling uses ultrahard grinding balls to rub and collide with metal. This process allows for flexible control of metal powder particle size and is relatively low-cost. However, abrasive particles inevitably get mixed in during the ball milling process, causing secondary contamination of the metal powder and making it difficult to obtain high-purity powder.

[0005] Metal sputtering is a time-consuming, energy-intensive, and low-yield method for preparing metal powders, making it unsuitable for mass production. Traditional electrolytic powder preparation processes, on the other hand, suffer from high energy consumption and water pollution, and can only achieve 3N-level yields, failing to meet the needs of the high-end market.

[0006] The inert gas condensation method for producing metal powders currently boasts the highest purity among all preparation processes, with powder particle sizes reaching the nanometer scale. Solid powder can be directly generated from metal ingots in a single step, completely avoiding secondary contamination caused by processing. However, this method has low production efficiency, time-consuming preparation steps such as vacuuming and temperature control, and high equipment costs. Therefore, to obtain high-quality, high-purity metal powders, it is necessary to modify and upgrade the equipment and thermal field based on the existing technology, reducing preparation time and energy consumption, improving powder production efficiency, and enhancing the reliability of the process thermal field. Summary of the Invention

[0007] The purpose of this invention is to provide a high-purity metal powder preparation equipment and process to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a high-purity metal powder preparation equipment, comprising: A furnace body, a heating device disposed within the furnace body, a crucible located in the heating area of ​​the heating device, and a collection device that cooperates with the crucible for collecting powder; The crucible is used to melt the metal ingot inside and generate metal vapor when heated, and the collection device is configured to condense and collect the metal vapor by means of an airflow.

[0009] Furthermore, the collecting device includes a storage tank and a flow guiding assembly disposed within the furnace body. The flow guiding assembly has a flow guiding hood capable of contacting the opening of the crucible. The flow guiding hood is connected to the storage tank via a connecting pipe, and the connecting pipe is provided with an air intake structure for introducing airflow to form a negative pressure within the crucible.

[0010] Furthermore, the connecting pipeline includes a first connecting pipe, an intermediate connecting pipe, and a second connecting pipe connected in sequence. The first connecting pipe is fixedly installed in the storage tank. The diameters of the holes at the connection ends of the first connecting pipe and the second connecting pipe with the intermediate connecting pipe decrease sequentially, forming a Venturi tube structure with the intermediate connecting pipe. The air intake structure is disposed on the first connecting pipe, and the air guide is connected to the lower side of the intermediate connecting pipe.

[0011] Furthermore, the flow guiding assembly also includes a sliding tube, a fixed tube, an abutment plate, and an elastic element; The fixed tube is fixedly connected to the intermediate connecting tube, the sliding tube is fitted around the outer periphery of the fixed tube and slides along its axial direction, the flow guide is rotatably connected to the lower end of the sliding tube, and the abutment plate is fixedly connected to the outside of the flow guide. The elastic element is disposed between the sliding tube and the fixed tube and is used to provide a preload force that moves the sliding tube downward, so that the abutment plate tends to remain in contact with the crucible opening.

[0012] Furthermore, it also includes a support mechanism for supporting and moving the crucible, the support mechanism including a movable base, a pivot and a counterweight; The movable seat is horizontally movably disposed inside the furnace body, and the crucible is rotatably connected to the movable seat via the pivot. The counterweight is disposed at one end of the pivot and is used to drive the crucible to tilt as the weight of the material inside the crucible decreases.

[0013] Furthermore, a linkage component is provided between the movable seat and the crucible. The linkage component is used to drive the crucible to move horizontally when the counterweight drives the crucible to tilt, so as to maintain the matching position with the flow guiding component.

[0014] Furthermore, the linkage assembly includes a swing arm, an arc-shaped rack, a driven gear, and a rack rod; The swing arm is fixed to the pivot, and the arc-shaped rack is disposed on the swing arm or the counterweight. The driven gear is rotatably connected to the movable seat and simultaneously meshes with the arc-shaped rack and the rack rod, which is fixedly installed inside the furnace body.

[0015] Furthermore, a feeding chamber is provided on one side of the furnace body. The feeding chamber is isolated from or connected to the inner cavity of the furnace body through a valve mechanism. The crucible is movably disposed in the feeding chamber and has a working position that extends into the furnace body for heating and a feeding position that retracts into the feeding chamber for feeding.

[0016] A process for preparing high-purity metal powder, using the high-purity metal powder preparation equipment described above, includes the following steps: Step S1: Place the metal ingot in the crucible and evacuate the inside of the furnace. Step S2: Heat the crucible to melt the metal ingot and form metal vapor; Step S3: Inert gas is introduced into the connecting pipe of the collecting device. The pressure difference generated by the airflow is used to draw the metal vapor in the crucible into the connecting pipe and mix it with the inert gas to condense and form metal powder. Step S4: Collect the metal powder into a storage tank.

[0017] Furthermore, in step S3, as the amount of molten metal in the crucible decreases, the crucible is gradually tilted to increase the surface area of ​​the molten metal, and the crucible is simultaneously moved horizontally to maintain a sealed contact with the flow guiding component. In step S2, heating to 1100°C or above causes the molten metal to volatilize. In step S3, metal vapor is drawn in through a venturi tube structure, and the particle size of the powder is controlled by adjusting the flow rate of the inert gas.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention employs a physical method of inert gas condensation, which, compared to traditional chemical methods, avoids the residue of reducing agents and other impurities, resulting in no chemical pollution. A continuous feeding module is constructed using a feeding hopper, lifting supports, valve plates, and a vacuum pump. This enables rapid charging without disrupting the high-temperature vacuum environment of the main furnace chamber, significantly reducing the wasted time caused by repeated vacuuming and temperature adjustments during traditional processes. 2. In this invention, a "Venturi tube" structure is used to connect the air intake and collection systems. The pressure difference is used to rapidly draw in metal vapor, allowing it to fully contact and condense with cold nitrogen, thus preparing nanoscale (10-30 nanometers) high-purity powder. The particle size of the powder can be flexibly adjusted by regulating the heating power, inert gas flow rate, and temperature. A conical guide hood is incorporated to gather the metal vapor and quickly guide it into the pipeline, reducing vapor escape. 3. In this invention, a counterweight, a swing arm, and a linkage assembly are used to automatically tilt the crucible opening as the weight of the molten metal inside the crucible decreases. This not only increases the surface area of ​​the melt to accelerate subsequent volatilization, but also compensates for the gaps created by the tilt through horizontal movement, ensuring that the guide shroud is always in close contact with the crucible opening and that all steam is collected. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a high-purity metal powder preparation equipment according to the present invention; Figure 2 This is a schematic diagram showing the positional relationship of the enclosing chamber, crucible, and conical flow guide after assembly in this invention; Figure 3 for Figure 2 A schematic diagram showing the positional relationship of a partially dissected structure from another perspective; Figure 4 for Figure 2 A schematic diagram showing the positional relationship of the central structure after omitting the surrounding warehouse; Figure 5 This is a schematic diagram showing the positional relationship of the conical guide shield, the abutment plate, and the sliding tube after assembly in this invention; Figure 6 for Figure 5 A schematic diagram showing the positional relationship of the middle section after it has been cut open; Figure 7 for Figure 6 A magnified schematic diagram of the positional relationship of a local structure at point A in the middle; Figure 8 for Figure 5 A schematic diagram of the positional relationships after the explosive decomposition of the medium structure.

[0020] The following are the labels on the attached figures: 1. Molecular pump; 2. Variable frequency vacuum pump system; 3. Vacuum pipeline; 4. One-way regulating needle valve; 5. Furnace door; 6. Stainless steel furnace body; 7. Storage tank; 8. Filter; 9. First connecting pipe; 10. Gas mass flow meter; 11. Nitrogen pipeline; 12. Crucible; 13. Enclosure; 14. Induction coil; 15. Lifting support; 16. Valve plate; 17. Thermocouple; 18. Feeding hopper; 19. Argon pipeline; 20. Argon control valve; 21. Weighing sensor; 22. 23. Vacuum bellows; 24. Vacuum pump; 25. Abutment plate; 26. Conical guide shield; 27. Sliding tube; 28. Spring; 29. ​​Intermediate connecting tube; 20. Second connecting tube; 31. Fixed tube; 32. Fixed tube; 33. Guide rod; 34. Swing arm; 35. Counterweight; 36. Arc-shaped rack; 37. Fixed column; 38. Moving seat; 39. Rack rod; 40. Driven gear; 41. Support arm; 42. Limit nut; 43. Connecting part; 44. Ball head; 45. Spherical mounting groove; 46. Connecting hole. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figures 1-8 This invention provides a technical solution: a high-purity metal powder preparation equipment, comprising a stainless steel furnace body 6 with a furnace door 5, a storage tank 7 movably disposed inside the stainless steel furnace body 6, the storage tank 7 being made of alumina ceramic material and used to collect the final metal powder; a filter 8 installed on the upper surface of the storage tank 7 for solid-gas separation; a molecular pump 1 connected to the upper surface of the stainless steel furnace body 6 via a vacuum pipe 3; a variable frequency vacuum pump system 2 connected between the molecular pump 1 and the vacuum pipe 3; the variable frequency vacuum pump system 2 is used to initially evacuate the inner cavity of the stainless steel furnace body 6, then the molecular pump 1 operates, further evacuating the inner cavity of the stainless steel furnace body 6 through the vacuum pipe 3, achieving a vacuum degree of 6×10⁻⁶. -3 The molecular pump 1 and the deformable vacuum pump system 2 evacuate the storage tank 7 through the filter 8, so that the gas in the storage tank 7 can pass through the filter 8 and enter the stainless steel furnace body 6, and then enter the vacuum pipeline 3 from the stainless steel furnace body 6 and then be discharged. A one-way regulating needle valve 4 is installed on the vacuum pipeline 3. The one-way regulating needle valve 4 is used to adjust the connection state between the molecular pump 1 and the stainless steel furnace body 6. like Figure 1As shown, a downward-extending feeding chamber 18 is integrally formed on the bottom side of the stainless steel furnace body 6 away from the furnace door 5. The feeding chamber 18 is hollow inside and closed at the bottom. The upper end of the feeding chamber 18 is open and communicates with the inner cavity of the stainless steel furnace body 6. A chamber door (not shown in the figure) is provided on the lower side of the feeding chamber 18. A through-hole type card interface is opened on the side of the storage tank 7 corresponding to the feeding chamber 18. In addition, an induction coil 14 is provided on the stainless steel furnace body 6 at the position corresponding to the card interface. A lifting support column 15 is vertically inserted through the bottom of the feeding chamber 18. The lifting support column 15 is driven by external hydraulic or pneumatic components to move vertically back and forth. The feeding chamber 18 can slide freely. One end of the lifting column 15 that passes through the feeding chamber 18 is fixedly connected to the surrounding chamber 13. The surrounding chamber 13 is hollow inside and open at the top. When the lifting column 15 moves upward, it can drive the surrounding chamber 13 to move upward synchronously and finally lock the surrounding chamber 13 into the locking interface. The diameter of the locking interface matches the outer diameter of the surrounding chamber 13. A valve plate 16 is also provided on the feeding chamber 18. When the lifting column 15 moves downward into place, the valve plate 16 is driven by an external driving element to move towards the inside of the feeding chamber 18, so that the valve plate 16 can close the feeding chamber 18, so that the feeding chamber 18 is divided into upper and lower spaces by the valve plate 16. Combination Figures 1 to 8 As shown, and please refer to the following: Figure 1 The inner bottom wall of the enclosure 13 is horizontally connected to a movable seat 36 via several linear guides and sliders. Each of the top two sides of the movable seat 36 is vertically fixed to a support arm 39. A pivot is horizontally rotatably connected to each of the two support arms 39. A crucible 12 is fixedly connected to the opposite ends of the two pivots. In other words, the crucible 12 is rotatably connected to the two support arms 39 via the pivots, allowing the opening of the crucible 12 to tilt by rotating the pivots on the support arms 39. The crucible 12 is used to hold a metal ingot. When the lifting support column 15 moves upward, the enclosure 13 can enter the center of the induction coil 14, so that when the induction coil 14 is energized, the crucible 12 can be heated, thus allowing the metal ingot to be calcined. The heat allows the metal ingot to be heated into a molten state, while simultaneously generating vapor. A thermocouple 17 is installed inside the lifting support column 15. The thermocouple 17 is used to detect the degree of heating of the crucible 12 by the induction coil 14, that is, to detect the temperature of the metal ingot. A vacuum bellows 22 is also installed at the bottom of the feeding chamber 18. A weighing sensor 21 is installed below the vacuum bellows 22. The weighing sensor 21 is installed on the lifting support column 15 and is used to detect the weight change of the metal ingot in the crucible 12. The lower end of the vacuum bellows 22 is fixed to the upper surface of the weighing sensor 21, so that the upper surface of the weighing sensor 21, the vacuum bellows 22 and the feeding chamber 18 are airtight. Combination Figures 1 to 8 As shown, with particular attention to 1 and 2. Figure 3A vacuum pump 23 is installed on the feeding chamber 18 to evacuate the inner cavity of the feeding chamber 18. An argon gas pipeline 19 is also installed at the bottom of the feeding chamber 18, and an argon gas control valve 20 is installed on the argon gas pipeline 19 to control the connection between the argon gas pipeline 19 and the feeding chamber 18. A nitrogen gas pipeline 11 is horizontally installed on the stainless steel furnace body 6, and a gas mass flow meter 10 is installed on the nitrogen gas pipeline 11 to control the connection between the nitrogen gas pipeline 11 and the inner cavity of the stainless steel furnace body 6, and to detect the amount of nitrogen gas introduced. A first connecting pipe 9 is horizontally fixed to the inner wall of the storage tank 7, and the first connecting pipe 9 is connected to the end of the nitrogen gas pipeline 11. The first connecting pipe 9 has a decreasing outer diameter at the end furthest from the nitrogen pipe 11, and a middle connecting pipe 28 is horizontally connected to the end of the first connecting pipe 9 with the smallest outer diameter. A second connecting pipe 29 is connected to the end of the middle connecting pipe 28 furthest from the first connecting pipe 9. The outer diameter of the end of the second connecting pipe 29 connected to the middle connecting pipe 28 increases sequentially, forming a "Venturi tube" structure. A fixed pipe 30 is vertically fixed to the lower periphery of the middle connecting pipe 28. A sliding pipe 26 is fitted around the periphery of the fixed pipe 30, allowing the sliding pipe 26 to slide freely vertically around the fixed pipe 30. A connecting part 41 (e.g., ...) is rotatably connected to the lower end of the sliding pipe 26. Figure 7 As shown), a conical guide shroud 25 is fixedly connected to the lower end of the connecting part 41. The outer diameter of the conical guide shroud 25 increases sequentially from top to bottom, and an abutment plate 24 extending horizontally outward in the radial direction is fixedly connected to the lower end of the conical guide shroud 25. The abutment plate 24 is used to abut against the top of the crucible 12 when the lifting support column 15 moves upward, and rotates as the mouth of the crucible 12 tilts, so that the surface of the abutment plate 24 remains in abutment against the crucible 12. Specifically, a protrusion is fixedly connected to the lower end of the sliding tube 26. A spherical mounting groove 43 is provided on the lower end face of the outlet. A ball head 42 is fitted in the spherical mounting groove 43 and can rotate omnidirectionally within the spherical mounting groove 43. The upper end of the connecting part 41 is fixed to the ball head 42. Thus, by rotating the ball head 42 within the spherical mounting groove 43, the conical guide tube 25 can be rotatably connected to the lower end of the sliding tube 26. A through hole 44 is provided on both the ball head 42 and the connecting part 41. The connecting hole 44 communicates with the inner cavity of the sliding tube 26. Combination Figures 3 to 8 As shown, and please refer to the following: Figure 8Two first ear plates are fixedly connected to the periphery of the sliding tube 26. A guide rod 31 is vertically fixedly inserted through the first ear plate. Two second ear plates are fixedly connected to the periphery of the fixed tube 30. The second ear plates are correspondingly arranged with the first ear plates. The upper end of the guide rod 31 passes through the two second ear plates respectively and can slide freely on the second ear plates. A limit nut 40 is threadedly fitted on the upper end of the guide rod 31. The limit nut 40 is used to limit the downward movement of the guide rod 31 to prevent the sliding tube 26 from detaching from the periphery of the fixed tube 30. A spring 27 is wrapped around the periphery of the guide rod 31. The two ends of the spring 27 elastically abut against the first ear plate and the second ear plate respectively in the direction of the elastic force, and have a downward elastic abutting force on the first ear plate, so that in the natural state, the first ear plate... The ear plate will drive the sliding tube 26 to slide downwards. A swing arm 32 is fixedly sleeved at the end of the pivot. An arc-shaped counterweight 33 is fixedly connected to the end of the swing arm 32 away from the pivot. The center of the arc of the counterweight 33 is coaxial with the axis of the pivot. The length direction of the swing arm 32 is at an angle to the axis of the crucible 12. When an appropriate amount of metal ingot is put into the crucible 12, the weight of the crucible 12 and the metal ingot will drive the crucible 12 to rotate, so that the crucible 12 rotates to a vertical position. When the weight of the crucible 12 and the metal ingot decreases, the weight of the counterweight 33 will act on the swing arm 32 and drive the swing arm 32 to swing downwards, thereby tilting the mouth of the crucible 12. In addition, the swing direction of the crucible 12 corresponds to the axis of the first connecting tube 9. Combination Figures 3 to 8 As shown, and please refer to the following: Figure 4 The outer arc surface of the counterweight 33 is provided with an arc-shaped rack 34. The center of the arc of the rack 34 is coaxial with the axis of the pivot. A rotating shaft is horizontally connected to the support arm 39 via a bearing. A driven gear 38 is fixedly sleeved on the rotating shaft. Fixed columns 35 are vertically fixed on opposite sides of the inner bottom wall of the enclosure 13. A rack rod 37 is horizontally fixed between the two corresponding fixed columns 35. The rack rod 37 meshes with the driven gear 38. At the same time, the arc-shaped rack 34 also meshes with the driven gear 38. Thus, as the weight of the crucible 12 and the metal ingot decreases, the counterweight 33 drives the swing arm 32 to swing downwards, thereby causing the arc-shaped rack 34 on the counterweight 33 to mesh with the driven gear 38. The driven gear 38 then meshes with the rack rod 37, thereby driving the moving seat 36 to move horizontally on the inner bottom wall of the enclosure 13. For example, refer to Figure 4As the weight of the crucible 12 and the metal ingot decreases, the counterweight 33 will drive the swing arm 32 to swing counterclockwise, thereby causing the arc-shaped rack 34 to mesh with the driven gear 38. The driven gear 38 will rotate clockwise and roll on the rack 37 from left to right. This causes the opening of the crucible 12 to swing counterclockwise and tilt while moving horizontally to the right. This allows the contact plate 24 to make better contact with the surface of the opening of the crucible 12, and keeps the conical guide shroud 25 as coaxial as possible with the crucible 12. This allows the vapor of the molten metal formed by the heating of the metal ingot in the crucible 12 to enter the sliding tube 26 through the conical guide shroud 25, thereby reducing the amount of vapor escaping from the gap between the contact plate 24 and the surface of the opening of the crucible 12.

[0023] Working principle of the invention: Taking the preparation of metallic copper powder as an example, the preparation process includes: Step 1: The storage tank 7 is loaded into the stainless steel furnace body 6 by an external robotic arm, and the furnace door 5 is closed. Step 2: Turn on the variable frequency vacuum pump system 2, open the one-way regulating needle valve 4, and evacuate the stainless steel furnace body 6 to between 1Pa and 5Pa. Then, turn on the molecular pump 1 to evacuate the furnace to a vacuum level of 6×10⁻⁶ Pa. -3 On the order of Pa, the lifting support column 15 moves upward and sends the crucible 12 into the stainless steel furnace body 6. The surface of the mouth of the crucible 12 will abut against the lower surface of the abutment plate 24 and generate an upward thrust on the abutment plate 24. This causes the abutment plate 24 to drive the conical guide shroud 25 and the sliding tube 26 to move upward, so that the sliding tube 26 slides on the periphery of the fixed tube 30. At this time, the total weight of the copper ingot in the crucible 12 and the crucible 12 is greater than the driving force of the counterweight 33 on the swing arm 32, so that the swing arm 32 will rotate upward and the crucible 12 will be in a vertical state. Step 3: Turn on the induction heating power supply to energize the induction coil 14 and use the electromagnetic field to induction crucible 12, thereby heating the metal ingot inside crucible 12. Since induction heating is prone to glow discharge effect in a vacuum environment, which can lead to arcing, a Teflon insulating coating can be applied to the outer wall of the induction coil 14 and wrapped with quartz fiber cloth. Cooling water is circulated inside the copper coil tube of the induction coil 14. It takes 1.5 hours for the high-purity copper ingot to be heated from room temperature to 1100℃. The ingot gradually melts and becomes a melt. It then begins to volatilize after the temperature exceeds 1100℃. In order to improve the volatilization efficiency, the process temperature is generally controlled at 1100℃ and above. Step 4: Enter the powdering stage. Turn on the gas mass flow meter 10, and then blow 5N nitrogen into the first connecting pipe 29 through the nitrogen pipeline 19 at a flow rate of 10-200 mL / min. When the nitrogen passes through the outer diameter decreasing end of the first connecting pipe 29, the dynamic pressure increases and the static pressure decreases due to the Venturi effect. When the nitrogen enters the intermediate connecting pipe 28, it will create a pressure difference in the crucible 12. Under the action of the pressure difference, the vapor in the crucible 12 will flow sequentially through the conical guide shroud 25 and the connecting hole 44. The sliding tube 26 and the fixed tube 30 enter the intermediate connecting tube 28, and then enter the second connecting tube 28 with the airflow. The airflow has a cooling effect, which cools the copper vapor and forms copper particles (with a particle size between 10-30 nanometers). These particles are then blown into the storage tank 7 made of alumina ceramic material. The outer diameter of the conical guide shroud 25 increases from top to bottom, which allows the steam to gather and quickly escape from the connecting hole 44. This allows the steam to quickly enter the intermediate connecting tube 28 and fully contact the nitrogen gas. The opening of vacuum pipe 3 can be controlled by adjusting the one-way regulating needle valve 4 on vacuum pipe 3, thereby controlling the pumping rate and maintaining it consistent with the nitrogen inlet flow rate to keep the furnace pressure balanced. The particle size of pure copper powder can be adjusted by changing the heating power, evaporation temperature, argon gas flow rate, and argon gas temperature. The higher the temperature, the faster the evaporation, the more copper vapor, and the larger the particle size. The lower the nitrogen temperature and the higher the flow rate, the smaller the particle size of the prepared copper micropowder. The volatilization process is controllable. The melt volatilization rate and powder particle size can be flexibly adjusted by controlling the heating power and the inert gas flow rate.

[0024] Step 5: As the copper molten liquid level in crucible 12 gradually decreases, the amount of molten liquid decreases, and the evaporation rate begins to accelerate. In order to ensure the consistency of powder particle size, the nitrogen flow rate is increased. At this time, the opening of the one-way regulating needle valve 4 is increased accordingly to keep the air intake and exhaust consistent. Furthermore, as the amount of melt in crucible 12 decreases, the driving force of the counterweight 33 on the swing arm 32 will gradually drive the swing arm 32 to swing downwards. This allows the opening of crucible 12 to gradually tilt as the amount of melt decreases. After tilting, the surface area of ​​the melt in crucible 12 increases, reducing the longitudinal depth of the melt and accelerating steam escape. Additionally, when crucible 12 tilts, the abutment plate 24 rotates within the spherical mounting groove 43 via the ball head 42, causing the surface of the abutment plate 24 to swing along with the crucible 12. Moreover, the counterweight 33 drives the swing arm 32... When the crucible 12 swings downwards, the arc-shaped rack 34 and the driven gear 38 mesh and drive the crucible 12. Then, through the meshing of the driven gear 38 and the rack 37, the crucible 12 moves to the right. This results in the right side of the crucible 12 being higher than its left side when the crucible 12 is tilted. This causes gaps to form on the left and right sides when the lower surface of the contact plate 24 abuts against the surface of the crucible 12's opening. This can lead to vapor escaping through these gaps without contacting the nitrogen and forming particles. Therefore, in this embodiment, the meshing of the driven gear 38 and the rack 37 causes the crucible 12 to move to the right (e.g., ...). Figure 4 The horizontal movement of the spring 27 against the first ear plate causes the abutment plate 24 to move downward, thereby reducing the gap until it disappears and preventing steam from escaping. Step 6: Weigh the crucible 12 using the weighing sensor 21 to determine the remaining amount of copper melt. After all the raw materials in the crucible 12 have evaporated, turn off the gas mass flow meter 10, close the one-way regulating needle valve 4 of the vacuum pipeline 3, move the lifting support column 15 down, and cause the crucible 12 to begin to descend. After entering the lower inner cavity of the feeding chamber 18, close the valve plate 16, and then open the argon control valve 20 to fill the chamber with flow-grade argon gas to accelerate the cooling of the crucible 12. When the temperature drops to 700℃, open the chamber door of the feeding chamber 18, put high-purity copper crystal material into the crucible 12, and close the chamber door. Step 7: Use vacuum pump 23 to evacuate the feeding chamber 18 to 6 Pa, and then fill it with argon to 90000 Pa. Repeat this process twice. Then evacuate the feeding chamber 18 to 6 Pa, open valve plate 16, and raise crucible 12 to the standard position. Step 8: Open the one-way regulating needle valve 4 to its maximum opening, and quickly evacuate the stainless steel furnace body 6 to a vacuum level of 10. -3 The process involves simultaneously heating and melting the high-purity copper raw material inside crucible 12.

[0025] Step 9: Repeat steps 3-6 to continuously prepare high-purity copper powder.

[0026] Step 10: After several consecutive cycles, once the upper limit of the storage tank 7 is reached, turn off the variable frequency vacuum pump system 2 and the one-way regulating needle valve 4. The induction coil 14 enters the cooling stage, which takes 2 hours, and the power drops to 0. After cooling for 3 hours, open the furnace door 5 of the stainless steel furnace body 6, take out the storage tank 7, and send it into the dry and dust-free room; Step 11: Using a robotic arm, clamp the storage tank 7, pour the collected pure copper powder into a sealed bag, seal and mark it; Step 12: The entire production process is now complete.

[0027] This embodiment describes a novel equipment and process that utilizes high-purity metal ingots, which are heated and melted in a stainless steel furnace 6 under vacuum, and then condensed into powder by inert gas through the volatilization of the melt.

[0028] 1) By constructing a continuous feeding module through lifting support column 15, valve plate 16, feeding hopper 18, and vacuum pump 23, effective isolation and rapid feeding are achieved, avoiding damage to the high-temperature vacuum environment of the main furnace chamber of stainless steel furnace body 6. This significantly reduces the ineffective time spent on repeated vacuuming and heating / cooling processes during each furnace opening, thereby improving preparation efficiency, significantly reducing equipment depreciation costs, and improving economic indicators.

[0029] 2) The surface of crucible 12 is coated with a silicon carbide corrosion-resistant film. The high hardness of silicon carbide overcomes the erosion of the traditional crucible 12 surface by the molten metal, and avoids the molten metal from penetrating into the pores of the traditional crucible, which greatly increases the service life of the crucible. At the same time, it reduces the contamination of the raw materials by the carbon elements entering the molten metal. In addition, during the rapid loading process of crucible 12 into the feeding chamber 18, crucible 12 still has a certain temperature. The silicon carbide coating can effectively prevent the oxidation of crucible 12, which plays a protective role and enables the continuous feeding function.

[0030] 3) A “Venturi tube” structure is formed by using a first connecting pipe 9, an intermediate connecting pipe 28 and a second connecting pipe 29. When nitrogen is introduced into the storage tank 7 at high speed, a pressure difference is formed in the crucible 12. Under the action of the pressure difference, the steam can quickly enter the intermediate connecting pipe 28 and come into full contact with the nitrogen.

[0031] 4) During the pulverization process of molten metal, as the melt level decreases, the distance between the upper surface of the melt and the guide hood (suction port) gradually increases. This increased distance leads to increased resistance to steam extraction and potential changes in the thermal gradient, resulting in a decrease in the natural evaporation rate. In this embodiment, the crucible 12 tilts after the melt weight decreases, significantly increasing the surface area of ​​the melt at its "lower" position. This increased area compensates for the efficiency loss caused by the increased distance. By increasing the evaporation area, a higher steam production rate can be maintained even when the remaining melt volume is low, thus ensuring the uniformity of the powder generation rate throughout the pulverization process and preventing a sharp drop in powder yield later. As the liquid deepens, the path for the heated liquid at the bottom to rise to the surface and release vapor is longer, resulting in greater thermal resistance. An inclined crucible effectively reduces the average depth of the melt in the axial direction (i.e., the "shallow pool effect"). A shallower melt layer allows heat to be transferred more quickly to the surface, promoting boiling or vigorous volatilization at lower thermal resistance, further improving thermal efficiency.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-purity metal powder preparation equipment, characterized in that, include: Furnace body (6), heating device (14) disposed in the furnace body (6), crucible (12) located in the heating area of ​​the heating device (14), and a collection device for collecting powder in conjunction with the crucible (12); The crucible (12) is used to melt the metal ingot inside it after heating and generate metal vapor, and the collection device is configured to condense and collect the metal vapor by airflow guidance.

2. The high-purity metal powder preparation equipment according to claim 1, characterized in that, The collection device includes a storage tank (7) and a flow guiding assembly disposed in the furnace body (6). The flow guiding assembly has a flow guiding hood (25) that can abut against the opening of the crucible (12). The flow guiding hood (25) is connected to the storage tank (7) through a connecting pipe. The connecting pipe is provided with an air intake structure for introducing airflow to form a negative pressure in the crucible (12).

3. The high-purity metal powder preparation equipment according to claim 2, characterized in that, The connecting pipeline includes a first connecting pipe (9), an intermediate connecting pipe (28), and a second connecting pipe (29) connected in sequence. The first connecting pipe (9) is fixedly installed in the storage tank (7). The diameters of the holes at the connection ends of the first connecting pipe (9) and the second connecting pipe (29) with the intermediate connecting pipe (28) decrease sequentially and form a Venturi tube structure with the intermediate connecting pipe (28). The air intake structure is installed on the first connecting pipe (9), and the flow guide (25) is connected to the lower side of the intermediate connecting pipe (28).

4. The high-purity metal powder preparation equipment according to claim 3, characterized in that, The flow guiding assembly also includes a sliding tube (26), a fixed tube (30), an abutment plate (24), and an elastic element (27). The fixed tube (30) is fixed to the intermediate connecting tube (28), the sliding tube (26) is fitted around the fixed tube (30) and slides along its axial direction, the flow guide (25) is rotatably connected to the lower end of the sliding tube (26), and the abutment plate (24) is fixed to the outside of the flow guide (25). The elastic element (27) is disposed between the sliding tube (26) and the fixed tube (30) and is used to provide a preload force for the sliding tube (26) to move downward, so that the abutment plate (24) tends to contact the mouth of the crucible (12).

5. The high-purity metal powder preparation equipment according to claim 1, characterized in that, It also includes a support mechanism for supporting and moving the crucible (12), the support mechanism including a moving base (36), a pivot and a counterweight (33). The movable seat (36) is horizontally movable inside the furnace body (6). The crucible (12) is rotatably connected to the movable seat (36) via the pivot. The counterweight (33) is located at one end of the pivot. The counterweight (33) is used to drive the crucible (12) to tilt as the weight of the material inside the crucible (12) decreases.

6. The high-purity metal powder preparation equipment according to claim 5, characterized in that, A linkage component is provided between the movable seat (36) and the crucible (12). The linkage component is used to drive the crucible (12) to move horizontally when the counterweight (33) drives the crucible (12) to tilt, so as to maintain the matching position with the flow guiding component.

7. The high-purity metal powder preparation equipment according to claim 6, characterized in that, The linkage assembly includes a swing arm (32), an arc-shaped rack (34), a driven gear (38), and a rack rod (37). The swing arm (32) is fixed to the pivot, and the arc-shaped rack (34) is disposed on the swing arm (32) or the counterweight (33); The driven gear (38) is rotatably connected to the movable seat (36) and simultaneously meshes with the arc-shaped rack (34) and the rack rod (37), which is fixedly installed inside the furnace body (6).

8. The high-purity metal powder preparation equipment according to claim 1, characterized in that, A feeding chamber (18) is provided on one side of the furnace body (6). The feeding chamber (18) is isolated from or connected to the inner cavity of the furnace body (6) through a valve mechanism. The crucible (12) is movably disposed in the feeding chamber (18) and has a working position that extends into the furnace body (6) for heating and a feeding position that retracts into the feeding chamber (18) for feeding.

9. A process for preparing high-purity metal powder, characterized in that, Using the high-purity metal powder preparation equipment as described in any one of claims 1-8, the process includes the following steps: Step S1: Place the metal ingot in the crucible (12) and evacuate the inside of the furnace body (6); Step S2: Heat the crucible (12) to melt the metal ingot and form metal vapor; Step S3: Inert gas is introduced into the connecting pipe of the collecting device. The pressure difference generated by the airflow is used to draw the metal vapor in the crucible (12) into the connecting pipe and mix with the inert gas to condense and form metal powder. Step S4: Collect the metal powder into the storage tank (7).

10. The process for preparing high-purity metal powder according to claim 9, characterized in that, In step S3, as the amount of molten metal in the crucible (12) decreases, the crucible (12) is gradually tilted to increase the surface area of ​​the molten metal, and the crucible (12) is simultaneously moved horizontally to maintain a sealed contact with the flow guiding assembly. In step S2, heating to 1100°C or above causes the molten metal to volatilize. In step S3, metal vapor is drawn in through a venturi tube structure, and the particle size of the powder is controlled by adjusting the flow rate of the inert gas.

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