Method for improving mixing uniformity of low-specific-gravity rare earth and tungsten powder
Through multi-step mixing methods, including pretreatment of rare earth powder and superimposing of tungsten powder, the problem of insufficient mixing uniformity of low-specific gravity rare earths and high-specific gravity tungsten powder is solved, and the product performance is significantly improved.
Patent Information
- Application Number
- CN202411907985.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-03-28
AI Technical Summary
The prior art is difficult to ensure the mixing uniformity of low-specific gravity rare earths and high-specific gravity tungsten powder, resulting in unstable performance of the final product.
A multi-step mixing method is adopted, including pretreatment of rare earth powder, equal amount of manual treatment, superimposed premix, low-temperature dehumidification, premixed powder sieving, powder mixing, secondary sieving and standstill treatment, through these steps, the mixing uniformity of the powder is improved.
The mixing uniformity of low-specific gravity rare earths and tungsten powder is significantly improved, thereby stably improving the performance of the final product.
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Figure CN119703064A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of diamond wire production, in particular to a method for improving the mixing uniformity of low-density rare earth and tungsten powder. Background Art
[0002] Diamond wire is a cutting tool that uses high-strength ultra-fine metal wire as the mother wire, and diamonds are evenly attached to the surface of the metal wire by electroplating, chemical plating or resin bonding. Compared with the traditional steel wire + mortar silicon wafer cutting method, it has the characteristics of high cutting efficiency, low pollution, and high wafer yield. At the same time, the trend of thinning is conducive to the thinning of silicon wafers, thereby increasing the wafer yield during cutting and reducing silicon material loss, thereby greatly reducing the cost of silicon wafers. Thanks to the excellent mechanical properties of tungsten wire, tungsten wire can achieve finer processing needs than carbon steel wire, and has higher cutting stability.
[0003] Doping tungsten can produce high-strength, ultra-fine tungsten wires, and the key factor for the stable performance of tungsten wires lies in the uniformity of the doped tungsten powder formula. In doped tungsten powder, mixing uniformity is an important factor affecting the performance of the final product. Especially when it comes to the mixing method of low-density rare earth and high-density tungsten powder, the conventional mixing method is to use a high-energy mixer to extend the mixing time once or in multiple stages, which is difficult to ensure uniformity and leads to unstable performance.
[0004] Therefore, it is necessary to develop a new mixing method to improve mixing uniformity. Summary of the invention
[0005] In order to overcome the shortcomings in the background technology, the present invention discloses a method for improving the mixing uniformity of low specific gravity rare earth and tungsten powders. The present invention arranges S1: pretreatment of rare earth powders, S2: equal amount manual treatment, S3: superimposed premixing, S4: low temperature dehumidification, S5: premixed powder screening, S6: powder mixing, S7: secondary screening and S8: static treatment mixing steps to achieve the purpose of improving the mixing uniformity of powders.
[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical scheme: A method for improving the uniformity of mixing low-density rare earth and tungsten powders comprises the following steps: S1: pretreating low-density rare earth powder in an inert gas environment, and low-temperature drying the pretreated low-density rare earth powder in a temperature environment of 60-200° C. for 4-24 hours to obtain pretreated rare earth powder with a Fisher particle size of 0.6 um-2.0 um; S2: Manual treatment of equal amounts: weighing equal amounts of high-density tungsten powder and the pretreated rare earth powder in step S1, and mixing the high-density tungsten powder and the rare earth powder in a mixing device in a 1:1 stacking manner to obtain a mixed powder; S3: premixing by stacking, the mixed powder obtained in step S2 is divided into 2-8 equal portions, each portion of the mixed powder after distribution is added to the mixing device with the high specific gravity tungsten powder in a ratio of 1:5 for premixing, each batch is mixed for 10-60 minutes after addition and then the next portion is added, all the mixed powders are mixed with the high specific gravity tungsten powder in the mixing device, and then mixed for 2-10 hours to obtain premixed powder; S4: low-temperature dehumidification, taking out the premixed powder prepared in S3, and leaving it at low temperature for 1-24 hours to eliminate the stress generated by high-speed powder mixing and increase powder fluidity; S5: Premixed powder is screened, and ultrasonic screening is used to eliminate impurities in the mixed powder obtained in S4, and high-frequency ultrasonic screening is used to break up the agglomeration of small particles of the premixed powder; S6: powder mixing, dividing the premixed powder prepared in S5 into 2-20 equal portions, and mixing each portion of the premixed powder with an equal amount of high specific gravity tungsten powder in a mixing device for 10-30 minutes in batches until the entire mixing process is completed; S7: secondary sieving, high-frequency ultrasonic sieving is performed again to eliminate impurities in the mixed powder obtained in S6 and break up small particle agglomerations; S8: Stand still for treatment in an environment with low temperature and humidity less than 40%.
[0007] Furthermore, in step S1, the pretreatment time of the low specific gravity rare earth powder is 12-72 hours.
[0008] Furthermore, the static treatment time in S8 is 2-48 hours.
[0009] Furthermore, the mixing device includes a mixing tank, a fixed frame and an ultrasonic vibration screen. The mixing tank is arranged on the fixed frame, and an ultrasonic vibration screen is provided at the lower end of the mixing tank. The mixed powder is mixed in the mixing tank. The fixed frame is composed of a supporting plate and supporting feet. Supporting feet are distributed at the four corners of the lower end surface of the supporting plate. The lower end of the mixing tank passes through the supporting plate, and the discharge end of the mixing tank is connected to the feed end of the ultrasonic vibration screen.
[0010] Furthermore, the mixing tank includes a tank body, a sealing cover, a first motor, a stirring device, a funnel and a discharge pipe. An observation window is provided on the side of the tank body, a sealing cover is provided at the upper end of the tank body to cooperate with it, the sealing cover is hinged to the tank body, a coaxially arranged funnel is provided at the lower end of the tank body, a discharge pipe is provided at the discharge end of the funnel, and a first motor is provided in the middle of the upper end of the sealing cover. The output shaft of the first motor passes through the sealing cover and is connected to the stirring device through a rotating shaft.
[0011] Furthermore, an air inlet pipe, a first exhaust pipe and a premixing barrel are provided on the upper end surface of the sealing cover, a valve is provided on the air inlet pipe, a gas cylinder is provided on the air inlet pipe, the gas cylinder is filled with inert gas, the gas cylinder is arranged on the upper surface of the supporting plate, a valve is provided on the first exhaust pipe, the first exhaust pipe is connected to an external vacuum pump, the lower end of the premixing barrel is connected to the mixing tank through the sealing cover, a second solenoid valve is provided at the lower end of the premixing barrel, a barrel cover matched with the premixing barrel is provided at the upper end of the premixing barrel, the barrel cover is hinged to the premixing barrel, a second exhaust pipe is provided on the barrel cover, the second exhaust pipe is connected to the premixing barrel through the barrel cover, and the second exhaust pipe is connected to the external vacuum pump.
[0012] Furthermore, a second motor is distributed on the side of the funnel, and the output shaft of the second motor passes through the funnel and is arranged in the mixing tank. A flying knife is provided on the output shaft of each second motor. The feed pipe is coaxially arranged with the funnel, and a first solenoid valve is provided at the lower end of the feed pipe. The first solenoid valve is connected to the feed end of the ultrasonic vibration screen.
[0013] The stirring device includes a connecting pipe, a supporting pipe and a stirring blade. The connecting pipe is coaxially arranged with the tank body, the lower end of the connecting pipe is blocked, a supporting pipe is distributed on the side of the connecting pipe, one end of the supporting pipe is connected with the connecting pipe, and the other end of the supporting pipe is provided with a stirring blade. The stirring blade is a hollow structure, the supporting pipe is connected with the stirring blade cavity, and jet holes are distributed on the stirring blade, and each jet hole is provided with an isolation net.
[0014] Furthermore, the stirring device also includes a guide tube and a filter tube, the guide tube, the filter tube and the connecting tube are coaxially arranged, the lower end of the guide tube is connected to the upper end of the connecting tube, the upper end of the guide tube is connected to the lower end of the filter tube, the guide tube is connected to the connecting tube, the guide tube is connected to the filter tube, an air pump is provided in the guide tube, the air outlet end of the air pump is connected to the connecting tube, and the air inlet end of the air pump is connected to the filter tube.
[0015] Furthermore, air inlet holes are distributed on the side of the filter tube, an isolation net is provided in each air inlet hole, and a desiccant bag is provided in the filter tube.
[0016] The method for improving the mixing uniformity of low-density rare earth and tungsten powders described in the present invention is highly practical and very convenient to use. Through the coordinated arrangement of S1-S3, the rare earth powder is preliminarily mixed, which is convenient for subsequent secondary mixing with high-density tungsten powder; through the coordinated arrangement of S4 and S5, the primary mixed powder is dehumidified and impurities are removed, thereby improving the quality of subsequent powder mixing; through the coordinated arrangement of S6-S8, the powder mixing is efficiently completed, the powder mixing is uniform, and the quality of subsequent products is improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the mixing device of the present invention; Figure 2 A side view of a mixing device according to the present invention; Figure 3 is a cross-sectional view of a mixing tank of the present invention; Figure 4 is a cross-sectional view of the stirring device of the present invention; Figure 5 It is a schematic diagram of the positional relationship between the flow guide tube and the filter tube of the present invention; Figure 6 It is a cross-sectional view of the premixing barrel of the present invention; Figure 7 The electron microscope image of the tungsten rod prepared by the present invention; Figure 8 This is an electron microscope image of a tungsten rod made by the existing mixing method; In the figure: 1. tank body; 2. sealing cover; 3. observation window; 4. bearing plate; 5. support foot; 6. ultrasonic vibrating screen; 7. first motor; 8. gas cylinder; 9. premix barrel; 10. barrel cover; 11. air inlet pipe; 12. first exhaust pipe; 13. second exhaust pipe; 14. second motor; 15. solenoid valve; 16. funnel; 17. feed pipe; 18. flying knife; 19. connecting pipe; 20. support pipe; 21. stirring blade; 22. jet hole; 23. guide pipe; 24. filter tube; 25. air inlet hole; 26. rotating shaft; 27. desiccant bag; 28. air pump; 29. second solenoid valve. DETAILED DESCRIPTION
[0018] The present invention can be explained in detail by the following examples, and the purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.
[0019] Combined with Figures 1 to 6 A method for improving the uniformity of mixing low-density rare earth and tungsten powders comprises the following steps: S1: pretreating low-density rare earth powder in an inert gas environment, and low-temperature drying the pretreated low-density rare earth powder in a temperature environment of 60-200° C. for 4-24 hours to obtain pretreated rare earth powder with a Fisher particle size of 0.6 um-2.0 um; S2: Manual treatment of equal amounts: weighing equal amounts of high-density tungsten powder and the pretreated rare earth powder in step S1, and mixing the high-density tungsten powder and the rare earth powder in a mixing device in a 1:1 stacking manner to obtain a mixed powder; S3: premixing by stacking, the mixed powder obtained in step S2 is divided into 2-8 equal portions, each portion of the mixed powder after distribution is added to the mixing device with the high specific gravity tungsten powder in a ratio of 1:5 for premixing, each batch is mixed for 10-60 minutes after addition and then the next portion is added, all the mixed powders are mixed with the high specific gravity tungsten powder in the mixing device, and then mixed for 2-10 hours to obtain premixed powder; S4: low-temperature dehumidification, taking out the premixed powder prepared in S3, and leaving it at low temperature for 1-24 hours to eliminate the stress generated by high-speed powder mixing and increase powder fluidity; S5: Premixed powder is screened, and ultrasonic screening is used to eliminate impurities in the mixed powder obtained in S4, and high-frequency ultrasonic screening is used to break up the agglomeration of small particles of the premixed powder; S6: powder mixing, dividing the premixed powder prepared in S5 into 2-20 equal portions, and mixing each portion of the premixed powder with an equal amount of high specific gravity tungsten powder in a mixing device for 10-30 minutes in batches until the entire mixing process is completed; S7: secondary sieving, high-frequency ultrasonic sieving is performed again to eliminate impurities in the mixed powder obtained in S6 and break up small particle agglomerations; S8: Stand still for treatment in an environment with low temperature and humidity less than 40%.
[0020] Furthermore, in step S1, the pretreatment time of the low specific gravity rare earth powder is 12-72 hours.
[0021] The static treatment time in S8 is 2-48 hours.
[0022] The mixing device includes a mixing tank, a fixing frame and an ultrasonic vibration screen 6. The mixing tank is arranged on the fixing frame. The ultrasonic vibration screen 6 is arranged at the lower end of the mixing tank. The mixed powder is mixed in the mixing tank. The fixing frame is composed of a supporting plate 4 and a supporting foot 5. The supporting feet 5 are distributed at the four corners of the lower end surface of the supporting plate 4. The lower end of the supporting foot 5 is fixed to the ground, so as to fix the mixing tank. The lower end of the mixing tank passes through the supporting plate 4. The discharging end of the mixing tank is connected to the feeding end of the ultrasonic vibration screen 6. The high-frequency ultrasonic sieving generated by the ultrasonic vibration screen 6 opens the agglomeration of small powder particles.
[0023] The mixing tank comprises a tank body 1, a sealing cover 2, a first motor 7, a stirring device, a funnel 16 and a discharge pipe 17. An observation window 3 is provided on the side of the tank body 1. A sealing cover 2 matched with the tank body 1 is provided on the upper end of the tank body 1. The sealing cover 2 is hinged to the tank body 1. A coaxially arranged funnel 16 is provided at the lower end of the tank body 1. A discharge pipe 17 is provided at the discharge end of the funnel 16. A first motor 7 is provided at the middle part of the upper end of the sealing cover 2. The output shaft of the first motor 7 passes through the sealing cover 2 and is connected to the stirring device through a rotating shaft 26. The first motor 7 drives the stirring device to rotate in the mixing tank to mix the powder.
[0024] The upper end surface of the sealing cover 2 is provided with an air inlet pipe 11, a first exhaust pipe 12 and a premixing barrel 9, the air inlet pipe 11 is provided with a valve, the air inlet pipe 11 is provided with a gas cylinder 8, the gas cylinder 8 is filled with inert gas, the gas cylinder 8 is arranged on the upper surface of the bearing plate 4, the inert gas in the gas cylinder 8 is injected into the mixing tank to avoid oxidation when the powder is mixed, the first exhaust pipe 12 is provided with a valve, the first exhaust pipe 12 is connected to an external vacuum pump, the vacuum pump discharges the air in the mixing tank, and it is convenient for the subsequent inert gas filling, the premixing The lower end of the barrel 9 is connected with the mixing tank through the sealing cover 2. The lower end of the premixing barrel 9 is provided with a second solenoid valve 29. The upper end of the premixing barrel 9 is provided with a barrel cover 10 which is arranged in coordination with the premixing barrel 9. The barrel cover 10 is hinged with the premixing barrel 9. A second exhaust pipe 13 is provided on the barrel cover 10. The second exhaust pipe 13 passes through the barrel cover 10 and is connected with the premixing barrel 9. The second exhaust pipe 13 is connected with an external vacuum pump. The vacuum pump discharges the air in the premixing barrel 9 to prevent outside air from entering the mixing tank and oxygen from mixing, thereby improving the quality of the mixed powder.
[0025] A second motor 14 is distributed on the side of the funnel 16, and the output shaft of the second motor 14 passes through the funnel 16 and is arranged in the mixing tank. A flying knife 18 is provided on the output shaft of each second motor 14. The flying knife 18 breaks up the powder material at the lower end of the mixing tank to ensure that the powder can be evenly mixed during the stirring process and improve the mixing efficiency. A feeding pipe 17 is coaxially arranged with the funnel 16, and a first solenoid valve 15 is provided at the lower end of the feeding pipe 17. The first solenoid valve 15 is connected to the feeding end of the ultrasonic vibration screen 6. After the first solenoid valve 15 is opened, the stirred powder enters the ultrasonic vibration screen 6 below.
[0026] The stirring device includes a connecting pipe 19, a supporting pipe 20 and a stirring blade 21. The connecting pipe 19 is coaxially arranged with the tank body 1. The lower end of the connecting pipe 19 is blocked. The supporting pipe 20 is distributed on the side of the connecting pipe 19. One end of the supporting pipe 20 is connected with the connecting pipe 19. The other end of the supporting pipe 20 is provided with a stirring blade 21. The stirring blade 21 is a hollow structure. The supporting pipe 20 is connected with the cavity of the stirring blade 21. The stirring blade 21 is distributed with air jet holes 22, and each air jet hole 22 is provided with an isolation net.
[0027] The stirring device also includes a guide tube 23 and a filter tube 24. The guide tube 23, the filter tube 24 and the connecting tube 19 are coaxially arranged. The lower end of the guide tube 23 is connected to the upper end of the connecting tube 19, and the upper end of the guide tube 23 is connected to the lower end of the filter tube 24. The guide tube 23 is in communication with the connecting tube 19, and the guide tube 23 is in communication with the filter tube 24. An air pump 28 is arranged in the guide tube 23, and the air outlet end of the air pump 28 is connected to the connecting tube 19, and the air inlet end of the air pump 28 is connected to the filter tube 24. The air pump 28 absorbs the inert gas in the mixing tank and sends it to each supporting tube through the connecting tube 19, enters the stirring blade 21 through the supporting tube 20, and is finally discharged through the jet hole 22 of the stirring blade 21, blowing air to the powder to facilitate the flow of the powder. While improving the mixing quality, the airflow can also accelerate the evaporation of the mixed water in the powder and reduce the formation of particulate matter.
[0028] The filter tube 24 has air inlet holes 25 on its side, each of which is provided with an isolation net. The filter tube 24 is provided with a desiccant bag 27. The inert gas in the mixing tank enters the filter tube through the air inlet holes. The desiccant in the desiccant bag 27 can absorb moisture in the inert gas to keep the inert gas dry.
[0029] A method for improving the uniformity of mixing low-density rare earth and tungsten powder described in the embodiment is to pretreat the rare earth powder in an inert gas environment, and dry the pretreated rare earth at a temperature of 60-200°C for 4-24 hours to obtain a pretreated rare earth with a Fisher particle size (FSSS.) of 0.6um-2.0um, and then manually weigh equal amounts of pretreated rare earth and high-density tungsten powder, and mix the two or more powders in a mixing device in a 1:1 multiple stacking manner, and distribute the powder obtained by S2 in 2-8 equal portions, and mix them with the high-density tungsten powder in batches in a ratio of 1:5 Premixing is performed in the mixing device, the powder is put into the mixing barrel, the sealing cover 2 is closed, the air in the mixing tank is exhausted by a vacuum pump, and after emptying, the gas cylinder 8 is opened to inject inert gas into the mixing tank to prevent oxidation when the powder is mixed, and then the first motor 7 is turned on. The first motor 7 drives the stirring device to rotate in the mixing tank to mix the powder. The air pump 28 absorbs the inert gas in the mixing tank and sends it to each support tube through the connecting pipe 19, enters the stirring blade 21 through the support tube 20, and finally is discharged through the jet hole 22 of the stirring blade 21, blowing air to the powder to facilitate the flow of the powder, improve the mixing quality, and at the same time, the air flow can also be increased. The water mixed in the powder is evaporated quickly to reduce the formation of particulate matter. The inert gas in the mixing tank enters the filter tube through the air inlet. The desiccant in the desiccant bag 27 can absorb the water in the inert gas and keep the inert gas dry. Then open the barrel cover 10, put a certain amount of mixed powder into the premixing barrel 9, use a vacuum pump to exhaust the air in the premixing barrel 9, avoid outside air from entering the mixing tank, avoid oxygen from mixing, and improve the quality of the mixed powder. After each batch is added, mix for 10-60 minutes before adding the next batch. After completion, mix for 2-10 hours to obtain a premixed powder. The premixed powder prepared in S3 is left to stand at low temperature for 1-24 hours to eliminate high The stress generated by the rapid mixed powder is reduced and the powder fluidity is increased. Then the first solenoid valve 15 is opened, and the powder enters the ultrasonic vibrating screen 6 below. Ultrasonic screening is used to eliminate impurities in the mixed powder obtained by S4. High-frequency ultrasonic screening is used to open the agglomeration of small particles of the premixed powder. Then the premixed powder obtained in S5 is divided into 2-20 equal parts, and mixed with high-density tungsten powder in batches in a mixing device. The same method is used for 10-30 minutes until the mixing process is completed. After the mixing is completed, high-frequency ultrasonic screening is performed again to eliminate impurities in the mixed powder obtained by S6 and open the agglomeration of small particles, and then it is left to stand in an environment of low temperature and humidity less than 40%.
[0030] The method of the present invention is used to mix a rare earth powder with a high specific gravity with a tungsten powder with a low specific gravity. The rare earth powder with a low specific gravity is lanthanum oxide. The electron microscope scanning image of the tungsten rod prepared by mixing lanthanum oxide and tungsten powder using the method of the present invention is as follows: Figure 7As shown in the figure, the lanthanum oxide in the tungsten rod is evenly distributed and uniform in size; while the traditional mixing method is used, that is, the lanthanum oxide and tungsten powder are directly poured together and mixed, and the electron microscope image of the tungsten rod obtained after mixing is as follows: Figure 8 As shown in the figure, it can be seen that the size of lanthanum oxide in the tungsten rod varies greatly and the uniformity is very poor.
[0031] The parts of the present invention that are not described in detail are prior art. Although the present invention is specifically demonstrated and introduced in conjunction with the preferred implementation scheme, there are many methods and approaches to specifically implement the technical solution. The above is only a preferred implementation scheme of the present invention, but technical personnel in the relevant field should understand that various changes can be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined in the attached claims, and all of them are within the scope of protection of the present invention.
Claims
1. A method for improving the uniformity of mixing low-density rare earth and tungsten powder, characterized in that: The following steps are involved: S1: pretreating low-density rare earth powder in an inert gas environment, and low-temperature drying the pretreated low-density rare earth powder in a temperature environment of 60-200° C. for 4-24 hours to obtain pretreated rare earth powder with a Fisher particle size of 0.6 um-2.0 um; S2: Manual treatment of equal amounts: weighing equal amounts of high-density tungsten powder and the pretreated rare earth powder in step S1, and mixing the high-density tungsten powder and the rare earth powder in a mixing device in a 1:1 stacking manner to obtain a mixed powder; S3: premixing by stacking, the mixed powder obtained in step S2 is divided into 2-8 equal portions, each portion of the mixed powder after distribution is added to the mixing device with the high specific gravity tungsten powder in a ratio of 1:5 for premixing, each batch is mixed for 10-60 minutes after addition and then the next portion is added, all the mixed powders are mixed with the high specific gravity tungsten powder in the mixing device, and then mixed for 2-10 hours to obtain premixed powder; S4: low-temperature dehumidification, taking out the premixed powder prepared in S3, and leaving it at low temperature for 1-24 hours to eliminate the stress generated by high-speed powder mixing and increase powder fluidity; S5: Premixed powder is screened, and ultrasonic screening is used to eliminate impurities in the mixed powder obtained in S4, and high-frequency ultrasonic screening is used to break up the agglomeration of small particles of the premixed powder; S6: powder mixing, dividing the premixed powder prepared in S5 into 2-20 equal portions, and mixing each portion of the premixed powder with an equal amount of high specific gravity tungsten powder in a mixing device for 10-30 minutes in batches until the entire mixing process is completed; S7: secondary sieving, high-frequency ultrasonic sieving is performed again to eliminate impurities in the mixed powder obtained in S6 and break up small particle agglomerations; S8: Stand still for treatment in an environment with low temperature and humidity less than 40%.
2. The method for improving the mixing uniformity of powders of different specific gravities according to claim 1, characterized in that: The pretreatment time of the low specific gravity rare earth powder in step S1 is 12-72 hours.
3. The method for improving the uniformity of mixing low-density rare earth and tungsten powder according to claim 1, characterized in that: The static treatment time in S8 is 2-48 hours.
4. The method for improving the uniformity of mixing low-density rare earth and tungsten powder according to claim 1, characterized in that: In step S2, the mixing device comprises a mixing tank, a fixing frame and an ultrasonic vibration screen (6); the mixing tank is arranged on the fixing frame, an ultrasonic vibration screen (6) is arranged at the lower end of the mixing tank, and the mixed powder is mixed in the mixing tank; the fixing frame is composed of a supporting plate (4) and supporting feet (5); the supporting feet (5) are distributed at the four corners of the lower end surface of the supporting plate (4); the lower end of the mixing tank passes through the supporting plate (4), and the discharge end of the mixing tank is connected to the feed end of the ultrasonic vibration screen (6).
5. The method for improving the uniformity of mixing low-density rare earth and tungsten powder according to claim 4, characterized in that: The mixing tank comprises a tank body (1), a sealing cover (2), a first motor (7), a stirring device, a funnel (16) and a discharge pipe (17); an observation window (3) is provided on the side of the tank body (1); a sealing cover (2) is provided at the upper end of the tank body (1) and is arranged in coordination with the sealing cover; the sealing cover (2) is hingedly connected to the tank body (1); a coaxially arranged funnel (16) is provided at the lower end of the tank body (1); a discharge pipe (17) is provided at the discharge end of the funnel (16); a first motor (7) is provided at the middle of the upper end of the sealing cover (2); an output shaft of the first motor (7) passes through the sealing cover (2) and is connected to the stirring device via a rotating shaft (26).
6. The method for improving the uniformity of mixing low-density rare earth and tungsten powder according to claim 5, characterized in that: The upper end surface of the sealing cover (2) is provided with an air inlet pipe (11), a first exhaust pipe (12) and a premixing barrel (9); the air inlet pipe (11) is provided with a valve; the air inlet pipe (11) is provided with a gas cylinder (8); the gas cylinder (8) is filled with an inert gas; the gas cylinder (8) is arranged on the upper surface of the bearing plate (4); the first exhaust pipe (12) is provided with a valve; the first exhaust pipe (12) is connected to an external vacuum pump; the lower end of the premixing barrel (9) passes through the sealing cover (2) and is connected to a mixing tank; the lower end of the premixing barrel (9) is provided with a second solenoid valve (29); the upper end of the premixing barrel (9) is provided with a barrel cover (10) arranged therewith; the barrel cover (10) is hinged to the premixing barrel (9); the barrel cover (10) is provided with a second exhaust pipe (13); the second exhaust pipe (13) passes through the barrel cover (10) and is connected to the premixing barrel (9); the second exhaust pipe (13) is connected to an external vacuum pump.
7. The method for improving the uniformity of mixing low-density rare earth and tungsten powder according to claim 5, characterized in that: A second motor (14) is distributed on the side of the funnel (16); an output shaft of the second motor (14) passes through the funnel (16) and is arranged in the mixing tank; a flying knife (18) is arranged on the output shaft of each second motor (14); a feed pipe (17) is coaxially arranged with the funnel (16); a first solenoid valve (15) is provided at the lower end of the feed pipe (17); and the first solenoid valve (15) is connected to a feed end of the ultrasonic vibration screen (6).
8. The method for improving the uniformity of mixing low-density rare earth and tungsten powder according to claim 5, characterized in that: The stirring device comprises a connecting pipe (19), a supporting pipe (20) and a stirring blade (21); the connecting pipe (19) is coaxially arranged with the tank body (1); the lower end of the connecting pipe (19) is blocked; a supporting pipe (20) is arranged on the side of the connecting pipe (19); one end of the supporting pipe (20) is connected to the connecting pipe (19); the other end of the supporting pipe (20) is provided with a stirring blade (21); the stirring blade (21) is a hollow structure; the supporting pipe (20) is connected to the cavity of the stirring blade (21); jet holes (22) are arranged on the stirring blade (21); and each jet hole (22) is provided with an isolation net.
9. The method for improving the uniformity of mixing low-density rare earth and tungsten powder according to claim 8, characterized in that: The stirring device further comprises a flow guide tube (23) and a filter tube (24); the flow guide tube (23), the filter tube (24) and the connecting tube (19) are coaxially arranged; the lower end of the flow guide tube (23) is connected to the upper end of the connecting tube (19); the upper end of the flow guide tube (23) is connected to the lower end of the filter tube (24); the flow guide tube (23) is in communication with the connecting tube (19); the flow guide tube (23) is in communication with the filter tube (24); an air pump (28) is arranged in the flow guide tube (23); the air outlet end of the air pump (28) is connected to the connecting tube (19); and the air inlet end of the air pump (28) is connected to the filter tube (24).
10. The method for improving the uniformity of mixing low-density rare earth and tungsten powder according to claim 9, characterized in that: The filter tube (24) is provided with air inlet holes (25) on the side thereof, each air inlet hole (25) is provided with an isolation net, and a desiccant bag (27) is provided in the filter tube (24).