Special pre-alloyed powder for geological drill bits and preparation method of ultrafine powder thereof

Abstract

The application discloses a special pre-alloy powder for geological drill bits and a preparation method of super-micro powder thereof, and comprises the following steps: S1, proportioned iron, cobalt, tin, copper and lanthanum are weighed; S2, the raw materials are put into a melting furnace to be heated and melted to form an alloy solution; S3, the alloy solution is made into alloy powder by using an atomizer; S4, the alloy powder is put into a low-temperature impact ball mill to be super-micro crushed; and S5, the super-micro alloy powder is deoxidized in an automatic reduction furnace. The low-temperature impact ball mill is designed in combination with the atomization process, so that the step-by-step gradient powder preparation is realized, the problems of cold welding and oxidation are avoided, the super-micro powder preparation of the pre-alloy powder is realized, and the quality of the final product, the drill bit, is improved.

Description

Technical Field

[0001] This invention relates to the field of grinding technology, and in particular to a pre-alloyed powder for geological drill bits and a method for preparing its ultrafine powder. Background Technology

[0002] Pre-alloyed powder refers to alloy powder prepared in advance using metallurgical methods, strictly following the chemical composition ratio of the target alloy. Each tiny particle of pre-alloyed powder contains all alloying elements, and its chemical composition is completely consistent with the final designed alloy system. The mainstream method for industrial production of pre-alloyed powder is atomization, which involves melting the pre-alloyed powder, atomizing it with water vapor, deoxidizing it in a reduction furnace, and sieving it. However, the existing water vapor atomization method easily results in irregular powder shapes, forming satellite powder and hollow powder, which can cause problems such as decreased density and fatigue cracks in the calcined drill bit. Although sieving is used for selection, the overall particle size is still too large. Even if unqualified powder is remelted and reused, it will still cause inconsistent product quality. Therefore, the process urgently needs optimization. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a pre-alloyed powder for geological drill bits and a method for preparing its ultrafine powder.

[0004] The objective of this invention is achieved through the following technical solution: a method for preparing ultrafine powder of pre-alloyed powder for geological drill bits, comprising the following steps, S1. Weigh out the raw materials of iron, cobalt, tin, copper and lanthanum according to the proportions; S2. The raw materials are put into a furnace and heated and melted to form an alloy solution; S3. The alloy solution is atomized into alloy powder using an atomizer; S4. The alloy powder is fed into a low-temperature impact ball mill for ultra-fine grinding; S5. The ultrafine alloy powder enters the automated reduction furnace for deoxidation.

[0005] Preferably, the low-temperature impact ball mill includes a chamber, an exhaust cover, a centrifuge cylinder, multiple impact balls, and multiple impact plates. The centrifuge cylinder is coaxially rotatably disposed inside the chamber. The impact plates and impact balls are located inside the centrifuge cylinder. The impact plates are vertically distributed around the axis of the centrifuge cylinder at intervals. The tail end of the impact plate is vertically hinged to the centrifuge cylinder. The impact plate reciprocates at an acute angle with its hinge axis as the center. Adjacent impact plates are staggered.

[0006] Preferably, the low-temperature impact ball mill further includes a limiting plate, which is annular. The outer edge of the limiting plate is sealed to the chamber body, and the inner edge of the limiting plate is sealed to the exhaust top cover. The bottom surface of the limiting plate is provided with a wave-shaped limiting groove that connects end to end. A limiting rod is vertically fixed at the first end of the impact plate, and the limiting rod is stuck in the limiting groove and slidably connected to it.

[0007] Preferably, the impact plate has a triangular structure, and the hypotenuse of the impact plate is a circular arc surface.

[0008] Preferably, each of the impact plates is provided with an arc plate, the convex surface of the arc plate facing the arc surface of the adjacent impact plate, one end of the arc plate is hinged to the moving end of the impact plate, the other end of the arc plate is slidably connected to the inner wall of the centrifuge, and an elastic element for controlling opening and closing is provided between the arc plate and the impact plate.

[0009] Preferably, the impact plate is provided with a torsion spring and a mounting post. The mounting post is located between the impact plate and the arc plate. The mounting post is vertically fixedly connected to the impact plate. The torsion spring is fitted onto the mounting post. One end of the torsion spring is fixedly connected to the impact plate, and the other end of the torsion spring is fixedly connected to the arc plate.

[0010] Preferably, the arc plate and the impact plate close together to form a cavity structure. The upper part of the arc plate is provided with a cover to seal the cavity structure. The arc plate is provided with multiple cold air vents. A second motor is provided below the chamber body. The output end of the second motor passes through and is rotatably connected to the chamber body. The output end of the second motor is fixedly connected to the centrifuge cylinder. The centrifuge cylinder is slidably connected to the bottom surface of the chamber body. Multiple nitrogen ports are provided on the bottom surface of the centrifuge cylinder and the chamber body respectively. The nitrogen ports are located below the cavity structure. A second gas guide channel is provided on the chamber body to connect the multiple nitrogen ports. A nitrogen pipe is provided on the second gas guide channel.

[0011] Preferably, the exhaust cover is provided with an exhaust port and an inlet, the exhaust port is provided with a classifying impeller, the exhaust cover is provided with a first motor to drive the classifying impeller to rotate, the centrifuge cylinder is provided with a plurality of injection angles, the plurality of injection angles are evenly spaced around the axis of the centrifuge cylinder, the bottom surface of the chamber is provided with a first air guide channel connecting the injection angles, and the first air guide channel is provided with a first high-pressure air pipe.

[0012] Preferably, the centrifuge cylinder and the bottom surface of the hopper are respectively provided with multiple flushing ports that run vertically through each other. The flushing ports are located in the gap formed by the impact plate and the inner wall of the centrifuge cylinder. The hopper is provided with a third air guide channel that connects the multiple flushing ports. The third air guide channel is provided with a second high-pressure air pipe.

[0013] The present invention has the following advantages: 1. A method for preparing ultrafine powder of pre-alloyed powder for geological drill bits is provided. The first step is to prepare small-particle powder by atomization. The second step is to crush the powder by nitrogen low-temperature cold extraction impact. This gradient powdering reduces the particle size of the alloy powder, laying a solid foundation for high-quality production of drill bits. At the same time, the low-temperature impact crushing solves the problem of local high-temperature cold welding that is easy to occur in the grinding process of existing metal powders. Moreover, under the protection of nitrogen, the oxidation of metal powder can be further avoided, reducing the difficulty and cost of subsequent alloy powder reduction treatment. 2. By setting impact plates and impact balls inside the centrifuge, the impact plates continuously throw balls to impact the centrifuge during the reciprocating swing process. Compared with the drum ball mill, this not only increases the number of impacts per revolution and speeds up production efficiency, but also reduces impact energy and avoids cold welding problems. 3. By designing a unique triangular impact plate and using an openable and closed arc plate, it is not only beneficial for projecting and impacting the impact ball, but also the cooperation between the impact plate and the arc plate can prevent the impact ball from approaching the center of rotation of the impact plate, so that the impact plate can reciprocate stably and continuously. 4. By introducing nitrogen gas into the space enclosed by the impact plate and the arc plate, the low-temperature cold gas can cool the impact plate, metal powder, and impact ball from different sides, making the cooling area more precise, avoiding the oxidation and cold welding problems of conventional grinding, and improving the production efficiency of ultrafine powder. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the process flow of the present invention; Figure 2 This is a schematic diagram of the overall structure of the present invention; Figure 3 This is a schematic diagram of the half-section structure of the present invention; Figure 4 This is a schematic diagram of the internal structure of the present invention; Figure 5 This is a schematic diagram of the impact plate structure of the present invention; Figure 6 This is a schematic diagram of the limiting plate structure from below according to the present invention.

[0015] In the diagram, 1. Chamber body; 2. Limiting plate; 3. Exhaust top cover; 4. First motor; 5. Exhaust port; 6. Classifying impeller; 7. Feed inlet; 8. Support leg; 9. Centrifuge cylinder; 10. Second motor; 11. Impact ball; 12. First air guide channel; 13. First high-pressure air pipe; 14. Impact plate; 15. Limiting rod; 16. Limiting groove; 17. Arc surface; 18. Arc plate; 19. Cover; 20. Torsion spring; 21. Mounting column; 22. Cold air outlet; 23. Nitrogen port; 24. Injection oblique nozzle; 25. Distributing cone; 26. Feeding port; 27. Second air guide channel; 28. Third air guide channel; 29. ​​Nitrogen pipe; 30. Second high-pressure air pipe. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0018] like Figure 1 As shown, a pre-alloyed powder for ultrafine geological drill bits is prepared according to the following method, including the following steps. S1. Weigh out the raw materials of iron, cobalt, tin, copper and lanthanum according to the proportions. The raw materials can be adjusted according to the actual situation. S2. The raw materials are put into a furnace and heated and melted to form an alloy solution; S3. The alloy solution is atomized into alloy powder using a water atomizer; S4. Alloy powder is put into a low-temperature impact ball mill for ultra-fine grinding. Materials such as copper have strong ductility at room temperature and cannot be ground and crushed. At the same time, during the grinding process at room temperature, metal powder will be cold welded to the surface of the grinding disc, which seriously affects the ultra-fine grinding of metal powder. A low-temperature impact ball mill is designed to replace the grinding disc for grinding metal powder by crushing it at low temperature, so as to solve the problem that metal powder is not easy to grind. S5. The ultrafine alloy powder enters the automated reduction furnace for deoxidation.

[0019] like Figure 1 , 2As shown, the low-temperature impact ball mill includes a chamber 1, an exhaust cover 3, a centrifuge cylinder 9, multiple impact balls 11, multiple impact plates 14, a limiting plate 2, and a classifying impeller 6. The bottom of the chamber 1 is supported by support legs 8. The centrifuge cylinder 9 is coaxially rotated inside the chamber 1, and its outer surface is tightly attached to the inner wall of the chamber 1. The limiting plate 2 is annular, with its outer edge sealingly connected to the chamber 1 and its inner edge sealingly connected to the exhaust cover 3. The exhaust cover 3 has an exhaust port 5 and a feed port 7. The existing classifying impeller 6 is installed inside the exhaust port 5. A first motor 4 that drives the classifying impeller 6 to rotate is installed on the exhaust port 5 cover. The existing classifying impeller 6 structure enables the screening function of crushed metal powder. A second motor 10 is installed below the chamber. The output end of the second motor 10 passes through and rotates to connect to the chamber 1. The output end of the second motor 10 is fixedly connected to the centrifuge cylinder 9, and the centrifuge cylinder 9 is driven to rotate by the second motor 10.

[0020] like Figure 4 As shown, the impact plate 14 has a triangular structure, with the hypotenuse of the impact plate 14 being a circular arc surface 17. Both the impact plate 14 and the impact ball 11 are located inside the centrifuge cylinder 9. The impact plates 14 are vertically distributed around the axis of the centrifuge cylinder 9 at intervals, and the height of the impact plate 14 is equal to the height of the centrifuge cylinder 9. The tail end of the impact plate 14, i.e. the right-angle end, is vertically hinged to the centrifuge cylinder 9 through a shaft. The impact plate 14 reciprocates at an acute angle with its hinge axis as the center. During the reciprocating motion, the impact ball 11 is thrown from the circular arc surface 17 onto the circular arc surface 17 of the adjacent impact plate 14, realizing the impact ball 11 and the impact plate 14 to break upon impact. In order to achieve impact breaking, the two adjacent impact plates 14 are staggered, so that one of the adjacent impact plates 14 is in a horizontal direction and the other is in a vertical direction as much as possible.

[0021] like Figure 6 As shown, in order to achieve alternating projection of impact balls 11 by the impact plate 14, the bottom surface of the limiting plate 2 is provided with a wave-shaped limiting groove 16 with the ends connected. The first end of the impact plate 14, that is, the end closest to the center of the centrifuge cylinder 9, is provided with a vertical limiting rod 15. One end of the limiting rod 15 is fixedly connected to the impact plate 14, and the other end of the limiting rod 15 is stuck in the limiting groove 16 and slidably connected to it. In the wave-shaped limiting groove 16, one of the adjacent limiting rods 15 is at the high point of the wave and the other is at the low point of the wave. When the wave is at the high point, the impact plate 14 is in a vertical state, and when the wave is at the low point, the impact plate 14 is in a horizontal state. During the rotation of the centrifuge cylinder 9, the impact plate 14 is driven to alternately change between the two states.

[0022] When each impact plate 14 reciprocates at an acute angle, the impact ball 11 gets stuck at the included angle of the impact plate 14, hindering the normal operation of the movement. An arc plate 18 is installed on each impact plate 14, with the convex surface of the arc plate 18 facing the arc surface 17 of the adjacent impact plate 14. One end of the arc plate 18 is hinged to the moving end of the impact plate 14 near the center of the centrifuge cylinder 9 via a shaft, and the other end of the arc plate 18 is slidably connected to the inner wall of the centrifuge cylinder 9. An elastic element is provided between the arc plate 18 and the impact plate 14 to control the opening and closing. The elastic element can always keep the arc plate 18 and the impact plate 14 open.

[0023] The elastic element can adopt various structures; here, a torsion spring 20 is selected. The impact plate 14 is equipped with a torsion spring 20 and a mounting post 21. The mounting post 21 is located between the impact plate 14 and the arc plate 18. The bottom end of the mounting post 21 is vertically fixed to the impact plate 14. The torsion spring 20 is fitted onto the mounting post 21. One end of the torsion spring 20 is fixedly connected to the impact plate 14, and the other end of the torsion spring 20 is fixedly connected to the arc plate 18. The torsion spring 20 can separate the arc plate 18 from the impact plate 14. The separated arc plate 15 and the adjacent impact plate 14 form a baffle structure that prevents the impact ball 11 from approaching the included angle, thereby avoiding the problem of the impact ball 11 getting stuck and causing the impact plate 14 to move.

[0024] like Figure 5 As shown, the arc plate 18 and the impact plate 14 can close to form a cavity structure. The upper part of the arc plate 18 is provided with a sealing cap 19 to seal the cavity structure. The sealing cap 19 is fixedly connected to the upper part of the arc plate 18. Multiple cold air vents 22 are opened on the arc plate 18. Multiple nitrogen ports 23 are respectively provided vertically on the bottom surfaces of the centrifuge cylinder 9 and the chamber 1. That is, nitrogen ports 23 are opened on both the centrifuge cylinder 9 and the chamber 1. Since the centrifuge cylinder 9 is rotating, when the vertically opened nitrogen ports 23 are connected, the nitrogen ports 23 are located below the cavity structure. The position of the slot 16 also matches the nitrogen port 23 on the chamber 1. The chamber 1 is provided with a second air guide channel 27 that connects multiple nitrogen ports 23. A nitrogen pipe 29 is provided on the second air guide channel 27. When the nitrogen port 23 is open, the arc plate 18 and the impact plate 14 are closed. The cold air ejected from the nitrogen pipe 29 can be sequentially sprayed through the second air guide channel 27, the nitrogen port 23, the cavity structure, and the cold air exhaust port 22 onto the adjacent arc surface 17 and the impact ball 11, thereby realizing the cooling function during the intermittent impact crushing process.

[0025] like Figure 4As shown, a distribution cone 25 is installed at the center of the centrifuge cylinder 9. Multiple injection nozzles 24 are provided inside the centrifuge cylinder 9. The multiple injection nozzles 24 are evenly spaced around the axis of the centrifuge cylinder 9 and close to the edge of the distribution cone 25. A first air guide channel 12 is provided on the top surface of the silo body 1 to connect the injection nozzles 24. The first air guide channel 12 has a groove-shaped structure and a first high-pressure air pipe 13 is provided on the first air guide channel 12. High-pressure gas can be continuously ejected from the injection nozzles 24 through the first high-pressure air pipe 13, so that a vortex is formed inside the silo body 1. In the vortex state, large powder particles are thrown to the sides and touch the impact plate 14, which facilitates the impact ball 11 to crush them. The crushed fine powder is discharged after being screened by the classifying impeller 6.

[0026] Since the arc plate 18, the impact plate 14, and the centrifuge cylinder 9 form a narrow space, a large amount of powder entering this space will also hinder the movement. Therefore, multiple flushing ports 26 are provided on the bottom surface of the centrifuge cylinder 9 and the silo body 1, which are connected vertically. The flushing ports 26 are located in the gap formed by the impact plate 14 and the inner wall of the centrifuge cylinder 9. The silo body is provided with a third air guide channel 28 that connects the multiple flushing ports 26. A second high-pressure air pipe 30 is provided on the third air guide channel 28. The high-pressure gas ejected from the second high-pressure air pipe 30 can promptly eject the powder from the narrow space, avoiding the problem of material jamming.

[0027] The centrifuge cylinder 9 is sealed and slidably connected to the bottom surface of the chamber 1. Even if the connection between the nitrogen port 23 and the material inlet 26 is not tight, the gas that escapes will be distributed between the centrifuge cylinder 9 and the chamber 1, forming a high-pressure gas film, reducing friction, preventing external powder from entering the gap between the centrifuge cylinder 9 and the chamber 1, and ensuring the smooth coaxial rotation function between the centrifuge cylinder 9 and the chamber 1.

[0028] Working principle: The first motor 4 and the second motor 10 are started, and alloy powder is fed into the feed inlet 7. The second motor 10 drives the centrifuge drum 9 to rotate. The impact balls 11 inside the centrifuge drum 9 roll onto the impact plate 14 under the centrifugal force generated by the rotation of the centrifuge drum 9. The impact plate 14 also rotates under the action of the centrifuge drum 9. The limiting rod 15 of the impact plate 14 is engaged in the limiting groove 16, causing the limiting rod 15 to slide within the limiting groove 16 under the action of the centrifuge drum 9. Since the limiting groove 16 is wavy, it causes the limiting rod 15 to make a wavy motion. The other end of the impact plate 14 is restricted by the pivot, causing the impact plate 14 to reciprocate at an acute angle around the hinge pivot. Adjacent impact plates 14 are misaligned, and the impact balls 11 that roll onto the arc surface 17 are thrown by the impact plate 14 towards the adjacent impact plate 14 in the vertical direction under the reciprocating swing. At the same time, the high-pressure airflow discharged from the first high-pressure air pipe enters the first air guide channel 12 and is distributed to the injection nozzles 24. The tangentially installed injection nozzles 24 generate a spiral airflow inside the centrifuge cylinder 9, and large particles of powder are thrown by the centrifugal airflow. Upon impact with the impact plate 14, the impact ball 11 undergoes a first impact and breakage. After being launched, it also impacts the large particles on the impact plate 14, resulting in a second impact and breakage. Nitrogen gas from the nitrogen pipe 29 enters the second gas channel 27. When the centrifuge cylinder 9 rotates to the point where the nitrogen inlet 23 is aligned vertically, nitrogen gas is ejected upwards from the bottom of the centrifuge cylinder 9. During the process of launching the impact ball 11 from the impact plate 14, the impact plate 14 rotates horizontally, and the edge of the arc plate 18 slides against the inner wall of the centrifuge cylinder 9. The arc plate 18 will interact with the impact plate 14... When the clamp is closed and the torsion spring 20 is compressed, the sealed space formed by the arc plate 18 and the impact plate 14 is located above the nitrogen port 23. Nitrogen is injected into the cavity, which cools the impact plate 14 on one hand, and the cold air is discharged through the cold air outlet 22 and rushes onto the arc surface 17 of the impact plate 14 on the other hand. This can simultaneously cool the metal powder on the arc surface 17 and the impact ball 11, avoiding cold welding problems during the impact process. Finally, qualified powder is discharged from the exhaust port 5 through the classifying impeller 6, and unqualified powder is returned to the centrifuge 9 for low-temperature impact crushing again.

[0029] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing ultrafine powder of pre-alloyed powder for geological drill bits, characterized in that, Includes the following steps, S1. Weigh out the raw materials of iron, cobalt, tin, copper and lanthanum according to the proportions; S2. The raw materials are put into a furnace and heated and melted to form an alloy solution; S3. The alloy solution is atomized into alloy powder using an atomizer; S4. The alloy powder is fed into a low-temperature impact ball mill for ultra-fine grinding; S5. The ultrafine alloy powder enters the automated reduction furnace for deoxidation.

2. The method for preparing ultrafine powder of pre-alloyed powder for geological drill bits according to claim 1, characterized in that, The low-temperature impact ball mill includes a chamber (1), an exhaust top cover (3), a centrifuge cylinder (9), multiple impact balls (11), and multiple impact plates (14). The centrifuge cylinder (9) is coaxially rotated inside the chamber (1). The impact plates (14) and the impact balls (11) are located inside the centrifuge cylinder (9). The impact plates (14) are vertically distributed around the axis of the centrifuge cylinder (9). The tail end of the impact plate (14) is vertically hinged to the centrifuge cylinder (9). The impact plate (14) reciprocates at an acute angle with its hinge axis as the center. Adjacent impact plates (14) are staggered.

3. The method for preparing ultrafine powder of pre-alloyed powder for geological drill bits according to claim 2, characterized in that, The low-temperature impact ball mill also includes a limiting plate (2), which is annular. The outer edge of the limiting plate (2) is sealed to the chamber body (1), and the inner edge of the limiting plate (2) is sealed to the exhaust top cover (3). The bottom surface of the limiting plate (2) is provided with a wave-shaped limiting groove (16) with the ends connected. The first end of the impact plate (14) is vertically fixed with a limiting rod (15), which is stuck in the limiting groove (16) and slidably connected to it.

4. The method for preparing ultrafine powder of pre-alloyed powder for geological drill bits according to claim 3, characterized in that, The impact plate (14) has a triangular structure, and the hypotenuse of the impact plate (14) is a circular arc surface (17).

5. The method for preparing ultrafine powder of pre-alloyed powder for geological drill bits according to claim 4, characterized in that, Each of the impact plates (14) is provided with an arc plate (18), the convex surface of the arc plate (18) faces the arc surface (17) of the adjacent impact plate (14), one end of the arc plate (18) is hinged to the moving end of the impact plate (14), and the other end of the arc plate (18) is slidably connected to the inner wall of the centrifuge cylinder (9). An elastic element for controlling opening and closing is provided between the arc plate (18) and the impact plate (14).

6. The method for preparing ultrafine powder of pre-alloyed powder for geological drill bits according to claim 5, characterized in that: The impact plate (14) is provided with a torsion spring (20) and a mounting post (21). The mounting post (21) is located between the impact plate (14) and the arc plate (18). The mounting post (21) is vertically fixed to the impact plate (14). The torsion spring (20) is fitted on the mounting post (21). One end of the torsion spring (20) is fixedly connected to the impact plate (14), and the other end of the torsion spring (20) is fixedly connected to the arc plate (18).

7. The method for preparing ultrafine powder of pre-alloyed powder for geological drill bits according to claim 5, characterized in that: The arc plate (18) and the impact plate (14) are closed to form a cavity structure. The upper part of the arc plate (18) is provided with a cover (19) to seal the cavity structure. The arc plate (18) is provided with multiple exhaust ports (22). The lower part of the housing (1) is provided with a second motor (10). The output end of the second motor (10) passes through and is rotatably connected to the housing (1). The output end of the second motor (10) is fixedly connected to the centrifuge cylinder (9). The centrifuge cylinder (9) is slidably connected to the bottom surface of the housing (1). The bottom surface of the centrifuge cylinder (9) and the housing (1) are respectively provided with multiple nitrogen ports (23) that are vertically connected. The nitrogen ports (23) are located below the cavity structure. The housing (1) is provided with a second gas guide channel (27) that connects the multiple nitrogen ports (23). The second gas guide channel (27) is provided with a nitrogen pipe (29).

8. The method for preparing ultrafine powder of pre-alloyed powder for geological drill bits according to claim 7, characterized in that: The exhaust top cover (3) is provided with an exhaust port (5) and a feed port (7). The exhaust port (5) is provided with a classifying impeller (6). The exhaust port (5) top cover is provided with a first motor (4) that drives the classifying impeller (6) to rotate. The centrifuge cylinder (9) is provided with multiple injection angles (24). The multiple injection angles (24) are evenly spaced around the axis of the centrifuge cylinder (9). The bottom surface of the housing (1) is provided with a first air guide channel (12) that connects the injection angles (24). The first air guide channel (12) is provided with a first high-pressure air pipe (13).

9. The method for preparing ultrafine powder of pre-alloyed powder for geological drill bits according to claim 8, characterized in that: The centrifuge tube (9) and the bottom surface of the shell (1) are respectively provided with a plurality of material inlets (26) that run vertically through each other. The material inlets (26) are located in the gap formed between the impact plate (14) and the inner wall of the centrifuge tube (9). The shell (1) is provided with a third air guide channel (28) that connects the plurality of material inlets (26). The third air guide channel (28) is provided with a second high-pressure air pipe (30).

10. A pre-alloyed powder for geological drill bits, based on the method of claim 1, characterized in that, The pre-alloyed powder is an ultrafine powder.

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