Automatic neodymium iron boron batching system and using method

Abstract

The invention discloses an automatic neodymium iron boron batching system and a using method, and particularly relates to the technical field of magnet preparation, the automatic neodymium iron boron batching system comprises a controller, four raw material hoppers, discharging valves, weighing sensors, a disc feeder and a stirring device, the raw material hoppers are used for containing neodymium iron boron raw materials with different component contents, the discharging valves are arranged at discharging ports of the raw material hoppers, and the weighing sensors are used for weighing the neodymium iron boron raw materials. A weighing sensor is installed on the raw material hopper, feeding ports of the disc feeders correspond to discharging ports of the raw material hopper, the stirring devices are arranged below the discharging ports of the disc feeders, and the discharging valves, the weighing sensor, the disc feeders and the stirring devices are all in signal connection with the controller. The controller can calculate the required mass of neodymium iron boron raw materials with different component contents in the raw material hoppers according to the set component contents and weight values of neodymium iron boron, and the controller can control opening and closing of the discharging valve according to information conveyed by the weighing sensor. The automatic proportioning device can realize automatic proportioning, and is high in precision, small in error and high in production efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of magnet preparation, and in particular to a neodymium iron boron automatic batching system and a use method thereof. Background Art

[0002] NdFeB permanent magnet material is a permanent magnet material based on the intermetallic compound Nd2Fe14B. The main components are rare earth elements neodymium (Nd), iron (Fe), and boron (B). The rare earth element is mainly neodymium (Nd). In order to obtain different properties, it can be partially replaced by other rare earth metals such as dysprosium (Dy) and praseodymium (Pr). Iron can also be partially replaced by other metals such as cobalt (Co) and aluminum (Al). The content of boron is relatively small, but it plays an important role in the formation of tetragonal crystal structure intermetallic compounds, which makes the compound have high saturation magnetization, high uniaxial anisotropy and high Curie temperature.

[0003] NdFeB with different contents has obvious differences in magnetic properties. In order to improve the cost-effectiveness of NdFeB permanent magnet materials, very strict requirements are put forward for the precise formula and the proportion, purity and accuracy of the addition of precious metals of micro-adjustment. In order to obtain a certain ratio of NdFeB permanent magnet materials, NdFeB raw materials with different content of components are currently mixed semi-automatically or fully manually. However, manual mixing is relatively random. When different operators make proportions, due to differences in operating habits, skill levels, etc., it is difficult to ensure that the results of each proportion are the same, and it is impossible to achieve accurate proportions. Summary of the invention

[0004] The purpose of the present invention is to provide an automatic NdFeB proportioning device and a method of use to solve the problems existing in the above-mentioned prior art, which can realize automatic proportioning with high precision, small error and high production efficiency.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides an automatic NdFeB batching system, comprising a controller, four raw material hoppers, a discharge valve, a weighing sensor, a disc feeder and a stirring device, each of the raw material hoppers is used to hold NdFeB raw materials with different component contents, the discharge port of the raw material hopper is provided with the discharge valve, the raw material hopper is installed with the weighing sensor, the weighing sensor is used to monitor the weight of the NdFeB raw material in the raw material hopper, the disc feeder is fixedly connected to the bottom of the raw material hopper, and the feed port of the disc feeder corresponds to the discharge port of the raw material hopper. The stirring device is placed below the discharge port of each disc feeder and is used to mix NdFeB raw materials with different component contents. The discharge valve, the weighing sensor, the stirring device and the disc feeder are all connected to the controller signal. The controller can calculate the required mass of NdFeB raw materials with different component contents in each raw material hopper according to the set content and weight value of each component of NdFeB. The weighing sensor can transmit monitoring information to the controller in real time, and the controller can control the opening, closing and opening size of the discharge valve.

[0007] Preferably, the disc feeder includes a bracket, a feed bin, a disc, a scraper and a driving device, the feed bin is fixedly connected to the top of the bracket, the feed bin is placed below the discharge port of the raw material hopper, the disc is rotatably connected to the bracket, the disc is placed below the feed bin, the driving device is mounted on the bracket, and the driving device is connected to the disc, and is used to drive the disc to rotate around its own axis, the scraper is fixedly connected to the outer side wall of the discharge pipe of the feed bin, and the bottom of the scraper can contact the disc, the bottom of the bracket has a discharge channel, and the scraper is used to guide the material that rotates with the disc to separate from the disc from the discharge channel.

[0008] Preferably, the stirring device comprises a barrel body, a stirring shaft and a stirring shaft driving device, the top of the barrel body is provided with an inlet, the stirring shaft is arranged in the barrel body, and the stirring shaft driving device is connected to the stirring shaft and drives the stirring shaft to rotate.

[0009] Preferably, the spiral blades of the stirring shaft are double spiral blades.

[0010] Preferably, it further comprises a frame, and each of the raw material hoppers is fixed on the top plate of the frame.

[0011] Preferably, the top cross-sectional shape of the raw material hopper is a square, and the bottom of the raw material hopper is a regular quadrangular pyramid.

[0012] Preferably, the weighing sensors are provided at the four corners of the top of the raw material hopper, the top of the weighing sensor is fixedly connected to the raw material hopper, the bottom of the weighing sensor is fixedly connected to the top plate of the frame, and the weighing sensor is a cantilever beam weighing sensor.

[0013] Preferably, guardrails are provided around the top plate of the frame.

[0014] The present invention also provides a method for using the NdFeB automatic batching system, comprising the following steps:

[0015] Step 1, transporting NdFeB raw materials with different component contents to each of the raw material hoppers by a belt conveyor;

[0016] Step 2: The component content of the NdFeB raw material in each of the raw material hoppers is transported to the controller, and the controller first calculates the weight of each of the raw material hoppers required for 75% of the target product NdFeB according to the content and weight value of each component of the target product NdFeB;

[0017] Step 3, the controller turns on the stirring device, and then controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper. When the weighing sensor detects that the discharge amount of the raw material hopper reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper enter the stirring device;

[0018] Step 4, the stirring device mixes the NdFeB raw materials with different component contents for the first time;

[0019] Step 5, after the first mixing operation of the stirring device has been performed for a certain period of time, the controller calculates the weight of each of the raw material hoppers required for a 20% ratio of the target product NdFeB;

[0020] Step 6, the controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper. When the weighing sensor detects that the discharge amount of the raw material hopper reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper enter the stirring device that has been mixed evenly for one discharge;

[0021] Step 7, the stirring device mixes the two materials for the second time;

[0022] Step 8, after the second mixing operation of the stirring device has been performed for a certain period of time, the controller calculates the weight of each of the raw material hoppers required for a 4.5% ratio of the target product NdFeB;

[0023] Step nine, the controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper. When the weighing sensor detects that the discharge amount of the raw material hopper reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper enter the stirring device that has mixed the secondary discharge evenly;

[0024] Step 10, the stirring device mixes the three materials for the third time;

[0025] Step 11, after the third mixing operation of the stirring device has been performed for a certain period of time, the operator analyzes the sample after the third mixing, calculates the content and weight value of each component in the sample, and the controller gives the weight of each raw material hopper required for the target product NdFeB according to the calculation results;

[0026] Step 12, the controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper. When the weighing sensor detects that the discharge amount of the raw material hopper reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper enter the stirring device that has been evenly mixed after three discharges;

[0027] Step thirteen, the stirring device mixes the four materials for the third time, and after mixing, conveys them to the next process.

[0028] Compared with the prior art, the present invention has achieved the following technical effects:

[0029] The present invention provides an automatic NdFeB batching system and a method for using the system. The controller can calculate the required mass of NdFeB raw materials with different component contents in each raw material hopper according to the set content and weight value of each component of NdFeB. The controller controls the opening and closing of each discharge valve to realize automatic and accurate material discharge. Finally, after final mixing by a stirring device, the set NdFeB ratio and weight are achieved. Accurate quality control is achieved through an intelligent and digital management system, and ultimately the quality and stability of NdFeB magnets are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic diagram of the structure of the NdFeB automatic batching system;

[0032] Figure 2This is the front view of the NdFeB automatic batching system;

[0033] Figure 3 It is a side view of the NdFeB automatic batching system;

[0034] Figure 4 It is the structural schematic diagram of the disc feeder;

[0035] Figure 5 It is the front view of the disc feeder;

[0036] Figure 6 It is a schematic diagram of the structure of the stirring device.

[0037] In the figure: 1-raw material hopper; 2-weighing sensor; 3-stirring device; 4-frame; 5-disc feeder; 6-bracket; 7-feeding bin; 8-disc; 9-scraper; 10-driving device; 11-discharging channel; 12-barrel; 13-stirring shaft; 14-stirring shaft driving device; 15-guardrail. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The purpose of the present invention is to provide an automatic NdFeB proportioning device and a method of use to solve the problems existing in the above-mentioned prior art, which can realize automatic proportioning with high precision, small error and high production efficiency.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Example 1

[0042] This embodiment provides a neodymium iron boron automatic batching system, such as Figure 1-3As shown, it includes a controller, multiple raw material hoppers 1, a discharge valve, a weighing sensor 2 and a stirring device 3. Each raw material hopper 1 is used to hold NdFeB raw materials with different component contents. The discharge port of the raw material hopper 1 is provided with a discharge valve. The raw material hopper 1 is equipped with a weighing sensor 2. The weighing sensor 2 is used to monitor the weight of the NdFeB raw material in the raw material hopper 1. The stirring device 3 is placed below the discharge port of each raw material hopper 1 to mix the NdFeB raw materials with different component contents. The discharge valve, the weighing sensor 2 and the stirring device 3 are all connected to the controller signal. The controller can calculate the required mass of the NdFeB raw materials with different component contents in each raw material hopper 1 according to the set content and weight value of each component of NdFeB. The weighing sensor 2 can transmit the monitoring information to the controller in real time. The controller can control the opening, closing and opening size of the discharge valve. The controller can calculate the required mass of NdFeB raw materials with different component contents in each raw material hopper 1 according to the set content and weight value of each component of NdFeB. The controller controls the opening and closing of each discharge valve to realize automatic and accurate material discharge. Finally, after the final mixing by the stirring device 3, the set NdFeB ratio and weight are achieved. The precise quality control is realized through the intelligent and digital management system, and the quality and stability of NdFeB magnets are finally improved. The controller has a logical interlocking function, which requires the stirring device 3 to be started first before the discharge valve can be opened. If the stirring device 3 is not started, all discharge valves cannot be opened. In addition, if the stirring device 3 fails, all discharge valves will be closed immediately. Only after the failure is eliminated, the controller controls the discharge valve to reopen and continues to complete the current discharge process according to the weight of the material already discharged. If any discharge valve fails to open, the controller immediately closes the remaining discharge valves, and the stirring device 3 automatically stops after running for 3 minutes. When the failure of the discharge valve is restored, the stirring device 3 is started first, and the controller controls the discharge valve to reopen and continues to complete the current discharge process according to the weight of the material already discharged.

[0043] It is further preferred in the implementation manner of this embodiment that Figure 4-5 As shown, the NdFeB automatic batching system also includes a disc feeder 5, which is fixedly connected to the bottom of the raw material hopper 1, and the feed port of the disc feeder 5 corresponds to the discharge port of the raw material hopper 1, the discharge port of the disc feeder 5 is located above the stirring device 3, and the disc feeder 5 is connected to the controller signal. The disc feeder 5 can discharge the material more evenly, which is very important for the production process that requires precise control of the material flow.

[0044] It is further preferred in the implementation of the present embodiment that the disc feeder 5 includes a bracket 6, a feed bin 7, a disc 8, a scraper 9 and a driving device 10, the feed bin 7 is fixedly connected to the top of the bracket 6, the feed bin 7 is placed below the discharge port of the raw material hopper 1, the disc 8 is rotatably connected to the bracket 6, the disc 8 is placed below the feed bin 7, the driving device 10 is mounted on the bracket 6, and the driving device 10 is connected to the disc, and is used to drive the disc 8 to rotate around its own axis, the scraper 9 is fixedly connected to the outer wall of the discharge pipe of the feed bin 7, and the bottom of the scraper 9 can contact the disc 8, the bottom of the bracket 6 has a discharge channel 11, and the scraper 9 is used to guide the material rotating with the disc 8 to separate from the disc 8 from the discharge channel 11. Preferably, the driving device 10 includes a variable frequency motor and a reducer. When the disc feeder 5 is working, the motor starts and drives the disc 8 to rotate at a certain speed through the reducer. The material falls from the feed bin 7 onto the rotating disc. Due to the rotation of the disc 8, the material moves toward the edge of the disc 8 under the action of centrifugal force. When the material moves to the discharge channel 11, the material is discharged through the discharge port under the action of the scraper 9, thereby realizing the falling process of the material. The controller can change the rotation speed of the disc 8 so that the disc feeder 5 can adapt to different production requirements.

[0045] It is further preferred in the implementation manner of this embodiment that Figure 6 As shown, the stirring device 3 includes a barrel body 12, a stirring shaft 13 and a stirring shaft driving device 14. An inlet is opened at the top of the barrel body 12, and the stirring shaft 13 is arranged in the barrel body 12. The stirring shaft driving device 14 is connected to the stirring shaft 13 and drives the stirring shaft 13 to rotate.

[0046] It is further preferred in the implementation manner of this embodiment that the spiral blades of the stirring shaft 13 are double spiral blades, which can stir more evenly.

[0047] It is further preferred in the implementation manner of this embodiment that the NdFeB automatic batching system further includes a frame 4 , and each raw material hopper 1 is fixed on the top plate of the frame 4 .

[0048] It is further preferred in the implementation manner of this embodiment that the top cross-sectional shape of the raw material hopper 1 is a square, and the bottom of the raw material hopper 1 is a regular quadrangular pyramid.

[0049] In the implementation of this embodiment, it is further preferred that weighing sensors 2 are provided at the four corners of the top of the raw material hopper 1, the top of the weighing sensor 2 is fixedly connected to the raw material hopper 1, the bottom of the weighing sensor 2 is fixedly connected to the top plate of the frame 4, and the weighing sensor 2 is a cantilever beam weighing sensor 2. Preferably, the model of the weighing sensor 2 is LC803-1T (2 tons) sensor, which is easy to disassemble and assemble, easy to debug, and has high accuracy.

[0050] It is further preferred in the implementation manner of this embodiment that guardrails 15 are provided around the top plate of the frame body 4 .

[0051] Example 2

[0052] This embodiment provides a method for using the NdFeB automatic batching system of Embodiment 1, comprising the following steps:

[0053] Step 1: transporting NdFeB raw materials with different content into raw material hoppers 1 respectively by belt conveyor;

[0054] Step 2: The component content of the NdFeB raw material in each raw material hopper 1 is transported to the controller, and the controller first calculates the weight of each raw material hopper 1 required for 75% of the target product NdFeB according to the content and weight value of each component of the target product NdFeB;

[0055] Step 3, the controller turns on the stirring device 3, and then controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper 1. When the weighing sensor 2 detects that the discharge amount of the raw material hopper 1 reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper 1 enter the stirring device 3;

[0056] Step 4, the stirring device 3 mixes the NdFeB raw materials with different content for the first time;

[0057] Step 5, after the first mixing operation of the stirring device 3 has been performed for a certain period of time, the controller calculates the weight of each raw material hopper 1 required for a 20% ratio of the target product NdFeB;

[0058] Step 6: The controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper 1. When the weighing sensor 2 detects that the discharge amount of the raw material hopper 1 reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper 1 enter the stirring device 3 that has been mixed evenly for the first discharge;

[0059] Step 7, the stirring device 3 mixes the two materials for the second time;

[0060] Step 8, after the second mixing operation of the stirring device 3 has lasted for a certain period of time, the controller calculates the weight of each raw material hopper 1 required for the target product NdFeB at a ratio of 4.5%;

[0061] Step nine, the controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper 1. When the weighing sensor 2 detects that the discharge amount of the raw material hopper 1 reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper 1 enter the stirring device 3 that has already mixed the secondary discharge evenly;

[0062] Step 10, the stirring device 3 mixes the three materials for the third time;

[0063] Step eleven, after the third mixing operation of the stirring device 3 has been carried out for a certain period of time, the operator analyzes the sample after the three mixings, calculates the content and weight value of each component in the sample, and the controller gives the weight of each raw material hopper 1 required for the target product NdFeB according to the calculation results; the quality of the material after the three mixings is tested, and the mixing parameters are appropriately adjusted according to the test results to ensure the accurate ratio of the final product.

[0064] Step 12: The controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper 1. When the weighing sensor 2 detects that the discharge amount of the raw material hopper 1 reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper 1 enter the stirring device 3 that has been evenly mixed after three discharges;

[0065] Step 13: The stirring device 3 mixes the four materials for the third time, and after the mixing is completed, it is transported to the next process.

[0066] By mixing the target NdFeB four times, NdFeB raw materials with different content can be better integrated. Multiple mixing can reduce mixing errors and improve product quality.

[0067] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A NdFeB automatic batching system, characterized by: The invention comprises a controller, four raw material hoppers, a discharge valve, a weighing sensor, a disc feeder and a stirring device. Each of the raw material hoppers is used to hold NdFeB raw materials with different composition contents. The discharge port of the raw material hopper is provided with the discharge valve. The weighing sensor is installed on the raw material hopper. The weighing sensor is used to monitor the weight of the NdFeB raw material in the raw material hopper. The disc feeder is fixedly connected to the bottom of the raw material hopper, and the feed port of the disc feeder corresponds to the discharge port of the raw material hopper. The stirring device is placed at Below the discharge port of each disc feeder is used to mix NdFeB raw materials with different component contents. The discharge valve, the weighing sensor, the stirring device and the disc feeder are all connected to the controller signal. The controller can calculate the required mass of NdFeB raw materials with different component contents in each raw material hopper according to the set content and weight value of each component of NdFeB. The weighing sensor can transmit monitoring information to the controller in real time, and the controller can control the opening, closing and opening size of the discharge valve.

2. The NdFeB automatic batching system according to claim 1, characterized in that: The disc feeder includes a bracket, a feed bin, a disc, a scraper and a driving device. The feed bin is fixedly connected to the top of the bracket, the feed bin is placed below the discharge port of the raw material hopper, the disc is rotatably connected to the bracket, the disc is placed below the feed bin, the driving device is installed on the bracket, and the driving device is connected to the disc, and is used to drive the disc to rotate around its own axis, the scraper is fixedly connected to the outer side wall of the discharge pipe of the feed bin, and the bottom of the scraper can contact the disc, the bottom of the bracket has a discharge channel, and the scraper is used to guide the material that rotates with the disc to separate from the disc from the discharge channel.

3. The NdFeB automatic batching system according to claim 1, characterized in that: The stirring device comprises a barrel body, a stirring shaft and a stirring shaft driving device. An inlet is opened on the top of the barrel body. The stirring shaft is arranged in the barrel body. The stirring shaft driving device is connected to the stirring shaft and drives the stirring shaft to rotate.

4. The NdFeB automatic batching system according to claim 3, characterized in that: The spiral blades of the stirring shaft are double spiral blades.

5. The NdFeB automatic batching system according to claim 1, characterized in that: It also includes a frame, and each of the raw material hoppers is fixed on the top plate of the frame.

6. The NdFeB automatic batching system according to claim 5, characterized in that: The top cross-sectional shape of the raw material hopper is a square, and the bottom of the raw material hopper is a regular quadrangular pyramid.

7. The NdFeB automatic batching system according to claim 6, characterized in that: The weighing sensors are arranged at the four corners of the top of the raw material hopper, the top of the weighing sensor is fixedly connected to the raw material hopper, the bottom of the weighing sensor is fixedly connected to the top plate of the frame, and the weighing sensor is a cantilever beam weighing sensor.

8. The NdFeB automatic batching system according to claim 7, characterized in that: Guardrails are arranged around the top plate of the frame.

9. A method for using the NdFeB automatic batching system according to any one of claims 1 to 8, characterized in that: The steps include: Step 1, transporting NdFeB raw materials with different component contents to each of the raw material hoppers by a belt conveyor; Step 2: The component content of the NdFeB raw material in each of the raw material hoppers is transported to the controller, and the controller first calculates the weight of each of the raw material hoppers required for 75% of the target product NdFeB according to the content and weight value of each component of the target product NdFeB; Step 3, the controller turns on the stirring device, and then controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper. When the weighing sensor detects that the discharge amount of the raw material hopper reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper enter the stirring device; Step 4, the stirring device mixes the NdFeB raw materials with different component contents for the first time; Step 5, after the first mixing operation of the stirring device has been performed for a certain period of time, the controller calculates the weight of each of the raw material hoppers required for a 20% ratio of the target product NdFeB; Step 6, the controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper. When the weighing sensor detects that the discharge amount of the raw material hopper reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper enter the stirring device that has been mixed evenly for one discharge; Step 7, the stirring device mixes the two materials for the second time; Step 8, after the second mixing operation of the stirring device has been performed for a certain period of time, the controller calculates the weight of each of the raw material hoppers required for a 4.5% ratio of the target product NdFeB; Step nine, the controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper. When the weighing sensor detects that the discharge amount of the raw material hopper reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper enter the stirring device that has mixed the secondary discharge evenly; Step 10, the stirring device mixes the three materials for the third time; Step 11, after the third mixing operation of the stirring device has been performed for a certain period of time, the operator analyzes the sample after the third mixing, calculates the content and weight value of each component in the sample, and the controller gives the weight of each raw material hopper required for the target product NdFeB according to the calculation results; Step 12, the controller controls the opening of the corresponding discharge valve according to the required discharge weight of each raw material hopper. When the weighing sensor detects that the discharge amount of the raw material hopper reaches the set value, the controller controls the corresponding discharge valve to close, and the NdFeB raw materials in each raw material hopper enter the stirring device that has been evenly mixed after three discharges; Step thirteen, the stirring device mixes the four materials for the third time, and after mixing, conveys them to the next process.

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