Batch purification treatment device and method for neodymium iron boron oil sludge

Abstract

The invention provides a neodymium iron boron oil sludge batch purification treatment device and method. The device structurally comprises a cleaning assembly, a solid-liquid separation assembly, a waste liquid collection assembly and a drying assembly. The cleaning tank is used for receiving the pumped cleaning agent and cleaning the neodymium iron boron oil sludge; the solid-liquid separation assembly comprises a sealable box body and a double-roller type magnetic interception mechanism arranged in the box body, the cleaning tank is welded to the bottom of the box body, and the solid-liquid separation assembly is used for conducting solid-liquid separation on the cleaned neodymium iron boron oil sludge to obtain waste liquid and solid oil sludge; the waste liquid collection assembly comprises a solution transfer tank, and the solution transfer tank is welded to the bottom of the box body and used for collecting waste liquid separated from the solid-liquid separation assembly; the drying assembly is used for performing vacuum drying treatment on the solid oil sludge separated by the solid-liquid separation assembly to obtain purified oil sludge; by means of the batch purification treatment device provided by the invention, batch purification treatment of neodymium iron boron oil sludge can be realized.

Description

Technical Field

[0001] This invention relates to the field of neodymium iron boron sludge treatment technology, and in particular to a batch purification treatment device and method for neodymium iron boron sludge. Background Technology

[0002] Sintered NdFeB permanent magnets possess excellent performance and are widely used in automobiles, home appliances, wind power, and consumer electronics, making them one of the most important types of permanent magnet materials on the market. In recent years, with the booming development of the electronics and information industry, wind power, and new energy vehicles, the demand for NdFeB has been increasing, and the annual production of sintered NdFeB has gradually increased, reaching 266,000 tons in my country in 2023. The production process of sintered NdFeB generates a large amount of production waste, accounting for approximately 30-40 wt.% of the total. Among this waste, sludge generated during machining accounts for the largest proportion, approximately 80-90 wt.%. This sludge contains 28-32 wt.% rare earth elements, making it highly valuable for recycling. Rare earth resources are non-renewable; therefore, both from the perspective of mitigating the environmental problems that rare earth mining may cause and from the perspective of strategic reserves of rare earth resources, it is essential to prioritize the use of economical and effective methods to recycle the valuable substances in NdFeB waste.

[0003] Existing short-process methods for treating NdFeB sludge waste are all laboratory-level. In the laboratory, ordinary beakers or flasks are mostly used for treatment. The waste is cleaned with organic solvents and surfactant solutions containing acids and bases. After magnetic separation, purified NdFeB powder with low carbon, hydrogen, and oxygen content and good magnetic properties is obtained directly.

[0004] However, using ordinary beakers or flasks for processing often has the following disadvantages: (1) It cannot be processed in large quantities and cannot be adapted to production; (2) After the current reaction device is cleaned, it is not easy to achieve multiple cleaning and multiple solid-liquid separation. It is necessary to manually use a magnet to attract the magnetic material in the container and then perform solid-liquid separation; (3) The liquid poured out contains a small amount of magnetic particles that are wasted and cannot be collected directly, which is time-consuming, laborious and wasteful of raw materials; (4) Due to the easy oxidation of neodymium iron boron sludge, it is easy to cause oxidation when cleaned directly in the air, resulting in very low cleaning efficiency; (5) After cleaning, it needs to be dried. At this time, transferring the material will cause oxidation. Summary of the Invention

[0005] In view of the above-mentioned problems in the prior art, the present invention provides a device and method for batch purification of NdFeB sludge to achieve batch purification of NdFeB sludge.

[0006] The specific details of the invention are as follows: In a first aspect, the present invention provides a batch purification and treatment device for neodymium iron boron sludge, comprising: a cleaning component, a solid-liquid separation component, a waste liquid collection component, and a drying component; The cleaning assembly includes a cleaning tank for receiving pumped cleaning agent and cleaning the NdFeB sludge. The solid-liquid separation assembly includes a sealable housing and a double-roller magnetic interception mechanism disposed within the housing. The cleaning tank is welded to the bottom of the housing. The solid-liquid separation assembly is used to perform solid-liquid separation on the cleaned NdFeB sludge to obtain waste liquid and solid sludge respectively. The waste liquid collection assembly includes a solution transfer tank, which is welded to the bottom of the box body and is used to collect the waste liquid separated from the solid-liquid separation assembly; The drying component is used to perform vacuum drying on the solid sludge separated by the solid-liquid separation component to obtain purified sludge.

[0007] Optionally, the cleaning assembly further includes a slurry pump, one end of which is connected to the slurry outlet at the bottom of the cleaning tank, and the other end is connected via a first three-way valve to the liquid injection port near the top of the cleaning tank and the solid-liquid separation assembly. Optionally, the cleaning tank is equipped with a mechanical stirring device to ensure that the NdFeB sludge entering the cleaning tank is fully mixed with the cleaning agent.

[0008] Optionally, the dual-roller magnetic interception mechanism consists of a scraper, a magnetic roller, and a rubber roller. The rubber roller is positioned higher than the magnetic roller, and the rubber roller and the magnetic roller rotate in opposite directions. The scraper is positioned in the direction of rotation of the magnetic roller, and the scraper is partially in contact with the magnetic roller.

[0009] Optionally, the waste liquid collection assembly further includes a solution pump and a waste liquid tank; One end of the solution pump is connected to the bottom of the solution transfer tank, and the other end is connected to the waste liquid tank and the cleaning tank respectively through a second three-way valve.

[0010] Optionally, the drying assembly includes a vacuum pump and a vacuum drying chamber; The vacuum pump is connected to the vacuum drying chamber and is used to evacuate the vacuum drying chamber.

[0011] Optionally, the chamber is equipped with an oxygen content analyzer, an air inlet, and an air outlet. The oxygen probe of the oxygen content analyzer is built into the chamber. The oxygen content analyzer is used to detect the oxygen removal status inside the chamber. The air inlet and air outlet are configured to replace the air inside the chamber with inert gas.

[0012] In a second aspect, the present invention provides a method for batch purification of NdFeB sludge, the method being applicable to the batch purification apparatus for NdFeB sludge described in the first aspect above, the method comprising: After purging the chamber with inert gas to remove air, the neodymium iron boron sludge is pumped into the cleaning tank and cleaned with the help of a cleaning agent. The mixture formed after cleaning in the cleaning tank is pumped into the solid-liquid separation component for solid-liquid separation, and waste liquid and solid sludge are obtained respectively. The waste liquid collection assembly collects the waste liquid separated by the solid-liquid separation assembly; The drying component performs vacuum drying on the solid sludge separated by the solid-liquid separation component to obtain purified sludge.

[0013] Optionally, the step of pumping the NdFeB sludge into a cleaning tank and cleaning it with the aid of a cleaning agent includes: Adjust the first three-way valve to form a passage between the slurry pump and the slurry outlet at the bottom of the cleaning tank and the liquid injection port near the top. The slurry pump pumps out the slurry deposited at the bottom of the cleaning tank and pumps it back into the cleaning tank until the cleaning process is completed. The step of pumping the mixture formed after cleaning the cleaning tank into the solid-liquid separation component includes: adjusting the first three-way valve to form a passage between the slurry pump and the solid-liquid separation component, wherein the slurry pump pumps all the mixture in the cleaning tank to the solid-liquid separation component.

[0014] Optionally, the waste liquid collection assembly collects the waste liquid separated from the solid-liquid separation assembly, including: When the NdFeB sludge content in the waste liquid received by the solution transfer tank exceeds a preset value, the second three-way valve is adjusted to form a passage between the solution pump and the cleaning tank. The solution pump then pumps the waste liquid received by the solution transfer tank into the cleaning tank to continue the cleaning process. When the NdFeB sludge content in the waste liquid received by the solution transfer tank is less than a preset value, the second three-way valve is adjusted to form a passage between the solution pump and the waste liquid tank, and the solution pump pumps the waste liquid received by the solution transfer tank into the waste liquid tank.

[0015] Compared with the prior art, the present invention has the following advantages: This invention provides a batch purification device for NdFeB sludge, comprising: a cleaning component, a solid-liquid separation component, a waste liquid collection component, and a drying component; the cleaning component includes a cleaning tank for receiving pumped cleaning agent and cleaning the NdFeB sludge; the solid-liquid separation component includes a sealable housing and a double-roller magnetic interception mechanism disposed within the housing, the cleaning tank being welded to the bottom of the housing, and the solid-liquid separation component for separating the cleaned NdFeB sludge into solid and liquid components, obtaining waste liquid and solid sludge respectively; the waste liquid collection component includes a solution transfer tank welded to the bottom of the housing for collecting the waste liquid separated by the solid-liquid separation component; the drying component is used to vacuum dry the solid sludge separated by the solid-liquid separation component to obtain purified sludge; the batch purification device provided by this invention enables batch purification of NdFeB sludge. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of a batch purification and treatment device for neodymium iron boron sludge provided in an embodiment of the present invention is shown. Figure 2 A flowchart of a method for batch purification of neodymium iron boron sludge provided in an embodiment of the present invention is shown.

[0018] Explanation of reference numerals in the attached figures: 1-Cleaning assembly; 2-Solid-liquid separation assembly; 3-Waste liquid collection assembly; 4-Drying assembly; 5-Feeding assembly; 101-Cleaning tank; 102-Slurry pump; 103-Mechanical stirring device; 104-First three-way valve; 201-Box body; 202-Double roller magnetic interception mechanism; 203-Oxygen content analyzer; 204-Air inlet; 205-Exhaust outlet; 206-Agitator; 301-Solution transfer tank; 302-Solution pump; 303-Waste liquid tank; 304-Second three-way valve; 401-Vacuum pump; 402-Vacuum drying chamber; 501-Solid liquid tank; 502-Feeding pump; 503-Control valve. Detailed Implementation

[0019] 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 following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention. Furthermore, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of the present invention.

[0020] Specific experimental steps or conditions are not specified in the embodiments; they can be performed according to the conventional experimental steps or conditions described in the prior art. Reagents and other instruments used, unless otherwise specified, are all commercially available conventional reagent products. Furthermore, the accompanying drawings are merely illustrative diagrams of the embodiments of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0021] Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of this specification.

[0022] In the description of this invention, it should be understood that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0023] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Existing NdFeB sludge purification technologies are mostly at the laboratory level, with small processing capacities, typically less than 1 kg per batch, which cannot meet the needs of industrial mass production. Furthermore, NdFeB readily reacts with oxygen, posing a high risk of oxidation. Current technologies struggle to maintain a completely oxygen-free environment throughout the process, resulting in purified sludge containing oxidized impurities, affecting subsequent recycling. Simultaneously, residual NdFeB particles in the wastewater after cleaning are directly discharged, and the cleaning agent cannot be recycled, leading to high consumption of raw materials and reagents. Feeding, discharging, and wastewater discharge largely rely on manual operation, and solid-liquid separation depends on natural sedimentation or simple filtration, making the process time-consuming. Therefore, this invention provides a batch purification device and method for NdFeB sludge, achieving batch purification of NdFeB sludge through deep synergy of various components. The specific implementation method is as follows: In a first aspect, the present invention provides a device for batch purification and treatment of neodymium iron boron sludge. Figure 1 A schematic diagram of a batch purification device for NdFeB sludge provided in an embodiment of the present invention is shown, as follows: Figure 1 As shown, it includes: a cleaning component 1, a solid-liquid separation component 2, a waste liquid collection component 3, and a drying component 4; See Figure 1 The cleaning assembly 1 includes a cleaning tank 101, which receives pumped cleaning agent. The cleaning tank 101 provides space for the NdFeB sludge to fully mix with the cleaning agent, allowing the NdFeB sludge to be cleaned under the action of the cleaning agent. The solid-liquid separation assembly 2 includes a sealable housing 201 and a double-roller magnetic interception mechanism 202 disposed within the housing. The cleaning tank 101 is welded to the bottom of the housing 201. The main function of the solid-liquid separation assembly 2 is to separate and collect magnetic solid particles from the cleaned NdFeB sludge mixture, and to remove as much liquid as possible from the surface of the collected solid particles. The waste liquid collection assembly 3 includes a solution transfer tank 301, which is welded to the bottom of the housing 201 and is used to collect the waste liquid separated from the solid-liquid separation assembly. The drying assembly 4 is used to perform vacuum drying on the solid sludge separated by the solid-liquid separation assembly 3 to obtain purified sludge.

[0025] In practical implementation, the NdFeB sludge batch purification treatment device provided by the present invention consists of four core modules: a cleaning component 1, a solid-liquid separation component 2, a waste liquid collection component 3, and a drying component 4. Each module works in concert through pipelines, pumps, valves, etc., with a high degree of integration, realizing the whole process of batch purification from sludge cleaning to solid-liquid separation to waste liquid recovery / circulation to vacuum drying; at the same time, it can maintain an oxygen-free environment throughout the process to avoid NdFeB oxidation.

[0026] It should be noted that due to the easy oxidation of NdFeB sludge, oxygen must be isolated during the cleaning process. Furthermore, after cleaning, the material needs to be separated into solid and liquid and dried under oxygen-free conditions. Therefore, the NdFeB sludge batch purification treatment device provided by this invention only needs to use inert gas to remove oxygen from the chamber before operation, so that the entire process of cleaning → solid-liquid separation → waste liquid recovery / recycling can be completed under inert gas protection. In addition, the drying component provides a low-temperature vacuum drying environment to dry the material and prevent oxidation.

[0027] In some embodiments, the cleaning assembly 1 further includes a slurry pump 102, one end of which is connected to the bottom slurry outlet of the cleaning tank 101, and the other end is connected to the liquid injection port near the top of the cleaning tank 101 and the solid-liquid separation assembly 2 via a first three-way valve 104.

[0028] In practice, the slurry pump 102 enables the slurry deposited at the bottom of the cleaning tank 101 to circulate internally within the cleaning tank 101, thereby enhancing the cleaning effect; and after cleaning, the mixture of neodymium iron boron sludge and cleaning agent in the cleaning tank 101 is sent to the solid-liquid separation component 2 for solid-liquid separation treatment.

[0029] Specifically, when the cleaning component 1 is working, the first three-way valve 104 is adjusted to form a passage between the slurry outlet at the bottom of the cleaning tank 101 and the liquid injection port near the top of the cleaning tank 101. The slurry pump 102 is started to pump out the NdFeB sludge slurry deposited at the bottom of the cleaning tank 101 during the cleaning process, and then send it back to the cleaning tank 101 through the liquid injection port near the top of the cleaning tank 101. This enhances the agitation effect between the NdFeB sludge and the cleaning agent, thereby enhancing the cleaning effect. When the solid-liquid separation component 2 is working, adjust the first three-way valve 104 to form a passage between the slurry outlet at the bottom of the cleaning tank 101 and the solid-liquid separation component 2, and start the slurry pump 102 to pump out all the mixture of neodymium iron boron sludge and cleaning agent contained in the cleaning tank 101 and transfer it to the solid-liquid separation component 2 for subsequent solid-liquid separation treatment.

[0030] It should be noted that a funnel-shaped container is fixed above the double-roller magnetic interception mechanism 202 inside the housing 101. When the slurry pump 102 pumps the mixture to be separated into the solid-liquid separation component 2, it is first pumped into the container. The mixture flows through the nozzle of the container to the double-roller magnetic interception mechanism to achieve the purpose of solid-liquid separation.

[0031] In some embodiments, a mechanical stirring device 103 is provided inside the cleaning tank 101 to ensure that the NdFeB sludge entering the cleaning tank 101 is fully mixed with the cleaning agent. The mechanical stirring device 103 inside the cleaning tank 101 can mechanically stir the NdFeB sludge and the cleaning agent, enhancing the agitation of the NdFeB sludge and the cleaning agent and improving the cleaning ability.

[0032] In some embodiments, the dual-roller magnetic trapping mechanism 202 serves as the core component of the solid-liquid separation operation, specifically consisting of a scraper, a magnetic roller, and a rubber roller. The rubber roller is positioned above the axis of the magnetic roller, forming a gap between them. This gap can be increased or decreased by adjusting the position of the rubber roller relative to the magnetic roller, dynamically adjusting according to the particle size of the NdFeB sludge and the concentration of the mixture. A scraper is positioned on the side or below the magnetic roller, with the scraper portion closely adhering to the magnetic roller. During operation, the rubber roller and magnetic roller rotate in opposite directions. As the magnetic roller rotates, a strong magnetic field is generated on its surface. When the solid-liquid mixture flows through the gap, the magnetic solid particles in the mixture are firmly adsorbed onto the surface of the magnetic roller by the magnetic field. Simultaneously, the elastic pressure of the rubber roller squeezes the mixture flowing through the gap, dislodging the liquid trapped between the magnetic solid particles. The liquid flows out along the surface of the magnetic roller or the side wall of the device, achieving deep dehydration and significantly reducing the energy consumption and time required for subsequent drying. Compared to simple magnetic adsorption, the solid dryness can be increased by 20%-50%. Furthermore, the magnetic solids adsorbed on the surface of the magnetic roller will be transferred from the roller gap to the scraper position as the roller rotates. At this time, most of the liquid has been removed by the rubber roller, and it is not easy to carry liquid when scraping.

[0033] In this invention, the rubber roller and the magnetic roller rotate in opposite directions, such as the rubber roller rotating counterclockwise and the magnetic roller rotating clockwise. The friction between the two can actively pull the mixed material into the roller gap, preventing the mixed material from accumulating at the feed inlet. At the same time, the elasticity of the rubber can contain a small amount of large particle impurities, preventing hard particles from getting stuck in the roller body.

[0034] This invention utilizes a linkage mechanism of magnetic roller (adsorption separation), rubber roller (extrusion dehydration), and scraper (solid collection) to separate and collect magnetic solid particles from the mixture, and to remove as much liquid as possible from the surface of the collected solid particles.

[0035] It should be noted that the scraper is positioned on the non-feeding side to ensure that it does not interfere with feeding and liquid discharge. The magnetic roller used in this invention consists of a cylindrical roller body and a built-in permanent magnet or electromagnetic coil. The surface of the magnetic roller body is mostly made of smooth and wear-resistant materials, such as stainless steel or wear-resistant coatings, to ensure that solid particles are easily adsorbed and not easily scratched.

[0036] See Figure 1The tank 201 is also equipped with an agitator 206 to prevent solid sludge in the mixture from settling at the bottom of the tank 201 due to gravity, thus preventing it from being effectively adsorbed by the magnetic roller and resulting in incomplete separation and a decrease in sludge recovery rate. Specifically, the agitator 206 keeps the mixture in suspension by continuously stirring at a low speed, such as 50-100 r / min, ensuring that the solid sludge particles are evenly distributed in the liquid, facilitating full contact and adsorption by the magnetic roller and improving separation efficiency. Experiments show that setting the agitator 206 can increase the recovery rate of NdFeB powder in the original sludge material from 80% to over 93%.

[0037] In some embodiments, the housing 201 is further equipped with an oxygen content analyzer 203, an air inlet 204, and an exhaust outlet 205. The oxygen probe of the oxygen content analyzer 203 is built into the housing 1. The oxygen content analyzer 203 is used to detect the oxygen removal status inside the housing 201. Inert gas (such as nitrogen) is introduced through the air inlet 204 (multiple) and air (multiple) is discharged through the exhaust outlet 205 to replace the internal air and maintain an oxygen-free environment with an oxygen content ≤0.1%, thus structurally preventing the oxidation of NdFeB. The oxygen content analyzer 203 can monitor the oxygen content inside the housing 201 in real time, providing data support for whether the inert gas replacement is complete and ensuring that the solid-liquid separation process is under oxygen-free protection.

[0038] See also Figure 1 The waste liquid collection assembly 3 also includes a solution pump 302 and a waste liquid tank 303. One end of the solution pump 302 is connected to the bottom of the solution transfer tank 301, and the other end is connected to the waste liquid tank 303 and the cleaning tank 101 respectively through a second three-way valve 304.

[0039] In specific implementation, the solution pump 302 provides power for the flow of waste liquid, driving the waste liquid to be transferred between the solution transfer tank 301 and the waste liquid tank 303, or to be transferred between the solution transfer tank 301 and the cleaning assembly 1. Due to the relatively fine particle characteristics of NdFeB sludge, even with magnetic separation, the waste liquid still contains a small amount of magnetic particles, which would be wasteful to discharge directly. Therefore, this embodiment of the invention is equipped with a solution circulation system, which allows the solution to pass through the solid-liquid separation device multiple times during discharge. This avoids waste of raw materials and improves cleaning efficiency. Specifically, the mixture after the first cleaning is separated in the solid-liquid separation assembly 2, and the separated waste liquid first flows into the solution transfer tank 301 by gravity. By detecting the sludge content of the waste liquid in the solution transfer tank 301, if the sludge content is greater than a preset value (e.g., 1%), the solution pump 302 pumps the waste liquid back to the cleaning tank 101 through the second three-way valve 304 to continue participating in the second cleaning. The above process is repeated until the sludge content in the waste liquid meets the discharge standards. That is, if the sludge content is less than or equal to a preset value, the waste liquid is pumped into the waste liquid tank 303 by the solution pump 302. The solution transfer tank 301 is set up to facilitate the detection of sludge content in the waste liquid and avoid misoperation; it can also realize the recycling of waste liquid with high sludge content (recovering NdFeB particles and cleaning agents, reducing consumption by 20%), and the targeted collection of waste liquid with low content, improving resource utilization and environmental protection; mechanized transportation reduces the risk of leakage.

[0040] See also Figure 1 The drying assembly 4 includes a vacuum pump 401 and a vacuum drying chamber 402; The vacuum pump 401 is connected to the vacuum drying chamber 402, and the vacuum pump 401 is used to perform vacuuming treatment on the vacuum drying chamber 402. Vacuum drying chamber 402 contains solid sludge after solid-liquid separation. Under the vacuum environment created by vacuum pump 401, moisture is quickly removed, and finally purified sludge with impurities ≤0.5% and oxygen content less than 3 wt.% is obtained. At the same time, the vacuum environment further isolates air, providing double protection and anti-oxidation effect. Low-temperature drying is used to obtain purified sludge, avoiding the oxidation of NdFeB caused by high temperature.

[0041] In some embodiments, the vacuum drying chamber 402 is located on one side of the housing 101, and the two are separated by a movable partition. The movable partition can be stably and sealed to the surrounding area. The movable partition opens the connection between the vacuum drying chamber 402 and the housing 101. When transferring solid sludge, the movable partition can be removed to directly transfer the solid sludge to the vacuum drying chamber 402 for drying, preventing the material from oxidizing during the transfer process.

[0042] See also Figure 1The batch purification device provided by the present invention may further include a feeding component 5, which consists of a raw liquid tank 501, a feeding pump 502, a control valve 503 and a pipeline. The sludge raw material is contained in the raw liquid tank 501, and the feeding pump 502 drives the sludge raw material to enter the cleaning tank 101 through the control valve 503 and mix with the cleaning agent.

[0043] The feeding assembly 5 can also be used to deliver cleaning agent to the cleaning tank 101, wherein the concentrate tank 501 is used to hold the cleaning agent and the cleaning agent is driven by the feed pump 502 to enter the cleaning tank 101 through the control valve 503.

[0044] Secondly, the present invention provides a method for batch purification of NdFeB sludge, the method being applicable to the batch purification apparatus for NdFeB sludge described in the first aspect above. Figure 2 A flowchart of the batch purification method for NdFeB sludge provided in an embodiment of the present invention is shown, as follows: Figure 2 As shown, the method includes: S1. Purge the chamber with inert gas to remove air, then pump the NdFeB sludge into the cleaning tank and clean it with the help of the cleaning agent. S2. Pump the mixture formed after cleaning in the cleaning tank into the solid-liquid separation component for solid-liquid separation to obtain waste liquid and solid sludge respectively. S3. The waste liquid collection component collects the waste liquid separated from the solid-liquid separation component. S4. The drying component performs vacuum drying on the solid sludge separated by the solid-liquid separation component to obtain purified sludge.

[0045] Compared with laboratory-level sintered NdFeB sludge purification technology, the batch purification method for NdFeB sludge provided in this invention increases the single-processing capacity to 10 kg. Experiments show that the device consumes less solution to process the same weight of sintered NdFeB sludge than the laboratory-level method, thus reducing costs.

[0046] In practice, the cleaning agents include alkaline cleaning agents and acidic cleaning agents. The alkaline cleaning agent can be composed of a mixture of NaOH, emulsifier and anhydrous ethanol; the acidic cleaning agent can be composed of a mixture of anhydrous ethanol and hydrochloric acid. When using it, the NdFeB sludge is first cleaned with an alkaline cleaning agent, and then the resulting sludge is cleaned with an acidic cleaning agent to reduce the oxygen content in the sludge.

[0047] In some embodiments, the step of pumping neodymium iron boron sludge into a cleaning tank and performing cleaning treatment with the aid of a cleaning agent includes: Adjust the first three-way valve to form a passage between the slurry pump and the slurry outlet at the bottom of the cleaning tank and the liquid injection port near the top. The slurry pump pumps out the slurry deposited at the bottom of the cleaning tank and pumps it back into the cleaning tank until the cleaning process is completed. The step of pumping the mixture formed after cleaning the cleaning tank into the solid-liquid separation component includes: adjusting a three-way valve to form a passage between the slurry pump and the solid-liquid separation component, wherein the slurry pump pumps all the mixture in the cleaning tank to the solid-liquid separation component.

[0048] In some embodiments, the waste liquid collection assembly collects the waste liquid separated from the solid-liquid separation assembly, including: When the NdFeB sludge content in the waste liquid received by the solution transfer tank exceeds a preset value, the three-way valve is adjusted to form a passage between the solution pump and the cleaning tank. The solution pump then pumps the waste liquid received by the solution transfer tank into the cleaning tank to continue the cleaning process. When the NdFeB sludge content in the waste liquid received by the solution transfer tank is less than a preset value, the three-way valve is adjusted to form a passage between the solution pump and the waste liquid tank, and the solution pump pumps the waste liquid received by the solution transfer tank into the waste liquid tank.

[0049] To enable those skilled in the art to more clearly understand the present invention, the following embodiments will be used to provide a detailed description of the apparatus and method for batch purification of neodymium iron boron sludge according to the present invention.

[0050] The following examples utilize Figure 1 The illustrated NdFeB sludge batch purification treatment device is used for... Example 1 Deoxygenation: An inert gas (such as nitrogen) is introduced into the chamber 201 through the air inlet 204 on the chamber to replace the air in the device. The oxygen content analyzer 203 monitors the oxygen content in the chamber 201 in real time and maintains an oxygen-free environment with an oxygen content of ≤0.1%. Cleaning: Start the cleaning assembly 1, add 5 kg of multi-wire cut sintered NdFeB sludge (raw sludge material, including NdFeB powder, organic matter, and impurities) to the cleaning tank 101, seal it, and purge with nitrogen to remove oxygen. Take 75 g NaOH, 500 ml OP emulsifier, and 25 L anhydrous ethanol and mix them evenly in the stock solution tank 501 to form an alkaline cleaning agent, which is then injected into the cleaning tank 101 through the feed pump 502. Start the slurry pump 102 and the stirring device 103 to stir and clean in a nitrogen atmosphere. At the same time, adjust the first three-way valve 104 to form a passage between the slurry pump 102 and the slurry outlet at the bottom of the cleaning tank 101, and the liquid injection port near the top of the cleaning tank 101. The slurry pump 102 pumps out the slurry deposited at the bottom of the cleaning tank and pumps it back into the cleaning tank 101, increasing the disturbance of the mixture in the cleaning tank 101 until the cleaning process is completed. Solid-liquid separation: After cleaning for 20 minutes, the solid-liquid separation component 2 is started. Inert gas (such as nitrogen) is introduced through the air inlet 204 and air is discharged through the exhaust port 205 to replace the internal air and maintain an oxygen-free environment with an oxygen content of ≤0.1%. The first three-way valve 104 is adjusted to form a passage between the slurry outlet at the bottom of the cleaning tank 101 and the solid-liquid separation component 2. The slurry pump 102 is started to pump all the mixture of neodymium iron boron sludge and cleaning agent contained in the cleaning tank 101 into a funnel-shaped container fixed above the double roller magnetic interception mechanism 202. The mixture flows through the tip of the container to the double roller magnetic interception mechanism for solid-liquid separation. Repeat cleaning / Complete cleaning: After solid-liquid separation is completed, open the waste liquid valve at the bottom of the tank 101 to discharge the waste liquid into the solution transfer tank 301. Detect the mud content of the waste liquid in the solution transfer tank 301. If the mud content is greater than the preset content, adjust the second three-way valve 304 to create a passage between the solution pump 302 and the cleaning tank 101. The solution pump 302 pumps the waste liquid received by the solution transfer tank 301 into the cleaning tank 101 for continued cleaning. Repeat the above steps until the mud content of the waste liquid is less than the preset content. Then, adjust the second three-way valve 304 to create a passage between the solution pump 302 and the waste liquid tank 303. The solution pump 302 pumps the waste liquid received by the solution transfer tank 301 into the waste liquid tank 303 to complete the alkaline washing.

[0051] Vacuum drying: By disassembling the movable partition at the connection of the vacuum drying chamber 402 in the housing 101, the collected solid sludge is transferred and placed in the vacuum drying chamber 402 for drying, thus obtaining dried sintered NdFeB purified sludge.

[0052] Content testing of the purified sludge obtained from solid-liquid separation component 2 revealed that, compared to the original sludge, the purified sludge exhibited Nd2Fe content. 14B single phase, oxygen content reduced to 2.85 wt.%, carbon content reduced to 0.64 wt.%.

[0053] Example 2 The difference between Example 2 and Example 1 is that after the cleaning (alkaline washing) step is completed, the purified sludge obtained from the solid-liquid separation component 2 is returned to the cleaning tank for acid washing; the specific operation is as follows: Take 40 ml of HCl and 25 L of anhydrous ethanol and mix them evenly in the stock solution tank 501 to form an acidic cleaning agent. Then, inject it into the cleaning tank 101 through the feed pump 502. Start the slurry pump 102 and the stirring device 103 to carry out cleaning in a nitrogen atmosphere. The cleaning process (repeated cleaning once) is the same as the steps shown in Example 1. The remaining solid-liquid separation and vacuum drying steps are the same as the process shown in Example 1, and will not be described again here.

[0054] Content testing of the acid-purified sludge obtained from solid-liquid separation component 2 revealed that, compared to the original sludge, the acid-purified sludge exhibited Nd₂Fe₂O₃ content. 14 B single phase, oxygen content reduced to 1.73 wt.%, carbon content reduced to 0.54 wt.%.

[0055] Example 3 The difference between Example 3 and Example 2 is that the processing volume of multi-wire cutting sintered NdFeB sludge is 9 kg; The alkaline cleaning agent used in alkaline washing is a mixture of 135 g NaOH, 900 ml OP emulsifier and 45 L anhydrous ethanol; The acidic cleaning agent used during pickling is a mixture of 70 ml HCl and 45 L anhydrous ethanol.

[0056] Content testing of the acid-purified sludge obtained from solid-liquid separation component 2 revealed that, compared to the original sludge, the purified sludge exhibited Nd₂Fe₂O₃ content. 14 B is a single phase, with oxygen content reduced to 1.82 wt.% and carbon content reduced to 0.56 wt.%.

[0057] Comparative Example 1 Add 50 g of multi-wire cut sintered NdFeB sludge, 6 ml of OP emulsifier, 0.9 g of NaOH, and 300 ml of anhydrous ethanol to a reaction vessel (beaker). Turn on the motor; the motor's rotation drives the agitator to rotate at high speed, accelerating the reaction between the cleaning agent and the sludge.

[0058] After the reaction is complete, turn off the motor power, use a magnet to adhere to the bottom of the reaction vessel to achieve solid-liquid separation, and pour the liquid directly out.

[0059] Repeat the above cleaning process twice. After cleaning, remove the material and dry it in an oxygen-free environment. The purified sludge is Nd2Fe.14 B single phase, oxygen content reduced to 3.21 wt.%, carbon content reduced to 0.62 wt.%.

[0060] Comparative Example 2 Add 50 g of multi-wire cut sintered NdFeB sludge, 6 ml of OP emulsifier, 0.9 g of NaOH, and 300 ml of anhydrous ethanol to a reaction vessel (beaker). Turn on the motor; the motor's rotation drives the stirring paddle to rotate at high speed, accelerating the reaction between the materials and the solution.

[0061] After the reaction is complete, turn off the motor power, use a magnet to adhere to the bottom of the reaction vessel to achieve solid-liquid separation, and pour the liquid directly out.

[0062] Repeat the above cleaning process twice. After cleaning, add 300 ml of anhydrous ethanol and 1.5 ml of HCl to the reaction vessel for acid washing. Repeat the cleaning process once. Then, take out the material and dry it in an oxygen-free environment.

[0063] Purified sludge is Nd2Fe 14 B single phase, oxygen content reduced to 2.24 wt.%, carbon content reduced to 0.51 wt.%.

[0064] The purified sludge treatment volume and C and O content obtained in the examples and comparative examples are shown in Table 1: Table 1. Purified sludge treatment volume and C and O content

[0065] As can be seen from Table 1 above, under the same material and solution conditions, the purification device in this embodiment can not only achieve large-scale processing, but also effectively remove organic matter and oxides from the material. After the reaction, it is easy to achieve solid-liquid separation, easy to directly dry the material under oxygen-free conditions, and has higher cleaning efficiency and automation, saving raw materials, time and labor.

[0066] It should be noted that the purification device provided in this embodiment is applicable to various types of sludge, not only the multi-wire cutting sludge mentioned above, but also machining sludge generated by other methods. The purification device can be adjusted by changing parameters such as the number of washes and the concentration of the cleaning solution.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0068] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and components involved are not necessarily essential to the present invention.

[0069] The above provides a detailed description of the NdFeB oil sludge batch purification device and method provided by the present invention. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A batch purification and treatment device for NdFeB sludge, characterized in that, include: Cleaning components, solid-liquid separation components, waste liquid collection components, and drying components; The cleaning assembly includes a cleaning tank for receiving pumped cleaning agent and cleaning the NdFeB sludge. The solid-liquid separation assembly includes a sealable housing and a double-roller magnetic interception mechanism disposed within the housing. The cleaning tank is welded to the bottom of the housing. The solid-liquid separation assembly is used to perform solid-liquid separation on the cleaned NdFeB sludge to obtain waste liquid and solid sludge respectively. The waste liquid collection assembly includes a solution transfer tank, which is welded to the bottom of the box body and is used to collect the waste liquid separated from the solid-liquid separation assembly; The drying component is used to perform vacuum drying on the solid sludge separated by the solid-liquid separation component to obtain purified sludge.

2. The NdFeB sludge batch purification and treatment device according to claim 1, characterized in that, The cleaning assembly also includes a slurry pump, one end of which is connected to the slurry outlet at the bottom of the cleaning tank, and the other end is connected to the liquid injection port near the top of the cleaning tank and the solid-liquid separation assembly via a first three-way valve.

3. The NdFeB sludge batch purification treatment device according to claim 1, characterized in that, The cleaning tank is equipped with a mechanical stirring device to ensure that the NdFeB sludge entering the cleaning tank is fully mixed with the cleaning agent.

4. The NdFeB sludge batch purification and treatment device according to claim 1, characterized in that, The dual-roller magnetic interception mechanism consists of a scraper, a magnetic roller, and a rubber roller. The rubber roller is positioned higher than the magnetic roller, and the rubber roller and the magnetic roller rotate in opposite directions. The scraper is positioned in the direction of rotation of the magnetic roller, and the scraper is partially in contact with the magnetic roller.

5. The NdFeB sludge batch purification and treatment device according to claim 1, characterized in that, The waste liquid collection assembly also includes a solution pump and a waste liquid tank; One end of the solution pump is connected to the bottom of the solution transfer tank, and the other end is connected to the waste liquid tank and the cleaning tank respectively through a second three-way valve.

6. The NdFeB sludge batch purification and treatment device according to claim 1, characterized in that, The drying assembly includes a vacuum pump and a vacuum drying chamber; The vacuum pump is connected to the vacuum drying chamber and is used to evacuate the vacuum drying chamber.

7. The NdFeB sludge batch purification and treatment device according to claim 1, characterized in that, The chamber is equipped with an oxygen content analyzer, an air inlet, and an air outlet. The oxygen probe of the oxygen content analyzer is built into the chamber. The oxygen content analyzer is used to detect the oxygen removal status inside the chamber. The air inlet and air outlet are configured to replace the air inside the chamber with inert gas.

8. A method for batch purification of NdFeB sludge, characterized in that, The method is applicable to the batch purification and treatment apparatus for NdFeB sludge according to any one of claims 1-7, and the method includes: After purging the chamber with inert gas to remove air, the neodymium iron boron sludge is pumped into the cleaning tank and cleaned with the help of a cleaning agent. The mixture formed after cleaning in the cleaning tank is pumped into the solid-liquid separation component for solid-liquid separation, and waste liquid and solid sludge are obtained respectively. The waste liquid collection assembly collects the waste liquid separated by the solid-liquid separation assembly; The drying component performs vacuum drying on the solid sludge separated by the solid-liquid separation component to obtain purified sludge.

9. The method for batch purification of NdFeB sludge according to claim 8, characterized in that, The process of pumping neodymium iron boron sludge into a cleaning tank and cleaning it with the aid of a cleaning agent includes: Adjust the first three-way valve to form a passage between the slurry pump and the slurry outlet at the bottom of the cleaning tank and the liquid injection port near the top. The slurry pump pumps out the slurry deposited at the bottom of the cleaning tank and pumps it back into the cleaning tank until the cleaning process is completed. The step of pumping the mixture formed after cleaning the cleaning tank into the solid-liquid separation component includes: adjusting the first three-way valve to form a passage between the slurry pump and the solid-liquid separation component, wherein the slurry pump pumps all the mixture in the cleaning tank to the solid-liquid separation component.

10. The method for batch purification of NdFeB sludge according to claim 8, characterized in that, The waste liquid collection assembly collects the waste liquid separated from the solid-liquid separation assembly, including: When the NdFeB sludge content in the waste liquid received by the solution transfer tank exceeds a preset value, the second three-way valve is adjusted to form a passage between the solution pump and the cleaning tank. The solution pump then pumps the waste liquid received by the solution transfer tank into the cleaning tank to continue the cleaning process. When the NdFeB sludge content in the waste liquid received by the solution transfer tank is less than a preset value, the second three-way valve is adjusted to form a passage between the solution pump and the waste liquid tank, and the solution pump pumps the waste liquid received by the solution transfer tank into the waste liquid tank.

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