A NdFeB blank grinding wastewater treatment system and treatment method

Abstract

The present invention relates to a NdFeB billet grinding wastewater treatment system and treatment method. The wastewater treatment system includes a wastewater collection tank, a lifting pump, a magnetic separator, a modular sludge automatic sedimentation and unloading device, a filter pump and a precision filtration system; the wastewater treatment method includes the following steps: S1 wastewater storage; S2 magnetic separator separation; S3 grinding waste sedimentation; S4 filtration treatment. The present invention adopts a "shallow pool sedimentation + continuous rotary unloading" mode, and through physical methods such as efficient sedimentation and high-precision filtration, without the need to add chemical agents such as debonding agents and flocculants, effectively achieves solid-liquid separation of grinding materials and water; basically achieves zero emissions, realizes the recycling of resources such as clean water, rare earth metals and abrasives, maximizes the utilization of resources, and reduces the cost of wastewater treatment and reuse; the treatment system of the present invention also has the advantages of large redundancy, strong stability, strong equipment continuity, high degree of automation, low operation and maintenance costs, and significantly reduces the labor intensity of personnel.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater treatment, and in particular relates to a system and method for treating NdFeB blank grinding wastewater. Background Art

[0002] Neodymium iron boron permanent magnets possess the strongest magnetic properties of any permanent magnet material discovered in the world. These high-performance NdFeB permanent magnets are primarily used in energy conservation, environmental protection, and new energy applications, including automotive, home appliances, wind power generation, energy-efficient elevators, automation, and smart consumer electronics. Designated as a national key new material and high-tech product, they enjoy strong support from relevant national industrial policies.

[0003] During the production of NdFeB permanent magnet materials, the raw materials are first processed into NdFeB billets through processes such as smelting, pulverizing, pressing, and sintering. The billets are brittle and require subsequent surface treatment using softer abrasives, primarily composed of silicon carbide and kaolin. The resulting grinding wastewater contains viscous sludge that easily hardens. Currently, there are no mature resource-based treatment systems and methods for grinding wastewater. Treatment primarily relies on the experience of other industries, using either a physicochemical process based on "chemical dosing + flocculation and sedimentation + filter press" or a membrane process based on "chemical dosing + membrane filtration + filter press." The wastewater is discharged only after meeting standards.

[0004] However, the above processing method has the following defects:

[0005] 1. Low water reuse rate: Due to the addition of desizing agents, demulsifiers, flocculants and other chemicals during the treatment process, the wastewater composition is complex and difficult to reuse. Multi-stage reverse osmosis purification is required, resulting in a low water reuse rate;

[0006] 2. Low treatment efficiency: For viscous sludge, it is very easy to adhere to the inner wall of the sedimentation device, the filter membrane of the membrane system and the filter cloth of the filter press. If the cleaning frequency is high, the sedimentation effect will be affected. If the cleaning frequency is low, the sludge will easily solidify and become compacted, making it difficult to clean. Regular shutdown maintenance is required, which affects the continuous treatment efficiency of wastewater.

[0007] 3. Low system reliability and poor stability: The volume of the sedimentation tank is usually proportional to the amount of liquid inlet. When treating large-volume wastewater, the sedimentation tank occupies a large space. In addition, once a failure occurs, the system needs to be shut down and the sedimentation tank needs to be emptied before maintenance operations can be carried out. Repairs are difficult and time-consuming. During this period, wastewater treatment cannot be carried out and the wastewater treatment system needs to be shut down. If membrane filtration is used for solid-liquid separation, sludge can easily clog the membrane pores and contaminate the membrane, requiring regular chemical cleaning with chemical solutions. The membrane system also needs to be replaced regularly, resulting in poor operability.

[0008] 4. High cost and high labor intensity: Some highly viscous sludge cannot be discharged by filter press due to its strong clogging of filter cloth; it also causes great clogging and pollution to the membrane system, requiring frequent cleaning with chemical agents, and the membrane flux recovery is poor, requiring regular membrane replacement, and high membrane cost; multi-stage sedimentation tanks are used for sedimentation, which occupies a large area and has high construction cost, and the sludge desilting operation inside the sedimentation tank is labor-intensive.

[0009] The above existing treatment methods have the defects of low water recovery benefit, low treatment efficiency, poor system operation stability, high cost, and high labor intensity, which are not conducive to the sustainable development of the industry. Therefore, it is urgent to design a treatment system and treatment method suitable for NdFeB billet grinding wastewater. Summary of the Invention

[0010] In view of the above problems existing in the prior art, the present invention provides a treatment system and method for NdFeB billet grinding wastewater to solve the above technical problems.

[0011] The specific technical solutions of the present invention for solving the above technical problems are as follows:

[0012] A NdFeB blank grinding wastewater treatment system, comprising a wastewater collection tank, a lift pump, a magnetic separator, a modular sludge automatic sedimentation and unloading device, a filter pump, and a precision filtration system;

[0013] The water inlet of the lifting pump is located at the bottom of the wastewater collection tank, and the water outlet of the lifting pump is connected to the water inlet of the magnetic separator; the liquid outlet of the magnetic separator is connected to the inlet end of the modular sludge automatic sedimentation and unloading device through a pipeline, and the overflow end of the modular sludge automatic sedimentation and unloading device is connected to the water inlet of the filter pump, and the water outlet of the filter pump is connected to the precision filtration system.

[0014] The present invention adopts the above technical features to achieve the following technical effects:

[0015] The equipment system of the treatment system of the present invention has a large redundancy, and there is no need for idle spare equipment. The overall effective operating load of the equipment is high and the stability is strong. It is especially suitable for materials with high viscosity, easy to compact, and strong adhesion. The single unit size of the modular sludge automatic sedimentation and unloading device of the treatment system of the present invention, as well as the flexible placement of different stacking methods such as vertical and horizontal between modules, are especially suitable for places with limited space or irregular space. The water inlet of the lifting pump of the treatment system of the present invention is located at the bottom of the collection tank, which can ensure that solid materials such as grinding waste will not accumulate and precipitate in large quantities in the wastewater collection tank. The treatment system of the present invention can combine the modular sludge automatic sedimentation and unloading device with efficient precipitation and the precision filtration system with high-precision filtration to perform solid-liquid separation of grinding material and water, without the addition of chemical agents, thereby reducing the cost of wastewater treatment and reuse.

[0016] This technical solution can also be improved as follows:

[0017] Furthermore, the modular sludge automatic sedimentation and unloading device includes a device body, an X-shaped shallow pool sedimentation tank and a unloading motor. At least one X-shaped shallow pool sedimentation tank is arranged in the device body. The inlet end of the X-shaped shallow pool sedimentation tank is connected to the inlet end of the device body, and the outlet end of the X-shaped shallow pool sedimentation tank is connected to the outlet end of the device body. The unloading motor is located on the outside of the device body, and the unloading motor is connected to the main shaft of the X-shaped shallow pool sedimentation tank.

[0018] The above further technical features have the following technical effects:

[0019] The treatment system of the present invention is an X-shaped shallow pool sedimentation tank for sludge sedimentation and separation. The upper side of the X-shaped shallow pool sedimentation tank is a "V"-shaped groove, and the lower side is an inverted "V"-shaped groove. The structures on both sides are consistent and symmetrically distributed, and the "V"-shaped grooves on both sides can both perform sludge sedimentation and separation. The V-shaped groove of the X-shaped shallow pool sedimentation tank combines the two functions of sedimentation and sludge aggregation. The sludge precipitated in the V-shaped groove is not easily disturbed by the water flow, and the sludge sedimentation effect is good. To achieve the same sedimentation effect, under the same cross-sectional dimensions, the V-shaped groove has a fast flow rate, a large processing capacity, and a high sedimentation efficiency. For treating the same wastewater, the X-shaped shallow pool sedimentation tank equipment occupies a small size. The main shaft of the X-shaped shallow pool sedimentation tank is connected to the unloading motor, and the unloading motor is controlled by the output signal of the control system, so that the X-shaped shallow pool sedimentation tank can be freely rotated 360° in the axial direction, thereby realizing the continuous switching of automatic unloading and sedimentation. During the rotation unloading, the V-shaped groove of the X-shaped shallow pool sedimentation tank is not easy to retain sludge, and the cleaning difficulty is small, which is convenient for rotation unloading. The X-shaped shallow sedimentation tank utilizes a "shallow sedimentation + continuous rotary unloading" model, eliminating the need for chemical agents such as debonders and flocculants, resulting in low water reuse costs. The number and size of the X-shaped shallow sedimentation tanks can be flexibly adjusted to site dimensions, improving space utilization.

[0020] Furthermore, the modular sludge automatic sedimentation and unloading device also includes a flow regulating valve, a scraper, a scraper cylinder, a material conveying system and a control system; the inlet end of the flow regulating valve is connected to the liquid outlet of the magnetic separator through a pipeline, and the outlet end of the flow regulating valve is connected to the inlet end of the device body; the scraper is located below the X-shaped shallow pool sedimentation tank, and the shape of the scraper is adapted to the inverted "V" groove below the X-shaped shallow pool sedimentation tank, the scraper cylinder is located outside the device body, the scraper cylinder is connected to the scraper, and the material conveying system is located at the lower part of the device body, and the flow regulating valve, the unloading motor, the scraper cylinder and the material conveying system are electrically connected to the control system.

[0021] The above further technical features have the following technical effects:

[0022] In the treatment system of the present invention, the scraper is located below the X-shaped shallow pool sedimentation tank. The shape of the scraper is adapted to the inverted "V" groove below the X-shaped shallow pool sedimentation tank, which can effectively improve the sludge scraping effect of the X-shaped shallow pool sedimentation tank. The scraper is connected to the scraper cylinder located outside the main body of the device, and the scraper cylinder is controlled by the control system output signal to achieve the scraping of sludge by the scraper. The flow regulating valve is electrically connected to the control system. The flow regulating valve can automatically detect the wastewater flow and summarize the signal and feed it back to the control system. The control system dynamically adjusts the opening of each flow regulating valve through a programmable logic controller (PLC) to ensure that the flow of each flow regulating valve remains dynamically consistent. The material conveying system is electrically connected to the control system, and the control system also adjusts the operation of the material conveying system through a programmable logic controller.

[0023] Furthermore, the wastewater collection tank adopts a cone-bottom structure and is equipped with a stirring device.

[0024] Furthermore, the magnetic separator is a rubber roller type magnetic separator.

[0025] Furthermore, the inner wall of the X-shaped shallow pool sedimentation tank adopts a corrosion-resistant non-stick coating, such as PTFE, ETFE, etc.

[0026] The above further technical features have the following technical effects: the amount of sludge adhesion can be effectively reduced.

[0027] Furthermore, a high material level probe is provided in the X-shaped shallow pool sedimentation tank.

[0028] The adoption of the above further technical features has the following technical effects: by detecting the sludge height in the sedimentation tank, a signal can be automatically given to perform unloading operations.

[0029] Furthermore, the modular sludge automatic sedimentation and unloading device also includes a material collecting hopper, which is arranged at the end of the material conveying system and is used to collect the separated grinding waste.

[0030] Furthermore, the edge of the scraper blade is coated with a layer of silica gel plate.

[0031] The adoption of the above further technical features has the following technical effects: while ensuring the sludge scraping effect of the X-shaped shallow pool sedimentation tank, the corrosion-resistant and non-stick coating on the inner wall of the X-shaped shallow pool sedimentation tank will not be scratched.

[0032] Furthermore, a nozzle is provided on the scraper, and water flow from the nozzle is directed toward the contact position between the inner wall of the X-shaped shallow pool sedimentation tank and the scraper.

[0033] The adoption of the above further technical features has the following technical effects: the scraper can further improve the scraping effect through the flushing effect of water flow during the scraping process, thereby reducing the sludge residue on the inner wall of the X-shaped shallow pool sedimentation tank.

[0034] Furthermore, the precision filtration system adopts a backwashable 0.2 micron microporous membrane filter element.

[0035] The use of the above further technical features has the following technical effects: after intercepting particulate impurities, this filter element can be backwashed with compressed air and reused, and the cumulative usage time can usually reach more than 1 year.

[0036] The present invention also provides a method for treating NdFeB blank grinding wastewater using the above-mentioned treatment system, comprising the following steps:

[0037] S1 wastewater storage: the NdFeB billet grinding wastewater from the NdFeB billet grinding system flows into the wastewater collection pool for temporary storage;

[0038] S2 magnetic separator separation: The NdFeB billet grinding wastewater in the wastewater collection pool is sent to the magnetic separator for separation through a lift pump, and rare earths such as praseodymium and neodymium in the wastewater are recovered, and a separated liquid is obtained at the same time;

[0039] S3 Grinding waste sedimentation and collection: the separated liquid enters the modular sludge automatic sedimentation and unloading device, so that the grinding waste in the separated liquid is automatically precipitated, discharged and collected, and overflow water is obtained at the same time;

[0040] S4 filtration treatment: The overflow water is sent to the precision filtration system through the filter pump for filtration treatment to obtain filtered water, and the filtered solid residue is collected.

[0041] Furthermore, rare earth metals such as praseodymium and neodymium recovered by the magnetic separator in S2 are reused in the NdFeB billet production process.

[0042] Furthermore, the grinding waste collected by the modular sludge automatic sedimentation and unloading device in S3 is reused in the grinding material production process.

[0043] Furthermore, the filtered water from the precision filtration system in S4 is reused to replenish the NdFeB billet grinding system.

[0044] The beneficial effects of the treatment system and method for NdFeB blank grinding wastewater provided by the present invention are as follows:

[0045] The processing system of the present invention has a large redundancy of the equipment system, does not need to idle spare equipment, has a high effective operating load of the entire equipment, and has strong stability, and is particularly suitable for materials with high viscosity, easy hardening, and strong adhesion.

[0046] The modular automatic sludge sedimentation and unloading device of the treatment system of the present invention has a flexible single size and can be stacked vertically, horizontally or in different ways between modules, making it particularly suitable for places with limited or irregular space. The number and size of the X-shaped shallow pool sedimentation tanks can be flexibly adjusted according to the site size to improve space utilization.

[0047] The treatment system of the present invention adopts the "shallow pool sedimentation + continuous rotary unloading" mode, does not require the addition of chemical agents such as debonders and flocculants, and has low water reuse costs.

[0048] The equipment of the treatment system of the present invention has a high degree of automation, and sludge sedimentation and unloading can be automatically operated without supervision. It only requires regular inspection of the system operation status, and the labor intensity of personnel is significantly reduced.

[0049] The equipment continuity of the treatment system of the present invention is strong, and the sludge sedimentation and unloading processes are carried out alternately in each X-shaped sedimentation tank, which can ensure that the water treatment system can operate continuously for 24 hours.

[0050] The equipment of the treatment system of the present invention can be regenerated by green methods such as compressed air backwashing and clean water flushing, and can be recycled. The system has low operation and maintenance costs, stable process, high degree of automation, and significantly reduces labor intensity.

[0051] The NdFeB blank grinding wastewater treatment method using the treatment system of the present invention basically achieves zero emission and can realize the recycling of resources such as clean water, rare earth metals and abrasives, thereby achieving maximum utilization of resources.

[0052] The NdFeB billet grinding wastewater treatment method using the treatment system of the present invention mainly performs solid-liquid separation of grinding material and water through physical methods such as efficient precipitation and high-precision filtration, without the need for adding chemical agents, thereby reducing the cost of wastewater treatment and reuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a schematic flow chart of a system for treating NdFeB blank grinding wastewater according to the present invention;

[0054] Figure 2 This is a schematic structural diagram of the modular sludge automatic sedimentation and unloading device of the present invention, including the device body, X-shaped shallow pool sedimentation tank, scraper and material conveying system;

[0055] Figure 3 This is a schematic structural diagram of an X-shaped shallow pool sedimentation tank of the present invention;

[0056] Figure 4 Schematic diagram of the structure of the scraper of the present invention;

[0057] Figure 5 Flow chart of the method for treating NdFeB blank grinding wastewater of the present invention;

[0058] Description of the marks in the figure:

[0059] 1. Wastewater collection tank; 2. Lifting pump; 3. Magnetic separator; 4. Modular sludge automatic sedimentation and unloading device; 5. Filter pump; 6. Precision filtration system; 7. Water storage tank; 8. Grinding system; 4-1. Flow control valve; 4-2. Device body; 4-3. X-shaped shallow pool sedimentation tank; 4-4. Scraper; 4-5. Unloading motor; 4-6. Scraper cylinder; 4-7. Material conveying system; 4-8. Material collection hopper; 4-9. High material level probe; 4-10. Control system; 4-11. Nozzle; 4-12. Silica gel plate; 4-13. Liquid outlet. DETAILED DESCRIPTION

[0060] The principles and features of the present invention are described below with reference to examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. Specific embodiment:

[0062] like Figure 1 As shown, a NdFeB billet grinding wastewater treatment system includes a wastewater collection tank 1, a lifting pump 2, a magnetic separator 3, a modular sludge automatic sedimentation and unloading device 4, a filter pump 5 and a precision filtration system 6. The wastewater collection tank 1 adopts a conical bottom structure and is equipped with a stirring device, and the magnetic separator 3 adopts a rubber roller type magnetic separator. The water inlet of the lifting pump 2 is located at the bottom of the wastewater collection tank 1, which can ensure that solid materials such as grinding waste will not accumulate and precipitate in large quantities in the wastewater collection tank 1; the water outlet of the lifting pump 2 is connected to the water inlet of the magnetic separator 3; the liquid outlet 4-13 of the magnetic separator 3 is connected to the inlet end of the modular sludge automatic sedimentation and unloading device 4 through a pipeline, the overflow end of the modular sludge automatic sedimentation and unloading device 4 is connected to the water inlet of the filter pump 5, and the water outlet of the filter pump 5 is connected to the precision filtration system 6. The precision filtration system 6 adopts a backwashable 0.2 micron microporous membrane filter element. After intercepting particulate impurities, this filter element can be backwashed with compressed air and reused. The cumulative usage time can usually reach more than 1 year.

[0063] For example Figure 2-Figure 4 As shown, the modular sludge automatic sedimentation and unloading device 4 includes a flow regulating valve 4-1, a device body 4-2, an X-shaped shallow pool sedimentation tank 4-3, a scraper 4-4, a unloading motor 4-5, a scraper cylinder 4-6, a material conveying system 4-7 and a control system 4-10.

[0064] The inlet of the flow control valve 4-1 is connected to the liquid outlet 4-13 of the magnetic separator 3 via a pipeline, and the outlet of the flow control valve 4-1 is connected to the inlet of the device body 4-2. The flow control valve 4-1 is electrically connected to the control system 4-10. The flow control valve 4-1 can automatically detect the wastewater flow rate and summarize the signal and feed it back to the control system 4-10. The control system 4-10 dynamically adjusts the opening of each flow control valve 4-1 through a programmable logic controller (PLC) to ensure that the flow rate of each flow control valve 4-1 remains dynamically consistent.

[0065] At least one X-shaped shallow pool sedimentation tank 4-3 is provided in the device body 4-2, and the inlet end of the X-shaped shallow pool sedimentation tank 4-3 is connected to the inlet end of the device body 4-2, and the outlet end of the X-shaped shallow pool sedimentation tank 4-3 is connected to the outlet end of the device body 4-2. The upper side of the X-shaped shallow pool sedimentation tank 4-3 is a "V"-shaped groove, and the lower side is an inverted "V"-shaped groove. The structures on both sides are consistent and symmetrically distributed, and the "V"-shaped grooves on both sides can be used for sludge sedimentation and separation. The number and size of the X-shaped shallow pool sedimentation tanks 4-3 can be flexibly adjusted according to the size of the site to improve space utilization. The number of X-shaped shallow pool sedimentation tanks 4-3 in this embodiment is 3. In order to effectively reduce the amount of sludge adhesion, the inner wall of the X-shaped shallow pool sedimentation tank 4-3 adopts a corrosion-resistant non-stick coating. In this embodiment, PTFE material is used. The main shaft of the X-shaped shallow pool sedimentation tank 4-3 is connected to the unloading motor 4-5 located outside the device body 4-2. The unloading motor 4-5 is controlled by the output signal of the control system 4-10, so that the X-shaped shallow pool sedimentation tank 4-3 can rotate freely 360° in the axial direction, thereby realizing the continuous switching of automatic unloading and sedimentation.

[0066] The scraper blade 4-4 is located below the X-shaped shallow pool sedimentation tank 4-3. It is connected to a scraper cylinder 4-6 located outside the device body 4-2. The scraper blade 4-4 scrapes away sludge via a control system 4-10 outputting signals to control the scraper cylinder 4-6. To effectively scrape sludge from the X-shaped shallow pool sedimentation tank 4-3, the scraper blade 4-4 is designed to fit the inverted "V" groove below the X-shaped shallow pool sedimentation tank 4-3. While ensuring effective sludge scraping from the X-shaped shallow pool sedimentation tank 4-3, the edge of the scraper blade 4-4 is coated with a layer of silicone sheet 4-12 to prevent scratching the corrosion-resistant, non-stick coating on the inner wall of the X-shaped shallow pool sedimentation tank 4-3. In order to further improve the scraping effect and reduce the sludge residue on the inner wall of the X-shaped shallow pool sedimentation tank 4-3, a nozzle 4-11 is provided on the scraper 4-4. The water flow of the nozzle 4-11 is directed toward the contact position between the inner wall of the X-shaped shallow pool sedimentation tank 4-3 and the scraper 4-4, so that the scraper 4-4 can be flushed by water during the scraping process.

[0067] A high-level sensor 4-9 is also installed within the X-shaped shallow sedimentation tank 4-3. By detecting the sludge level in the sedimentation tank, it automatically generates a signal to initiate discharge. The material conveying system 4-7 is located at the bottom of the device body 4-2 and is electrically connected to the control system 4-10. The modular sludge automatic sedimentation and discharge device 4 also includes a material collection hopper 4-8, located at the end of the material conveying system 4-7, for collecting separated grinding waste.

[0068] like Figure 1 、 Figure 5 As shown, the above-mentioned treatment system is used to treat NdFeB billet grinding wastewater. In this embodiment, the NdFeB billet grinding wastewater contains materials with high viscosity, easy to harden, and strong adhesion, which are composed of silicon carbide, kaolin, etc. The treatment method for this NdFeB billet grinding wastewater includes the following steps:

[0069] S1 wastewater storage: the NdFeB billet grinding wastewater from the NdFeB billet grinding system 8 flows into the wastewater collection tank 1 for temporary storage;

[0070] S2 magnetic separator separation: The NdFeB billet grinding wastewater in the wastewater collection tank 1 is sent to the magnetic separator 3 through the lifting pump 2 for separation, and rare earth elements such as praseodymium and neodymium in the wastewater are recovered and reused in the NdFeB billet production process, while obtaining a separated liquid;

[0071] S3 Grinding waste sedimentation: The separation liquid follows the pipeline through the flow regulating valve 4-1 into the sludge automatic sedimentation and unloading device, and flows into the X-shaped shallow pool sedimentation tank 4-3 for sludge sedimentation and separation. When the sludge accumulates to a high material level, the high material level probe 4-9 provided in the X-type shallow pool sedimentation tank 4-3 gives a start signal, the corresponding flow regulating valve 4-1 is automatically closed, and the unloading motor 4-5 is automatically opened. The X-type shallow pool sedimentation tank 4-3 is driven by the unloading motor 4-5 to rotate 180 degrees. After the rotation is in place, the unloading motor 4-5 is automatically closed, and most of the sludge automatically falls off to the bottom material conveying system 4-7 under the action of gravity; then the sludge scraper cylinder 4-6 is started, driving the sludge scraper 4-4 to scrape the residual sludge in the X-type shallow pool sedimentation tank 4-3, completing the automatic unloading; the sludge scraper cylinder 4-6 is closed, the X-type shallow pool sedimentation tank 4-3 resumes working state, and the corresponding flow regulating valve 4-1 is automatically opened, completing an automatic sedimentation and unloading work cycle, and the sludge is discharged and collected in the material collection bucket 4-8. The collected grinding waste is reused in the grinding material production process. At the same time, overflow water is obtained. In this embodiment, the supernatant in the X-shaped shallow pool sedimentation tank 4-3 is discharged into the water storage tank 7 through a pipe connected to the liquid outlet 4-13.

[0072] S4 filtration treatment: The overflow water is sent to the precision filtration system 6 through the filter pump 5 for filtration treatment to obtain filtered water, which is then reused for water replenishment in the NdFeB billet grinding system 8, and the filtered solid residue is collected.

[0073] The above-mentioned treatment system treats NdFeB billet grinding wastewater through physical methods such as efficient sedimentation and high-precision filtration, employing a "shallow pool sedimentation + continuous rotary unloading" model. This eliminates the need for adding chemical agents such as debonders and flocculants, effectively achieving solid-liquid separation between the abrasive and water. Using suspended solids as a measure of solid matter, the system can reduce suspended solids from 4167mg / l to 40mg / l, achieving a 99% removal rate for abrasive and other solids. This method essentially achieves zero emissions and allows for the recycling of resources such as clean water, rare earth metals, and abrasives, maximizing resource utilization and reducing wastewater treatment and reuse costs.

[0074] At the same time, the equipment system of the treatment system of the present invention has large redundancy, and there is no need for idle spare equipment. The overall effective operating load of the equipment is high and the stability is strong. It is especially suitable for materials with high viscosity, easy to harden and strong adhesion; the equipment has strong continuity, and the sludge sedimentation and unloading processes are carried out alternately in each X-shaped sedimentation tank, which can ensure that the water treatment system can operate continuously for 24 hours; the equipment has a high degree of automation, and sludge sedimentation and unloading can be realized in unattended automatic operation. Only regular inspections of the system operation status are required, and the labor intensity of personnel is significantly reduced; the equipment can be regenerated by green methods such as compressed air backwashing and clean water flushing, and can be recycled. The system has low operating and maintenance costs, stable processes, and a high degree of automation, which significantly reduces the labor intensity of personnel.

[0075] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A NdFeB billet grinding wastewater treatment system, characterized in that: It includes wastewater collection tank, lifting pump, magnetic separator, modular sludge automatic sedimentation and unloading device, filter pump and precision filtration system; The water inlet of the lift pump is located at the bottom of the wastewater collection tank, and the water outlet of the lift pump is connected to the water inlet of the magnetic separator; the liquid outlet of the magnetic separator is connected to the inlet end of the modular sludge automatic sedimentation and unloading device through a pipeline, the overflow end of the modular sludge automatic sedimentation and unloading device is connected to the water inlet of the filter pump, and the water outlet of the filter pump is connected to the precision filtration system; The modular sludge automatic sedimentation and unloading device includes a device body, an X-shaped shallow pool sedimentation tank and a unloading motor. At least one X-shaped shallow pool sedimentation tank is arranged in the device body. The inlet end of the X-shaped shallow pool sedimentation tank is connected to the inlet end of the device body, and the outlet end of the X-shaped shallow pool sedimentation tank is connected to the outlet end of the device body. The unloading motor is located on the outside of the device body and is connected to the main shaft of the X-shaped shallow pool sedimentation tank.

2. The wastewater treatment system according to claim 1, characterized in that The modular sludge automatic sedimentation and unloading device also includes a flow regulating valve, a scraper, a scraper cylinder, a material conveying system and a control system; the inlet end of the flow regulating valve is connected to the liquid outlet of the magnetic separator through a pipeline, and the outlet end of the flow regulating valve is connected to the inlet end of the device body; the scraper is located below the X-shaped shallow pool sedimentation tank, and the shape of the scraper is adapted to the inverted "V" groove below the X-shaped shallow pool sedimentation tank. The scraper cylinder is located on the outside of the device body, and the scraper cylinder is connected to the scraper. The material conveying system is located at the lower part of the device body, and the flow regulating valve, the unloading motor, the scraper cylinder and the material conveying system are electrically connected to the control system.

3. The wastewater treatment system according to claim 1, characterized in that The wastewater collection tank adopts a cone-bottom structure and is equipped with a stirring device; the magnetic separator adopts a rubber roller type magnetic separator.

4. The wastewater treatment system according to claim 2, characterized in that The inner wall of the X-shaped shallow pool sedimentation tank adopts a corrosion-resistant non-stick coating.

5. The wastewater treatment system according to claim 2, characterized in that: A high material level probe is provided in the X-shaped shallow pool sedimentation tank.

6. The wastewater treatment system according to claim 2, characterized in that: The edge of the scraper is covered with a layer of silica gel plate.

7. The wastewater treatment system according to claim 2, characterized in that: The scraper is provided with a nozzle, and the water flow of the nozzle is directed toward the contact position between the inner wall of the X-shaped shallow pool sedimentation tank and the scraper.

8. The wastewater treatment system according to claim 3, characterized in that: The precision filtration system adopts a backwashable 0.2 micron microporous membrane filter element.

9. A method for treating NdFeB billet grinding wastewater using the treatment system according to any one of claims 1 to 8, characterized in that: The steps include: S1 wastewater storage: the NdFeB billet grinding wastewater from the NdFeB billet grinding system flows into the wastewater collection pool for temporary storage; S2 magnetic separator separation: The NdFeB billet grinding wastewater in the wastewater collection pool is sent to the magnetic separator for separation through a lift pump to recover the praseodymium and neodymium rare earth in the wastewater and obtain a separated liquid at the same time; S3 Grinding waste sedimentation and collection: the separated liquid enters the modular sludge automatic sedimentation and unloading device, so that the grinding waste in the separated liquid is automatically precipitated, discharged and collected, and overflow water is obtained at the same time; S4 filtration treatment: The overflow water is sent to the precision filtration system through the filter pump for filtration treatment to obtain filtered water, and the filtered solid residue is collected.

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