Method and system for recycling high-purity rare earth metals from waste rare earth permanent magnet materials

Abstract

The application discloses a high-purity rare earth metal recovery method and system of waste rare earth permanent magnet material, and relates to the technical field of rare earth metal recovery. The method comprises the following steps: performing acid immersion treatment on material particles; continuously monitoring the acid immersion solution by using a pH meter to obtain a pH monitoring value sequence; performing fluctuation trend analysis on the pH monitoring value sequence, and performing centrifugal separation on the acid immersion solution when the analysis result meets preset requirements to obtain an extraction solution; adding the extraction solution into an extraction box for rotary extraction; performing dynamic periodic detection on the extraction process until preset extraction stop conditions are met, obtaining an extraction solution, precipitating and crystallizing the extraction solution, cleaning and drying the precipitate, and obtaining a high-purity rare earth metal salt; and reducing and smelting the high-purity rare earth metal salt to obtain a high-purity rare earth metal. The technical problem of low recovery efficiency of waste rare earth permanent magnet material in the prior art is solved, and the technical effect of improving the recovery efficiency of rare earth metal is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of rare earth metal recovery, in particular to a high-purity rare earth metal recovery method and system for waste rare earth permanent magnet materials. BACKGROUND

[0002] Rare earth permanent magnet materials are widely used in new energy, electronics, aerospace and other fields as an important high-performance material. However, a large amount of waste rare earth permanent magnet materials is inevitably generated in the production, processing and product upgrading process. These waste materials contain rich rare earth resources, and if they cannot be reasonably and effectively recycled, not only will the rare earth resources be wasted, but also potential harm to the environment will be caused. The existing waste rare earth permanent magnet material recovery methods mostly have problems of low recovery efficiency, complex processing process, high cost and the like. Therefore, how to efficiently recover rare earth metals from waste rare earth permanent magnet materials has become a technical problem to be solved in the current rare earth recovery field. SUMMARY

[0003] The application provides a high-purity rare earth metal recovery method and system for waste rare earth permanent magnet materials, and solves the technical problem of low recovery efficiency of waste rare earth permanent magnet materials in the prior art.

[0004] In a first aspect, the application provides a high-purity rare earth metal recovery method for waste rare earth permanent magnet materials, which comprises the following steps:

[0005] The waste rare earth permanent magnet material is mechanically crushed into material particles, and the material particles are subjected to acid leaching treatment according to a preset leaching parameter group by using a preset chemical solvent. In the acid leaching treatment process, the pH meter is used to continuously monitor the acid leaching solution to obtain a sequence of pH monitoring values. The sequence of pH monitoring values is subjected to fluctuation trend analysis, and when the analysis result meets the preset requirement, the acid leaching solution is subjected to centrifugal separation to obtain an extraction solution. The extraction solution is added into an extraction box body through a waste material adding assembly, an extractant high-pressure ejection assembly arranged on the extraction box body is used to add an extractant into the extraction box body, and the extraction box body is driven by a motor to rotate at a first rotation speed for rotary extraction. The extraction process is dynamically and periodically detected until a preset extraction stop condition is met, an extraction solution is obtained, the extraction solution is subjected to precipitation crystallization, the precipitate is washed and dried, and a high-purity rare earth metal salt is obtained. The high-purity rare earth metal salt is subjected to reduction smelting to obtain a high-purity rare earth metal.

[0006] In a second aspect, the application provides a high-purity rare earth metal recovery system for waste rare earth permanent magnet materials, which comprises the following steps:

[0007] The processing module is used for mechanically crushing waste rare earth permanent magnet material into material particles, and performing acid leaching treatment on the material particles according to a preset leaching parameter group by using a preset chemical solvent; the monitoring module is used for continuously monitoring the acid leaching solution by using a pH meter during the acid leaching treatment process, and obtaining a pH monitoring value sequence; the analysis module is used for performing fluctuation trend analysis on the pH monitoring value sequence, and performing centrifugal separation on the acid leaching solution when the analysis result meets a preset requirement, to obtain an extraction solution; the extraction module is used for adding the extraction solution into an extraction box through a waste material adding assembly, adding an extractant into the extraction box through an extractant high-pressure spouting assembly arranged on the extraction box, and rotating and extracting the extraction box at a first rotating speed by driving the first rotating assembly through a motor; the detection module is used for performing dynamic and periodic detection on the extraction process until a preset extraction stop condition is met, to obtain an extracted solution, performing precipitation crystallization on the extracted solution, and performing cleaning and drying on the precipitate, to obtain a high-purity rare earth metal salt; and the smelting module is used for reducing and smelting the high-purity rare earth metal salt, to obtain a high-purity rare earth metal.

[0008] One or more technical solutions provided in the present application have at least the following technical effects or advantages:

[0009] Firstly, waste rare earth permanent magnet material is mechanically crushed into material particles, and acid leaching treatment is performed on the material particles according to a preset leaching parameter group by using a preset chemical solvent; during the acid leaching treatment process, the acid leaching solution is continuously monitored by using a pH meter, and a pH monitoring value sequence is obtained. Then, fluctuation trend analysis is performed on the pH monitoring value sequence, and centrifugal separation is performed on the acid leaching solution when the analysis result meets a preset requirement, to obtain an extraction solution. Then, the extraction solution is added into an extraction box through a waste material adding assembly, an extractant is added into the extraction box through an extractant high-pressure spouting assembly arranged on the extraction box, and the extraction box is rotated and extracted at a first rotating speed by driving the first rotating assembly through a motor; and dynamic and periodic detection is performed on the extraction process until a preset extraction stop condition is met, to obtain an extracted solution, perform precipitation crystallization on the extracted solution, and perform cleaning and drying on the precipitate, to obtain a high-purity rare earth metal salt. Finally, the high-purity rare earth metal salt is reduced and smelted, to obtain a high-purity rare earth metal. The technical problem of low waste rare earth permanent magnet material recovery efficiency in the prior art is solved, and the technical effect of improving rare earth metal recovery efficiency is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0011] Figure 1 A schematic diagram of a method for recycling high-purity rare earth metals from waste rare earth permanent magnet materials provided in an embodiment of this application;

[0012] Figure 2 This is a schematic diagram of a high-purity rare earth metal recycling system for waste rare earth permanent magnet materials provided in an embodiment of this application.

[0013] Explanation of reference numerals in the attached diagram: Processing module 11, Monitoring module 12, Analysis module 13, Extraction module 14, Detection module 15, Smelting module 16. Detailed Implementation

[0014] This application provides a method and system for recycling high-purity rare earth metals from waste rare earth permanent magnet materials, thereby solving the technical problem of low recycling efficiency of waste rare earth permanent magnet materials in the prior art.

[0015] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0016] It should be noted that the terms "comprising" and "having" are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to these processes, methods, products, or devices.

[0017] Example 1, as Figure 1 As shown, this application provides a method for recycling high-purity rare earth metals from waste rare earth permanent magnet materials, wherein the method includes:

[0018] Waste rare earth permanent magnet materials are mechanically crushed into material particles, and then acid-leached using a preset chemical solvent according to a preset leaching parameter set.

[0019] In this embodiment, waste rare earth permanent magnet materials are crushed into fine particles by mechanical crushing equipment to increase the specific surface area of ​​the material, thereby improving the efficiency of subsequent leaching treatment. The crushed material particles are sent into a reaction vessel and acid leaching is performed using a preset chemical solvent (such as sulfuric acid, hydrochloric acid, and other acidic solvents). During the acid leaching process, the chemical solvent is added according to the preset parameter set (acid concentration, liquid-solid ratio, reaction temperature, reaction time, and stirring speed), stirring is started, and the temperature is heated to the target temperature.

[0020] During the acid leaching process, the pH meter is used to continuously monitor the acid leaching solution, and a sequence of pH monitoring values is obtained.

[0021] During the acid leaching process, the PH meter probe is immersed in the solution of the acid leaching reactor, and the pH monitoring value sequence is generated by continuously monitoring according to the preset monitoring frequency (such as recording data once every 30 seconds).

[0022] The pH monitoring value sequence is analyzed for fluctuation trend, and when the analysis result meets the preset requirement, the acid leaching solution is centrifuged to obtain the to-be-extracted solution.

[0023] Further, the preset requirement is that the fluctuation variance of the pH monitoring value is less than or equal to the preset fluctuation variance.

[0024] In the embodiments of the present application, the obtained pH monitoring value sequence is analyzed for fluctuation trend, that is, the fluctuation variance of the pH monitoring value is calculated to evaluate the change of the solution acidity; when the fluctuation variance of the pH value is less than or equal to the preset fluctuation variance threshold, it indicates that the acid leaching reaction has reached the expected stable state, and the reaction is completed. At this time, the acid leaching solution is centrifuged to remove solid impurities, and the to-be-extracted solution is obtained. The to-be-extracted solution contains rare earth metal ions dissolved by the acid leaching process, and the solid impurities have been removed after centrifugal separation.

[0025] The to-be-extracted solution is added to the extraction box through the waste material adding assembly, the extraction agent is added to the extraction box through the extraction agent high-pressure jetting assembly arranged on the extraction box, and the extraction box is rotated at a first rotation speed by the motor driving the first rotating assembly.

[0026] The to-be-extracted solution is introduced into the extraction box through the waste material adding assembly; then, the preset extraction agent is introduced into the extraction box in the form of high-pressure jetting through the extraction agent high-pressure jetting assembly arranged on the extraction box. For example, the extraction agent is pressurized by a high-pressure plunger pump and sprayed into the extraction box along the tangential direction of the inner wall of the extraction box through an annular nozzle array, forming a spiral liquid film cover layer. The extraction agent reacts with the rare earth metal ions in the to-be-extracted solution to extract the rare earth metal from the solution, forming an easily separated extraction solution.

[0027] The extraction box is rotated around the horizontal axis at a preset first rotation speed by the motor driving the first assembly. During the rotation, the solution and the extraction agent are continuously mixed and contacted, which enhances the efficiency of the dissolution and extraction reaction.

[0028] The extraction process is dynamically and periodically detected until the preset extraction stopping condition is met, the extraction solution is obtained, the extraction solution is precipitated and crystallized, and the precipitate is washed and dried to obtain a high-purity rare earth metal salt.

[0029] The extraction reaction is carried out in the extraction tank, and the extraction process is dynamically and periodically detected to ensure that the rare earth metal ions in the solution to be extracted are fully reacted with the extractant. Specifically, the concentration of the solute in the solution and the activity of the extractant are sampled and analyzed within a preset detection period to form a concentration change data sequence and an activity coefficient sequence. By analyzing the trend of these sequences, it is determined whether the extraction reaction tends to be stable, and then it is evaluated whether the preset extraction stop condition is reached, such as the solute concentration being lower than the set concentration threshold or the extractant activity tending to be stable.

[0030] Once the detection result shows that the extraction process has met the stop condition, the extraction operation is terminated immediately, and the obtained extraction solution after the reaction is collected, which is enriched with the target rare earth metal ions, and then subjected to precipitation crystallization treatment. In the precipitation crystallization stage, the rare earth metal ions are precipitated from the solution in the form of high-purity salt by adjusting the pH value, adding a precipitating agent or controlling the temperature. The obtained precipitate is filtered, washed to remove residual impurities, and then subjected to low-temperature drying treatment, finally obtaining a high-purity rare earth metal salt with high purity and low impurity content.

[0031] Further, the extraction process is dynamically and periodically detected until the preset extraction stop condition is met, and the extraction solution is obtained, including:

[0032] The extractant activity detection and solute concentration detection are carried out according to the first sampling detection period to obtain the extractant activity coefficient sequence and the solute concentration detection result sequence. The extractant activity coefficient sequence and the solute concentration detection result sequence are analyzed respectively, and based on the analysis result, it is determined whether the extractant supplement is needed, and the first sampling detection period is dynamically adjusted to obtain the extractant activity sampling detection period and the solute concentration sampling detection period. The extraction process is dynamically and periodically detected based on the extractant activity sampling detection period and the solute concentration sampling detection period until the preset extraction stop condition is met, and the extraction solution is obtained.

[0033] Further, the preset extraction stop condition is that the solute concentration is lower than the preset solute concentration threshold.

[0034] The system periodically detects the reaction system in the extraction box according to a preset first sampling detection period during the extraction process, respectively collects and analyzes the extractant activity and solute concentration, and thus obtains an extractant activity coefficient sequence and a solute concentration detection result sequence. The extractant activity coefficient is used to reflect the residual reaction capacity of the extractant in the reaction process, and the solute concentration is used to evaluate the extraction degree of the metal ions to be extracted. By analyzing the change trend of the extractant activity coefficient sequence and the solute concentration detection result sequence, it is determined whether the current extraction reaction has the risk of exhaustion of the extractant or reduction of the reaction efficiency, and whether the extractant needs to be supplemented into the extraction box to maintain the reaction efficiency is determined. According to the analysis result, the originally set first sampling detection period is dynamically adjusted, and a new extractant activity sampling detection period and a solute concentration sampling detection period are respectively generated, so that the detection frequency can adapt to the change of the reaction state. When the reaction changes greatly, the sampling period is automatically shortened to improve the response speed; when the reaction tends to be stable, the period is lengthened to reduce resource consumption.

[0035] Based on the extractant activity sampling detection period and the solute concentration sampling detection period, the subsequent extraction process is dynamically periodically detected, data is continuously collected and updated, and the judgment is updated until the preset extraction stop condition (such as the solute concentration falling below the preset solute concentration threshold) is met, at which time the extraction process is ended and the final extraction solution is output.

[0036] Further, the extractant activity coefficient sequence and the solute concentration detection result sequence are respectively analyzed, and whether the extractant needs to be supplemented is determined according to the analysis result, and the first sampling detection period is dynamically adjusted to obtain an extractant activity sampling detection period and a solute concentration sampling detection period, including:

[0037] It is judged whether there is data less than or equal to the preset extractant activity coefficient threshold and the preset solute concentration threshold in the extractant activity coefficient sequence and the solute concentration detection result sequence. If yes, a first extractant adding instruction and a first period dynamic adjustment instruction are obtained; based on the first extractant adding instruction, the extractant high-pressure jetting assembly is called to add extractant into the extraction box; based on the first period dynamic adjustment instruction, the first sampling detection period is reduced by one-half to obtain an extractant activity sampling detection period and a solute concentration sampling detection period.

[0038] After obtaining the sequence of extractant activity coefficient and the sequence of solute concentration detection results, the system performs real-time analysis on the two sequences respectively to determine whether there is a sign of efficiency decline in the current extraction process. Specifically, the system determines whether there is a data value in the sequence that is less than or equal to the preset extractant activity coefficient threshold and the preset solute concentration threshold. If either of the conditions is met, it indicates that the extractant activity has decreased significantly or the target solute has been extracted, at which point the extraction process is close to completion or the reaction conditions need to be strengthened to maintain the extraction efficiency.

[0039] Once the above conditions are met, the system automatically generates a first extractant addition instruction and a first periodic dynamic adjustment instruction. Based on the first extractant addition instruction, the system controls the extractant high-pressure injection assembly to add a certain amount of extractant to the extraction tank to restore the active environment required for the reaction. At the same time, based on the first periodic dynamic adjustment instruction, the original first sampling detection period is reduced to half of the original period, thereby increasing the subsequent detection frequency and enhancing the system's response capability to changes in the reaction state. Finally, the updated detection period is set as the new extractant activity sampling detection period and the solute concentration sampling detection period, respectively, providing a basis for subsequent dynamic detection and process control, and ensuring that the entire extraction process continues to operate under efficient and stable conditions.

[0040] Further, when there is no data in the sequence of extractant activity coefficient and the sequence of solute concentration detection results that is less than or equal to the preset extractant activity coefficient threshold and the preset solute concentration threshold, single-point gradient analysis is performed on the sequence of extractant activity coefficient and the sequence of solute concentration detection results to obtain a sequence of extractant activity coefficient gradient decline and a sequence of solute concentration gradient decline. Based on the sequence of extractant activity coefficient gradient decline, a trend analysis of the extractant activity coefficient is performed to obtain an extractant activity coefficient trend factor, and the first sampling detection period is adjusted based on the extractant activity coefficient trend factor to obtain an extractant activity sampling detection period. Based on the sequence of solute concentration gradient decline, a trend analysis of the solute concentration is performed to obtain a solute concentration trend factor, and the first sampling detection period is adjusted based on the solute concentration trend factor to obtain a solute concentration sampling detection period.

[0041] When analyzing the sequence of extractant activity coefficient and the sequence of solute concentration detection results, if there is no data in the detection sequence that is less than or equal to the preset extractant activity coefficient threshold and the preset solute concentration threshold, it indicates that the current extraction process is still in the stable reaction stage and has not triggered significant abnormality or extraction completion conditions. At this time, the system performs single-point gradient analysis on the sequence of extractant activity coefficient and the sequence of solute concentration detection results, i.e., calculates the change amplitude of adjacent detection points in the sequence to obtain a gradient sequence reflecting the change rate, and forms a sequence of extractant activity coefficient gradient decline and a sequence of solute concentration gradient decline, respectively.

[0042] The extractant activity coefficient gradient is calculated as follows: wherein, is the extractant activity coefficient at time t, is the extractant activity coefficient at time t+1, is the time interval.

[0043] The solute concentration gradient is calculated as follows: wherein, is the solute concentration at time t, is the solute concentration at time t+1, is the time interval.

[0044] If the gradient is positive, it means that the variable is increasing (e.g., the solute concentration is increasing or the extractant activity is increasing); if the gradient is negative, it means that the variable is decreasing (e.g., the solute concentration is decreasing or the extractant activity is decreasing).

[0045] Based on the descending sequence of the extractant activity coefficient gradient, a trend analysis is performed to extract representative features of the change trend, and a statistical central trend gradient and a change amplitude are obtained to generate an extractant activity coefficient trend factor, which is used to quantify the decline speed and fluctuation degree of the extractant activity in the reaction. According to the extractant activity coefficient trend factor, the first sampling detection period is dynamically adjusted to obtain an optimized extractant activity sampling detection period, so as to more accurately match the actual demand of the reaction process for the detection frequency. Similarly, the system performs a concentration trend analysis based on the descending sequence of the solute concentration gradient to obtain a solute concentration trend factor, which reflects the concentration decline trend of the target rare earth metal in the current solution. According to the solute concentration trend factor, the first sampling detection period is dynamically adjusted to obtain an optimized extractant activity sampling detection period.

[0046] Further, the extractant activity coefficient trend analysis based on the descending sequence of the extractant activity coefficient gradient obtains an extractant activity coefficient trend factor, including:

[0047] A central gradient is selected from the descending sequence of the extractant activity coefficient gradient, wherein the central gradient is the mode of the extractant activity coefficient gradient in the descending sequence of the extractant activity coefficient gradient; a trend center neighborhood is constructed according to a preset trend radius with the central gradient as the trend center; a trend center neighborhood density of the trend center neighborhood is calculated; an edge of the trend center neighborhood is diffused according to a preset diffusion bandwidth, and a diffusion stop identification is performed in combination with the trend center neighborhood density to determine a target trend center neighborhood; a mean value of the target trend center neighborhood is calculated to obtain the extractant activity coefficient trend factor.

[0048] Preferably, a central gradient is selected from the descending sequence of the activity coefficient gradient of the extractant, i.e. the mode of the activity coefficient gradient of the extractant in the descending sequence of the activity coefficient gradient of the extractant; a trend center neighborhood is constructed with the central gradient as the trend center and in combination with a preset trend radius, i.e. an interval set formed by extending upwards and downwards in the numerical dimension with the central gradient as the core, for capturing gradient change points similar to the dominant trend. The number of gradient points contained in the trend center neighborhood is calculated, and the trend center neighborhood density is obtained therefrom, for reflecting the significance of the trend mode. The trend center neighborhood is subjected to edge diffusion processing according to a preset diffusion bandwidth, i.e. the neighborhood range is gradually expanded and the density of the diffusion region is recalculated. After each diffusion step, whether the preset diffusion stop condition is reached is judged by comparing the difference between the diffusion trend center neighborhood density and the original trend center neighborhood density: when the diffusion density is not lower than the original density and the density difference is less than or equal to a set threshold, it is considered that the current diffusion range has stabilized, the diffusion is stopped, and the same is taken as the target trend center neighborhood. Finally, the mean value of all gradient values in the target trend center neighborhood is calculated, which is taken as the activity coefficient trend factor of the extractant activity change, for comprehensively reflecting the speed and direction of the current decrease in the extractant activity.

[0049] Further, the trend center neighborhood is subjected to edge diffusion according to a preset diffusion bandwidth, and the diffusion stop identification is performed in combination with the trend center neighborhood density, to determine the target trend center neighborhood, including:

[0050] The trend center neighborhood is subjected to edge diffusion according to a preset diffusion bandwidth, to obtain a diffusion trend center neighborhood; when the diffusion trend center neighborhood density of the diffusion trend center neighborhood is greater than or equal to the trend center neighborhood density, and the difference between the diffusion trend center neighborhood density and the trend center neighborhood density is less than or equal to a preset difference, the diffusion is stopped, and the diffusion trend center neighborhood is taken as the target trend center neighborhood; when the diffusion trend center neighborhood density of the diffusion trend center neighborhood is less than the trend center neighborhood density, the trend center neighborhood is taken as the target trend center neighborhood.

[0051] Preferably, the trend center neighborhood is numerically expanded according to a preset diffusion bandwidth, that is, one diffusion step interval is added to the upper and lower boundaries of the center gradient neighborhood, respectively, to form a diffusion trend center neighborhood containing more gradient points; the density in the diffusion trend center neighborhood is calculated, that is, the number or proportion of gradient data points contained in the neighborhood is counted, to obtain the diffusion trend center neighborhood density. The diffusion trend center neighborhood density is compared with the original trend center neighborhood density to determine whether the diffusion has introduced noise interference and whether the trend boundary has stabilized: if the diffusion trend center neighborhood density is greater than or equal to the original trend center neighborhood density, and the density difference between the two does not exceed the preset tolerance threshold (that is, the difference is less than or equal to the preset difference), it is considered that the diffusion has not introduced noise interference, and the trend boundary has stabilized, the diffusion operation is terminated, and the current diffusion trend center neighborhood is confirmed as the target trend center neighborhood. Otherwise, if the diffusion trend center neighborhood density is less than the original trend center neighborhood density, it indicates that the data points outside the trend boundary are not beneficial to trend identification or even constitute interference, and the system terminates the diffusion and retains the original trend center neighborhood as the final target trend center neighborhood.

[0052] Further, calculating the mean value of the target trend center neighborhood to obtain the extractant activity coefficient trend factor further comprises:

[0053] Determining whether the extractant activity coefficient trend factor meets a preset tolerance threshold, and if not, obtaining extract abnormality early warning information; and warning the extraction process according to the extract abnormality early warning information.

[0054] After determining the target trend center neighborhood, all gradient values in the neighborhood are statistically calculated to obtain a numerical mean value as a quantitative index of the overall trend of the extractant activity change in the current period, which is denoted as an extractant activity coefficient trend factor. The trend factor can accurately reflect the decline speed or stability of the extractant activity over time, and is used to determine whether the extraction process has potential abnormalities or needs to be adjusted.

[0055] After the calculation is completed, the system compares the trend factor with a preset tolerance threshold to determine whether the current activity change is within a normal range. If the trend factor does not meet the set tolerance threshold condition (such as too fast decline speed, fluctuation amplitude exceeding the limit, etc.), it indicates that the effective activity of the extractant is abnormally decaying, which may lead to a significant decrease in subsequent extraction efficiency or misjudgment of the extraction endpoint. The system will immediately generate corresponding extract abnormality early warning information. Based on the extract abnormality early warning information, the system can prompt the operator for intervention through a human-machine interface, or automatically start an emergency adjustment process such as supplementing the extractant in advance, adjusting the rotation speed, and strengthening the mixing, to ensure the continuous and stable operation of the extraction process.

[0056] Reducing and smelting the high-purity rare earth metal salt to obtain a high-purity rare earth metal.

[0057] After obtaining the high-purity rare earth metal salt, reduction smelting is performed to extract the high-purity rare earth metal from the metal salt.

[0058] Exemplarily, the obtained high-purity rare earth metal salt (such as rare earth chloride, nitrate, etc.) is mixed with a reducing agent (such as hydrogen, carbon or metal reducing agent, etc.); according to the chemical properties of the selected rare earth metal, an appropriate reducing agent is selected to react with the metal salt, which is usually performed at high temperature; through the reduction reaction, the rare earth metal ions in the metal salt are reduced to the corresponding rare earth metal, and the solid metal is precipitated.

[0059] In summary, the embodiments of the present application have at least the following technical effects:

[0060] Firstly, the waste rare earth permanent magnet material is mechanically crushed into material particles, and the material particles are subjected to acid leaching treatment according to a preset leaching parameter group by using a preset chemical solvent; during the acid leaching treatment process, the pH meter is used to continuously monitor the acid leaching solution to obtain a sequence of pH monitoring values. Next, the sequence of pH monitoring values is subjected to fluctuation trend analysis, and when the analysis result meets the preset requirement, the acid leaching solution is subjected to centrifugal separation to obtain an extraction solution. Then, the extraction solution is added into the extraction box body through the waste material adding assembly, the extractant adding is performed into the extraction box body through the extractant high-pressure spouting assembly arranged on the extraction box body, and the extraction box body is driven by the first rotating assembly to rotate at a first rotating speed for rotary extraction; and the extraction process is dynamically and periodically detected until the preset extraction stopping condition is met, and an extraction solution is obtained. The extraction solution is subjected to precipitation crystallization, and the precipitate is washed and dried to obtain a high-purity rare earth metal salt. Finally, the high-purity rare earth metal salt is subjected to reduction smelting to obtain a high-purity rare earth metal. The technical problem of low waste rare earth permanent magnet material recovery efficiency in the prior art is solved, and the technical effect of improving the rare earth metal recovery efficiency is achieved.

[0061] Embodiment two, based on the same inventive concept as the high-purity rare earth metal recovery method of the waste rare earth permanent magnet material in the foregoing embodiments, as Figure 2 shown, the present application provides a high-purity rare earth metal recovery system for waste rare earth permanent magnet material, wherein the system comprises:

[0062] The processing module 11 is used for treating the waste rare earth permanent magnet material by mechanically crushing into material particles, and performing acid leaching treatment on the material particles according to a preset leaching parameter group by using a preset chemical solvent; the monitoring module 12 is used for continuously monitoring the acid leaching solution by using a pH meter during the acid leaching treatment, and obtaining a pH monitoring value sequence; the analysis module 13 is used for performing fluctuation trend analysis on the pH monitoring value sequence, and performing centrifugal separation on the acid leaching solution when the analysis result meets a preset requirement, to obtain an extraction solution; the extraction module 14 is used for adding the extraction solution into an extraction box through a waste material adding assembly, adding an extractant into the extraction box through an extractant high-pressure ejection assembly arranged on the extraction box, and rotating the extraction box at a first rotation speed by driving a first rotating assembly by a motor; the detection module 15 is used for performing dynamic and periodic detection on the extraction process until a preset extraction stop condition is met, to obtain an extraction solution, performing precipitation crystallization on the extraction solution, and performing cleaning and drying on the precipitate, to obtain a high-purity rare earth metal salt; and the smelting module 16 is used for reducing and smelting the high-purity rare earth metal salt, to obtain a high-purity rare earth metal.

[0063] Further, the detection module 15 is used to perform the following method:

[0064] The extractant activity detection and the solute concentration detection are performed according to a first sampling detection period, to obtain an extractant activity coefficient sequence and a solute concentration detection result sequence; the extractant activity coefficient sequence and the solute concentration detection result sequence are analyzed respectively, whether the extractant supplement is to be performed is determined according to the analysis result, and the first sampling detection period is dynamically adjusted, to obtain an extractant activity sampling detection period and a solute concentration sampling detection period; the extraction process is detected dynamically and periodically based on the extractant activity sampling detection period and the solute concentration sampling detection period, until a preset extraction stop condition is met, to obtain the extraction solution.

[0065] Further, the detection module 15 is used to perform the following method:

[0066] The preset extraction stop condition is that the solute concentration is lower than a preset solute concentration threshold.

[0067] Further, the detection module 15 is used to perform the following method:

[0068] determining whether there is data less than or equal to a preset extractant activity coefficient threshold value and a preset solute concentration threshold value in the extractant activity coefficient sequence and the solute concentration detection result sequence, if yes, obtaining a first extractant adding instruction and a first period dynamic adjustment instruction; based on the first extractant adding instruction, calling the extractant high-pressure eruption assembly to add extractant into the extraction tank; based on the first period dynamic adjustment instruction, reducing the first sampling detection period by one-half, obtaining an extractant activity sampling detection period and a solute concentration sampling detection period.

[0069] Further, the detection module 15 is used to execute the following method:

[0070] When there is no data less than or equal to a preset extractant activity coefficient threshold value and a preset solute concentration threshold value in the extractant activity coefficient sequence and the solute concentration detection result sequence, performing single-point gradient analysis on the extractant activity coefficient sequence and the solute concentration detection result sequence to obtain an extractant activity coefficient gradient descent sequence and a solute concentration gradient descent sequence; based on the extractant activity coefficient gradient descent sequence, performing extractant activity coefficient trend analysis to obtain an extractant activity coefficient trend factor, adjusting the first sampling detection period according to the extractant activity coefficient trend factor to obtain an extractant activity sampling detection period; based on the solute concentration gradient descent sequence, performing solute concentration trend analysis to obtain a solute concentration trend factor, adjusting the first sampling detection period according to the solute concentration trend factor to obtain a solute concentration sampling detection period.

[0071] Further, the detection module 15 is used to execute the following method:

[0072] selecting a central gradient from the extractant activity coefficient gradient descent sequence, wherein the central gradient is the mode of the extractant activity coefficient gradient in the extractant activity coefficient gradient descent sequence; taking the central gradient as a trend center, constructing a trend center neighborhood according to a preset trend radius; calculating a trend center neighborhood density of the trend center neighborhood; performing edge diffusion on the trend center neighborhood according to a preset diffusion bandwidth, and combining the trend center neighborhood density to perform diffusion stop identification, to determine a target trend center neighborhood; calculating a mean value of the target trend center neighborhood to obtain the extractant activity coefficient trend factor.

[0073] Further, the detection module 15 is used to execute the following method:

[0074] According to the preset diffusion bandwidth, the trend center neighborhood is edge-diffused to obtain a diffusion trend center neighborhood; when a diffusion trend center neighborhood density of the diffusion trend center neighborhood is greater than or equal to a trend center neighborhood density, and a difference between the diffusion trend center neighborhood density and the trend center neighborhood density is less than or equal to a preset difference, the diffusion is stopped, and the diffusion trend center neighborhood is taken as the target trend center neighborhood; when the diffusion trend center neighborhood density of the diffusion trend center neighborhood is less than the trend center neighborhood density, the trend center neighborhood is taken as the target trend center neighborhood.

[0075] Further, the detection module 15 is configured to perform the following method:

[0076] It is determined whether the extractant activity coefficient trend factor meets a preset tolerance threshold, and if not, extract abnormal early warning information is obtained; and the extract process is warned according to the extract abnormal early warning information.

[0077] Further, the analysis module 13 is configured to perform the following method:

[0078] The preset requirement is that a fluctuation variance of the pH monitoring value is less than or equal to a preset fluctuation variance.

[0079] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. The above-mentioned description is made for specific embodiments of the present application. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0080] The above-mentioned is only the preferred embodiment of the present application, and does not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

[0081] The present specification and drawings are only exemplary descriptions of the present application, and should be considered to cover any and all modifications, changes, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art can make various modifications and changes to the present application without departing from the scope of the present application. Thus, if these modifications and changes of the present application belong to the scope of the present application and its equivalents, the present application intends to include these modifications and changes.

Claims

1. A method for recovering high-purity rare earth metals from waste rare earth permanent magnet material, characterized by, The method comprises: The method comprises: During the acid leaching process, the pH of the acid leaching solution is continuously monitored using a pH meter to obtain a sequence of pH monitoring values; Performing fluctuation trend analysis on the sequence of pH monitoring values, and when the analysis result meets the preset requirement, performing centrifugal separation on the acid leaching solution to obtain a to-be-extracted solution; Add the to-be-extracted solution into the extraction box through the waste material adding assembly, add the extractant into the extraction box through the extractant high-pressure spouting assembly arranged on the extraction box, and drive the first rotating assembly by the motor to rotate the extraction box at a first rotating speed for rotary extraction; Performing dynamic and periodic detection on the extraction process until the preset extraction stop condition is met, obtaining an extraction solution, precipitating and crystallizing the extraction solution, and cleaning and drying the precipitate to obtain a high-purity rare earth metal salt; Reducing and smelting the high-purity rare earth metal salt to obtain a high-purity rare earth metal; The method comprises: Performing extractant activity detection and solute concentration detection according to a first sampling and detection period to obtain a sequence of extractant activity coefficients and a sequence of solute concentration detection results; Performing analysis on the sequence of extractant activity coefficients and the sequence of solute concentration detection results, respectively, determining whether extractant supplement is needed according to the analysis result, and dynamically adjusting the first sampling and detection period to obtain an extractant activity sampling and detection period and a solute concentration sampling and detection period; Performing dynamic and periodic detection on the extraction process based on the extractant activity sampling and detection period and the solute concentration sampling and detection period until the preset extraction stop condition is met to obtain the extraction solution.

2. The method of recovering high purity rare earth metals from waste rare earth permanent magnetic material according to claim 1, wherein The preset extraction stop condition is that the solute concentration is lower than a preset solute concentration threshold.

3. The method of claim 1, wherein the waste rare earth permanent magnet material is a sintered magnet material. The method comprises: If there is data less than or equal to a preset extractant activity coefficient threshold and a preset solute concentration threshold in the sequence of extractant activity coefficients and the sequence of solute concentration detection results, a first extractant adding instruction and a first period dynamic adjustment instruction are obtained; Based on the first extractant adding instruction, the extractant high-pressure spouting assembly is called to add the extractant into the extraction box; Based on the first period dynamic adjustment instruction, the first sampling and detection period is reduced by one-half to obtain the extractant activity sampling and detection period and the solute concentration sampling and detection period.

4. The method of recovering high purity rare earth metals from waste rare earth permanent magnetic materials according to claim 3, wherein The method comprises: When there is no data less than or equal to a preset extractant activity coefficient threshold and a preset solute concentration threshold in the sequence of extractant activity coefficients and the sequence of solute concentration detection results, single-point gradient analysis is performed on the sequence of extractant activity coefficients and the sequence of solute concentration detection results to obtain a sequence of extractant activity coefficient gradient decreases and a sequence of solute concentration gradient decreases; The extractant activity coefficient trend analysis is performed based on the gradient descending sequence of the extractant activity coefficient, to obtain an extractant activity coefficient trend factor, and the first sampling and detection period is adjusted according to the extractant activity coefficient trend factor, to obtain an extractant activity sampling and detection period. The solute concentration trend analysis is performed based on the gradient descending sequence of the solute concentration, to obtain a solute concentration trend factor, and the first sampling and detection period is adjusted according to the solute concentration trend factor, to obtain a solute concentration sampling and detection period.

5. The method of recovering high purity rare earth metals from waste rare earth permanent magnetic materials according to claim 4, wherein The extractant activity coefficient trend analysis is performed based on the gradient descending sequence of the extractant activity coefficient, to obtain an extractant activity coefficient trend factor, including: A central gradient is selected from the gradient descending sequence of the extractant activity coefficient, wherein the central gradient is the mode of the gradient descending sequence of the extractant activity coefficient; A trend center neighborhood is constructed according to a preset trend radius, with the central gradient as the trend center; The trend center neighborhood density of the trend center neighborhood is calculated; Edge diffusion is performed on the trend center neighborhood according to a preset diffusion bandwidth, and diffusion stop identification is performed in combination with the trend center neighborhood density, to determine a target trend center neighborhood; The mean value of the target trend center neighborhood is calculated, to obtain the extractant activity coefficient trend factor.

6. The method of recovering high purity rare earth metals from waste rare earth permanent magnetic materials according to claim 5, wherein Edge diffusion is performed on the trend center neighborhood according to a preset diffusion bandwidth, and diffusion stop identification is performed in combination with the trend center neighborhood density, to determine a target trend center neighborhood, including: Edge diffusion is performed on the trend center neighborhood according to a preset diffusion bandwidth, to obtain a diffusion trend center neighborhood; When the diffusion trend center neighborhood density of the diffusion trend center neighborhood is greater than or equal to the trend center neighborhood density, and the difference between the diffusion trend center neighborhood density and the trend center neighborhood density is less than or equal to a preset difference value, the diffusion is stopped, and the diffusion trend center neighborhood is taken as the target trend center neighborhood; When the diffusion trend center neighborhood density of the diffusion trend center neighborhood is less than the trend center neighborhood density, the trend center neighborhood is taken as the target trend center neighborhood.

7. The method of recovering high purity rare earth metals from waste rare earth permanent magnetic material according to claim 5, wherein The mean value of the target trend center neighborhood is calculated, to obtain the extractant activity coefficient trend factor, and the method further includes: It is judged whether the extractant activity coefficient trend factor meets a preset tolerance threshold, and if not, extractant abnormality early warning information is obtained; The extractant abnormality early warning information is used to perform early warning on the extraction process.

8. The method of recovering high purity rare earth metals from waste rare earth permanent magnetic materials according to claim 1, wherein The preset requirement is that the fluctuation variance of the pH monitoring value is less than or equal to a preset fluctuation variance.

9. A high purity rare earth metal recovery system for scrap rare earth permanent magnet material, characterized by, The system comprises: A processing module is configured to mechanically crush the waste rare earth permanent magnet material into material particles, and perform acid leaching treatment on the material particles according to preset leaching parameters by using a preset chemical solvent; A monitoring module is configured to continuously monitor the acid leaching solution by using a pH meter during the acid leaching treatment, to obtain a sequence of pH monitoring values; An analysis module is configured to perform fluctuation trend analysis on the sequence of pH monitoring values, and perform centrifugal separation on the acid leaching solution when the analysis result meets a preset requirement, to obtain a to-be-extracted solution; The extraction module is used for adding the solution to be extracted into an extraction box through the waste adding assembly, adding an extractant into the extraction box through the extractant high-pressure ejection assembly arranged on the extraction box, and rotating the extraction box at a first rotating speed by driving the first rotating assembly by a motor. The detection module is used for dynamically and periodically detecting the extraction process until a preset extraction stop condition is met, obtaining an extraction solution, precipitating and crystallizing the extraction solution, cleaning and drying the precipitate, and obtaining a high-purity rare earth metal salt. The smelting module is used for reducing and smelting the high-purity rare earth metal salt to obtain a high-purity rare earth metal.

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