A method and system for optimizing a rare earth leaching process based on ion exchange zones

Abstract

The application provides a rare earth ore leaching process optimization method and system based on ion exchange area, and belongs to the leaching process optimization field.The method first determines a target leaching area, and arranges an electrode monitoring network; a three-dimensional coordinate system is preset based on the target leaching area, and electrode positions are marked; background resistivity data are collected before injection of leaching agents, preprocessed and then imported into the coordinate system, injection positions are marked, and the background resistivity at the injection positions is calculated; the leaching agents are injected, resistivity is monitored in real time, and a resistivity change rate is calculated based on the resistivity; a time-advance point position curve of each injection position is constructed based on the resistivity change rate; the advance points at all injection positions at each time are connected, and the moving track of the advance line is inverted; corresponding to each advance time in the coordinate system, the moving tracks of the ion exchange area and the mother liquor area are respectively inverted based on the resistivity change rate, the leaching process is analyzed, and parameters are adjusted. The application improves the leaching efficiency and effect of the leaching process.

Description

Technical Field

[0001] This invention belongs to the field of leaching process optimization, specifically relating to a method and system for optimizing rare earth leaching processes based on ion exchange regions. Background Technology

[0002] Ion-adsorption rare earth minerals are mineral resources in which rare earth ions are adsorbed onto the mineral in ionic form. They are used for rare earth resource extraction and have significant application value in high-tech fields such as new energy, electronic information, and aerospace. Currently, ion-adsorption rare earth minerals are mainly mined using in-situ leaching. This process involves injecting a leaching agent into the ore body, causing an ion exchange reaction between the agent and the rare earth ions in the ore body, transferring the rare earth ions into the leachate. The rare earths are then extracted by recovering the leachate. In the in-situ leaching process, the quality of the leaching process directly affects the leaching cycle, rare earth recovery rate, leaching agent dosage, and environmental friendliness; therefore, continuous optimization of the leaching process is necessary.

[0003] In existing technologies, leaching process optimization generally focuses on optimizing the use of leaching agents to improve rare earth ion leaching rates, shorten production cycles, and reduce environmental pollution. However, judging the leaching effect mainly relies on empirical models and limited sampling data, which is highly unreliable. The injected leaching agent may not fully react with the rare earth elements before forming a dominant flow channel and flowing out prematurely, resulting in low rare earth ion recovery rates, significant waste of leaching agents, and substantial environmental risks. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method and system for optimizing rare earth leaching processes based on ion exchange regions.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows:

[0006] In a first aspect, embodiments of the present invention provide a method for optimizing rare earth leaching processes based on ion exchange regions, the method comprising the following steps:

[0007] Step S1: Determine the target leaching area and deploy an electrode monitoring network; based on the target leaching area, preset a three-dimensional coordinate system and mark the electrode positions;

[0008] Step S2: Before injecting the leaching agent, collect the background resistivity data of the target leaching area, preprocess it and import it into the coordinate system; at the same time, mark each preset leaching agent injection position in the coordinate system, and extract the background resistivity data at each injection position based on the background resistivity data of the target leaching area.

[0009] Step S3: Inject leaching agent, monitor resistivity in real time, and calculate resistivity change rate based on resistivity.

[0010] Step S4: Extract the resistivity change rate at the initial injection time of the leaching agent at each injection position in the coordinate system. Take the points with the same horizontal coordinate but different vertical coordinates as the injection positions and with the same resistivity change rate as the leading points corresponding to the next moment, and construct the time-leading point position curve for each injection position. Connect the leading points at all injection positions at each moment to deduce the movement trajectory of the leading line.

[0011] Step S5: For each forward moment in the corresponding coordinate system, extract points whose resistivity change rate is lower than the forward resistivity change rate but greater than or equal to the stability threshold and whose ordinate is higher than the forward point, and connect all points into a region, which is defined as the ion exchange region; as the forward line moves, the movement trajectory of the ion exchange region with time is reconstructed.

[0012] Step S6: For each forward moment in the corresponding coordinate system, extract points whose resistivity change rate is less than the stability threshold and whose ordinate is higher than the ion exchange zone, connect all points into a region, and define it as the mother liquor region; as the forward line moves, the movement trajectory of the mother liquor region is reconstructed.

[0013] Step S7: Based on the obtained resistivity, resistivity change rate, time-front position curve, front line movement trajectory, ion exchange zone movement trajectory, and mother liquor zone movement trajectory, analyze the leaching process and adjust the process parameters.

[0014] In a preferred embodiment of the present invention, step S7, which involves analyzing the leaching process and adjusting the process parameters, includes:

[0015] Step S71: When an abnormally high resistivity area is detected in the target leaching area, it is determined that the ore body fractures are not well developed and the leaching agent cannot penetrate effectively. The corresponding injection position of the area is marked in the coordinate system, and the operation at the corresponding injection position is stopped. This point is marked as an abnormal point. Injection boreholes are added around the abnormal point to avoid the abnormal point and ensure that the leaching agent can penetrate into the ore body evenly.

[0016] Step S72: When the position of the leading point in the time-leading point position curve does not change significantly with time, it is determined that the injection amount or injection rate of the leaching agent is insufficient, and the injection rate or injection amount of the leaching agent is increased at the corresponding injection position.

[0017] Step S73: When the current front line continues to expand into a non-target leaching area, mark the corresponding injection position in the coordinate system, reduce the leaching agent injection rate at the corresponding injection position, and avoid leaching agent waste and pollution to the surrounding environment.

[0018] Step S74: When the residence time of the ion exchange zone trajectory in a certain area is less than the residence threshold, or when the resistivity of a certain area in the mother liquor zone is higher than the resistivity threshold of the mother liquor zone and the resistivity change rate is less than the stability threshold, it is determined that the ore body porosity is too large, the leaching agent penetrates the ion exchange zone rapidly, and the exchange reaction with rare earth ions is not sufficient. The injection position corresponding to this area is marked on the coordinate system, and intermittent or alternating injection is performed at the corresponding injection position to change the infiltration path of the leaching solution and achieve sufficient exchange between the leaching agent and rare earth ions. At the same time, this step can also recirculate the low-concentration mother liquor for secondary leaching.

[0019] Step S75: When the resistivity change rate of a certain area in the mother liquor zone is greater than the stability threshold, it is determined that the injection flow rate is unbalanced. The injection position and resistivity corresponding to that area in the coordinate system are obtained. For the injection position corresponding to low resistivity, the leaching agent injection rate is reduced; for the injection position corresponding to high resistivity, the leaching agent injection rate is increased to stabilize the resistivity fluctuation.

[0020] Step S76: When the trajectory range of the ion exchange zone and the mother liquor zone covers the guide hole, mark the injection position corresponding to the guide hole in the coordinate system, reduce the injection rate of the leaching agent at the corresponding injection position, or add a guide hole to prevent mother liquor loss, leaching agent waste and pollution to the surrounding environment.

[0021] In a preferred embodiment of the present invention, step S1, when deploying the electrode monitoring network, includes:

[0022] Step S11: Determine the target leaching area and analyze the location and geological characteristics, hydrogeological conditions, engineering geological conditions, environmental geological conditions and relevant properties of the soil. Based on the mine topography, ore body distribution range and orientation of the ion-adsorption rare earth ore, conduct on-site investigation, determine the monitoring method according to the situation, and determine the layout range and shape of the electrode monitoring network.

[0023] Step S12: Based on the topography, geological conditions and expected seepage range of the target leaching area, and taking into account the scale of the ore body and the requirements for monitoring accuracy, reasonably set the electrode spacing and plan and deploy a monitoring network consisting of multiple electrodes on the surface.

[0024] Step S13: Insert the electrodes vertically into a preset depth below the ground surface to ensure good contact between the electrodes and the soil or rock, reducing the impact of contact resistance on the monitoring data; connect the electrodes with insulated wires to form a complete electrode monitoring network.

[0025] In a preferred embodiment of the present invention, the electrode spacing is 2-5m.

[0026] In a preferred embodiment of the present invention, the electrode is inserted vertically into the ground at a depth of 0.5-1.5m.

[0027] In a preferred embodiment of the present invention, the stability threshold is set in the range of 0.3 to 0.8%; optimally, the stability threshold is 0.5%.

[0028] In a preferred embodiment of the present invention, a moisture sensor is provided in the leaching agent channel.

[0029] As a preferred embodiment of the present invention, the preprocessing of background resistivity data in step S2 includes: firstly, smoothing the data using the moving average method to eliminate high-frequency interference; then, removing outliers from the data using the 3σ criterion to avoid the impact of abnormal data on subsequent analysis; and finally, normalizing the smoothed and outlier-removed data to make the background resistivity data of different monitoring points comparable.

[0030] In a preferred embodiment of the present invention, the formula for calculating the rate of change of resistivity based on resistivity in step S3 is as follows:

[0031] (1)

[0032] In equation (1), Indicates the rate of change of resistivity; This indicates the resistivity monitored in real time. This represents the background resistivity.

[0033] In a preferred embodiment of the present invention, in the ion exchange zone defined in step S5, rare earth ions (REs) with high valence and low mobility in the ore body are present. 3+ With the low-valence, high-mobility cation M in the leaching agent + Ion exchange occurs.

[0034] Secondly, embodiments of the present invention also provide a rare earth leaching process optimization system based on ion exchange regions. The system includes: an electrode monitoring network, a coordinate system establishment module, a data acquisition and calculation module, a front analysis module, an ion exchange region identification module, a mother liquor region identification module, and a process analysis and adjustment module. The electrode monitoring network and the data acquisition and calculation module constitute a high-density resistivity measurement subsystem.

[0035] The electrode monitoring network is deployed in the target leaching area as a data acquisition terminal.

[0036] The coordinate system establishment module is used to preset a three-dimensional coordinate system based on the target leaching area and mark the electrode positions;

[0037] The data acquisition and calculation module is used to collect background resistivity data of the target leaching area before injecting the leaching agent, and import it into the coordinate system after preprocessing; at the same time, it marks each preset leaching agent injection position in the coordinate system, and extracts the background resistivity data at each injection position based on the background resistivity data of the target leaching area; it is also used to inject the leaching agent, monitor the resistivity in real time, and calculate the resistivity change rate based on the resistivity.

[0038] The forward analysis module is used to extract the resistivity change rate at the initial injection time of the leaching agent at each injection position in the coordinate system. Points with the same horizontal coordinate but different vertical coordinates and the same resistivity change rate as the injection positions are used as the forward points corresponding to the next moment, and the time-forward point position curve of each injection position is constructed. The forward points at all injection positions at each moment are connected to reverse the movement trajectory of the forward line.

[0039] The ion exchange region identification module is used to extract points with resistivity change rate lower than the resistivity change rate of the front and greater than or equal to the stability threshold and ordinate higher than the front point at each front moment in the corresponding coordinate system, and connect all points into a region, which is defined as the ion exchange region; as the front line moves, the movement trajectory of the ion exchange region with time is reconstructed.

[0040] The mother liquor zone identification module is used to extract points with resistivity change rate less than the stability threshold and ordinate higher than the ion exchange zone at each forward moment in the corresponding coordinate system, connect all points into a region, and define it as the mother liquor zone; as the forward line moves, the movement trajectory of the mother liquor zone is reconstructed.

[0041] The process analysis and adjustment module is used to analyze the leaching process and adjust the process parameters based on the obtained resistivity, resistivity change rate, time-front position curve, front line movement trajectory, ion exchange zone movement trajectory, and mother liquor zone movement trajectory.

[0042] The solutions of the embodiments of the present invention have the following beneficial effects:

[0043] The rare earth leaching process optimization method and system based on ion exchange regions provided in this invention can reflect the dynamic ion exchange process in real time by dynamically monitoring changes in soil resistivity, avoiding the lag problem of traditional offline detection. By combining multiple characteristic parameters and ion exchange mechanisms to divide the reaction stages, it clearly distinguishes the three stages of leaching agent penetration, ion exchange, and reaction equilibrium, and accurately determines the occurrence and end of ion exchange. The experimental device used in the whole method is easy to build and operate, the monitoring process is highly automated, and the data processing method is mature, making it suitable for ion-adsorption rare earth mines of different scales and geological conditions.

[0044] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a flowchart of the rare earth leaching process optimization method based on ion exchange region as described in the embodiments of the present invention;

[0047] Figure 2 This is a resistivity inversion diagram before leaching in an application example of this invention;

[0048] Figure 3 This is a resistivity inversion diagram of the leaching process in an application example of the present invention. Detailed Implementation

[0049] After discovering the aforementioned problems, the inventors of this application conducted a detailed study on existing in-situ leaching processes and the use of leaching agents. The study revealed that after the leaching agent is introduced into the mine, it categorizes into a leading zone, an ion exchange zone, and a mother liquor stabilization zone. Real-time, accurate, and wide-range identification of the ion exchange zone in ion-adsorption rare earth ores can provide precise guidance for the leaching agent injection process, enabling precise control of the leaching reaction. This optimizes leaching process parameters, improves rare earth recovery rates, and avoids leaching agent waste and environmental pollution.

[0050] High-density resistivity (ERT) is a geophysical exploration method that infers geological structure or fluid properties by measuring the resistivity distribution underground. The resistivity of soil and rock masses is highly sensitive to the concentration of fluid ions in their pores. During leaching, the injected leaching agent reacts with rare earth ions (such as REs)... 3+ An ion exchange reaction occurs, and the types and concentrations of ions in the solution change significantly before and after the reaction, leading to a change in formation resistivity. This provides a theoretical basis for using resistivity changes to monitor the ion exchange reaction process in mineral leaching. However, current technologies have not yet been able to effectively utilize the dynamic changes in resistivity to identify the changes and states of the ion exchange reaction zone in real time and accurately, so as to guide the use of leaching agents and optimize the leaching process.

[0051] It should be noted that the defects in the above-mentioned prior art solutions are all the result of the inventors' practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed by the embodiments of the present invention in the following text should be the inventors' contributions to the present invention.

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can also be combined with each other.

[0053] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, the terms "first," "second," "third," "fourth," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0054] Based on the above in-depth analysis, this invention provides a method and system for optimizing rare earth leaching processes based on ion exchange regions. Using an electrode monitoring network deployed in-situ in the mining area, in-situ resistivity data is collected, leaching agent is continuously injected and monitored synchronously, abnormal resistivity change rates are calculated, ion exchange regions are identified and delineated, and finally, dynamic tracking and feedback control are implemented to adjust parameters such as the injection location, injection volume, and injection rate of the leaching agent in real time, thereby optimizing the leaching process.

[0055] like Figure 1 As shown, the optimization method for rare earth leaching process based on ion exchange regions includes the following steps:

[0056] Step S1: Determine the target leaching area and deploy an electrode monitoring network; based on the target leaching area, a three-dimensional coordinate system is preset and the electrode positions are marked.

[0057] In this step, the electrodes in the electrode monitoring network are selected from corrosion-resistant copper or titanium alloy electrodes to avoid corrosion of the electrodes in the leaching agent and groundwater, which would affect the monitoring results. The specific steps for deploying the electrode monitoring network are as follows:

[0058] Step S11: Determine the target leaching area and analyze the location and geological characteristics, hydrogeological conditions, engineering geological conditions, environmental geological conditions and relevant properties of the soil. Based on the mine topography, ore body distribution range and orientation of the ion-adsorption rare earth ore, conduct on-site investigation, determine the monitoring method according to the situation, and determine the layout range and shape of the electrode monitoring network.

[0059] Step S12: Based on the topography, geological conditions, and expected seepage range of the target leaching area, and considering the ore body size and monitoring accuracy requirements, the electrode spacing is reasonably set, and a monitoring network consisting of multiple electrodes is planned and deployed on the surface. Generally, the electrode spacing is 2-5m. For areas with denser ore body distribution and higher monitoring accuracy requirements, the electrode spacing can be appropriately reduced; for areas with more dispersed ore body distribution, the electrode spacing can be appropriately increased.

[0060] Step S13: Insert the electrodes vertically into the ground at a depth of 0.5-1.5m below the surface to ensure good contact between the electrodes and the soil or rock, reducing the impact of contact resistance on the monitoring data; connect the electrodes with insulated wires to form a complete electrode monitoring network, which is then integrated with the monitoring platform to form a high-density resistivity measurement system.

[0061] In addition, a moisture sensor can be installed in the leaching agent channel before the leaching operation to measure the real-time flow rate of the leaching agent in the channel.

[0062] Step S2: Before injecting the leaching agent, collect the background resistivity data of the target leaching area, preprocess it and import it into the coordinate system; at the same time, mark each preset leaching agent injection position in the coordinate system, and extract the background resistivity data at each injection position based on the background resistivity data of the target leaching area.

[0063] In this step, one or more full-coverage measurements are performed on the target leaching area to obtain three-dimensional resistivity data volumes of the formation under the background field in different areas of the mine, which serve as the benchmark for subsequent resistivity variation analysis. During the acquisition process, data is continuously collected for a predetermined period (usually 1-2 weeks) according to a preset acquisition frequency (generally once per hour) to obtain stable and reliable background resistivity data. Since the acquired background resistivity data may contain interference signals caused by external electromagnetic interference, unstable electrode contact, and other factors, it needs to be preprocessed.

[0064] The preprocessing includes: first, smoothing the data using the moving average method to eliminate high-frequency interference; then, removing outliers from the data using the 3σ criterion to avoid the impact of abnormal data on subsequent analysis; and finally, normalizing the smoothed and outlier-removed data to make the background resistivity data of different monitoring points comparable.

[0065] Step S3: Inject leaching agent, monitor resistivity in real time, and calculate resistivity change rate based on resistivity.

[0066] In this step, starting from the initial injection of the leaching agent, the injection proceeds according to the preset injection location, injection rate, and injection volume. Simultaneously, resistivity monitoring is activated, and the entire electrode monitoring network is automatically and cyclically measured at preset time intervals (e.g., once per hour) to obtain dynamic apparent resistivity datasets in real time.

[0067] This step may also include: using a preset moisture sensor to monitor the flow rate of the leaching agent in the injection area, and adjusting the operating parameters of the infusion pump in a timely manner when abnormal fluctuations occur in the flow rate to ensure the stability of the leaching agent injection process.

[0068] When calculating the true resistivity and relative rate of change, based on in-situ resistivity data and real-time monitored apparent resistivity data, the resistivity change rate of each electrode at different times is calculated according to the resistivity change rate calculation formula. The formula is as follows:

[0069] (1)

[0070] In equation (1), Indicates the rate of change of resistivity; This indicates the resistivity monitored in real time. This represents the background resistivity.

[0071] Step S4: Extract the resistivity change rate at the initial injection time of the leaching agent at each injection position in the coordinate system. Points with the same horizontal coordinate but different vertical coordinates and the same resistivity change rate as the injection positions are taken as the leading points corresponding to the next moment. Construct the time-leading point position curve for each injection position. Connect the leading points at all injection positions at each moment to deduce the movement trajectory of the leading line.

[0072] In this step, within the target leaching area, i.e., the leaching operation area, the injection of the leaching agent triggers an active ion exchange reaction within the formation. This reaction directly leads to significant fluctuations in the ion concentration of the formation fluid, and the change in ion concentration increases the rate of change in resistivity; while high concentrations of cations (M... + The injection of leaching agent causes a sharp increase in the conductivity of the solution, resulting in a significant decrease in resistivity. As time progresses and leaching agent is continuously injected into the ore body, the position of the normal front extends from the starting point within the ore body over time. The front point, as the boundary between the injected and uninjected areas, maintains a consistently high rate of resistivity change. Therefore, a curve reflecting the change in the position of the front point over time can be plotted in a coordinate system with the mine as the main component.

[0073] Connecting the leading points at all injection locations at a given moment allows us to reconstruct the leaching leading line or leading face of the leaching area at that current moment. Viewed from the mine cross-section, this appears as a curve; viewed from the mine body, it forms a leading face, thus visually reflecting the injection status of the leaching agent throughout the target leaching area. Since injection locations are typically situated on or near ridges, the mine cross-section directly reflects the leaching leading line. Therefore, this embodiment uses the reconstructed leading line to analyze the leaching situation.

[0074] Step S5: For each forward moment in the corresponding coordinate system, extract points whose resistivity change rate is lower than the forward resistivity change rate but greater than or equal to the stability threshold and whose ordinate is higher than the forward point, and connect all points into a region, which is defined as the ion exchange region; as the forward line moves, the movement trajectory of the ion exchange region with time is reconstructed.

[0075] This step identifies ion exchange regions, where rare earth ions (REs) with high valence and low mobility exist within the ore body. 3+ With the low-valence, high-mobility cation M in the leaching agent + Ion exchange occurs, causing a change in the total ionic molar conductivity of the solution. This is due to RE... 3+ The conductivity contribution is lower than M + The resistivity in this region will rise relative to the pure leaching agent region, forming an abnormal resistivity rise zone; at this time, ion exchange is proceeding normally, and the resistivity change rate is significantly lower than that of the front, so the ion exchange region can be identified by the resistivity change rate.

[0076] In this step, the stability threshold is set in the range of 0.3~0.8%; optimally, the stability threshold is 0.5%. When the rate of change of resistivity is greater than or equal to the stability threshold, the resistivity is constantly changing significantly, indicating that the ion exchange reaction is taking place, and therefore the corresponding region is defined as the ion exchange region.

[0077] Step S6: For each forward moment in the corresponding coordinate system, extract points whose resistivity change rate is less than the stability threshold and whose ordinate is higher than the ion exchange zone, connect all points into a region, and define it as the mother liquor region; as the forward line moves, the movement trajectory of the mother liquor region is reconstructed.

[0078] In this step, the mother liquor region is identified using a stability threshold. When the rate of change in resistivity is less than the stability threshold, it indicates that the resistivity remains essentially constant or consistently stays within a relatively stable range. This signifies that the ion exchange reaction is essentially complete, with no significant resistivity change, and is therefore defined as the mother liquor region. This region is rich in RE. 3+ Meanwhile, leaching agent is continuously injected, and at this point, no obvious ion exchange reaction occurs. The mother liquor contains cations from the leaching agent and leached rare earth ions, and its resistivity is between that of pure leaching agent and undisturbed formation water.

[0079] Step S7: Based on the obtained resistivity, resistivity change rate, time-front position curve, front line movement trajectory, ion exchange zone movement trajectory, and mother liquor zone movement trajectory, analyze the leaching process and adjust the process parameters.

[0080] This step involves adjusting the process parameters, including the following steps:

[0081] Step S71: When an abnormally high resistivity area is detected in the target leaching area, it is determined that the ore body fractures are not well developed and the leaching agent cannot penetrate effectively. The corresponding injection position of the area is marked in the coordinate system, and the operation at the corresponding injection position is stopped. This point is marked as an abnormal point. Injection boreholes are added around the abnormal point to avoid the abnormal point and ensure that the leaching agent can penetrate into the ore body evenly.

[0082] Step S72: When the position of the leading point in the time-leading point position curve does not change significantly with time, it is determined that the injection amount or injection rate of the leaching agent is insufficient, and the injection rate or injection amount of the leaching agent is increased at the corresponding injection position.

[0083] Step S73: When the current front line continues to expand into a non-target leaching area, mark the corresponding injection position in the coordinate system, reduce the injection rate of leaching agent at the corresponding injection position, and avoid leaching agent waste and pollution to the surrounding environment.

[0084] Step S74: When the residence time of the ion exchange zone trajectory in a certain area is less than the residence threshold, or when the resistivity of a certain area in the mother liquor zone is higher than the resistivity threshold of the mother liquor zone and the resistivity change rate is less than the stability threshold, it is determined that the ore body porosity is too large, the leaching agent rapidly penetrates the ion exchange zone, and the exchange reaction with rare earth ions is not sufficient. The injection position corresponding to this area is marked in the coordinate system, and intermittent or alternating injection is performed at the corresponding injection position to change the infiltration path of the leaching solution and achieve sufficient exchange between the leaching agent and rare earth ions. At the same time, this step can also recirculate the low-concentration mother liquor for secondary leaching.

[0085] In this step, the residence threshold and the mother liquor resistivity threshold are set according to the actual situation. If the residence time of the leaching agent in the ion exchange zone is too short, it will not be sufficient to complete the ion exchange reaction. Therefore, the residence time in a certain area of ​​the ion exchange zone is obtained by tracking the process and compared with the residence threshold to determine whether the ion exchange reaction is complete. The residence threshold is the shortest time required for the leaching agent to complete ion exchange in a set unit area. The resistivity change rate in the mother liquor zone is relatively stable, and the resistivity itself remains within a relatively stable range. The upper limit of the resistivity range of the mother liquor zone is set as the mother liquor resistivity threshold. When the resistivity is higher than the upper limit of the stable range, i.e., the mother liquor resistivity threshold, it indicates that the resistivity is too high and the leaching agent is insufficient. Accordingly, the process parameters are adjusted accordingly.

[0086] Step S75: When the resistivity change rate of a certain area in the mother liquor zone is greater than the stability threshold, it is determined that the injection flow rate is unbalanced. The injection position and resistivity corresponding to that area in the coordinate system are obtained. For the injection position corresponding to low resistivity, the leaching agent injection rate is reduced; for the injection position corresponding to high resistivity, the leaching agent injection rate is increased to stabilize the resistivity fluctuation.

[0087] Step S76: When the trajectory range of the ion exchange zone and the mother liquor zone covers the guide hole, mark the injection position corresponding to the guide hole in the coordinate system, reduce the injection rate of the leaching agent at the corresponding injection position, or add a guide hole to prevent mother liquor loss, leaching agent waste and pollution to the surrounding environment.

[0088] Based on the same idea, this invention also provides a rare earth leaching process optimization system based on ion exchange regions. The system includes: an electrode monitoring network, a coordinate system establishment module, a data acquisition and calculation module, a front analysis module, an ion exchange region identification module, a mother liquor region identification module, and a process analysis and adjustment module. The electrode monitoring network and the data acquisition and calculation module constitute a high-density resistivity measurement subsystem.

[0089] The electrode monitoring network is deployed in the target leaching area as a data acquisition terminal.

[0090] The coordinate system establishment module is used to preset a three-dimensional coordinate system based on the target leaching area and mark the electrode positions;

[0091] The data acquisition and calculation module is used to collect background resistivity data of the target leaching area before injecting the leaching agent, and import it into the coordinate system after preprocessing; at the same time, it marks each preset leaching agent injection position in the coordinate system, and extracts the background resistivity data at each injection position based on the background resistivity data of the target leaching area; it is also used to inject the leaching agent, monitor the resistivity in real time, and calculate the resistivity change rate based on the resistivity.

[0092] The forward analysis module is used to extract the resistivity change rate at the initial injection time of the leaching agent at each injection position in the coordinate system. Points with the same horizontal coordinate but different vertical coordinates and the same resistivity change rate as the injection positions are used as the forward points corresponding to the next moment, and the time-forward point position curve of each injection position is constructed. The forward points at all injection positions at each moment are connected to reverse the movement trajectory of the forward line.

[0093] The ion exchange region identification module is used to extract points with a resistivity change rate lower than the resistivity change rate of the front and a ordinate higher than the front point at each front moment in the corresponding coordinate system, and connect all the points into a region, which is defined as the ion exchange region; as the front line moves, the movement trajectory of the ion exchange region with time is reconstructed.

[0094] The mother liquor region identification module is used to extract points with a resistivity change rate higher than the resistivity change rate of the front point and a ordinate higher than the ion exchange region at each front moment in the corresponding coordinate system. All points are connected into a region, which is defined as the mother liquor region. As the front line moves, the movement trajectory of the mother liquor region is reconstructed.

[0095] The process analysis and adjustment module is used to analyze the leaching process and adjust the process parameters based on the obtained resistivity, resistivity change rate, time-front position curve, front line movement trajectory, ion exchange zone movement trajectory, and mother liquor zone movement trajectory.

[0096] The rare earth leaching process optimization method and system based on ion exchange regions described in this invention were applied to laboratory-scale model leaching simulation verification, and then applied to actual leaching in a mine. In the simulation, soil samples were first prepared, and during this process, long-term... Width The heights are 50. 5 A 15cm acrylic box. The soil sample, consisting of three layers of tightly compacted ion-type rare earth minerals, was placed inside.

[0097] An experimental setup system was constructed, consisting of a box-type model, a peristaltic pump, electrodes, and resistivity monitoring equipment. The data processing terminal was a laptop computer with built-in data recording and analysis software.

[0098] Before starting the leaching process, a leaching agent is prepared. A leaching agent with a concentration of 2% magnesium sulfate is prepared in the laboratory and placed in a volumetric flask to study the effect of the leaching agent on the change in resistivity during the ion exchange process.

[0099] Set up a coordinate system and mark the positions of the deployed electrodes within it; collect in-situ resistivity data before injecting the leaching agent, preprocess it, and import it into the coordinate system; mark each preset leaching agent injection position in the coordinate system, and calculate the in-situ resistivity data at each injection position based on the in-situ resistivity data collected by the electrode monitoring network. For example... Figure 2 The image shown is a graph of resistivity data before the leaching agent was injected.

[0100] The leaching agent is injected according to the preset injection location, injection rate, and injection volume. Dynamic monitoring is initiated. During the injection process, the leaching agent is injected into the soil sample in the acrylic box at regular intervals and in quantitative and continuous amounts. The injection time is set to 30 minutes, the injection volume is 100 ml, and the leaching agent is kept at "0 water head" at all times. Simultaneously, the resistivity acquisition device is activated, with the sampling frequency set to 100 Hz and the voltage level set to 1 V. During the leaching agent injection process, the resistivity is recorded every 10 minutes. The resistivity data is monitored in real time, uploaded and stored synchronously, and the corresponding resistivity change rate is calculated based on the resistivity monitored by each electrode.

[0101] like Figure 3As shown, after injecting the leaching agent, the leading edge, ion exchange zone, and mother liquor zone of the leaching area are reconstructed. In the coordinate system, with each injection location as the starting point, a time-leading edge position curve, ion exchange zone and its movement trajectory, and mother liquor zone and its movement trajectory are constructed for each injection location. The resistivity change pattern is analyzed, and the resistivity change rate is calculated. When an abnormally high resistivity area is detected in the leaching area, this area may have underdeveloped ore body fractures and ineffective leaching agent penetration. Operations at the current injection location are stopped, and this location is marked as an anomaly. Injection holes are added around the anomaly point to avoid it, ensuring that the leaching agent can penetrate evenly into the ore body. The overall size of the leading edge zone is relatively reduced. When there is no significant change in the leading edge, the injection location is determined by the coordinate position. The cause is analyzed as insufficient injection volume or injection rate of the leaching agent. The injection rate or volume of the leaching agent is increased at the current injection location. When the leading edge continues to expand into non-ore body areas, the injection location is determined by the coordinate position, and the injection rate of the leaching agent at the current injection location is reduced to avoid wasting the leaching agent and polluting the surrounding environment.

[0102] As can be seen from the above technical solutions, the rare earth leaching process optimization method and system based on ion exchange regions provided by the embodiments of the present invention can reflect the dynamic ion exchange process in real time by dynamically monitoring changes in soil resistivity, thus avoiding the lag problem of traditional offline detection. By combining multiple characteristic parameters and ion exchange mechanisms to divide the reaction stages, the three stages of leaching agent penetration, ion exchange, and reaction equilibrium are clearly distinguished, and the occurrence and end of ion exchange are accurately determined. The experimental device used in the whole method is easy to build and operate, the monitoring process is highly automated, the data processing method is mature, and it is suitable for ion-adsorption rare earth mines of different scales and geological conditions.

[0103] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed, and is not intended to limit the scope of the claimed invention, but merely to illustrate preferred embodiments of the invention. Those skilled in the art should understand that the scope of the invention is not limited to the specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for optimizing rare earth leaching processes based on ion exchange regions, characterized in that, The method includes the following steps: Step S1: Determine the target leaching area and deploy an electrode monitoring network; based on the target leaching area, preset a three-dimensional coordinate system and mark the electrode positions; Step S2: Before injecting the leaching agent, collect the background resistivity data of the target leaching area, preprocess it and import it into the coordinate system; at the same time, mark each preset leaching agent injection position in the coordinate system, and extract the background resistivity data at each injection position based on the background resistivity data of the target leaching area. Step S3: Inject leaching agent, monitor resistivity in real time, and calculate resistivity change rate based on resistivity. Step S4: Extract the resistivity change rate at the initial injection time of the leaching agent at each injection position in the coordinate system. Take the points with the same horizontal coordinate but different vertical coordinates as the injection positions and with the same resistivity change rate as the leading points corresponding to the next moment, and construct the time-leading point position curve for each injection position. Connect the leading points at all injection positions at each moment to deduce the movement trajectory of the leading line. Step S5: For each forward moment in the corresponding coordinate system, extract points whose resistivity change rate is lower than the forward resistivity change rate but greater than or equal to the stability threshold and whose ordinate is higher than the forward point, and connect all points into a region, which is defined as the ion exchange region; as the forward line moves, the movement trajectory of the ion exchange region with time is reconstructed. Step S6: For each forward moment in the corresponding coordinate system, extract points whose resistivity change rate is less than the stability threshold and whose ordinate is higher than the ion exchange zone, connect all points into a region, and define it as the mother liquor region; as the forward line moves, the movement trajectory of the mother liquor region is reconstructed. Step S7: Based on the obtained resistivity, resistivity change rate, time-front position curve, front line movement trajectory, ion exchange zone movement trajectory, and mother liquor zone movement trajectory, analyze the leaching process and adjust the process parameters.

2. The method according to claim 1, characterized in that, Step S7, which involves analyzing the leaching process and adjusting the process parameters, includes: Step S71: When an abnormally high resistivity area is detected in the target leaching area, it is determined that the ore body fractures are not well developed and the leaching agent cannot penetrate effectively. The injection position corresponding to this area is marked in the coordinate system, the operation at the corresponding injection position is stopped, and this point is marked as an abnormal point. Injection boreholes are added around the abnormal point. Step S72: When the position of the leading point in the time-leading point position curve does not change significantly with time, it is determined that the injection amount or injection rate of the leaching agent is insufficient, and the injection rate or injection amount of the leaching agent is increased at the corresponding injection position. Step S73: When the current front line continues to expand into a non-target leaching area, mark the injection position corresponding to the area in the coordinate system and reduce the leaching agent injection rate at the corresponding injection position. Step S74: When the residence time of the ion exchange zone trajectory in a certain area is less than the residence threshold, or when the resistivity of a certain area in the mother liquor zone is higher than the resistivity threshold of the mother liquor zone and the resistivity change rate is less than the stability threshold, it is determined that the ore body porosity is too large, the leaching agent penetrates the ion exchange zone rapidly, and the exchange reaction with rare earth ions is not sufficient. The injection position corresponding to the area is marked in the coordinate system, and intermittent or alternating injection is carried out at the corresponding injection position to change the infiltration path of the leaching solution and achieve sufficient exchange between the leaching agent and rare earth ions. Step S75: When the resistivity change rate of a certain area in the mother liquor zone is greater than the stability threshold, it is determined that the injection flow rate is unbalanced. The injection position and resistivity corresponding to that area in the coordinate system are obtained. For the injection position corresponding to low resistivity, the leaching agent injection rate is reduced; for the injection position corresponding to high resistivity, the leaching agent injection rate is increased to stabilize the resistivity fluctuation. Step S76: When the trajectory range of the ion exchange zone and the mother liquor zone covers the guide hole, mark the injection position corresponding to the guide hole in the coordinate system, reduce the leaching agent injection rate at the corresponding injection position, or add a guide hole.

3. The method according to claim 1, characterized in that, Step S1, when deploying the electrode monitoring network, includes: Step S11: Determine the target leaching area and analyze the location and geological characteristics, hydrogeological conditions, engineering geological conditions, environmental geological conditions and relevant properties of the soil. Based on the mine topography, ore body distribution range and orientation of the ion-adsorption rare earth ore, conduct on-site investigation, determine the monitoring method according to the situation, and determine the layout range and shape of the electrode monitoring network. Step S12: Based on the topography, geological conditions and expected seepage range of the target leaching area, and taking into account the scale of the ore body and the requirements for monitoring accuracy, reasonably set the electrode spacing and plan and deploy a monitoring network consisting of multiple electrodes on the surface. Step S13: Insert the electrodes vertically into a preset depth below the ground surface to ensure good contact between the electrodes and the soil or rock, reducing the impact of contact resistance on the monitoring data; connect the electrodes with insulated wires to form a complete electrode monitoring network.

4. The method according to claim 3, characterized in that, The electrode spacing is 2-5m; the electrodes are inserted vertically into the ground to a depth of 0.5-1.5m below the surface.

5. The method according to claim 3, characterized in that, A moisture sensor is installed in the leaching agent channel.

6. The method according to claim 1, characterized in that, The stability threshold is set in the range of 0.3 to 0.8%.

7. The method according to claim 1, characterized in that, The preprocessing of background resistivity data in step S2 includes: first, smoothing the data using the moving average method to eliminate high-frequency interference; then, removing outliers from the data using the 3σ criterion to avoid the impact of abnormal data on subsequent analysis; and finally, normalizing the smoothed and outlier-removed data to make the background resistivity data from different monitoring points comparable.

8. The method according to claim 1, characterized in that, The formula for calculating the rate of change of resistivity based on resistivity in step S3 is as follows: (1) In equation (1), Indicates the rate of change of resistivity; This indicates the resistivity monitored in real time. This represents the background resistivity.

9. The method according to claim 1, characterized in that, In the ion exchange zone defined in step S5, rare earth ions (REs) with high valence and low mobility in the ore body... 3+ With the low-valence, high-mobility cation M in the leaching agent + Ion exchange occurs.

10. A rare earth leaching process optimization system based on ion exchange regions, characterized in that, The system includes: an electrode monitoring network, a coordinate system establishment module, a data acquisition and calculation module, a front analysis module, an ion exchange zone identification module, a mother liquor zone identification module, and a process analysis and adjustment module; the electrode monitoring network and the data acquisition and calculation module constitute a high-density resistivity measurement subsystem; wherein... The electrode monitoring network is deployed in the target leaching area as a data acquisition terminal. The coordinate system establishment module is used to preset a three-dimensional coordinate system based on the target leaching area and mark the electrode positions; The data acquisition and calculation module is used to collect background resistivity data of the target leaching area before injecting the leaching agent, and import it into the coordinate system after preprocessing; at the same time, it marks each preset leaching agent injection position in the coordinate system, and extracts the background resistivity data at each injection position based on the background resistivity data of the target leaching area; it is also used to inject the leaching agent, monitor the resistivity in real time, and calculate the resistivity change rate based on the resistivity. The forward analysis module is used to extract the resistivity change rate at the initial injection time of the leaching agent at each injection position in the coordinate system. Points with the same horizontal coordinate but different vertical coordinates and the same resistivity change rate as the injection positions are used as the forward points corresponding to the next moment, and the time-forward point position curve of each injection position is constructed. The forward points at all injection positions at each moment are connected to reverse the movement trajectory of the forward line. The ion exchange region identification module is used to extract points with resistivity change rate lower than the resistivity change rate of the front and greater than or equal to the stability threshold and ordinate higher than the front point at each front moment in the corresponding coordinate system, and connect all points into a region, which is defined as the ion exchange region; as the front line moves, the movement trajectory of the ion exchange region with time is reconstructed. The mother liquor zone identification module is used to extract points with resistivity change rate less than the stability threshold and ordinate higher than the ion exchange zone at each forward moment in the corresponding coordinate system, and connect all points into a region, which is defined as the mother liquor zone; as the forward line moves, the movement trajectory of the mother liquor zone is reconstructed. The process analysis and adjustment module is used to analyze the leaching process and adjust the process parameters based on the obtained resistivity, resistivity change rate, time-front position curve, front line movement trajectory, ion exchange zone movement trajectory, and mother liquor zone movement trajectory.

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