Ionic rare earth in-situ seepage controlled mining method and system

Abstract

The invention discloses an ionic rare earth in-situ seepage controlled mining method and system thereof, comprising the steps of obtaining geological and hydrological exploration data, constructing a three-dimensional map of a mining area, and taking representative ore layer samples for testing; determining a liquid injection boundary; identifying cracks and faults in a bedrock floor, designing the position and structure of an impermeable layer, and constructing an impermeable layer; constructing a three-dimensional seepage field model of a mining area, delineating a difficult-to-penetrate area, a plastic area, a seepage convergence area, and a liquid accumulation area in an ore body; designing a liquid injection system and an extraction system, and constructing an intelligent control system; arranging liquid injection holes and an automatic liquid injection device on the top of the ore body, placing a wetting line monitoring sensor in the difficult-to-penetrate area and the plastic area, installing a vacuum extraction device in the seepage convergence area and the liquid accumulation area, forming an injection and extraction automatic control system, and realizing precise control of liquid injection and extraction; and carrying out a "leaching-liquid collection-leaching" cycle operation through the injection and extraction automatic control system to realize in-situ leaching of ionic rare earths.

Description

Technical Field

[0001] The invention relates to the technical field of rare earth resource mining, and in particular to an ionic rare earth in-situ seepage controlled mining method and a system thereof. Background Art

[0002] Ionic rare earths refer to rare earth elements that are adsorbed on the surface of minerals or exist in the mineral lattice in the form of ions. This type of rare earth resource is mainly found in weathering crust elution-type rare earth deposits, which are usually formed by the elution, migration and adsorption and deposition of rare earth elements under certain conditions of long-term weathering of rare earth-rich granite or other rocks. Due to their unique formation mechanism and occurrence state, ionic rare earth deposits are significantly different from traditional rare earth deposits (such as bastnaesite, monazite, etc.) in terms of mining and smelting.

[0003] The mining of ionic rare earth deposits usually adopts in-situ leaching technology, which requires the construction of an effective impermeable layer under the ore body to prevent the leaching solution from leaking into the groundwater, causing resource loss and environmental pollution. Since ionic rare earth elements are adsorbed on the surface of minerals in ionic state, their leaching efficiency and resource recovery rate are usually low, and the selection of leaching agents and leaching processes need to be optimized.

[0004] For example, patent document CN110055414A discloses that a comprehensive geophysical method is introduced into the existing in-situ leaching process to detect the development of faults, cracks and fragmentation of the bedrock floor; and a grouting technology is introduced into the existing in-situ leaching process to construct an impermeable layer on the poorly developed bedrock floor to prevent the leaching liquid from entering the groundwater through the bedrock floor and causing loss of rare earth resources.

[0005] Patent document CN116926350A discloses that the rare earth ion exchange and migration process can be accelerated through ultrasonic action, the leaching effect can be enhanced, and the rare earth leaching rate can be increased.

[0006] Patent document CN115220110A discloses a non-destructive monitoring method for in-situ leaching of ion-adsorption rare earth ores, which includes geophysical resistivity data acquisition, inversion constraints, resistivity data interpretation, drilling verification, rock and soil coring and physical property testing. Finally, the migration range of the leaching liquid within the mining area can be accurately delineated, and irregular environmental monitoring can be carried out.

[0007] However, ionic rare earth deposits are mostly distributed in mountainous areas. The complex terrain conditions bring difficulties to mining operations, especially the layout of injection and collection systems under steep slopes and complex geological conditions, and environmental protection issues are also very prominent. Therefore, how to further improve the automation and intelligence level of the mining process to achieve precise control and optimize mining efficiency is an important technical challenge currently faced. Summary of the invention

[0008] The purpose of the present invention is to provide an ionic rare earth in-situ seepage controlled mining method and system thereof, so as to overcome some deficiencies existing in the prior art.

[0009] Based on the first main aspect of the present invention, a method for in-situ seepage controlled mining of ionic rare earth is provided, the method comprising the following steps:

[0010] S1, obtain geological and hydrological exploration data, build a three-dimensional map of the mining area in combination with remote sensing data, and take representative ore samples for testing;

[0011] S2, considering the influence of ore layer thickness, steep slope area, internal special boundary and steep slope area, determine the injection boundary;

[0012] S3, identify the cracks and faults in the bedrock floor, design the location and structure of the anti-seepage layer; construct and calculate the crack influence coefficient K, fault influence coefficient F and comprehensive permeability coefficient k, determine the thickness h of the anti-seepage layer and the material requirement M, and construct the anti-seepage layer;

[0013] S4, construct a three-dimensional seepage field model of the mining area to delineate the impermeable area, plastic area, seepage convergence area and liquid accumulation area in the ore body;

[0014] S5, design the injection system and extraction system, and design the injection and extraction automatic control system, use mathematical models to simulate the leaching process, and optimize the leaching efficiency;

[0015] S6, arrange injection holes and automatic injection devices on the top of the ore body, place infiltration line monitoring sensors in the difficult-to-permeate area and plastic area, install vacuum extraction equipment in the seepage collection area and liquid accumulation area, and form an injection and extraction automatic control system to achieve precise control of leaching liquid injection and extraction;

[0016] S7, through the injection and extraction automatic control system, carry out the "leaching-liquid collection-leaching" cycle operation to achieve in-situ leaching of ionic rare earths; and establish a real-time monitoring system to monitor various parameters during the mining process; according to the monitoring data, timely adjust the mining plan;

[0017] S8, treat the extracted leaching liquid, extract rare earth elements, and treat the wastewater to meet discharge standards; after mining is completed, site restoration is carried out, including soil improvement and vegetation restoration.

[0018] As a further preferred solution, in step S1, obtaining geological and hydrological exploration data includes at least the following technical means:

[0019] (1) Geological exploration technology:

[0020] Geological Radar (GPR): Used to detect underground structures such as faults, fissures, etc.

[0021] Seismic exploration: Determining geological structure by analyzing the response of underground rocks to seismic waves.

[0022] Electromagnetic surveying (EM): measuring the electromagnetic properties of underground rocks to identify areas of mineralization.

[0023] (2) Hydrogeological Exploration:

[0024] Hydrologging: measuring groundwater levels and the physical and chemical properties of water.

[0025] Groundwater flow models: simulate groundwater flow and determine hydrogeological conditions.

[0026] (3) Remote sensing technology:

[0027] Satellite remote sensing: Use of high-resolution satellite imagery to identify land surface features and changes.

[0028] Unmanned aerial vehicles (UAVs) carry out aerial photogrammetry and multispectral / hyperspectral imaging.

[0029] In step S1, the three-dimensional map of the mining area is constructed by using GIS (Geographic Information System) software or digital terrain model (DTM) or geological modeling software such as Surpac, Gemcom or one or more of them.

[0030] In step S1, taking representative ore samples for testing includes drilling at a determined sampling point to obtain ore samples; and using a combination of X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) to determine the ore grade.

[0031] As a further preferred solution, in step S2, determining the injection boundary includes the following steps:

[0032] S21, use geological exploration data to determine the distribution, thickness and ore grade of mineral layers; obtain terrain data such as slope, aspect and elevation through topographic mapping; use remote sensing images and field surveys to determine internal special boundaries (such as graves, electric poles, etc.) and steep areas.

[0033] S22, using geological exploration data, such as drilling data, calculate the thickness of the ore layer T:

[0034] T=z2-z1

[0035] S23, calculate the slope using the digital terrain model (DTM):

[0036]

[0037] Where, d h is the elevation change per unit distance, d x is the horizontal distance.

[0038] S24, using GIS software to analyze remote sensing images and terrain data, identify the location of special boundaries. For special boundaries, such as graves, a buffer zone is set, and no injection holes are arranged in the buffer zone.

[0039] S25, identify areas of sudden changes in terrain, such as scarps, which may be formed by geological structures or erosion. Scarps are identified by analyzing the rate of change of elevation. To achieve this, when the rate of change exceeds the set threshold, it is determined to be a steep step.

[0040] S26, considering the above factors, spatial analysis was performed in GIS environment to determine the injection boundary. Multi-criteria evaluation (MCE) method was used to assign weights to each factor and make a comprehensive score.

[0041] S27, using 3D geological modeling software, the above analysis results are visualized in 3D to assist in determining the injection boundary.

[0042] S28, estimating the number, spacing and depth of the injection holes according to the determined injection boundary.

[0043] Calculate the number of injection wells N:

[0044]

[0045] In the formula, A z is the injection area, A w is the grid area of ​​a single injection well.

[0046] As a further preferred solution, in step S3, geological exploration data including stratum structure, fracture development, fault distribution and groundwater flow rate obtained by seismic exploration, electromagnetic exploration and drilling are collected. Fracture and fault identification can identify the locations of fractures and faults in the bedrock floor through geological maps and exploration reports. Then, the permeability of fractures and faults is evaluated to determine their impact on the seepage control of the ore body.

[0047] Specifically, the fracture influence coefficient K, fault influence coefficient F and comprehensive permeability coefficient k are constructed and calculated, and the thickness of the anti-seepage layer h and the material requirement M are determined according to the following steps:

[0048] First, the crack influence coefficient K is calculated based on the crack frequency, crack width, crack length and other parameters of the identified cracks:

[0049]

[0050] Where n f is the crack frequency (number of cracks / unit length), w f is the crack width and L is the crack length.

[0051] According to the number, width, affected area and other parameters of the identified faults, the fault influence coefficient F is calculated:

[0052]

[0053] Where n d is the number of faults / unit area, w d is the fault width, and S is the fault affected area.

[0054] According to the fracture influence coefficient K and fault influence coefficient F, the comprehensive permeability coefficient k is calculated:

[0055] k=k0×(1+K×F)

[0056] Where k0 is the original permeability of bedrock, K and F are the influence coefficients of cracks and faults, respectively.

[0057] According to the above three coefficients, determine the thickness h of the anti-seepage layer and the material requirement M:

[0058]

[0059] M=h×A×ρ

[0060] Where P is the required anti-seepage pressure, σ is the tensile strength of the anti-seepage material, k is the comprehensive permeability coefficient, k0 is the original permeability coefficient of bedrock, A is the coverage area of ​​the anti-seepage layer, and ρ is the density of the anti-seepage material.

[0061] On the basis of the above, further determine the area that needs to be reinforced and the best location of the anti-seepage layer. Select suitable anti-seepage materials, such as cement slurry, bentonite, polymer, etc., to construct the anti-seepage layer.

[0062] As a further preferred solution, in step S4, constructing a three-dimensional seepage field model of the mining area, delineating the impermeable area, plastic area, seepage convergence area and liquid accumulation area in the ore body includes the following steps:

[0063] S41, collect geological, hydrological, topographical and other data of the mining area, and obtain permeability parameters of the ore layer, such as permeability coefficient.

[0064] S42, use geostatistical software (such as GSLIB, Isatis, etc.) for geological modeling. Construct a three-dimensional geological model of the ore body, including the distribution, thickness and permeability of the ore layer.

[0065] S43, using computational fluid dynamics software (such as ANSYS, FLAC3D, etc.) to perform seepage simulation and solve the seepage field using finite element method or finite difference method.

[0066] S44, Determination of physical and mechanical parameters of soils and rocks by laboratory tests and field trials. Determination of permeability using Darcy's law.

[0067] S45, based on the simulation results and geological model, identify the impermeable areas, plastic areas, seepage collection areas and liquid accumulation areas. Use GIS software for spatial analysis to assist in identifying and delineating areas.

[0068] S46, calibrate the seepage model by comparing it with the field monitoring data, and adjust the model parameters until the simulation results match the actual observations.

[0069] As a further preferred solution, in step S5, the injection system and the extraction system are designed, and the injection and extraction automatic control system is designed, and the leaching process is simulated using a mathematical model to optimize the leaching efficiency, including the following steps:

[0070] S51, design the location and spacing of injection holes based on the geometry and permeability characteristics of the ore body. Use a 3D geological model to assist in visualizing the optimal layout of injection holes.

[0071] S52, determine the depth of the injection hole to ensure that it reaches the effective part of the ore body. Design the diameter of the injection hole to optimize the injection rate and pressure of the liquid. Select appropriate injection equipment, such as a reciprocating pump or a centrifugal pump, and the corresponding control system.

[0072] S53, design extraction wells in the low part of the ore body or the seepage collection area to optimize the collection of leachate. Select efficient extraction equipment, such as vacuum pumps or centrifugal pumps, and extraction control systems.

[0073] S54, design the liquid accumulation area to collect the leachate and ensure its effective connection with the extraction well. Deploy pressure, flow and concentration sensors in the injection hole and extraction well. Build and use the data acquisition system to collect sensor data.

[0074] S55, build a central control system with built-in feedback control-based algorithms to automatically adjust the injection and extraction rates. Establish a communication network between field equipment and the central control system. Mathematical models simulate the leaching process.

[0075] S56, build a physical model based on the geological characteristics of the ore body, including its geometry, size, permeability, etc. Use mathematical equations such as the continuity equation and Darcy's law to describe the movement of fluids in porous media. Apply the finite element method (FEM) or finite difference method (FDM) for numerical simulation. Parameterize the model based on geological exploration and laboratory test data. Use professional numerical simulation software such as COMSOL Multiphysics, ANSYS, etc. to solve the model.

[0076] S57, apply optimization algorithms, such as genetic algorithm, particle swarm optimization, etc., to improve leaching efficiency. Analyze simulation results to identify efficiency bottlenecks in the leaching process. Finally, perform sensitivity analysis to determine the key parameters that affect leaching efficiency.

[0077] In step S6, an injection hole and an automatic injection device are arranged on the top of the ore body, a wetting line monitoring sensor is placed in the impermeable area and the plastic area, and a vacuum extraction device is installed in the seepage collection area and the liquid accumulation area to form an injection and extraction automatic control system. The precise control of the injection and extraction of the leaching liquid includes the following steps:

[0078] S61, design the location, depth and diameter of the injection hole according to the numerical simulation results in the previous step. Select a suitable automatic injection pump, such as a peristaltic pump or a diaphragm pump, to achieve precise control. Install an integrated flow meter and pressure sensor to monitor the injection rate and pressure in real time.

[0079] S62, deploy electronic pressure sensors or fiber optic sensors in the impermeable and plastic areas to monitor the changes in the infiltration line. Use wireless or wired transmission systems to send monitoring data to the central control system.

[0080] S63, uses a data acquisition system (DAS) to collect sensor data and applies signal processing technology to extract useful information.

[0081] S64, install vacuum pumps and related extraction pipelines in the seepage collection area and the liquid accumulation area. Install water-gas separators to separate and collect the leachate. Use automatic valve control systems to open or close the extraction equipment as needed.

[0082] S65, set up a feedback control algorithm in the system to automatically adjust the injection and extraction process, and implement PID (proportional-integral-differential) control or other advanced control strategies.

[0083] S66, the central control system integrates control software and hardware interfaces; designs user interfaces to enable real-time monitoring and manual intervention of the system;

[0084] S67, establish a wired or wireless communication network between field devices and the central control system; implement remote access capabilities to allow operators to monitor and control field devices from the control center; install integrated diagnostic tools to perform real-time evaluation of system status and fault diagnosis;

[0085] S68, integrates the injection system, monitoring sensors, extraction equipment and central control system into a coordinated injection and extraction automatic control system; adds safety mechanisms.

[0086] As a further preferred solution, in step S7, a "leaching-liquid collection-leaching" cycle operation is carried out through an injection and extraction automatic control system to achieve in-situ leaching of ionic rare earths; and a real-time monitoring system is established to monitor various parameters during the mining process; and the mining plan is adjusted in a timely manner according to the monitoring data, including the following steps:

[0087] S71, start the automatic injection device to inject the leaching agent (such as ammonium sulfate solution) into the ore body. Adjust the injection rate to ensure that the leaching agent evenly penetrates the ore body.

[0088] S72, monitor the leaching process to ensure that the rare earth ions react fully with the leaching agent and maintain a certain time period to maximize the leaching efficiency of the rare earth.

[0089] S73, start the vacuum extraction equipment to collect the leaching solution containing rare earth ions and transport the leaching solution to the processing facility through the extraction well and pipeline system.

[0090] S74, automatically or manually start the next round of injection according to the rare earth concentration in the collected liquid and the response of the ore body.

[0091] S75, monitors the flow rate, concentration, pH value, temperature and other parameters of the leachate. Monitors groundwater level changes and possible environmental pollution in real time. Collects sensor data in real time. Transmits monitoring data to the central control system via wired or wireless communication networks.

[0092] S76, analyze the collected data to evaluate leaching efficiency and environmental impact. Use the data analysis results to provide decision support for the adjustment of mining plans.

[0093] According to the second main aspect of the present invention, there is provided an ionic rare earth in-situ seepage controlled mining system, the system comprising:

[0094] (1) Liquid injection system, including:

[0095] The injection holes are arranged at the top of the ore body, and their positions, depths and diameters are designed based on the numerical simulation results to achieve precise control;

[0096] An automatic injection pump, integrated with the injection port, is used to adjust the injection rate and pressure;

[0097] The flow meter and pressure sensor are installed near the injection hole to monitor the injection status in real time.

[0098] (2) Monitoring sensors, including:

[0099] Electronic pressure sensors or fiber optic sensors are deployed in the impermeable and plastic areas to monitor changes in the infiltration line;

[0100] Data acquisition system collects sensor data and transmits it to the central control system.

[0101] (3) Extraction system, including:

[0102] Vacuum pumps and extraction pipes are installed in the seepage collection area and the liquid accumulation area to collect the leachate;

[0103] A water-gas separator for separating and collecting the leachate;

[0104] Automatic valve control system opens or closes the extraction equipment as needed.

[0105] (4) Central control system, including:

[0106] Control algorithm, which automatically adjusts the injection and extraction rates based on feedback control;

[0107] Communication network, connecting field equipment with central control system to achieve data transmission and remote control;

[0108] User interface, providing real-time monitoring of system status and manual intervention functions;

[0109] Integrated diagnostic tools for real-time evaluation of system status and fault diagnosis.

[0110] (5) Integrated safety module to ensure safe operation of the system, including emergency stop button, overload protection, etc.

[0111] Compared with existing technologies, this ion-type rare earth in-situ seepage control mining technology has achieved efficient, environmentally friendly and intelligent resource development. Through precise geological exploration and three-dimensional map construction, we can accurately locate the best location for injection and extraction and optimize the mining layout.

[0112] Secondly, the intelligent design of the injection system and extraction system, combined with real-time monitoring and data analysis, not only improves the leaching rate and recovery rate of rare earths, but also reduces production costs.

[0113] In this technical solution, the leaching efficiency is significantly improved while the impact on the environment is reduced through precise monitoring of the poorly permeable areas and plastic areas, as well as effective management of the seepage collection areas and liquid accumulation areas.

[0114] In addition, the automated injection and lifting control system reduces human intervention and improves the safety and reliability of operations. The establishment of a real-time monitoring system allows us to respond immediately to any changes in the mining process and adjust the mining plan in a timely manner, ensuring the stability and continuity of mining activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0115] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0116] Figure 1 A process flow chart of an embodiment of the present invention is shown;

[0117] Figure 2 A schematic diagram of terrain and injection boundary delineation according to an embodiment of the present invention is shown;

[0118] Figure 3 A schematic diagram of the distribution of the thickness of a mineral layer according to an embodiment of the present invention is shown;

[0119] Figure 4 A schematic diagram of a steep slope area according to an embodiment of the present invention is shown;

[0120] Figure 5 A schematic diagram of an internal special boundary of an embodiment of the present invention is shown;

[0121] Figure 6 A schematic diagram of the designed injection range of an ore body according to an embodiment of the present invention is shown;

[0122] Figure 7 A schematic diagram of liquid injection grid and depth zoning according to an embodiment of the present invention is shown;

[0123] Figure 8 A schematic diagram showing the arrangement of a liquid injection system and an extraction system for an ore body according to an embodiment of the present invention is shown;

[0124] Fig. 9 A schematic diagram (I) showing the spatial position of ore body information and liquid collection engineering according to an embodiment of the present invention;

[0125] Fig.10 A schematic diagram (II) showing the spatial position of ore body information and liquid collection engineering according to an embodiment of the present invention. DETAILED DESCRIPTION

[0126] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings so that the purpose, features and advantages of the present invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.

[0127] In the following description, certain specific details are set forth for the purpose of illustrating the various disclosed embodiments to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0128] References throughout the specification to "one embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0129] like Figure 1 As shown, the in-situ seepage controlled mining system of ionic rare earth of the present invention comprises:

[0130] (1) Liquid injection system, including:

[0131] The injection holes are arranged at the top of the ore body, and their positions, depths and diameters are designed based on the numerical simulation results to achieve precise control;

[0132] An automatic injection pump, integrated with the injection port, is used to adjust the injection rate and pressure;

[0133] The flow meter and pressure sensor are installed near the injection hole to monitor the injection status in real time.

[0134] (2) Monitoring sensors, including:

[0135] Electronic pressure sensors or fiber optic sensors are deployed in the impermeable and plastic areas to monitor changes in the infiltration line;

[0136] Data acquisition system collects sensor data and transmits it to the central control system.

[0137] (3) Extraction system, including:

[0138] Vacuum pumps and extraction pipes are installed in the seepage collection area and the liquid accumulation area to collect the leachate;

[0139] A water-gas separator for separating and collecting the leachate;

[0140] Automatic valve control system opens or closes the extraction equipment as needed.

[0141] (4) Central control system, including:

[0142] Control algorithm, which automatically adjusts the injection and extraction rates based on feedback control;

[0143] Communication network, connecting field equipment with central control system to achieve data transmission and remote control;

[0144] User interface, providing real-time monitoring of system status and manual intervention functions;

[0145] Integrated diagnostic tools for real-time evaluation of system status and fault diagnosis.

[0146] (5) Integrated safety module to ensure safe operation of the system, including emergency stop button, overload protection, etc.

[0147] The execution subject of the above system includes but is not limited to at least one of the electronic devices such as a server and a terminal that can be configured to execute the method provided in the embodiment of the present application. In other words, the ionic rare earth in-situ seepage control mining system can be executed by software or hardware installed in a terminal device or a server device, and the software can be a blockchain platform.

[0148] The server includes but is not limited to: a single server, a server cluster, a cloud server or a cloud server cluster, etc.

[0149] The server can be an independent server or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, content delivery networks (CDN), as well as big data and artificial intelligence platforms.

[0150] Example 1: The specific implementation method of the rare earth recovery project of Changting Zhongfang I-15 ore body is as follows:

[0151] Step S1: Acquire geological and hydrological exploration data, build a three-dimensional map of the mining area in combination with remote sensing data, and take representative ore layer samples for testing.

[0152] During the exploration phase of the Zhongfang I-15 ore body, geological radar (GPR), seismic exploration, and electromagnetic exploration (EM) were used to obtain underground structural information, including faults and fissures. At the same time, groundwater levels and hydrogeological conditions were analyzed through hydrological logging and groundwater flow models. High-resolution satellite images and sensors carried by drones were used to analyze surface features, and GIS software was used to create a three-dimensional map of the mining area. On this basis, representative ore samples were obtained through drilling, and X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) were used to determine the ore grade.

[0153] The Changting Zhongfang I-15 ore body rare earth recovery project is located in the eastern part of the Changting Zhongfang rare earth mining area. The mineral resources mainly include rare earth, limestone, dolomite, silica, potassium feldspar, kaolin and other minerals, and the mining industry is underdeveloped. The fully weathered ore is stored in the lower part of the residual slope accumulation layer. The ore color is yellow-brown to reddish brown, the structure is relatively loose, and the rare earth ion phase grade is 0.010-0.200×10-2, and the highest is 0.289×10-2.

[0154] The mineral composition of the ore is mainly clay minerals (50-70%), quartz (20-30%) and feldspar (5-30%). Rare earth elements are mainly adsorbed on the surface and between particles of clay minerals in the form of cations. The rare earth grade varies with the weathering degree of the granite weathering crust. The ore grade tends to decrease from the ridge to the foot of the mountain. There are no industrial ore bodies in the valley and the areas near both sides. There are only low-grade ore bodies or mineralized bodies. The vertical change pattern is: low-high-low, showing a gradual phenomenon, and the boundary is not obvious.

[0155] Step S2: Determine the injection boundary by considering the influence of the ore layer thickness, steep slope area, internal special boundary and steep slope area.

[0156] Considering the economic benefits of mining, the ore layer in the injection area cannot be too thin, otherwise it will increase production costs; for areas with steep slopes, landslides are easy to occur if conventional injection methods are used; there are usually some special areas in the ore body, such as graves, electric poles, etc., and the injection holes need to be arranged away from these special areas; steep slope areas are also extremely prone to landslides. Therefore, when delineating the injection boundary, the influence of ore layer thickness, steep slope areas, internal special boundaries and steep slope areas should be considered. The injection boundary of the Zhongfang I-15 ore body is determined based on the above four factors, such as Figure 2 shown.

[0157] The ionic rare earth resource reserve estimation software was used to calculate the spatial distribution of rare earth grade in the Zhongfang I-15 ore body, and a graph was drawn showing the variation of ore layer thickness with spatial position. The results are shown in Figure 2. Figure 3 The area with a ore layer thickness greater than 3m is taken as the injection area, and the injection boundary is preliminarily determined.

[0158] According to the ore body topography, we searched for areas with a slope greater than 30°. As a result, we found that the Zhongfang I-15 ore body has many areas with steep slopes, such as Figure 4 shown.

[0159] There are two large tombs within the injection boundary. It is recommended not to inject liquid within 5m around the tombs, and the injection well construction should avoid this area. There is a dense rock rolling area on the surface of the south side of the I-15 ore body. Since it is impossible to construct the injection hole, this area is deducted from the design. The specific location is as follows Figure 5 shown.

[0160] Therefore, according to the exploration data, the area with a thickness of more than 3m of the ore layer is determined as the injection area, and the area with a slope greater than 30° is considered to avoid arranging injection holes in these landslide-prone areas. At the same time, special areas in the ore body, such as graves and electric poles, are identified, and the injection holes need to be arranged away from these areas. For steep slope areas, the areas with dense surface vegetation will be further confirmed after clearing the surface, and spatial analysis will be performed in the GIS environment to determine the injection boundary. No steep slope areas have been found in the I-15 ore body mountain, and the areas with dense surface vegetation need to be further confirmed after clearing the surface. Through correction, the injection boundary area was finally determined to be 33668m 2 The designed injection range of the ore body is as follows: Figure 6 shown.

[0161] Step S3: Identify cracks and faults in the bedrock floor and design the location and structure of the anti-seepage layer.

[0162] Identify cracks and faults in the bedrock floor through geological exploration data and evaluate their permeability. Calculate the crack influence coefficient, fault influence coefficient and comprehensive permeability coefficient to determine the thickness of the anti-seepage layer and the material requirement. Select appropriate anti-seepage materials, such as cement slurry, bentonite, etc., to construct an anti-seepage layer to prevent liquid leakage.

[0163] Firstly, geological exploration of the Zhongfang I-15 ore body has been completed through geological radar (GPR), seismic exploration and electromagnetic exploration (EM), collecting data such as the distribution, frequency, width and length of fractures and faults.

[0164] According to the crack frequency, crack width, crack length and other parameters of the identified cracks, the crack influence coefficient K is calculated:

[0165]

[0166] Where n f is the crack frequency (number of cracks / unit length), w f is the crack width and L is the crack length.

[0167] According to the number, width, affected area and other parameters of the identified faults, the fault influence coefficient F is calculated:

[0168]

[0169] Where n d is the number of faults / unit area, w d is the fault width, and S is the fault affected area.

[0170] According to the fracture influence coefficient K and fault influence coefficient F, the comprehensive permeability coefficient k is calculated:

[0171] k=k0×(1+K×F)

[0172] Where k0 is the original permeability of bedrock, K and F are the influence coefficients of cracks and faults, respectively.

[0173] According to the above three coefficients, determine the thickness h of the anti-seepage layer and the material requirement M:

[0174]

[0175] M=h×A×ρ

[0176] Where P is the required anti-seepage pressure, σ is the tensile strength of the anti-seepage material, k is the comprehensive permeability coefficient, k0 is the original permeability coefficient of bedrock, A is the coverage area of ​​the anti-seepage layer, and ρ is the density of the anti-seepage material.

[0177] Through the analysis of exploration data, the main fracture zones and fault lines were identified in the bedrock floor. It was found that the fracture frequency in a certain area was 5 fractures / meter, the average width was 0.05 meters, and the length was 10 meters; the number of faults was 2, the average width was 0.2 meters, and the affected area was 100 square meters. The hydraulic conductivity of the fractures and faults was calculated and determined through water injection tests. According to the permeability evaluation of the fractures and faults, the thickness and material requirements of the anti-seepage layer were determined. At the construction site, according to the design drawings and calculation parameters, grouting equipment was used to inject cement slurry along the fractures and faults to construct an anti-seepage layer. During the construction process, the grouting pressure and flow were monitored in real time to ensure that the anti-seepage layer was uniform and continuous. After the construction was completed, the quality of the anti-seepage layer was verified by drilling sampling and permeability testing. Ensure that the anti-seepage layer achieves the expected anti-seepage effect.

[0178] Step S4: construct a three-dimensional seepage field model of the mining area.

[0179] Collect geological, hydrological, topographical and other data of the mining area, use geological statistical software for geological modeling, and construct a three-dimensional geological model of the ore body. Use computational fluid dynamics software for seepage simulation, and use finite element method or finite difference method to solve the seepage field. Determine the physical and mechanical parameters of soil and rock through laboratory tests and field tests, and use Darcy's law to determine the permeability coefficient. According to the simulation results and geological model, identify the impermeable area, plastic area, seepage convergence area and liquid accumulation area.

[0180] Through 3D visualization software, we can get Figure 7 The mesh parameters for liquid injection within the grid line area of ​​the inner area are 1.5m×1.5m, the mesh parameters for liquid injection within the grid line area of ​​the middle area are 2m×2m, and the mesh parameters for liquid injection within the outer area are 3.0m×3.0m.

[0181] Step S5: Design the injection system and extraction system, and build an intelligent control system.

[0182] Design the location and spacing of injection holes according to the geometry and permeability characteristics of the ore body, and use a three-dimensional geological model to assist in visualizing the optimal layout of injection holes. Determine the depth and diameter of the injection holes to optimize the injection rate and pressure of the liquid. Select appropriate injection equipment and a matching control system. Design extraction wells in the low part of the ore body or the seepage convergence area, and select efficient extraction equipment and extraction control systems. Design liquid accumulation areas to collect leachate and ensure its effective connection with the extraction wells. Deploy pressure, flow, and concentration sensors in the injection holes and extraction wells, and establish a data acquisition system to collect sensor data.

[0183] Step S6: Achieve precise control of immersion liquid injection and extraction.

[0184] Arrange injection holes and automatic injection devices on the top of the ore body, select suitable automatic injection pumps, install integrated flow meters and pressure sensors, and monitor the injection rate and pressure in real time. Deploy electronic pressure sensors or fiber optic sensors in the impermeable and plastic areas to monitor changes in the infiltration line. Use a data acquisition system to collect sensor data, and apply signal processing technology to extract useful information. Install vacuum pumps and related extraction pipelines in the seepage collection area and liquid accumulation area, and install water-gas separators to separate and collect leachate. Use an automatic valve control system to open or close the extraction equipment as needed. Set up a feedback control-based algorithm in the system to automatically adjust the injection and extraction process.

[0185] The idea behind the design of the extraction and liquid collection project is to construct a horizontal bedrock anti-seepage curtain around the mining area and a vertical anti-seepage curtain around the ore body; wells are drilled on the surface to pass through the ore body to form self-controlled extraction wells for liquid collection, and 25 extraction wells have been completed.

[0186] Considering the large height difference of each ore block and the stability of the mountain during the mining process, the idea of ​​layered liquid collection is adopted to design the liquid collection project; the tunnel opening is designed in the valley to facilitate soil discharge; considering the construction safety, connecting ports are set every 30 to 40 meters; the elevation of the liquid collection project is slightly higher than the semi-weathered surface and below the ore layer. The tunnel is supported by metal steel frame pipes in time with the excavation. The outer diameter of the steel frame pipe is 48mm and the wall thickness is 3.5mm. In areas where the ore body is more broken or seeping, support should be strengthened to ensure that support is carried out while excavating to prevent unsafe accidents such as sudden roof collapse and edge collapse. The leachate collection pool is designed to be 10m long × 10m wide × 3m, with a capacity of 300m 3 In summary, the design of the injection system and extraction system of the I-15 ore body is as follows: Figure 8 shown.

[0187] The spatial positions of residual slope accumulation layer, low-grade layer, mineral layer, liquid collection project, semi-weathered layer and water surface are obtained through 3D visualization software. Fig. 9 and Fig.10 As shown. Fig. 9 and Fig.10It can be seen that the elevation of the liquid collection project is basically below the ore layer, and there is basically no waste of resources because the liquid collection project is above the ore layer. It should be noted that during construction, whether there is a semi-weathered layer that is difficult to construct, if so, after reaching the semi-weathered layer, the tunnel extends along the semi-weathered layer to ensure the efficiency of liquid collection.

[0188] Step S7: carrying out a cycle of "leaching-liquid collection-leaching".

[0189] Start the automatic injection device to inject the leaching agent into the ore body, and adjust the injection rate to ensure that the leaching agent evenly penetrates the ore body. Monitor the leaching process to ensure that the rare earth ions react fully with the leaching agent. Start the vacuum extraction equipment to collect the leachate containing rare earth ions. Automatically or manually start the next round of injection based on the rare earth concentration in the collected liquid and the response of the ore body. Monitor the flow, concentration, pH value, temperature and other parameters of the leachate, and monitor the changes in the groundwater level and possible environmental pollution in real time. Collect sensor data in real time and transmit the monitoring data to the central control system through wired or wireless communication networks.

[0190] There are two leaching liquid delivery pumps, each with a power of 45KW. The power supply is drawn from the outlet cabinet of the 1000KVA power distribution room in the ore dressing plant and is laid in YJLV3*300+2*150 cable conduits. The water pump is equipped with a main frequency conversion cabinet, and each branch is equipped with a 45KW fan water pump type frequency converter. The frequency conversion main cabinet needs to be equipped with a zero ground bar and good grounding protection.

[0191] The power supply for the remaining electrical equipment (including clean water delivery pump, leachate delivery pump, leachate transfer pump, air compressor, directional drill, etc.) is provided by 315KVA low-voltage distribution room outlet cabinet, which is connected to two 3P400A circuit breakers and leads to two 3X240mm2+1X120mm2 YJLV22-1KV aluminum core cables, which are laid overhead and distributed in the on-site primary distribution box.

[0192] A grounding device must be installed on site to ensure that the grounding resistance is less than 4Ω. The power distribution cabinet and water pump are well connected to the grounding device to ensure grounding stability. Surge protection devices are installed in the power distribution cabinet.

[0193] Step S8: Treat the extracted leaching liquid to extract rare earth elements, and treat the wastewater until it meets discharge standards.

[0194] The leachate is processed through treatment facilities to extract rare earth elements, and appropriate chemical methods are used to precipitate or extract rare earth ions from the solution. The treated wastewater must meet environmental protection standards before it can be discharged. After mining is completed, site restoration is carried out, including soil improvement and vegetation restoration, to reduce the impact of mining activities on the environment.

[0195] During the trial mining process, we strengthened the regulation of injection intensity and method, and added surrounding water quality monitoring and process flow monitoring posts to better improve the mother liquor recovery rate and minimize the impact of mining on the surrounding environment.

[0196] Through the detailed implementation of the above 8 steps, the in-situ seepage controlled mining of ionic rare earths in the Zhongfang I-15 ore body was carried out efficiently and environmentally friendly. Accurate geological exploration, intelligent injection and extraction system design, real-time monitoring and data analysis, and environmental restoration measures jointly ensure the sustainable development of rare earth resources. This case demonstrates an innovative mining method, which has important reference value for the mining of similar ore bodies.

[0197] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0198] Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that all changes that fall within the meaning and range of equivalent elements of the claims are embraced in the present invention.

[0199] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, system or module including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, system or module. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the existence of other identical elements in the process, method, system or module including the elements.

[0200] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features invented herein.

Claims

1. An ionic rare earth in-situ seepage controlled mining method, characterized in that: The steps include: S1, obtain geological and hydrological exploration data, build a three-dimensional map of the mining area in combination with remote sensing data, and take representative ore samples for testing; S2, considering the influence of ore layer thickness, steep slope area, internal special boundary and steep slope area, determine the injection boundary; S3, identify the cracks and faults in the bedrock floor, design the location and structure of the anti-seepage layer; construct and calculate the crack influence coefficient K, fault influence coefficient F and comprehensive permeability coefficient k, determine the thickness h of the anti-seepage layer and the material requirement M, and construct the anti-seepage layer; S4, construct a three-dimensional seepage field model of the mining area to delineate the impermeable area, plastic area, seepage convergence area and liquid accumulation area in the ore body; S5, design the injection system and extraction system, and build an intelligent control system, use mathematical models to simulate the leaching process, and optimize the leaching efficiency; S6, arrange injection holes and automatic injection devices on the top of the ore body, place infiltration line monitoring sensors in the difficult-to-permeate area and plastic area, install vacuum extraction equipment in the seepage collection area and liquid accumulation area, and form an injection and extraction automatic control system to achieve precise control of leaching liquid injection and extraction; S7, through the injection and extraction automatic control system, carry out the "leaching-liquid collection-leaching" cycle operation to achieve in-situ leaching of ionic rare earths; and establish a real-time monitoring system to monitor various parameters during the mining process; according to the monitoring data, timely adjust the mining plan; S8, treat the extracted leaching liquid, extract rare earth elements, and treat the wastewater to meet discharge standards; after mining is completed, site restoration is carried out, including soil improvement and vegetation restoration; Step S2 includes the following steps: S21, using geological exploration data to determine the distribution, thickness and ore grade of the mineral layer; obtaining terrain data such as slope, aspect and elevation through topographic mapping; using remote sensing images and field surveys to determine internal special boundaries and steep areas; S22, using geological exploration data, such as drilling data, calculate the thickness of the ore layer T: T=z2-z1 S23, calculate the slope using the digital terrain model (DTM): Where, d h is the elevation change per unit distance, d x is the horizontal distance; S24, analyzing remote sensing images and terrain data through GIS software to identify the location of special boundaries; for the special boundaries, a buffer zone is set, and no injection holes are arranged in the buffer zone; S25, identify areas with sudden changes in terrain, and identify steep slopes by analyzing the rate of change of elevation To achieve this, when the rate of change exceeds the set threshold, it is determined to be a steep hill; S26, considering the influence of ore thickness, steep slope area, internal special boundary and steep slope area, spatial analysis is carried out in GIS environment to determine the injection boundary; using multi-criteria evaluation method, weight is assigned to each factor and comprehensive score is given; S27, using 3D geological modeling software, the analysis results are visualized in 3D to assist in determining the injection boundary; S28, estimating the number, spacing and depth of the injection holes according to the determined injection boundary; Calculate the number of injection wells N: In the formula, A z is the injection area, A w is the grid area of ​​a single injection well.

2. The ionic rare earth in-situ seepage controlled mining method according to claim 1, characterized in that: In step S1, the three-dimensional map of the mining area is constructed by using one or more of GIS software, digital terrain model or geological modeling software.

3. The ionic rare earth in-situ seepage controlled mining method according to claim 1 or 2, characterized in that: In step S1, taking representative ore samples for testing includes drilling at a determined sampling point to obtain ore samples; and using an ion mass spectrometry technique combined with X-ray fluorescence spectroscopy and inductively coupled plasma to determine the ore grade.

4. The ionic rare earth in-situ seepage controlled mining method according to claim 1 or 2, characterized in that: The construction and calculation of the fracture influence coefficient K, the fault influence coefficient F and the comprehensive permeability coefficient k, and the determination of the anti-seepage layer thickness h and the material requirement M are carried out in the following steps: First, the crack influence coefficient K is calculated based on the crack frequency, crack width, crack length and other parameters of the identified cracks: Where n f is the crack frequency, w f is the crack width, L is the crack length; According to the number, width, affected area and other parameters of the identified faults, the fault influence coefficient F is calculated: Where n d is the number of faults / unit area, w d is the fault width, S is the fault affected area; According to the fracture influence coefficient K and fault influence coefficient F, the comprehensive permeability coefficient k is calculated: k=k0×(1+K×F) Where k0 is the original permeability coefficient of bedrock, K and F are the influence coefficients of cracks and faults, respectively; According to the above three coefficients, determine the thickness h of the anti-seepage layer and the material requirement M: M=h×A×ρ Where P is the required anti-seepage pressure, σ is the tensile strength of the anti-seepage material, k is the comprehensive permeability coefficient, k0 is the original permeability coefficient of bedrock, A is the coverage area of ​​the anti-seepage layer, and ρ is the density of the anti-seepage material.

5. The ionic rare earth in-situ seepage controlled mining method according to claim 1 or 2, characterized in that: In step S4, constructing a three-dimensional seepage field model of the mining area and delineating the impermeable area, plastic area, seepage convergence area and liquid accumulation area in the ore body includes the following steps: S41, collect geological, hydrological and topographic data of the mining area; obtain permeability parameters of the ore layer; S42, geological modeling using geostatistical software; constructing a three-dimensional geological model of the ore body, including the distribution, thickness and permeability of the ore layer; S43, use computational fluid dynamics software to simulate seepage flow; use finite element method or finite difference method to solve the seepage field; S44, Determine physical and mechanical parameters of soils and rocks by laboratory tests and field trials; Determine permeability using Darcy's law; S45, based on the simulation results and geological model, identify the impermeable area, plastic area, seepage collection area and liquid accumulation area; Use GIS software to conduct spatial analysis to assist in identifying and delineating areas; S46, calibrate the seepage model by comparing with the field monitoring data; adjust the model parameters until the simulation results are consistent with the actual observations.

6. The ionic rare earth in-situ seepage controlled mining method according to claim 1 or 2, characterized in that: In step S5, the injection system and the extraction system are designed, and the injection and extraction automatic control system is designed. The leaching process is simulated using a mathematical model, and the leaching efficiency is optimized, including the following steps: S51, design the location and spacing of injection holes according to the geometry and permeability characteristics of the ore body; use a three-dimensional geological model to assist in visualizing the optimal layout of injection holes; S52, determine the depth of the injection hole to ensure that it reaches the effective part of the ore body; design the diameter of the injection hole to optimize the injection rate and pressure of the liquid; select appropriate injection equipment and its supporting control system; S53, design extraction wells at the low point of the ore body or the seepage collection area to optimize the collection of leachate; select efficient extraction equipment and extraction control system; S54, design the liquid accumulation area to collect the leachate and ensure its effective connection with the extraction well; deploy pressure, flow and concentration sensors in the injection hole and extraction well; establish and use the data acquisition system to collect sensor data; S55, build a central control system with built-in feedback control-based algorithms to automatically adjust the injection and extraction rates; establish a communication network between field equipment and the central control system; and simulate the leaching process with a mathematical model; S56, establish a physical model based on the geological characteristics of the ore body, use mathematical equations to describe the movement of fluids in porous media; apply finite element method or finite difference method for numerical simulation; parameterize the model based on geological exploration and laboratory test data; use professional numerical simulation software to solve the model; S57, apply optimization algorithms to improve leaching efficiency; analyze simulation results to identify efficiency bottlenecks in the leaching process; and finally perform sensitivity analysis to determine the key parameters that affect leaching efficiency.

7. The ionic rare earth in-situ seepage controlled mining method according to claim 1 or 2, characterized in that: In step S6, an injection hole and an automatic injection device are arranged on the top of the ore body, a wetting line monitoring sensor is placed in the impermeable area and the plastic area, and a vacuum extraction device is installed in the seepage collection area and the liquid accumulation area to form an injection and extraction automatic control system. The precise control of the injection and extraction of the leaching liquid includes the following steps: S61, design the position, depth and diameter of the injection hole according to the numerical simulation results in the previous step; select a suitable automatic injection pump to achieve precise control; install an integrated flow meter and pressure sensor to monitor the injection rate and pressure in real time; S62, deploy electronic pressure sensors or fiber optic sensors in the impermeable and plastic areas to monitor the changes in the infiltration line; use wireless or wired transmission systems to send monitoring data to the central control system; S63, using data acquisition system to collect sensor data; applying signal processing technology to extract useful information; S64, install vacuum pumps and related extraction pipelines in the seepage collection area and liquid accumulation area; install water-gas separators to separate and collect leachate; use automatic valve control systems to open or close extraction equipment as needed; S65, set up a feedback control-based algorithm in the system to automatically adjust the injection and extraction process; implement PID control or other advanced control strategies; S66, the central control system integrates control software and hardware interfaces; designs user interfaces to enable real-time monitoring and manual intervention of the system; S67, establish a wired or wireless communication network between field equipment and the central control system; implement remote access capabilities; install integrated diagnostic tools to perform real-time evaluation of system status and fault diagnosis; S68 integrates the injection system, monitoring sensors, extraction equipment and central control system into a coordinated injection and extraction automatic control system; and adds safety mechanisms.

8. An ionic rare earth in-situ seepage controlled mining system for implementing the method of claim 1, characterized in that: The system at least includes a liquid injection system, a monitoring sensor, an extraction system, a central control system and an integrated safety module.

9. The ionic rare earth in-situ seepage controlled mining system according to claim 8, characterized in that: The injection system at least comprises: The injection holes are arranged at the top of the ore body, and their positions, depths and diameters are designed based on the numerical simulation results to achieve precise control; An automatic injection pump, integrated with the injection port, is used to adjust the injection rate and pressure; Flow meter and pressure sensor are installed near the injection hole to monitor the injection status in real time; The monitoring sensor at least comprises: Electronic pressure sensors or fiber optic sensors are deployed in the impermeable and plastic areas to monitor changes in the infiltration line; Data acquisition system, which collects sensor data and transmits it to the central control system; The extraction system at least comprises: Vacuum pumps and extraction pipes are installed in the seepage collection area and the liquid accumulation area to collect the leachate; A water-gas separator for separating and collecting the leachate; Automatic valve control system opens or closes the extraction equipment as needed.

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