An efficient and safe mining method for deep multi-layer overlapping ore bodies

Abstract

The present invention relates to the field of mineral processing technology, and in particular to a method for efficient and safe mining of deep multi-layer overlapping ore bodies, comprising the following steps: three-dimensional geological modeling, conducting geological exploration in the area to be mined and obtaining geological data to construct an ore body model; digging monitoring holes in sections and constructing a real-time monitoring system for geological changes; excavating a secondary transfer layer in the overlapping area of ​​the ore body and constructing support; opening a backfill mine room in the secondary transfer layer and constructing a main tunnel and a main filling pipeline; dividing the ore body into a first mining area and a second mining area, and mining the first mining area or the second mining area respectively by caving or tailings backfilling. In the present invention, by pre-constructing an ore body model in the multi-layer overlapping ore body, subsequent construction is facilitated, and a real-time monitoring system for geological changes is constructed for early warning. At the same time, a secondary transfer layer is constructed in the surrounding rock to transfer the filling pipeline and tunnel construction, thereby reducing production risks and achieving safe, stable and cost-effective effects.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and in particular to a method for efficiently and safely mining a deep multi-layer overlapping ore body. Background Art

[0002] The vigorous development of the current industrial system has led to a continuous increase in demand for mineral resources. Now shallow ore bodies are becoming increasingly depleted, and mining is extending to deeper areas. The mining of ore bodies deep in the veins has become an important direction of the domestic mining industry.

[0003] However, deep ore bodies are characterized by deep burial depth, complex stratigraphic structures, and the development of weak interlayers. The mining of deep, multi-layered, overlapping ore bodies faces many challenges. First, as the mining depth increases, the ground pressure increases, and ground pressure disasters such as rock bursts and rockbursts occur frequently, posing a serious threat to mine safety. Secondly, the presence of weak interlayers reduces the stability of the rock mass, increasing the difficulty of tunnel support and stope management. During deep mining, deformation of the tunnel surrounding rock is a common and serious problem. Since deep mines are greatly affected by ground pressure and stress, the surrounding rock is prone to deformation and instability, which may lead to tunnel collapse, equipment damage, and casualties. In addition, deep environments such as high temperature and high humidity place higher demands on equipment performance and the health of mining personnel.

[0004] Therefore, there is a need for a safe, efficient and cost-effective method for mining deep multi-layer overlapping ore bodies. Summary of the Invention

[0005] The main purpose of the present invention is to provide an efficient and safe mining method for deep multi-layer overlapping ore bodies, aiming to solve the problems of danger and high cost of existing mining methods for deep multi-layer overlapping ore bodies.

[0006] To achieve the above object, the present invention provides a method for efficiently and safely mining a deep multi-layer overlapping ore body, the method comprising the following steps:

[0007] 3D geological modeling: Conduct geological exploration in the area to be mined and obtain geological data to build an ore body model;

[0008] Based on the ore body model, monitoring holes are dug in sections and a real-time monitoring system for geological changes is established through the monitoring holes.

[0009] Construct a secondary transfer layer based on the ore body model, excavate a 2-5m high secondary transfer layer horizontally in the surrounding rock in the overlapping area of ​​multiple ore bodies, and build support for the secondary transfer layer;

[0010] A backfill chamber is opened in the secondary transfer layer, and a main tunnel and main filling pipeline are constructed to connect the surface filling station and the chamber through the main filling pipeline;

[0011] Based on the ore body model, the ore body is divided into a first mining area and a second mining area. The first mining area is mined by the caving method, and the second mining area is mined by the tailings backfill method.

[0012] Furthermore, the three-dimensional geological modeling includes the steps of conducting geological exploration in the area to be mined and obtaining geological data to construct an ore body model:

[0013] Drill holes in the area to be mined and collect drilling data as well as geophysical and geochemical data;

[0014] Organize the acquired drilling data and geochemical data, and perform noise reduction and filtering on the drilling data, geophysical data, and geochemical data to obtain accurate geological data;

[0015] Import geological data into 3D geological modeling software and determine the geological horizon boundaries, major faults, fault trends, ore body shape, ore body size, and spatial distribution in the area to be mined;

[0016] Kriging method is used to estimate resources and determine the reserves and grade distribution of the ore body.

[0017] Furthermore, the step of digging monitoring holes in sections based on the ore body model and constructing a real-time monitoring system for geological changes through the monitoring holes includes:

[0018] Based on the ore body model, stress monitoring holes are excavated in sections in the area to be mined, with a hole diameter of 50-100 mm and a depth of 1-2 meters;

[0019] A stress sensor is fixedly installed in the stress monitoring hole, the gap of the stress sensor is filled with cement slurry, and a protective bracket is installed on the outside of the stress sensor;

[0020] Drill microseismic monitoring holes every 100-200 meters around the area to be mined, with a diameter of 50-100 mm and a depth of 1-3 meters;

[0021] Install a microseismic sensor in the microseismic monitoring hole, fill the gap between the microseismic sensor and the microseismic sensor with cement slurry, and install a protective bracket on the outside of the microseismic sensor;

[0022] A wireless sensor network and data acquisition and processing modules are set up in the area to be mined to monitor geological changes in the area in real time.

[0023] Furthermore, the steps of constructing a secondary transfer layer based on the ore body model, horizontally excavating a secondary transfer layer with a height of 2-5m in the overlapping area of ​​multiple ore bodies, and constructing support for the secondary transfer layer include:

[0024] Based on the ore body model, the stable surrounding rock area surrounding the ore body is divided into safety layers from the surface downward;

[0025] A secondary transfer layer with a height of 2-5 meters is excavated horizontally within the safety layer;

[0026] Install prestressed anchor rods, drill holes on the inner wall of the secondary transfer layer and insert the prestressed anchor rods into the holes to apply prestress to the prestressed anchor rods;

[0027] Lay steel mesh on the inner wall of the secondary transfer layer, and fix multiple steel meshes with binding wires;

[0028] Use shotcrete equipment to evenly spray concrete onto the steel mesh to form a support layer.

[0029] Furthermore, the steps of constructing a secondary transfer layer based on the ore body model, horizontally excavating a secondary transfer layer with a height of 2-5m in the overlapping area of ​​multiple ore bodies, and constructing support for the secondary transfer layer also include:

[0030] Drilling grouting holes on the inner wall of the secondary transfer layer;

[0031] Use grouting equipment to inject cement slurry into the grouting hole;

[0032] Stress sensors, displacement sensors and crack monitors are arranged on the inner wall of the secondary transfer layer and are connected to a real-time monitoring system for geological changes.

[0033] Furthermore, the steps of opening a backfill chamber in the secondary transfer layer, constructing a main tunnel and a main filling pipeline, and connecting the surface filling station and the chamber via the main filling pipeline include:

[0034] Based on the ore body model, the main tunnel and main filling pipeline are drilled downward from the surface filling station;

[0035] A mixing tank is dug in the secondary transfer layer and connected to the surface filling station through the main filling pipeline;

[0036] An auxiliary filling pipeline is excavated downward from the mixing tank. The mixing tank is used to connect the main filling pipeline and the auxiliary filling pipeline. The mixing tank performs secondary mixing on the filling slurry mixed at the surface filling station.

[0037] Furthermore, the steps of dividing the ore body into a first mining area and a second mining area based on the ore body model, mining the first mining area by the block caving method, and mining the second mining area by the tailings backfill method include:

[0038] Based on the ore body model, the thick and stable ore body is divided into the first mining area, and the fault, fracture development area and weak zone are divided into the second mining area;

[0039] The main and auxiliary adit tunnels are excavated below the first mining area to transport ore and facilitate personnel access.

[0040] Excavate and construct the middle tunnel in sections on the side of the first mining area, and install support and ground pressure monitoring equipment on the inner wall of the middle tunnel;

[0041] Drill blasting holes at intervals of 20-25 meters on the inner wall of the middle tunnel and carry out caving blasting in sections;

[0042] The second mining area is divided into a mining area and a stope. Support and ground pressure monitoring equipment are installed in the mining area, and branch filling pipelines are laid to connect to the stope. One end of the branch filling pipeline is connected to the main filling pipeline, and the other end of the branch filling pipeline is connected to the stope. Multiple branch filling pipelines form a filling pipeline network.

[0043] A ventilation and drainage system is constructed in the stope to remove the gas and free water generated during mining and filling. At the same time, transport tunnels, return air tunnels, ore accumulation tunnels and retreat tunnels are excavated to form a mining system.

[0044] Blasting holes are drilled along the set mining face in the stope, and explosives are loaded into the blasting holes for layered mining. The ore obtained is transported out of the stope, and the empty area that has been mined is the goaf;

[0045] Filling slurry is injected into the goaf through the filling pipeline network, and the filling slurry forms stable surrounding rock after solidification.

[0046] This method pre-builds a 3D geological model, uses it to categorize and plan the ore models within multiple, overlapping ore bodies, and establishes a real-time geological change monitoring system to monitor ground pressure and other geological information and provide early warnings, ensuring safe and efficient mining. Furthermore, by constructing a secondary transfer layer within the ore body's surrounding rock, the risks of ground pressure and stress during the direct drilling of filling pipes and tunnels from the surface into the ore body are avoided, reducing the construction costs of these pipes and tunnels, thereby achieving a safe, stable, and cost-effective mining method. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0048] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0049] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0050] As shallow ore bodies are gradually exhausted, mining is extending to deeper areas. The mining of deep, multi-layered overlapping ore bodies has become an important direction of the domestic mining industry. These ore bodies are deeply buried, have complex stratigraphic structures, developed weak interlayers, and have poor rock stability, which poses huge challenges to traditional mining methods.

[0051] Furthermore, during the mining of deep, multi-layered, overlapping ore bodies, heterogeneous interfaces exist. Heterogeneous interfaces refer to the contact surface or transition zone between rock masses with different lithologies, mechanical properties, and structural characteristics. The existence of these interfaces can have a significant impact on the safety and economic viability of mining. Due to the differences in the physical and mechanical properties of the rock masses on both sides of the heterogeneous interface, stress concentration, reduced surrounding rock stability, and roadway deformation can occur. Therefore, a safe, stable, and cost-effective mining method is needed in deep, multi-layered, overlapping mining.

[0052] Based on this, an embodiment of the present invention provides an efficient and safe mining method for deep multi-layer overlapping ore bodies, the specific steps of which are as follows:

[0053] S10. Three-dimensional geological modeling: conduct geological exploration in the area to be mined and obtain geological data to construct an ore body model; drill holes in the area to be mined and collect drilling data as well as geophysical and geochemical data; organize the obtained drilling data and geochemical data, and perform noise reduction and filtering on the drilling data, geophysical and geochemical data to obtain accurate geological data; import the geological data into three-dimensional geological modeling software and determine the geological horizon boundaries, major faults, fault trends, ore body shape, ore body size, and spatial distribution in the area to be mined; use the Kriging method to estimate resources and determine the reserves and grade distribution of the ore body.

[0054] Specifically, the information obtained by three-dimensional geological modeling includes drilling data including drilling location, drilling depth, core description, ore body thickness, grade and other information; geophysical data is physical data obtained through geophysical exploration data such as electromagnetic, gravity, and magnetic methods; geochemical data includes the chemical composition analysis results of soil, rock, water samples and other components. It is understandable that it can also include geological maps such as geological plan maps, cross-section maps, geological structure maps, as well as historical production data such as ore grade, mining volume, and recovery rate of mined areas.

[0055] Operators standardize and organize the collected data and convert it into a software format that can be used for modeling. For example, drilling data is converted into CSV and Excel formats, and geological maps are converted into DXF or DWG formats. The data is then imported into 3D geological modeling software (such as Leapfrog, Surpac, Datamine, Micromine, etc.). The boundaries of different geological layers, the location and direction of major faults, and the shape, scale, and spatial distribution of the ore body are then determined based on the drill cores. This allows the operator to identify and predict potential geological risks such as faults, collapses, and water gushing, and determine the optimal mining path and method.

[0056] It can be understood that Kriging is a regression algorithm that performs spatial modeling and prediction (interpolation) of random processes / random fields based on covariance functions.

[0057] S20. Based on the ore body model, monitoring holes are excavated in sections, and a real-time monitoring system for geological changes is constructed through the monitoring holes. Based on the ore body model, stress monitoring holes are excavated in sections in the area to be mined, with a hole diameter of 50-100 mm and a depth of 1-2 meters. Stress sensors are fixedly installed in the stress monitoring holes, and the gaps of the stress sensors are filled with cement slurry, and protective brackets are installed on the outside of the stress sensors. Microseismic monitoring holes are drilled every 100-200 meters on the periphery of the area to be mined, with a hole diameter of 50-100 mm and a depth of 1-3 meters. Microseismic sensors are installed in the microseismic monitoring holes, and the gaps of the microseismic sensors are filled with cement slurry, and protective brackets are installed on the outside of the microseismic sensors. A wireless sensor network and a data acquisition and processing module are installed in the area to be mined to monitor the geological changes in the area to be mined in real time.

[0058] Specifically, with the center of the area to be mined as the target, drilling is carried out at a density of 1-5 holes per square meter, with a hole diameter of 50-100 mm and a depth of 1-2 meters. The drilled holes are stress monitoring holes, which are used to set stress sensors. The stress sensors are used to monitor ground pressure. After the stress sensors are set up, the gaps need to be filled with cement slurry obtained by mixing cement with adhesives, and protective brackets are arranged around the sensors to prevent damage to the sensors.

[0059] Specifically, operators arrange ground pressure sensors and displacement sensors at locations prone to ground pressure changes based on the ore body model to ensure that the monitoring range covers the ore body; install microseismic sensors on the periphery and deep inside the mining area to capture microseismic activity data in real time, and transmit the monitoring data emitted by the sensors to the ground data processing center. The monitoring data is analyzed and processed in real time through the wireless sensor network and data acquisition and processing modules of the data processing center to identify abnormal changes and potential risks and provide early warning information.

[0060] S30. Construct a secondary transfer layer based on the ore body model. Excavate a 2-5m high secondary transfer layer horizontally in the surrounding rock at the overlapping area of ​​multiple ore bodies and construct support for the secondary transfer layer. Based on the ore body model, divide the stable surrounding rock area surrounding the ore body into a safety layer from the surface downward. Excavate a 2-5m high secondary transfer layer within the safety layer. Install prestressed anchor rods by drilling holes in the inner wall of the secondary transfer layer and inserting the prestressed anchor rods into the holes to apply prestress to the prestressed anchor rods. Lay steel mesh on the inner wall of the secondary transfer layer, securing the multiple steel meshes with tying wire. Use sprayed concrete equipment to evenly spray concrete onto the steel mesh to form a support layer. Drill grouting holes in the inner wall of the secondary transfer layer. Use grouting equipment to inject cement slurry into the grouting holes. Install stress sensors, displacement sensors, and crack monitors on the inner wall of the secondary transfer layer and connect them to the real-time geological change monitoring system.

[0061] It is understandable that the rocks surrounding the ore body, including the rock bodies located around the rock field, are called surrounding rocks. The properties of the surrounding rocks are different from those of the ore body, and their stability has a significant impact on the safety of the mining process. In the present invention, the secondary transfer layer is opened in the surrounding rock that wraps the ore body. By opening the secondary transfer layer, excessive stress concentration can be avoided, and the sharp angle intersection between the tunnels and between the tunnels and the structural faults can be reduced, so that the distance between adjacent mining projects can avoid stress accumulation, and the ore body layer with the risk of impact ground pressure can be relieved of pressure, so that the elastic deformation accumulated in the ore body can be effectively controlled and released, thereby releasing the stress of the surrounding rock and reducing the risk of tunnel deformation.

[0062] In detail, in the present invention, for the heterogeneous interface of deep multi-layer overlapping ore bodies, a secondary transfer layer with a height of 2-5 meters is excavated to bypass the heterogeneous interface, and the ore body to be mined area is reinforced by the secondary transfer layer, so as to avoid the difficulty in adjusting the drilling position when encountering weak interlayers during vertical downward direct mining or inclined downward direct mining in the existing technology, and the inability to adjust according to actual conditions.

[0063] In the present invention, a secondary transfer layer is used as a transfer layer to transport ore, fill slurry, and reinforce the tunnels and filling pipes by installing prestressed anchors and concrete support layers. It is understood that the prior art includes room-and-pillar mining, which involves retaining some ore within the space where the ore is mined to support the upper rock layer. In the present invention, a secondary transfer layer is created in the surrounding rock and provided with support, forming a stable transfer layer. This avoids the need to maintain excessively long tunnels and pipes when digging directly from the ground to the ore body, reduces the cost of maintaining stability, and improves the safety of deep excavation.

[0064] S40. A backfill chamber is opened in the secondary transfer layer, and a main tunnel and a main filling pipeline are constructed, and the surface filling station and the chamber are connected through the main filling pipeline. Based on the ore body model, the main tunnel and the main filling pipeline are drilled downward from the surface filling station. A mixing tank is excavated in the secondary transfer layer, and the mixing tank is connected to the surface filling station through the main filling pipeline. An auxiliary filling pipeline is excavated downward from the mixing tank, and the mixing tank is used to connect the main filling pipeline and the auxiliary filling pipeline. The mixing tank performs secondary mixing on the filling slurry mixed at the surface filling station.

[0065] In the present invention, a stirring tank with a depth of 1-2 meters and an area according to actual needs is excavated at the bottom of the secondary transfer layer. The stirring tank is connected to the surface filling station through the main filling pipeline. The surface filling station mixes the mined tailings with an adhesive (such as polyurethane) to obtain a filling slurry, which is injected into the stirring tank through the main filling pipeline. The stirring tank is also provided with a stirring device (such as a vibrating device). The stirring tank provided in the secondary transfer layer can be used to stir the filling slurry for a second time to prevent the filling slurry from being subjected to large friction in the main filling pipeline, which would result in a reduced flow rate at the same conveying volume and affect the conveying efficiency. The stirring tank and stirring device provided in the secondary transfer layer can optimize the particle size distribution of the filling slurry, reduce the content of coarse particles and sharp particles, reduce friction between particles and between particles and the pipe wall, improve particle grading, and optimize the characteristics of the filling slurry. The filling slurry is adjusted in the mixing tank and then introduced into the auxiliary filling pipeline to achieve the effect of adjusting the conveying parameters. By adjusting the conveying speed of the filling slurry, the resistance caused by turbulence and turbulence can be reduced to ensure that the filling slurry will not settle in the pipeline. At the same time, it can maintain stable transportation and avoid resistance changes caused by flow fluctuations due to frequent start-stop or speed changes. The conveying pressure can also be reasonably designed according to the conveying distance and height difference of the auxiliary filling pipeline to ensure that the filling slurry maintains a suitable pressure gradient in the entire pipeline.

[0066] S50. Based on the ore body model, the ore body is divided into the first mining area and the second mining area. The first mining area is mined by the caving method, and the second mining area is mined by the tailings backfill method. Based on the ore body model, the thick and stable ore body is divided into the first mining area, and the fault, fissure development area and the weak zone are divided into the second mining area; the main horizontal tunnel and the auxiliary horizontal tunnel are excavated and laid out below the first mining area for ore transportation and personnel entry and exit; the middle section of the roadway is excavated in sections on the side of the first mining area, and support and ground pressure monitoring equipment are set up on the inner wall of the middle section of the roadway; blasting holes are drilled on the inner wall of the middle section of the roadway at intervals of 20-25 meters, and caving blasting is carried out in sections; the second mining area is divided into the waiting area and the mining site, and support and ground pressure monitoring equipment are set up in the waiting area, and support and ground pressure monitoring equipment connecting the mining site are laid out. Filling pipeline, one end of the branch filling pipeline is connected to the main filling pipeline, and the other end of the branch filling pipeline is connected to the mining area, and multiple branch filling pipelines form a filling pipeline network; a ventilation and drainage system is built in the mining area to discharge the gas and free water generated during mining and filling, and at the same time, transportation tunnels, return air tunnels, ore accumulation tunnels and retreat tunnels are excavated to form a mining system; blasting holes are drilled along the set mining face in the mining area, and explosives are loaded into the blasting holes for layered mining, and the obtained ore is transported out of the mining area. The hollow area that has been mined is the goaf; filling slurry is injected into the goaf through the filling pipeline network, and the filling slurry forms stable surrounding rock after solidification.

[0067] In this example, a mining area with poor surrounding rock stability, moderate ore stability, thick ore bodies, and relatively low ore value is designated as a first mining area. Sublevel caving is used for mining in this first mining area. Multiple functional roadways, chutes, and hoppers are horizontally separated along the ore body in the first mining area, with each functional roadway spaced 15-25 meters apart. The functional roadways include haulage roadways and drill-and-blast roadways. The haulage roadways are used for ore transportation, ventilation, and drainage; the drill-and-blast roadways are used for drilling and blasting operations; and the chutes and hoppers are located beneath the ore body to collect and lower the ore.

[0068] Specifically, within the drill-and-blast tunnel, blast holes are drilled into the ore body according to the designed hole pattern parameters. Blasting holes are primarily straight and fan-shaped, with diameters typically ranging from 64 to 102 mm. Explosives are then loaded into the blast holes, and staged, micro-difference blasting is employed to control the blasting effect. After blasting, the ore body collapses under its own weight and the pressure of the overlying rock formation. The ore falls from the upper section into the chute and funnel below. The chute transports the collapsed ore to the main haul tunnel, where it is then transported out of the mine by haulage equipment. After a staged mining operation is completed, the mining process gradually advances upward or forward, forming a continuous mining cycle.

[0069] In this embodiment, the ore body with low surrounding rock strength, prone to collapse after mining, requiring filling and support, and located in an area with dense buildings and sensitive ecological environment, and requiring prevention of surface subsidence and cracking is divided into a second mining area, and the tailings filling method is used for excavation in the second mining area. After excavation of the ore body in the second mining area, the tailings are transported to the surface filling station, and the tailings are mixed with the adhesive and then transported back to the goaf through the filling pipeline. The filling process can be one of high-concentration slurry transportation or gravity filling, among which high-concentration slurry transportation is preferred. The use of the tailings filling method in the second mining area can improve the mining recovery rate of the mine, reduce surface subsidence and environmental pollution, and realize the comprehensive utilization of tailings.

[0070] The present invention achieves the effect of reducing mining costs by pre-constructing a three-dimensional geological model and classifying and planning the ore body models in multiple overlapping ore bodies through the three-dimensional geological model. A real-time geological change monitoring system is also constructed to monitor and warn of ground pressure and other geological information, ensuring the safety and efficiency of the mining process. At the same time, the ore body model is used to divide the ore body into multiple mining areas, and secondary transfer layers are constructed in the surrounding rocks of multiple ore bodies. This reduces the difficulty and cost of building tunnels and filling pipes, avoids the risk of deformation caused by ground pressure or stress, and enables the selection of different mining plans based on the mining difficulty, achieving safe, stable, and cost-effective mining results.

[0071] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An efficient and safe mining method for deep multi-layer overlapping ore bodies, characterized in that: The following steps are involved: 3D geological modeling: Conduct geological exploration in the area to be mined and obtain geological data to construct an ore body model: Drill holes in the area to be mined and collect borehole data as well as geophysical and geochemical data; organize the acquired borehole and geochemical data, and perform noise reduction and filtering on the borehole, geophysical, and geochemical data to obtain accurate geological data; import the geological data into 3D geological modeling software and determine the geological horizon boundaries, major faults, fault trends, ore body shape, ore body size, and spatial distribution in the area to be mined; use Kriging to estimate resources and determine the reserves and grade distribution of the ore body; Based on the ore body model, monitoring holes are dug in sections and a real-time monitoring system for geological changes is established through the monitoring holes. A secondary transfer layer is constructed based on the ore body model. A 2-5m high secondary transfer layer is excavated horizontally in the surrounding rock in the overlapping areas of multiple ore bodies, and support is constructed for the secondary transfer layer. Based on the ore body model, the stable surrounding rock area surrounding the ore body is divided into a safety layer from the surface downward. A 2-5m high secondary transfer layer is excavated horizontally within the safety layer. Prestressed anchor rods are installed by drilling holes into the inner wall of the secondary transfer layer and inserting the prestressed anchor rods into the holes to apply prestress to the prestressed anchor rods. A steel mesh is laid on the inner wall of the secondary transfer layer, and the multiple steel meshes are secured with tying wire. Use shotcrete equipment to evenly spray concrete onto the steel mesh to form a support layer; A backfill chamber is opened in the secondary transfer layer, and a main tunnel and main filling pipeline are constructed to connect the surface filling station and the chamber through the main filling pipeline; Based on the ore body model, the ore body is divided into the first mining area and the second mining area, and the first mining area is mined by the caving method, and the second mining area is mined by the tailings backfill method: Based on the ore body model, the thick and stable ore body is divided into the first mining area, and the fault, fracture development area and weak zone are divided into the second mining area; the main horizontal tunnel and the auxiliary horizontal tunnel are excavated and laid under the first mining area for ore transportation and personnel entry and exit; the middle section roadway is excavated in sections on the side of the first mining area, and support and ground pressure monitoring equipment are set up on the inner wall of the middle section roadway; blasting holes are drilled on the inner wall of the middle section roadway at intervals of 20-25 meters, and caving blasting is carried out in sections; the second mining area is divided into the waiting area and In the mining area, support and ground pressure monitoring equipment are set up and branch filling pipes connecting to the mining area are laid. One end of the branch filling pipe is connected to the main filling pipe, and the other end of the branch filling pipe is connected to the mining area. Multiple branch filling pipes form a filling pipe network; a ventilation and drainage system is built in the mining area to discharge the gas and free water generated during the mining and filling process. At the same time, transportation tunnels, return air tunnels, ore accumulation tunnels and retreat tunnels are excavated to form a mining system; blasting holes are drilled along the set mining face in the mining area, and explosives are loaded into the blasting holes for layered mining. The obtained ore is transported out of the mining area. The hollow area that has been mined is the goaf; filling slurry is injected into the goaf through the filling pipe network, and the filling slurry forms stable surrounding rock after solidification.

2. The efficient and safe mining method for deep multi-layer overlapping ore bodies according to claim 1, characterized in that: The steps of digging monitoring holes in sections based on the ore body model and building a real-time monitoring system for geological changes through the monitoring holes include: Based on the ore body model, stress monitoring holes are excavated in sections in the area to be mined, with a hole diameter of 50-100 mm and a depth of 1-2 meters; A stress sensor is fixedly installed in the stress monitoring hole, the gap of the stress sensor is filled with cement slurry, and a protective bracket is installed on the outside of the stress sensor; Drill microseismic monitoring holes every 100-200 meters around the area to be mined, with a diameter of 50-100 mm and a depth of 1-3 meters; Install a microseismic sensor in the microseismic monitoring hole, fill the gap between the microseismic sensor and the microseismic sensor with cement slurry, and install a protective bracket on the outside of the microseismic sensor; A wireless sensor network and data acquisition and processing modules are set up in the area to be mined to monitor geological changes in the area in real time.

3. The efficient and safe mining method for deep multi-layer overlapping ore bodies according to claim 1, characterized in that: The steps of constructing a secondary transfer layer based on the ore body model, horizontally excavating a secondary transfer layer with a height of 2-5m in the overlapping area of ​​multiple ore bodies, and constructing support for the secondary transfer layer also include: Drilling grouting holes on the inner wall of the secondary transfer layer; Use grouting equipment to inject cement slurry into the grouting hole; Stress sensors, displacement sensors and crack monitors are arranged on the inner wall of the secondary transfer layer and are connected to a real-time monitoring system for geological changes.

4. The efficient and safe mining method for deep multi-layer overlapping ore bodies according to claim 1, characterized in that: The steps of opening a backfill chamber in the secondary transfer layer, constructing a main tunnel and a main filling pipeline, and connecting the surface filling station and the chamber via the main filling pipeline include: Based on the ore body model, the main tunnel and main filling pipeline are drilled downward from the surface filling station; A mixing tank is dug in the secondary transfer layer and connected to the surface filling station through the main filling pipeline; An auxiliary filling pipeline is excavated downward from the mixing tank. The mixing tank is used to connect the main filling pipeline and the auxiliary filling pipeline. The mixing tank performs secondary mixing on the filling slurry mixed at the surface filling station.