Efficient and safe mining method for deep multilayer overlapped ore body

Abstract

The invention relates to the technical field of mineral processing, in particular to an efficient and safe mining method for a deep multi-layer overlapped ore body, which comprises the following steps: three-dimensional geological modeling: carrying out geological exploration in a to-be-mined area and obtaining geological data, and constructing an ore body model; monitoring holes are dug in a segmented mode, and a geological change real-time monitoring system is constructed; a secondary transfer layer is excavated in the overlapping area of the ore body, and a support is constructed; backfill chambers are formed in the secondary transfer layer, and a main roadway and a main filling pipeline are constructed; the ore body is divided into a first mining area and a second mining area, and the first mining area or the second mining area is mined through a caving method or a tailing backfilling method. According to the method, follow-up construction is facilitated by pre-constructing the ore body model in the multi-layer overlapped ore body, a geological change real-time monitoring system is constructed for early warning, meanwhile, a secondary transfer layer is constructed at the surrounding rock to transfer filling pipeline and roadway construction, the production risk is reduced, and the effects of safety, stability and low cost are achieved.

Description

Technical Field

[0001] The 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. Shallow ore bodies are now 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 stratigraphy, and the development of weak interlayers. The mining of deep multi-layer overlapping ore bodies faces many challenges. First, with the increase in mining depth, the ground pressure increases, and ground pressure disasters such as impact ground pressure and rock burst occur frequently, seriously threatening mine safety. Secondly, the existence of weak interlayers reduces the stability of the rock mass, increases the difficulty of tunnel support and mine site management. In the process of deep mining, deformation of 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 requirements on equipment performance and the operating 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 efficient and safe mining of deep multi-layer overlapping ore bodies, 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 constructed through the monitoring holes;

[0009] Construct a secondary transfer layer based on the ore body model, excavate a secondary transfer layer with a height of 2-5m 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 a main filling pipeline are constructed, and the surface filling station and the chamber are connected 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, and 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] The obtained drilling data and geochemical data are sorted, and the drilling data, geophysical data and geochemical data are denoised and filtered to obtain accurate geological data;

[0015] Import the address data into the 3D geological modeling software and determine the geological horizon boundaries, major faults, fault trends, ore body shapes, ore body scales, 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, and the gap of the stress sensor is filled with cement slurry, and a protective bracket is installed outside the stress sensor;

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

[0021] A microseismic sensor is installed in the microseismic monitoring hole, and the gap of the microseismic sensor is filled with cement slurry, and a protective bracket is installed outside the microseismic sensor;

[0022] A wireless sensor network and a data acquisition and processing module are set up in the area to be mined to monitor the geological changes in the area to be mined 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 in 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, and apply prestress to the prestressed anchor rods;

[0027] A steel mesh is laid on the inner wall of the secondary transfer layer, and multiple steel meshes are fixed 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 through 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 with 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 caving method, and mining the second mining area by 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 are excavated below the first mining area to transport ore and facilitate the entry and exit of personnel;

[0040] Excavate and construct the middle tunnel in sections on the side of the first mining area, and set up 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 waiting area and a mining site, support and ground pressure monitoring equipment are set up in the waiting area, and branch filling pipelines connected to the mining site are laid out, 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 site, and multiple branch filling pipelines form a filling pipeline network;

[0043] A ventilation and drainage system is built in the mining area to discharge the gas and free water generated during mining and filling. At the same time, transportation 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 stratified 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] In the present invention, three-dimensional geological modeling is pre-constructed, and the ore body models in the multi-layer overlapping ore bodies are classified and planned through three-dimensional geological modeling, and a real-time monitoring system for geological changes is constructed to monitor and give early warnings to ground pressure and other geological information, so as to ensure the safety and efficiency of the mining process. At the same time, by constructing a secondary transfer layer at the surrounding rock of the ore body, the risk of being easily affected by ground pressure and stress in the process of drilling filling pipes and tunnels directly from the ground to the ore body is avoided, and the construction cost of filling pipes and tunnels is also reduced, so as to achieve a safe, stable and cost-effective mining method. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. 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 only used for descriptive purposes and cannot 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" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a 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 and 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, posing huge challenges to traditional mining methods.

[0051] In addition, during the mining process of deep multi-layer overlapping ore bodies, there will be heterogeneous interfaces, which refer to the contact surface or transition zone between rock bodies with different lithology, different mechanical properties, and different structural characteristics. The existence of these interfaces will have a significant impact on the safety and economy of mining. Due to the differences in the physical and mechanical properties of the rock bodies on both sides of the heterogeneous interface, stress concentration, reduced surrounding rock stability, and roadway deformation may occur. Therefore, a safe, stable, and economically efficient mining method is needed in the process of deep multi-layer 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, and the specific steps 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, collect drilling data as well as geophysical data and geochemical data; organize the obtained drilling data and geochemical data, and reduce noise and filter the drilling data, geophysical data and geochemical data to obtain accurate geological data; import the address data into the three-dimensional geological modeling software and determine the geological stratum boundaries, main faults, fault trends, ore body shape, ore body scale, and spatial distribution in the area to be mined; use the Kriging method to estimate the resource volume 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 can be understood that it can also include address patterns such as geological plans, profiles, and 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 them into software formats that can be used for modeling, such as converting drilling data into CSV and Excel formats, converting geological maps into DXF or DWG formats, and importing them into 3D geological modeling software (such as Leapfrog, Surpac, Datamine, Micromine, etc.). Then, based on the drill cores, they determine the boundaries of different geological strata, the location and direction of major faults, and the shape, scale and spatial distribution of the ore body, so as to identify and predict potential address risks such as faults, collapses, water gushing, etc., and determine the best mining path and method.

[0056] It can be understood that Kriging is a regression algorithm for 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, taking 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 avoid damage to the sensors.

[0059] In detail, 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 from 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, horizontally excavate a secondary transfer layer with a height of 2-5m in the surrounding rock in 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 from the surface downward into a safety layer; horizontally excavate a secondary transfer layer with a height of 2-5 meters in the safety layer; 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; lay steel mesh on the inner wall of the secondary transfer layer, and fix multiple steel meshes with binding wires; use spraying concrete equipment to evenly spray concrete on the steel mesh to form a support layer. Drill grouting holes on the inner wall of the secondary transfer layer; use grouting equipment to inject cement slurry into the grouting holes; set stress sensors, displacement sensors and crack monitors on the inner wall of the secondary transfer layer and connect them to the real-time monitoring system of geological changes.

[0061] It is understandable that the rock surrounding the ore body, including the rock body located around the rock field, is called surrounding rock. The properties of the surrounding rock are different from those of the ore body, and its 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 rock burst 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 interfaces of deep multi-layer overlapping ore bodies, a secondary transfer layer with a height of 2-5 meters is excavated to bypass the heterogeneous interfaces, 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 prior art, and the inability to adjust according to actual conditions.

[0063] In the present invention, the secondary transfer layer is used as a transfer layer to transfer ore, fill mud and achieve the effect of reinforcing the tunnel and filling pipe by setting prestressed anchor rods and concrete support layers. It can be understood that the prior art has a room-and-pillar mining method, that is, retaining part of the ore in the space of the mined ore to support the upper rock layer. In the present invention, the secondary transfer layer is opened in the surrounding rock and the support is constructed to form a stable transfer layer, avoiding the need to maintain a stable tunnel and pipe too long due to direct excavation from the ground to the ore body, reducing the cost of maintaining stability, and improving 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 with 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 pool 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 pool is connected to the surface filling station through the main filling pipeline. The surface filling station mixes the tailings after mining with an adhesive (such as polyurethane) to obtain a filling slurry, which is injected into the stirring pool through the main filling pipeline. The stirring pool is also provided with a stirring device (such as a vibrating device). The filling slurry can be stirred for a second time by the stirring pool provided in the secondary transfer layer to prevent the filling slurry from being subjected to greater friction in the main filling pipeline, which causes a decrease in flow rate under the same conveying amount and affects the conveying efficiency. By providing a stirring pool and a stirring device in the secondary transfer layer, the particle size distribution of the filling slurry can be optimized for a second time, the content of coarse particles and sharp particles can be reduced, the friction between particles and between particles and the pipe wall can be reduced, the particle grading can be improved, and the filling slurry characteristics can be optimized. The filling slurry is adjusted in the mixing tank and then passed 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, stable transportation can be maintained to avoid resistance changes caused by flow fluctuations due to frequent start and 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 mining area and the mining site, and support and ground pressure monitoring equipment are set up in the waiting mining area, and support and ground pressure monitoring equipment connecting the mining site are set up. 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. 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. 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 recovery, 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 embodiment, a mining area with poor surrounding rock stability, moderate ore stability, thick ore body and relatively low ore value is divided into a first mining area, and the sublevel caving method is used for mining in the first mining area. Multiple functional tunnels, chutes and funnels are horizontally separated along the ore body in the first mining area, and each functional tunnel is spaced 15-25 meters apart. The functional tunnels include transportation tunnels and drilling and blasting tunnels, wherein the transportation tunnels are used for ore transportation, ventilation and drainage; the drilling and blasting tunnels are used for drilling and blasting operations; the chutes and funnels are set below the ore body for collecting and lowering the ore.

[0068] Specifically, in the drilling and blasting tunnel, according to the designed hole network parameters, blasting holes are drilled into the ore body. The types of blasting holes are mainly straight holes and fan-shaped holes, and the hole diameter is generally 64-102mm. Explosives are loaded into the blasting holes, and segmented micro-difference blasting is used to control the blasting effect. After blasting, the ore body collapses under the action of its own weight and the pressure of the upper rock formation. The ore collapses from the upper part to the chute and funnel at the lower part. The collapsed ore is transported to the main transportation tunnel through the chute, and then transported out of the mine by transportation equipment. After a segmented mining is completed, it gradually advances upward or forward to form 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 the 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 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. 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 can also achieve the comprehensive utilization of tailings.

[0070] The present invention achieves the effect of reducing mining costs by pre-constructing three-dimensional geological modeling and classifying and planning the ore body models in the multi-layer overlapping ore bodies through three-dimensional geological modeling. A real-time monitoring system for geological changes is also constructed to monitor and warn ground pressure and other geological information, so as to ensure the safety and efficiency of the mining process. At the same time, the ore body is divided into multiple mining areas through the ore body model, and a secondary transfer layer is constructed at the surrounding rock of multiple ore bodies, which reduces the construction difficulty and cost of tunnels and filling pipes, avoids the risk of deformation caused by ground pressure or stress, and can also select different mining plans according to the difficulty of mining, so as to achieve a safe, stable and cost-effective mining effect.

[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 changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied 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 build an ore body model; Based on the ore body model, monitoring holes are dug in sections, and a real-time monitoring system for geological changes is constructed through the monitoring holes; Construct a secondary transfer layer based on the ore body model, excavate a secondary transfer layer with a height of 2-5m horizontally in the surrounding rock in the overlapping area of ​​multiple ore bodies, and build support for the secondary transfer layer; 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 ore body is divided into a first mining area and a 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.

2. The efficient and safe mining method for deep multi-layer overlapping ore bodies according to claim 1, characterized in that: 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: Drill holes in the area to be mined and collect drilling data as well as geophysical and geochemical data; The obtained drilling data and geochemical data are sorted, and the drilling data, geophysical data and geochemical data are denoised and filtered to obtain accurate geological data; Import the address data into the 3D geological modeling software and determine the geological horizon boundaries, major faults, fault trends, ore body shapes, ore body scales, and spatial distribution in the area to be mined; Kriging method is used to estimate resources and determine the reserves and grade distribution of the ore body.

3. 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 constructing 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, and the gap of the stress sensor is filled with cement slurry, and a protective bracket is installed outside the stress sensor; Drill microseismic monitoring holes every 100-200 meters around the area to be mined, with a hole diameter of 50-100 mm and a depth of 1-3 meters; A microseismic sensor is installed in the microseismic monitoring hole, and the gap of the microseismic sensor is filled with cement slurry, and a protective bracket is installed outside the microseismic sensor; A wireless sensor network and a data acquisition and processing module are set up in the area to be mined to monitor the geological changes in the area to be mined in real time.

4. 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 surrounding rock in the overlapping area of ​​multiple ore bodies, and constructing support for the secondary transfer layer include: Based on the ore body model, the stable surrounding rock area surrounding the ore body is divided into safety layers from the surface downward; A secondary transfer layer with a height of 2-5 meters is excavated horizontally in the safety layer; Install prestressed anchor rods, drill holes on the inner wall of the secondary transfer layer and insert the prestressed anchor rods into the holes, and apply prestress to the prestressed anchor rods; A steel mesh is laid on the inner wall of the secondary transfer layer, and multiple steel meshes are fixed with binding wires; Use shotcrete equipment to evenly spray concrete onto the steel mesh to form a support layer.

5. The efficient and safe mining method for deep multi-layer overlapping ore bodies according to claim 4, 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.

6. 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 through 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 with the auxiliary filling pipeline. The mixing tank performs secondary mixing on the filling slurry mixed at the surface filling station.

7. The efficient and safe mining method for deep multi-layer overlapping ore bodies according to claim 1, characterized in that: 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 caving method, and mining the second mining area by tailings backfill method include: 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 and auxiliary adit are excavated below the first mining area to transport ore and facilitate the entry and exit of personnel; Excavate and construct the middle tunnel in sections on the side of the first mining area, and set up support and ground pressure monitoring equipment on the inner wall of the middle tunnel; Drill blasting holes at intervals of 20-25 meters on the inner wall of the middle tunnel and carry out caving blasting in sections; The second mining area is divided into a waiting area and a mining site, support and ground pressure monitoring equipment are set up in the waiting area, and branch filling pipelines connected to the mining site are laid out, 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 site, 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. 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 stope, and explosives are loaded into the blasting holes for stratified mining. The ore obtained is transported out of the stope, and the empty 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.