Pressure relief mining method for deep high-stress thick and large ore body

Abstract

The invention provides a deep high-stress thick and large ore body pressure relief mining method, and relates to a deep mining technology, a pressure relief roadway is arranged outside a rock stratum moving angle of an ore body hanging wall, the pressure relief roadway and a vertical pressure relief vertical groove jointly cut a rock body structure, the integrity of primary surrounding rock is manually weakened, and a continuous and effective pressure relief zone is formed. In the stoping process, the undercutting roadway with the horizontal pressure relief cutting groove is arranged in advance, and the stress concentration area is further dispersed; meanwhile, the horizontal pressure relief grooves are filled with large-aperture filling bodies, a structure that the grooves and the filling bodies are coupled is formed, surrounding rock deformation is effectively limited, the overall stability of a roadway and a stope is improved, and the sudden ground pressure and rockburst risks in the deep mining process are remarkably reduced.

Description

Technical Field

[0001] This invention relates to deep mining technology, specifically to a method for decompression mining of deep, high-stress, thick ore bodies. Background Technology

[0002] With the increasing depth of mineral resource extraction, the level of geostress faced by mines has significantly increased. The stability of the surrounding rock in deep, high-stress roadways has become one of the core issues restricting safe and efficient mining. Especially in the mining of thick ore bodies, due to the large scale and complex structure of the ore body, the stress environment of the surrounding rock is extremely complex, often leading to serious accidents such as surrounding rock failure, rock bursts, spalling, and roof collapses, which directly threaten the safety of mine production and the lives of personnel.

[0003] Currently, engineering methods mainly employ measures such as reinforced support, local pre-splitting blasting, or optimized mining sequence to control stress and surrounding rock deformation. However, these methods are mostly passive controls or have limited effectiveness, failing to fundamentally solve the problem of surrounding rock instability caused by high ground stress. Furthermore, the mining of thick ore bodies often utilizes traditional methods such as large stopes or open-cut methods, which suffer from low recovery efficiency, low equipment utilization, and high safety risks, severely impacting resource recovery rates and economic benefits. Therefore, there is an urgent need for an innovative technology that combines active stress relief capabilities with efficient mining organization to effectively address the dual challenges of deep high ground stress and the mining of thick ore bodies. Summary of the Invention

[0004] This invention provides a method for decompression mining of deep, high-stress, thick ore bodies. Its purpose is to mitigate the high-stress environment that occurs during deep mining and improve the safety of subsequent mining by actively controlling the high stress.

[0005] To achieve the above objectives, embodiments of the present invention provide a method for decompression mining of deep, high-stress, thick ore bodies, comprising the following steps:

[0006] S100. The ore body is divided into stages and segments in two phases;

[0007] S200. The ore body is divided into multiple panels along the strike of the ore body at a predetermined distance, and each panel is divided into two stopes. In each stope, a stope is arranged along the strike of the ore body.

[0008] S300. Decompression roadways are arranged outside the rock strata movement angle on the hanging wall of the ore body. Each stage has one decompression roadway, and decompression vertical trenches are arranged on the hanging wall of each segment.

[0009] S310. Cut the bottom of the mining area in the panel to form a bottom-pulling roadway, and cut at a preset distance on both sides of the bottom-pulling roadway to form a horizontal pressure relief cutting groove, and fill the large-diameter filling material at the same time during the cutting; arrange fan-shaped medium-deep holes upward in the bottom-pulling roadway;

[0010] S400. The ore body is mined, with each stage being mined in an alternating manner, and each stope being mined in a retreating manner.

[0011] Preferably, in step S100, the ore body is divided into formation stages in the vertical direction, and each stage is further divided into segments;

[0012] A mining ramp is arranged in the footwall of the ore body to connect the sections, and cross-cutting roadways are arranged between the sections.

[0013] Preferably, a wide column is left between the mining areas within each panel.

[0014] Preferably, the height of the pressure relief trough is the same as the height of the mine.

[0015] Preferably, each panel is equipped with a chute, a filling return air connection duct, and a panel return air skylight.

[0016] Preferably, after mining is completed, the goaf of the stage or mining area is filled in.

[0017] The above-described solution of the present invention has the following beneficial effects:

[0018] In this application, a three-dimensional stress relief structure, including a stress relief tunnel, a stress relief cutting groove, and a large-diameter filling body, is designed to relieve stress before the ore body is mined, thereby reducing the high stress in the surrounding rock during the mining process.

[0019] Specifically, stress relief roadways are arranged outside the rock strata movement angle in the hanging wall of the ore body. Together with vertical stress relief trenches, these roadways cut the rock mass structure, artificially weakening the integrity of the original surrounding rock and forming a continuous and effective stress relief zone. During mining, bottom roadways with horizontal stress relief cutting trenches are arranged in advance to further disperse stress concentration areas. At the same time, the horizontal stress relief trenches are filled with large-diameter fillers, forming a coupled structure between the trenches and the fillers. This effectively restricts the deformation of the surrounding rock, improves the stability of various roadways and the overall mining area, and significantly reduces the risk of sudden ground pressure and rock bursts during deep mining.

[0020] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the longitudinal cross-section of the ore body;

[0022] Figure 2 yes Figure 1 A sectional view along the middle II-II direction;

[0023] Figure 3 yes Figure 2 Enlarged view of section A;

[0024] Figure 4 yes Figure 1 A sectional view along the middle III-III direction;

[0025] Figure 5 yes Figure 4 Enlarged view of section B.

[0026] [Explanation of Labels in the Attached Image]

[0027] 1-Ore body, 2-Pressure relief roadway, 3-Pressure relief vertical trench, 4-Rock stratum movement angle, 5-Bottom-pulling roadway, 6-Horizontal pressure relief cutting groove, 7-Large-diameter filling body, 8-Fan-shaped medium-deep hole, 9-Mining preparation ramp, 10-Through-vein roadway, 11-Passway, 12-Filled return air connecting roadway, 13-Panel return air shaft, 15-Modular filled retaining wall, 16-Concrete pouring surface, 17-Transport roadway. Detailed Implementation

[0028] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0029] like Figures 1-5 As shown, this application provides a method for decompression mining of deep, high-stress, thick ore bodies. This method is suitable for mining depths exceeding 1000 meters, ore body thickness exceeding 80 meters, and original rock stress fields with dip angles of 20°-40°. For metal deposits with a pressure of ≥30 MPa, the decompression mining method for this deep, high-stress, thick ore body includes the following steps:

[0030] S100. The ore body 1 is divided into stages and segments in two stages.

[0031] The ore body 1 is divided into several stages vertically using a phased approach. Within each stage, further phased divisions are used to further subdivide each stage into segments. A mining ramp 9 is arranged in the footwall of the ore body 1 to connect the segments. A cross-cutting roadway 10 is set between the segments, and the cross-cutting roadway 10 connects to a transport roadway 17. The transport roadway 17 is used to transport equipment between the segments, enabling orderly mining of each stage and segment.

[0032] In this embodiment, the ore body 1 is divided into stages according to a standard of 60 meters in height, and then further divided into stages within each stage according to a standard of 20 meters in height.

[0033] S200. Along the strike of orebody 1, divide orebody 1 into multiple panels at predetermined distances, and each panel into two stopes. Within each stope, arrange the stopes along the strike of orebody 1. Wide pillars are left between the stopes within each panel.

[0034] In this embodiment, multiple panels are divided at 200-meter intervals along the strike of ore body 1. Within each panel, two mining areas are divided along the strike of ore body 1. Each mining area is 80 meters long, and a 20-meter wide column is left between the mining areas. Mining rooms are arranged along the strike of ore body 1 within each mining area.

[0035] Each panel is equipped with a chute 11, a filling return air connection duct 12, and a panel return air skylight 13 for transportation or ventilation.

[0036] S300. A pressure relief roadway 2 is arranged outside the rock strata movement angle 4 on the hanging wall of ore body 1. A pressure relief roadway 2 is set up in each stage. Pressure relief vertical grooves 3 are arranged at the hanging wall of each segment to cut off or weaken the continuous transmission of high stress in the hanging wall of ore body 1.

[0037] Preferably, the height of the pressure relief vertical trough 3 is the same as the height of the mine, and the specifications of the mine are 15 meters wide, 20 meters high and 80 meters long.

[0038] In this embodiment, the high-stress environment of the hanging wall of the ore body 1 is broken through by the cooperation of the pressure relief roadway 2 and the pressure relief vertical channel 3.

[0039] Furthermore, in S310, a bottom-cutting roadway 5 is formed at the bottom of the mining area. Horizontal pressure-relief cutting grooves 6 are formed by cutting along the sides of the bottom-cutting roadway 5 at predetermined intervals. These grooves extend from the rock surface into the rock mass, and are simultaneously filled during cutting. The filler material is a large-pore filler 7, such as large-pore cementitious sand filler. The large-pore filler 7 appropriately supplements the bearing capacity of the surrounding rock. As the large-pore filler 7 compresses under pressure until it is fully compacted, it promptly transfers and releases most of the stress accumulated in the shallow part of the surrounding rock, achieving an unloading effect. This reduces surrounding rock deformation and improves the stability of the roadway.

[0040] In this application, a pressure relief zone is formed by the combination of a pressure relief roadway 2, a pressure relief vertical groove 3, and a horizontal pressure relief cutting groove 6 filled with large-diameter filler 7. This reduces the horizontal stress around the mining area by about 30% to 45% and the vertical stress by about 25% to 35%, thereby achieving active pressure relief of the deep and thick ore body 1 and facilitating the improvement of the safety of subsequent mining.

[0041] In this embodiment, the horizontal pressure relief cutting groove 6 cut on the bottom roadway 5 is 1 meter deep, 0.5 meters wide and 0.5 meters high.

[0042] Preferably, fan-shaped medium-deep holes 8 are arranged upwards in the bottom tunnel 5, and the rock drilling rig is used to make evenly distributed holes on the inner wall of the bottom tunnel 5 to achieve efficient rock breaking.

[0043] After the ore body 1 is divided and pre-treated, the ore body 1 is mined in stages or mining areas. The ore is transported to the surface through the bottom roadway 5, the cross-vein roadway 10, and the transport roadway 17.

[0044] In step S400, mining is carried out in an alternating manner at each stage. When mining within the stope, a retreating mining method is used. Specifically, when mining the stope, a retreating mining process from two wings to the center is adopted. The two wings refer to the two ends of the ore body 1, i.e., the left and right sides in Figure 2. The retreating mining from two wings to the center utilizes fresh airflow to enter the bottom roadway 5 through the cross-cut roadway 10 to clean the mining face, and then flows through the filling return air connecting roadway 12 from the two wings of the panel to the panel return air shaft 13. While ensuring ventilation installation, the blasting is delayed for rapid dispersion.

[0045] After mining is completed, the goaf in the stage or mining area is filled. In this embodiment, taking the completion of mining in the stage as an example, the bottom roadway 5 is filled with filling material, and modular filling retaining walls 15 are used for temporary support at both ends of the bottom roadway 5. After the filling material is solidified, the temporary support is removed, and concrete is poured at the removed location to form a concrete surface 16.

[0046] In this application, a strategy of depressurization before mining is adopted to actively control high stress in deep areas, artificially weakening the integrity of the original surrounding rock and forming a continuous depressurization zone. During the mining process, a bottom-pull roadway 5 with horizontal depressurization cutting grooves 6 is arranged in advance to further disperse the stress concentration area. The horizontal depressurization cutting grooves 6 are adjusted simultaneously to effectively limit the deformation of the surrounding rock, improve the stability of the bottom-pull roadway 5 and the mining area, and significantly reduce the risk of sudden ground pressure and rock bursts in deep mining.

[0047] Furthermore, this application divides the thick orebody 1 into several independent panels, achieving spatial segmentation and functional integration, reducing the exposure range of a single area, and optimizing stress distribution. It also provides a site and application foundation for subsequent intelligent multi-equipment collaboration.

[0048] For example, this application can also install a safety warning system on mining equipment to achieve comprehensive early warning through multiple methods. This could involve installing UWB terminals on the mining equipment and having personnel wear corresponding beacons to achieve real-time, high-precision positioning of the relative positions of personnel and mining equipment within the mining area. When the distance between personnel and equipment becomes too close, the UWB terminal can be triggered to issue warnings via alarm bells, lights, etc.

[0049] Furthermore, this application may also include access control at the entrances and exits of the mining area to issue warnings for unauthorized equipment entering; and video surveillance equipment may be deployed at key locations along the transportation route, such as bends and intersections, to achieve automatic trapezoidal positioning and real-time monitoring of the operation process based on motion detection.

Claims

1. A method for decompression mining of deep, high-stress, thick ore bodies, characterized in that, Includes the following steps: S100. The ore body (1) is divided into stages and segments in two stages; S200. Divide the ore body (1) into multiple panels along the strike of the ore body (1) at a predetermined distance, and divide each panel into two mining areas. Arrange the mining rooms along the strike of the ore body (1) in each mining area. S300. Decompression roadways (2) are arranged outside the rock strata movement angle (4) of the hanging wall of the ore body (1). Each stage has a decompression roadway (2), and decompression vertical trenches (3) are arranged at the hanging wall of each segment. S310. Cut the bottom of the mining area in the panel to form a bottom-pulling roadway (5), and cut the two sides of the bottom-pulling roadway (5) at a predetermined distance to form a horizontal pressure relief cutting groove (6), and fill the large-diameter filling body (7) simultaneously during the cutting; arrange the fan-shaped medium-deep holes (8) upward in the bottom-pulling roadway (5). S400. Mining of the ore body (1) is carried out in a manner of mining every other stage and mining in a retreating manner for each stope.

2. The method for decompression mining of deep, high-stress, thick ore bodies according to claim 1, characterized in that: In step S100, the ore body (1) is divided into formation stages in the vertical direction, and each stage is further divided into segments; A mining ramp (9) is arranged in the footwall of the ore body (1) to connect the sections, and a cross-cutting roadway (10) is arranged between the sections.

3. The method for decompression mining of deep, high-stress, thick ore bodies according to claim 2, characterized in that: Wide columns are left between the mining areas within each panel.

4. The method for decompression mining of deep, high-stress, thick ore bodies according to claim 1, characterized in that: The height of the pressure relief vertical channel (3) is the same as the height of the mine.

5. The method for decompression mining of deep, high-stress, thick ore bodies according to claim 3, characterized in that: Each panel is equipped with a chute (11), a filling return air connection duct (12), and a panel return air ceiling (13).

6. The method for decompression mining of deep, high-stress, thick ore bodies according to claim 1, characterized in that: After mining is completed, the goaf areas of the stage or mining area are filled in.

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