A method for improving the efficiency of ore extraction from the first mining layer in downward slicing horizontal access mining

Abstract

The present application relates to the technical field of non-ferrous mine mining, in particular to a method for improving the ore extraction efficiency of the first mining layer of downward slicing horizontal access mining, to solve the problems that ore transfer is time-consuming and laborious and the temporary ore stacking point is complicated to set, which affects the mining site environment management and the overall mining extraction efficiency when the first mining layer of downward slicing horizontal access mining is mined. The method first determines the positions of each slicing connecting passage and corresponding short chute, then excavates the uphill first slicing connecting passage into the ore body, excavates the slicing passage at the same time, finally excavates the chute connecting passage until the short chute, excavates the downhill sixth slicing connecting passage to the bottom of the short chute, and installs a vibrating ore-drawing machine at the bottom of the first to sixth slicing short chute, which realizes the rapid and convenient extraction and transfer of ore, reduces the ore transfer link, shortens the ore extraction time of the stope, greatly improves the ore extraction efficiency of the stope, and cancels the temporary ore stacking point of the stope, effectively avoiding the problems of poor mining site environment and unscientific management.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous mining technology, specifically to a method for improving the ore extraction efficiency of the first mining layer in downward stratified horizontal approach mining. Background Technology

[0002] Downward-layered horizontal access backfilling mining is a mature mining method. It is used to mine thick, unstable, and broken ore bodies. The ore body is vertically divided into sections, and within each section, multiple horizontal layers are vertically divided. Mining proceeds from top to bottom. Preparatory works are arranged in the hanging wall or footwall of the ore body. The main preparatory works include preparatory ramps, section roads, layer connecting roads, and ore passes. Mining is carried out in the stope by approach, using a retreating sequential mining method. Each panel has an external ore pass located outside the ore body and section roads. The ore pass is connected to the stope through an external ore pass connecting road. Mining proceeds from top to bottom within each section, starting with the first layer, i.e., the first mining layer. Rock drilling is carried out using a rock drilling rig. Ore is removed from the stope using a loader. The loader shovels ore from the stope approach through the layer connecting road, section road, and ore pass connecting road to the external ore pass in the panel for unloading. At the bottom of the ore pass, a vibratory chuck loads the ore into mine cars and transports it to the intermediate ore pass or crushing station. When mining begins in the first mining layer, the mine is in its early stages, and the development and preparation systems are often not fully constructed, causing many inconveniences to normal mining operations. Furthermore, since ore passes are vertical structures, they can only be excavated after the upper and lower sections are completed. Therefore, the formation of ore passes often lags behind other preparation works. If an external ore pass for a panel is not built, normal ore production in the stope will be affected and become very difficult. Ore needs to be shoveled and transported to a temporary stockpile point in the stope, and then loaded onto ore trucks by a loader to be transported to the crushing station. This results in long ore transport distances, multiple ore transfer links, and increased working time for ore transfer equipment, leading to lower mining efficiency. Additionally, due to the limited space in the stope, setting up temporary stockpiles is very difficult, causing many inconveniences to stope production, creating a poor working environment, and making on-site management of mining operations extremely challenging. Summary of the Invention

[0003] This invention provides a method for improving the ore extraction efficiency of the first mining layer in downward stratified horizontal approach mining, in order to solve the problems existing in the background mentioned above.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A method for improving the ore extraction efficiency of the first mining layer in a downward stratified horizontal approach mining method includes the following steps: Step 1: Determine the locations of the first, sixth, second, fourth, third, and fifth layer connecting tunnels and their corresponding short chutes. The short chutes are located at the boundaries of the hanging wall and footwall of the ore body.

[0005] Step 2: First, excavate the first layered connecting tunnel uphill into the ore body, then excavate the layered tunnels, with each layered tunnel located at the boundary between the upper and lower hanging walls of the ore body to facilitate the excavation of the pass connecting tunnel. Finally, excavate the pass connecting tunnel until the location of the short pass.

[0006] Step 3: Continue excavating the sixth connecting tunnel down the slope to the bottom of the short chute.

[0007] Step 4: Finally, excavate the short chutes corresponding to the first, sixth, second, fourth, third, and fifth layer connecting tunnels, and install ore discharge machines at the bottom of the short chutes. The short chutes are supported by shotcrete mesh and double-reinforced concrete with steel plates.

[0008] Step 5: The ore mined from the first layer of the access road is dumped into the short chute for storage by a loader. The ore truck then reaches the bottom of the short chute via the sixth layer connecting road downhill in Step 3, and is loaded with ore by the vibrating ore feeder.

[0009] The present invention has the following beneficial effects: This invention provides a method for improving the ore extraction efficiency of the first mining layer in downhill stratified horizontal approach mining. First, the locations of each stratified connecting roadway and corresponding short chutes are determined. Then, the first stratified connecting roadway is excavated uphill into the ore body, while simultaneously excavating the stratified roads. Finally, the chutes connecting roadway is excavated until the short chutes are reached. Next, the sixth stratified connecting roadway is excavated downhill to the bottom of the short chutes. Ore discharge machines are installed at the bottom of the first to sixth stratified short chutes. This method enables rapid and convenient ore extraction and transfer, reduces ore transfer steps, shortens the ore extraction time in the stope, and greatly improves the ore extraction efficiency. Simultaneously, it eliminates the need for temporary ore stockpiles in the stope, effectively avoiding problems such as poor on-site environment and unscientific management. This method solves the current problems in downhill stratified horizontal approach mining where ore transfer is time-consuming and labor-intensive, and the setting of temporary stockpiles is cumbersome, affecting on-site environmental management and overall ore extraction efficiency. Attached Figure Description

[0010] Figure 1 This is a structural diagram of the overall planar layout within the mine according to the present invention.

[0011] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure at point AA.

[0012] The meanings of the reference numerals in the attached figures are as follows: 1. Segmented roadway; 2. Layered connecting roadway; 3. First layer connecting roadway; 4. Sixth layer connecting roadway; 5. Second layer connecting roadway; 6. Fourth layer connecting roadway; 7. Third layer connecting roadway; 8. Fifth layer connecting roadway; 9. Short ore pass; 10. Access road; 11. Layered roadway; 12. Ore pass connecting roadway; 13. Ore body. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0014] A method for improving the ore extraction efficiency of the first mining layer in down-layer horizontal approach mining includes the following steps: Step 1: Determine the locations of the first layer connecting tunnel 3, the sixth layer connecting tunnel 4, the second layer connecting tunnel 5, the fourth layer connecting tunnel 6, the third layer connecting tunnel 7, and the fifth layer connecting tunnel 8, as well as the corresponding short chute 9. The short chute 9 is located at the boundary between the hanging wall and footwall of the ore body 13.

[0015] Step 2: First, the first layered connecting tunnel 3 is excavated uphill into the ore body 13, then the layered tunnel 11 is excavated, and the layered tunnel 11 is located at the boundary of the upper and lower ore bodies 13. Finally, the ore pass connecting tunnel 12 is excavated until the location of the short ore pass 9.

[0016] Step 3: Continue excavating down the slope to the bottom of the sixth layer connecting tunnel 4 to the short chute 9.

[0017] Step 4: Finally, excavate the short chutes 9 corresponding to the first layer connecting tunnel 3, the sixth layer connecting tunnel 4, the second layer connecting tunnel 5, the fourth layer connecting tunnel 6, the third layer connecting tunnel 7, and the fifth layer connecting tunnel 8, and install ore discharge machines at the bottom of each short chute 9.

[0018] Step 5: The ore mined from the first layer access road 10 is dumped into the short chute 9 by a loader. The ore truck then reaches the bottom of the short chute 9 via the sixth layer connecting road 4 that goes downhill in step 3, and is loaded with ore by the ore discharge machine.

[0019] In practice, the ore body being mined in a certain mine is a thick ore body with a central section height of 150m and a subsection height of 24m. Each subsection is divided into 6 mining layers, with a layer height of 4m. Mining proceeds from top to bottom, dividing the ore body into panels with a strike length of 100m. Preparation works are arranged in the wall surrounding rock of the ore body, mainly including a preparation ramp, subsection roadway 1, layer connecting roadway 2, and a central pass. After these preparation works are completed, the first layer of mining begins in the panel. Because ore extraction is very difficult before the central pass is built, ore from the first layer access face 10 is shoveled and stored at the panel entrance, causing many problems for panel management. After improvement, the sixth layer connecting roadway 4 is excavated ahead of schedule, and a short pass 9 is excavated between the first layer connecting roadway 3 and the sixth layer connecting roadway 4. The first layer connecting roadway 3 and the second layer connecting roadway 4 are pre-designed to connect the panel. The locations of connecting tunnel 5, third-layer connecting tunnel 7, fourth-layer connecting tunnel 6, fifth-layer connecting tunnel 8, and sixth-layer connecting tunnel 4 have all been determined. The determination of these connecting tunnels 2 is to ensure smooth transition between layers in the future and to avoid imbalance in the transition of layers in the panel, which could lead to production stoppage in the panel. At the same time, the location of the short chute 9 from the first-layer connecting tunnel 3 to the sixth-layer connecting tunnel 4 has been pre-set. The location of the short chute 9 is near the boundary of the hanging wall ore body 13, so that the short chute 9 can serve the mining of the entire first mining layer. The cross-section of the short chute 9 is circular, with a tunneling diameter of 5.8m, a net diameter of 5m, and a length of 16m. The first-layer connecting tunnel 3 is uphill. After the first-layer connecting tunnel 3 enters the ore body 13, the layer tunnel 11 is tunneled at the boundary of the hanging wall ore body 13. After the layer tunnel 11 is completed, the chute connecting tunnel 12 is tunneled until the location of the short chute 9 is reached. The sixth-level connecting tunnel 4 is a downhill section. After the sixth-level connecting tunnel 4 is excavated, the short chute 9, connecting the first-level connecting tunnel 3 to the sixth-level connecting tunnel 4, will be excavated according to the designed location. The short chute 9 is supported by shotcrete mesh + double-reinforced concrete + steel plate support. The steel plate is 20mm thick, the shotcrete is 100mm thick, the main reinforcement of the reinforced concrete is φ18 threaded steel with a spacing of 250mm, the secondary reinforcement is φ12 threaded steel with a spacing of 300mm, the concrete thickness is 300mm, and the concrete strength grade is C30. A bottom structure is set at the bottom of the short chute 9, and a vibrating ore feeder is installed. The ore mined from the first-level connecting tunnel 3's access road 10 is dumped into the short chute 9 by a loader and stored in the short chute 9. The ore in access road 10 can be continuously hauled out by the loader until all the ore at the working face is removed, and then the next mining step can be carried out. Finally, the ore trucks reach the bottom of the short pass 9 via the sixth-level connecting tunnel 4, where the ore is loaded using the vibrating feeder and then transported to the intermediate pass or crushing station. The short pass 9 continues to be used during mining operations in the third-level connecting tunnel 7, fourth-level connecting tunnel 6, and fifth-level connecting tunnel 8. The use of the short pass 9 significantly shortens the ore extraction time of access road 10, improves ore extraction efficiency and panel mining efficiency, and greatly improves the industrial hygiene environment of the panel.

Claims

1. A method for improving the ore extraction efficiency of the first mining layer in downward stratified horizontal approach mining, characterized in that, Includes the following steps: Step 1: Determine the locations of the first layer connecting tunnel (3), the sixth layer connecting tunnel (4), the second layer connecting tunnel (5), the fourth layer connecting tunnel (6), the third layer connecting tunnel (7), and the fifth layer connecting tunnel (8), as well as the corresponding short chute (9). The short chute (9) is located at the boundary between the hanging wall and footwall of the ore body (13). Step 2: First, excavate the first layered connecting tunnel (3) uphill into the ore body (13), then excavate the layered tunnel (11), and the layered tunnel (11) is located at the boundary of the upper and lower ore bodies (13). Finally, excavate the ore pass connecting tunnel (12) until the location of the short ore pass (9). Step 3: Continue excavating the sixth layer connecting tunnel (4) down the slope to the bottom of the short chute (9); Step 4: Finally, excavate the short chute (9) corresponding to the first layer connecting tunnel (3), the sixth layer connecting tunnel (4), the second layer connecting tunnel (5), the fourth layer connecting tunnel (6), the third layer connecting tunnel (7) and the fifth layer connecting tunnel (8), and install a vibrating ore discharge machine at the bottom of the short chute (9); Step 5: The ore mined from the first layered approach (10) is dumped into the short chute (9) by a loader and stored. The ore truck then reaches the bottom of the short chute (9) via the sixth layered connecting road (4) downhill in step 3, and is loaded with ore by the vibrating ore discharge machine.

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