A method of continuous mechanized mining of inclined thin ore bodies

Abstract

This invention discloses a continuous mechanized mining method for inclined thin ore bodies, belonging to the field of underground mining, including the following steps: S1, stope division and preparation engineering layout; S2, mining; S3, stope ventilation, roof support and ore transportation; S4, stope backfilling; S5, repeating steps S2 to S4 until all ore in the stope is mined out. In step S2, the panel is mined sequentially from bottom to top and from one side to the other. Before blasting, a flexible retaining wall is erected on the side of the bottom cutting roadway near the blasting area. At the intersection of the bottom cutting roadway and the cutting uphill section, medium-deep holes are drilled along the strike from both sides of the ore body for blasting. In step S4, when it is predicted that the exposed area or span will exceed the limit after the next cycle of blasting, the stope is partially backfilled. In this embodiment, no pillars are set in the stope, reducing the ore loss caused by leaving pillars. The mine's own waste rock and tailings are used as backfill materials, realizing the resource utilization of waste materials.

Description

Technical Field

[0001] This invention relates to the field of underground mining technology, and in particular to a continuous mechanized mining method for inclined thin ore bodies. Background Technology

[0002] Gently dipping thin ore bodies (typically referring to ore bodies with a dip angle of 5°–30° and a thickness between 0.8 meters and 5.0 meters) are a common and challenging type of ore body in metallic and non-metallic deposits, widely found in sedimentary bauxite and phosphate deposits, as well as some stratabound or vein deposits (such as certain gold and antimony deposits). Currently, for the mining of such ore bodies, traditional mining techniques such as the full-face method and the room-and-pillar method are commonly used in China. These methods typically retain irregularly, non-uniformly, or regularly arranged pillars in the stope to support the roof and surrounding rock, thus ensuring the safety of stope workers to a certain extent.

[0003] However, the above methods have gradually revealed several prominent problems in practical applications. First, the large number of permanent or temporary pillars left in the mining area not only results in a high rate of mineral resource loss, but also makes subsequent pillar recovery difficult and unsafe, easily leading to secondary disasters such as roof instability. Second, the lack of timely and effective treatment of goaf areas, with their complex shapes and scattered distribution, poses long-term risks to mine ground pressure management and goaf disposal, and also restricts the optimization of mining area structure and the improvement of resource recovery rate. In addition, in terms of mining technology, existing methods mostly rely on shallow-hole drilling for ore extraction, supplemented by electric scrapers or small loaders. The process is cumbersome, with low mechanization and poor production continuity, resulting in low efficiency and high labor intensity for single shifts, making it difficult to meet the needs of modern large-scale and intensive mining. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a continuous mechanized mining method for inclined thin ore bodies.

[0005] A continuous mechanized mining method for inclined thin ore bodies according to an embodiment of the present invention includes the following steps: S1. Division of mining areas and layout of mining preparation engineering: Divide the mining area into several independent mining areas along the strike of the ore body, excavate the transport roadway along the footwall of the ore body, and excavate the connecting roadway of the mining area along the dip of the ore body. In each mining area, excavate the cutting roadway along the bottom plate of the ore body, and excavate the cutting incline along the pillar boundary to connect the upper and lower cutting roadways. At the same time, excavate the connecting roadway of the mining area to connect with the connecting roadway of the mining area, forming a passage for personnel, equipment and ore transportation. S2. Mining: The panel adopts a sequential mining approach from bottom to top and from one side to the other. Before blasting, a flexible retaining wall is erected on the side of the bottom cutting tunnel near the blasting area. At the intersection of the bottom cutting tunnel and the cutting uphill section, medium-deep holes are drilled along the strike from both sides of the ore body for blasting. S3. Ventilation, roof support and ore transportation in the stope: Directional ventilation is carried out after blasting. The roof is roughened by a remote-controlled shovel trolley. Active support is implemented in the fractured area, interlayer or area with poor stability of the roof. After support, the collapsed ore is transported to the panel connecting roadway through the stope connecting roadway by a remote-controlled loader. S4. Stope backfilling: When it is predicted that the exposed area or span will exceed the limit after the next cycle of blasting, the stope is partially backfilled. The backfilling steps include: using a backfilling retaining wall to block the lower stope connecting road, conveying backfilling material to the empty area to form a trapezoidal backfill body, and after the backfill body has been cured to the design strength, further piling waste rock on top of it to make the backfill area fully connected to the roof, and erecting a flexible retaining wall on the side of the waste rock near the blasting area and reserving compensation space. S5. Repeat steps S2 to S4 until all the ore in the mining area has been extracted.

[0006] A continuous mechanized mining method for inclined thin ore bodies according to an embodiment of the present invention has at least the following beneficial effects: 1. High resource recovery rate: No pillars are set in the mining area, which reduces the loss of mineral resources caused by leaving pillars.

[0007] 2. Significantly improved safety: The use of flexible retaining walls to buffer the impact of blasting, the use of remote-controlled equipment for high-risk operations, timely and proactive roof support, and backfilling of voids have ensured the safety of mining operations.

[0008] 3. High degree of mechanization and continuity: With medium-deep hole blasting and remote-controlled shovel loader as the core, the main links of ore falling and ore extraction have been mechanized, which has greatly improved the efficiency of operation.

[0009] 4. Good economic and environmental benefits: Using the mine's own waste rock and tailings as backfill materials realizes the resource utilization of waste, reduces backfilling costs, and reduces the accumulation of tailings on the surface, which meets the requirements of green mine development.

[0010] According to some embodiments of the present invention, in step S2, the length of ore along the dip direction of the ore body is controlled for each blast. , so that: During the initial blast, ; During subsequent demolitions, , or ; During the initial blast The value is the width of the cutting lane, which is used during subsequent blasting. The length of the reserved void along the dip direction of the ore body is defined by Y, which is the void utilization coefficient, ranging from 0.3 to 0.5; k is the rock loosening coefficient, ranging from 1.2 to 1.8; and B is the stope width. This represents the maximum exposed area of ​​the mining area. This represents the maximum span of the mining area.

[0011] According to some embodiments of the present invention, in step S4, the filling material includes paste, whole tailings or graded tailings, the filling cementing material in the paste is 42.5 grade or higher silicate cement or red mud, smelting slag or cementing material based on red mud or smelting slag, the 3d or 7d uniaxial compressive strength of the filling body is not less than 1.2MPa, and the 28d uniaxial compressive strength is not less than 1.5MPa.

[0012] According to some embodiments of the present invention, in step S1: the ore body is divided into panels along the dip direction, the width of the panels is 100-300m, the ore blocks are arranged perpendicular to the strike, the length is 100-300m, the width is 40-60m, the width of the top pillar is 3-6m, the width of the bottom pillar is 4-6m, the width of the inter-pillar is 6-10m, and the width of the cutting horizontal tunnel and the cutting uphill is 3-4m.

[0013] According to some embodiments of the present invention, in step S1: when the dip angle of the ore body is greater than 14°, the panel is arranged along the pseudo-dip direction so that the working dip angle of the mining area is less than 14°, so as to meet the working requirements of the trackless equipment.

[0014] According to some embodiments of the present invention, in step S2: the medium-deep holes are arranged in a fan shape or in parallel, and the blasting contour line adopts pre-splitting blasting or smooth blasting technology.

[0015] According to some embodiments of the present invention, when the ore body thickness is greater than 1.8m, the cutting level and cutting incline heights are consistent with the ore body thickness, and full-face one-time mining is adopted; When the ore body thickness is no more than 1.8m, the cutting tunnel height is no less than 1.8m. First, the surrounding rock is blasted and stripped to create working space. The waste rock generated from the stripping is used for auxiliary filling of the empty area, and then blasting is carried out to extract the ore.

[0016] According to some embodiments of the present invention, in step S3: during the directional ventilation process, the air flows sequentially through the lower transport level, the panel connecting roadway, the stope connecting roadway, the cutting incline, the stope, the cutting incline, the stope connecting roadway and the panel connecting roadway, and finally is discharged along the upper transport level; Active support uses slotted pipe anchors, resin anchors, or anchor cables, with the length of the anchor or the length of the anchored section not less than the thickness of the direct top plate.

[0017] According to some embodiments of the present invention, the flexible retaining wall includes a rubber pad and a steel frame, the thickness of the flexible retaining wall is 0.15 to 0.30 m, and the remote-controlled loader is a low-profile device.

[0018] According to some embodiments of the present invention, no permanent or temporary pillars are set in the stope, and the stability of the roof is controlled by filling, smooth blasting or pre-splitting blasting and active support.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a top view of a stope using a continuous mechanized mining method for inclined thin ore bodies according to an embodiment of the present invention; Figure 2 for Figure 1 Sectional view of AA; Figure 3 for Figure 1 Sectional view of BB; Figure 4 for Figure 1 A sectional view of CC.

[0021] Icon labels: 1. Ore body; 2. Transport roadway; 3. Panel connecting roadway; 4. Cutting roadway; 5. Cutting incline; 6. Stope connecting roadway; 7. Roof pillar; 8. Bottom pillar; 9. Interstitial pillar; 10. Medium-deep borehole; 11. Filling retaining wall; 12. Collapsed ore; 13. Waste rock; 14. Filling body; 15. Roof surrounding rock; 16. Bottom surrounding rock; 17. Roof support; 18. Flexible retaining wall. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] See Figure 1 , Figure 2 , Figure 3 and Figure 4 A continuous mechanized mining method for inclined thin ore bodies according to an embodiment of the present invention includes the following steps: S1. Division of mining areas and layout of mining preparation engineering: Divide the mining area into several independent mining areas along the strike of ore body 1, excavate the transport roadway 2 along the footwall of ore body 1, and excavate the connecting roadway 3 along the dip of ore body 1. In each mining area, excavate the cutting roadway 4 along the bottom plate of ore body 1, and excavate the cutting incline 5 along the boundary of the pillar 9 to connect the upper and lower cutting roadways 4. At the same time, excavate the mining area connecting roadway 6 to connect with the connecting roadway 3 of the mining area, forming a passage for personnel, equipment and ore transportation.

[0026] The system offers excellent safety isolation, ensuring each stope operates independently. Accidents (such as roof falls or water inrushes) are confined to a single stope, preventing cascading damage. The cutting incline 5 connects the upper and lower sections, forming a natural ventilation loop. Fresh air enters the stope via cutting incline 5, while polluted air is exhausted from the other side, minimizing ventilation dead zones. The transport level 2, in conjunction with the stope connecting roadway 6 and the panel connecting roadway 3, allows for convenient, short-distance ore transport, reducing handling distances, lowering transportation costs, and improving production efficiency.

[0027] S2. Mining: The panel adopts a bottom-up, side-to-side sequential mining approach. Bottom-up mining allows the ore to fall under its own weight, saving on transportation costs. Side-to-side sequential mining allows for unidirectional advancement of the working face, simplifying organization and preventing cross-interference. Before blasting, a flexible retaining wall 18 is erected on the side of the bottom cutting level 4 closest to the blasting area. During blasting, the ore moves towards the footwall under the action of detonation gases. The retaining wall blocks flying rocks, forming a natural accumulation under gravity. The flexible material (wire rope mesh or rubber curtain) absorbs impact energy, preventing broken ore from directly impacting the bottom pillar 8 or the filling body 14. At the intersection of the bottom cutting level 4 and the cutting incline 5, medium-deep holes 10 are drilled along the strike from both sides of the ore body 1 for blasting, resulting in high ore extraction efficiency.

[0028] S3. Mining Ventilation, Roof Support 17, and Ore Transportation: Directional ventilation is implemented after blasting. Blasting generates large amounts of toxic gases and dust, which are rapidly diluted and discharged through directional ventilation, shortening waiting time and allowing personnel to enter the working face earlier, thus improving efficiency. A remote-controlled roof roughening trolley is used to roughen the roof, operating remotely away from areas prone to loose rock falling, improving safety. Active support is implemented in fractured areas, interlayers, or areas with poor stability, providing precise support and timely control of surrounding rock deformation to prevent localized roof falls from escalating into large-scale collapses.

[0029] After support is provided, a remote-controlled loader is used to transport the collapsed ore 12 through the stope connecting roadway 6 to the panel connecting roadway 3. The equipment is only allowed to enter after the working face is stabilized to avoid the roof collapsing and damaging the equipment or injuring people during the mining process. The operation is remote-controlled and away from the blasting fly rock area, roof fall area, and dust area. The loader is transported directly from the stope to the panel connecting roadway 3 through the connecting road, which is a short transportation chain and highly efficient.

[0030] S4. Stope Backfilling: When it is predicted that the exposed area or span will exceed the limit after the next blasting cycle, the stope is partially backfilled. The backfilling steps include: sealing the lower stope connecting roadway 6 with a backfilling retaining wall 11 to form a sealed void, ensuring that the backfill material will not overflow from the connecting roadway and guaranteeing the compactness of the backfill. Backfill material is transported to the void to form a trapezoidal backfill body 14. After the backfill body 14 has cured to the design strength, waste rock 13 is piled up to ensure that the backfill area is fully connected to the roof. A flexible retaining wall 18 is erected on the side of the waste rock 13 closest to the blasting area, with reserved compensation space. The flexible retaining wall 18 effectively resists the impact of the next round of blasting. There are a large number of gaps between the piled waste rock 13, which can further absorb blasting energy and reduce the impact of blasting impact on the backfill body 14 and the roof rock 15.

[0031] S5. Repeat steps S2 to S4 until all the ore in the mining area has been extracted.

[0032] A continuous mechanized mining method for inclined thin ore bodies according to an embodiment of the present invention has at least the following beneficial effects: 1. High resource recovery rate: No pillars are set in the mining area, which reduces the loss of mineral resources caused by leaving pillars.

[0033] 2. Significantly improved safety: The use of flexible retaining walls to buffer blasting impact, remote control equipment for high-risk operations, timely and proactive roof support, and void filling technologies have ensured the safety of mining operations.

[0034] 3. High degree of mechanization and continuity: With medium-deep hole blasting and remote-controlled shovel loader as the core, the main links of ore falling and ore extraction have been mechanized, which has greatly improved the efficiency of operation.

[0035] 4. Good economic and environmental benefits: By using the mine's own waste rock 13 and tailings as backfill materials, the resource utilization of waste materials is realized, the backfilling cost is reduced, and the surface tailings accumulation is reduced, which meets the requirements of green mine development.

[0036] In some embodiments, see Figure 1 , Figure 2 and Figure 3 In step S2, the length of ore blasted along the dip direction of ore body 1 is controlled for each blast. , so that: During the initial blast, .

[0037] During subsequent demolitions, , or .

[0038] During the initial blast The value is 4 width for cutting the horizontal tunnel, and during subsequent blasting... The length of the reserved void along the dip direction of ore body 1 is defined by Y, which is the void utilization coefficient, ranging from 0.3 to 0.5; k is the rock loosening coefficient, ranging from 1.2 to 1.8; and B is the stope width. This represents the maximum exposed area of ​​the mining area. This is the maximum span of the mining area. The blasting width is strictly linked to the width of the reserved open area to ensure that the blasted ore has sufficient compensation space and that roof falls will not occur due to excessive span or exposed area.

[0039] In some embodiments, see Figures 1 to 3 In step S4, the filling material can be paste, whole tailings, or graded tailings. Paste slurry has good fluidity and can flow by gravity to all corners of the goaf, resulting in high compaction of the filling body, minimal goaf residue, and good roof support. Whole tailings filling can fully utilize tailings from the concentrator, eliminating the need for additional aggregate purchases, resulting in high waste utilization and lower costs. When using graded tailings filling, coarse particles form the skeleton, while fine particles fill the voids, resulting in a reasonable particle size distribution and high strength of the filling body, making it suitable for stopes with large spans and high stress.

[0040] The filling cementitious material in the paste uses silicate cement of grade 42.5 or higher, or red mud, smelting slag, and cementitious materials prepared based on them. Grade 42.5 cement is a medium-to-high grade, with high early strength, rapid strength development, and a short curing period, which is conducive to accelerating the mining-filling cycle. Using smelting waste such as red mud and smelting slag as cementitious materials can further realize the resource utilization of solid waste. The 3-day or 7-day uniaxial compressive strength of the filling body 14 is not less than 1.2 MPa, and this strength can be reached in 3 days, which means that only 3 days are needed after filling before the next round of mining operations can be carried out, significantly shortening the mining-filling cycle time; the 28-day uniaxial compressive strength is not less than 1.5 MPa, ensuring long-term strength. The filling body 14 can effectively bear the pressure of the overlying strata and reduce the stress concentration in the mining area.

[0041] In some embodiments, see Figures 1 to 3 In step S1, the width of both the cutting horizontal tunnel 4 and the cutting uphill tunnel 5 is 3-4m. This width meets the passage requirements of the remote-controlled loader, while the small excavation cross-section reduces the amount of work and saves time and cost.

[0042] In some embodiments, see Figures 1 to 3 In step S1: When the dip angle of ore body 1 is greater than 14°, the panel is arranged along the pseudo-dip direction so that the working dip angle of the mining area is less than 14°, which meets the maximum climbing capacity requirement (≤14°) of the trackless equipment (loader). All roadway cross-sectional dimensions are designed according to the requirements for the passage of trackless equipment.

[0043] In some embodiments, see Figures 1 to 3 In step S2: the medium-deep holes 10 can be arranged in a fan shape or in parallel. When arranged in a fan shape, the hole openings are concentrated in the center of the drilling tunnel and spread outwards in a radial pattern. The blasting range can be flexibly controlled by adjusting the drilling angle. When arranged in parallel, all the holes are arranged in parallel along the strike, the explosives are evenly distributed, the ore blocks are uniform in size after blasting, and the collapse boundary is neat.

[0044] When using pre-splitting blasting technology to control the blasting profile, pre-splitting holes are arranged along the designed profile line and detonated before the main blasting zone, forming a regular pre-splitting surface to effectively prevent subsequent main blasts from disturbing the remaining surrounding rock. When using smooth blasting technology, after the main blasting zone is detonated, smooth holes around the profile line are detonated to neatly remove the reserved smooth blasting layer, trim the excavation face, eliminate the uneven traces left by the main blast, and form a smooth and flat rock wall.

[0045] In some embodiments, see Figures 1 to 3 When the thickness of ore body 1 is greater than 1.8m, the heights of cutting horizontal tunnel 4 and cutting uphill tunnel 5 are consistent with the thickness of ore body 1, and full-face single-pass mining is adopted. The tunnel height is the same as the ore body thickness, and the ore is blasted out in one pass, without stratification or multiple passes, resulting in high ore extraction efficiency and fewer mining steps.

[0046] When the thickness of ore body 1 is no more than 1.8m, the height of the cutting tunnel 4 should be no less than 1.8m. During mining, the roof surrounding rock 15 is first blasted and stripped to create the necessary working space, and the waste rock 13 generated from the stripping is used to assist in filling the goaf; then the ore is blasted down. For thin ore bodies with a thickness of only a little over 1 meter, personnel and equipment cannot enter directly. Excavating the tunnel height to more than 1.8m can ensure the safety of personnel passage and the operating space of equipment.

[0047] In some embodiments, see Figures 1 to 3 In step S3: During directional ventilation, the airflow sequentially flows through the lower transport level 2, panel connecting roadway 3, stope connecting roadway, cutting incline 5, and stope, then from the stope through the other side cutting incline 5, stope connecting roadway, and panel connecting roadway 3, finally exiting through the upper transport level 2. The ventilation system adopts a bottom-in, top-out arrangement, with hot exhaust gas naturally rising. The ventilation direction is consistent with the thermal transport direction, which can effectively reduce fan energy consumption. Active support (roof support 17) uses slotted pipe anchors, resin anchors, or anchor cables. Slotted pipe anchors are suitable for working conditions with large surrounding rock deformation, have good pressure deformation capacity, and are not easily sheared; resin anchors have strong anchoring force and are suitable for stable rock strata with good surrounding rock conditions; anchor cables have high bearing capacity and are suitable for large-span or thick-layered roofs. The length of the anchor or the anchoring section of the anchor cable is not less than the thickness of the direct roof, and a safety margin is reserved. The design takes into account local variations in the thickness of the direct top plate, ensuring that the anchorage length requirements are met even at the thinnest point of the top plate.

[0048] In some embodiments, see Figures 1 to 3 The flexible retaining wall 18 consists of rubber pads and a steel frame. The rubber pads act as a buffer and sealing layer, absorbing impact energy through compression deformation; the steel frame serves as a rigid skeleton, ensuring the overall stability of the retaining wall structure. The flexible retaining wall 18 has a thickness of 0.15–0.30 m, a compact structure, and saves space. The remote-controlled loader uses a low-profile design with a low center of gravity, good stability, strong anti-overturning ability, and high safety.

[0049] In some embodiments, see Figures 1 to 3 No permanent or temporary pillars are installed in the stope. Stability control of the roof rock is achieved through methods such as backfilling, smooth blasting or pre-splitting blasting, and active support. The absence of pillars in the stope reduces ore loss caused by pillar installation and improves ore recovery.

[0050] Practical application of the embodiments of this application: Taking a gently dipping thin orebody in a mine as an example, orebody 1 has a dip angle of 17° and a thickness of 2.5m. Orebody 1 has a stable occurrence and good surrounding rock stability (RMR value of 65-75). The ore grade is Al2O3: 68%, A / S: 6.85. Orebody 1 is located at a depth of 250m underground. The bottom surrounding rock 16 of orebody 1 is argillaceous siltstone, and the top surrounding rock 15 is carbonaceous shale. The geological structure is simple, with no obvious faults or fractures. The maximum exposed area of ​​the stope is... =400m 2 The span is =12m.

[0051] Mining area division and preparation engineering layout: According to the present invention, the panel is first divided along the dip direction of ore body 1, with a panel length of 200m. The panel is then divided into several ore blocks along the strike direction of ore body 1, arranged perpendicular to the strike. Each ore block is 200m long and 50m wide. The top pillar 7 is 3m wide, the bottom pillar 8 is 4m wide, and the inter-pillar 9 is 8m wide. A transport roadway 2 (three-center arch cross-section, 4m wide and 3.5m high) is excavated along the footwall of ore body 1. A connecting roadway 3 (3.5m wide and 3.5m high) is excavated along the dip direction of ore body 1.

[0052] Within each stope, a cutting level roadway 4 (rectangular cross-section, 3.5m wide, 3.0m high) is excavated along the bottom plate of ore body 1, and an uphill cutting roadway 5 (rectangular cross-section, 4.5m wide, 3.0m high) is excavated along the boundary of pillar 9, connecting the upper and lower cutting level roadways 4. Simultaneously, a stope connecting roadway 6 (rectangular cross-section, 4m wide, 3.5m high) is excavated every 50m to connect with the panel connecting roadway 3, forming a passageway for personnel, equipment, and ore transportation.

[0053] Considering that the dip angle of ore body 1 is 17°, slightly greater than 14°, the panel is arranged along the pseudo-dip direction to control the working dip angle of the mining area at 12°, which meets the climbing capacity requirements of trackless equipment (loaders) (climbing capacity ≤ 14°). The cross-sectional dimensions of all roadways meet the passage requirements of trackless equipment.

[0054] Mining: The panel is mined sequentially from bottom to top and from one side to the other. First, starting at the intersection of the bottom cutting horizontal tunnel 4 and the cutting uphill tunnel 5, medium-deep holes 10 (diameter 76mm, spacing 0.5m×0.5m, depth 22.5m) are drilled along the strike from both sides of the ore body 1. The blast holes are arranged in parallel with a spacing of 1.5m.

[0055] Smooth blasting technology was used at the blasting outline, reducing the amount of explosive charge (0.3 kg per meter of hole depth) to create a regular blasting surface and reduce damage to the surrounding rock. Before blasting, a flexible retaining wall 18 (composed of rubber pads and a steel frame, 0.2 m thick) was erected on the side of the bottom cut tunnel 4 near the blasting zone to buffer the impact of blasted rocks on the bottom surrounding rock 16.

[0056] During the initial blasting, the reserved empty zone has an inclined length. =3.5m (cutting level tunnel width 4), empty area utilization coefficient Y=0.4, rock loosening coefficient k=1.3, calculated as follows ≤3.5×0.4 / ((1.3-1))=4.67m. The initial blasting length is set as follows. =4.5m. During subsequent blasting, =4.5m, =4.5m, B=50m, =400m², =12m, calculated as (4.5m+4.5m)×(50m-8m)=378m²≤400m², which meets the stability requirements of the mining area. Since the thickness of ore body 1 is 2.5m>1.8m, full-face single-pass mining is adopted, the cutting roadway height is consistent with the thickness of ore body 1, and smooth blasting is carried out along the outline.

[0057] Ventilation, support, and ore transportation: Directional ventilation is implemented after blasting: fresh air flows sequentially through the lower transport level 2, panel connecting roadway 3, stope connecting roadway 6, cutting incline 5, stope, cutting incline 5, stope connecting roadway 6, and panel connecting roadway 3, finally exiting along the upper transport level 2. A remote-controlled shoveling trolley is used to roughen the roof, and active support is implemented in the fractured roof area. Slotted pipe anchors (1.8m long) are selected with a spacing of 1.5m × 1.5m, combined with anchor mesh (6mm diameter steel bars, 100mm × 100mm mesh, 1500mm × 2000mm anchor mesh) for support. After support, a low-profile remote-controlled loader transports the blasted ore 12 via stope connecting roadway 6 to panel connecting roadway 3, from where it is transported by a trackless transport vehicle (15t loading capacity) to the panel ore pass.

[0058] Goaf backfilling: When it is predicted that the exposed area or span will exceed the limit after the next blasting cycle, local backfilling shall be performed. The local backfilling steps are as follows: a. The lower mining area connecting road 6 is sealed off by using a filling retaining wall 11 (composed of precast concrete slabs); b. Transport tailings backfill material (cement content 15%, water-solid ratio 0.8) to the goaf area to form a trapezoidal backfill body 14; c. After the filling body 14 is cured, waste rock 13 is piled on top to fill the triangular area that is not connected to the top. d. Erect a flexible retaining wall 18 on the side of the waste rock 13 near the blasting zone, and reserve a compensation space of 1.5 to 3.5m for the next blast.

[0059] The filling cementitious material used is 42.5 grade ordinary Portland cement. The uniaxial compressive strength of the filling body at 14 3d / 7d is 1.3MPa / 1.4MPa, and the uniaxial compressive strength at 28d is 1.8MPa.

[0060] Implementation Results: Through the implementation of this embodiment, all ore in the stope was extracted, with no pillars remaining. The recovery rate of ore body 1 was 88.5%, approximately 20%–25% higher than the traditional room-and-pillar method. Operational safety was significantly improved, with a marked reduction in the roof instability accident rate. The degree of mechanization and continuity was high; key processes such as blasting in the medium-deep hole 10 and remote-controlled shovel loader extraction were mechanized, significantly improving operational efficiency. The resource utilization rate of waste rock 13 and tailings reached 95%, meeting the requirements for green mine development.

[0061] This embodiment demonstrates that the continuous mechanized mining method for gently inclined thin ore bodies of the present invention can effectively solve the problems of high resource loss rate, low degree of mechanization, and poor stability of goaf in traditional mining methods, and achieve safe, efficient, and low-loss mining of ore body 1, with significant technical advantages and economic benefits.

[0062] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for the continuous mechanized mining of inclined thin ore bodies, characterized in that, Includes the following steps: S1. Division of mining areas and layout of mining preparation engineering: Divide the mining area into several independent mining areas along the strike of the ore body, excavate the transport roadway along the footwall of the ore body, and excavate the connecting roadway of the mining area along the dip of the ore body. In each mining area, excavate the cutting roadway along the bottom plate of the ore body, and excavate the cutting incline along the pillar boundary to connect the upper and lower cutting roadways. At the same time, excavate the connecting roadway of the mining area to connect with the connecting roadway of the mining area, forming a passage for personnel, equipment and ore transportation. S2. Mining: The panel adopts a sequential mining approach from bottom to top and from one side to the other. Before blasting, a flexible retaining wall is erected on the side of the bottom cutting tunnel near the blasting area. At the intersection of the bottom cutting tunnel and the cutting uphill section, medium-deep holes are drilled along the strike from both sides of the ore body for blasting. S3. Ventilation, roof support and ore transportation in the stope: Directional ventilation is carried out after blasting. The roof is roughened by a remote-controlled shovel trolley. Active support is implemented in the fractured area, interlayer or area with poor stability of the roof. After support, the collapsed ore is transported to the panel connecting roadway through the stope connecting roadway by a remote-controlled loader. S4. Stope backfilling: When it is predicted that the exposed area or span will exceed the limit after the next cycle of blasting, the stope is partially backfilled. The backfilling steps include: using a backfilling retaining wall to block the lower stope connecting road, conveying backfilling material to the empty area to form a trapezoidal backfill body, and after the backfill body has been cured to the design strength, further piling waste rock on top of it to make the backfill area fully connected to the roof, and erecting a flexible retaining wall on the side of the waste rock near the blasting area and reserving compensation space. S5. Repeat steps S2 to S4 until all the ore in the mining area has been extracted.

2. The continuous mechanized mining method for inclined thin ore bodies according to claim 1, characterized in that, In step S2, the length of the ore along the ore body tendency direction is controlled for each blasting such that: During the initial blast, ; At the time of the subsequent blasting, , or ; During the initial blast The value is the width of the cutting lane, which is used during subsequent blasting. The length of the reserved void along the dip direction of the ore body is defined by Y, which is the void utilization coefficient, ranging from 0.3 to 0.5; k is the rock loosening coefficient, ranging from 1.2 to 1.8; and B is the stope width. This represents the maximum exposed area of ​​the mining area. This represents the maximum span of the mining area.

3. A method of continuous mechanized mining of a dipping thin ore body according to claim 1, characterized in that, In step S4, the filling material includes paste, whole tailings or graded tailings. The filling cementitious material in the paste is 42.5 grade or higher silicate cement or red mud, smelting slag or cementitious material based on red mud or smelting slag. The uniaxial compressive strength of the filling body at 3d or 7d is not less than 1.2MPa, and the uniaxial compressive strength at 28d is not less than 1.5MPa.

4. A method of continuous mechanized mining of a dipping thin ore body as claimed in claim 1, wherein, In step S1: the panel is divided along the dip direction of the ore body. The width of the panel is 100-300m. The ore blocks are arranged perpendicular to the strike direction, with a length of 100-300m and a width of 40-60m. The width of the top pillar is 3-6m, the width of the bottom pillar is 4-6m, the width of the inter-pillar is 6-10m, and the width of the cutting horizontal tunnel and the cutting uphill is 3-4m.

5. A method of continuous mechanized mining of a dipping thin ore body as claimed in claim 1, wherein, In step S1: When the dip angle of the ore body is greater than 14°, the panel is arranged along the pseudo-dip direction so that the working dip angle of the mining area is less than 14°, so as to meet the requirements of the trackless equipment.

6. A continuous mechanized mining method for inclined thin ore bodies according to claim 1, characterized in that, In step S2: the medium-deep holes are arranged in a fan shape or in parallel, and the blasting outline adopts pre-splitting blasting or smooth blasting technology.

7. A method of continuous mechanized mining of a dipping thin ore body as claimed in claim 1, wherein, When the ore body thickness is greater than 1.8m, the cutting level and cutting incline height are consistent with the ore body thickness, and full-section one-time mining is adopted; When the ore body thickness is no more than 1.8m, the cutting tunnel height is no less than 1.8m. First, the surrounding rock is blasted and stripped to create working space. The waste rock generated from the stripping is used for auxiliary filling of the empty area, and then blasting is carried out to extract the ore.

8. A method of continuous mechanized mining of a dipping thin ore body as claimed in claim 1, wherein, In step S3: During directional ventilation, air flows sequentially through the lower transport level, panel connecting roadway, stope connecting roadway, cutting incline, stope, cutting incline, stope connecting roadway and panel connecting roadway, and finally exits along the upper transport level; Active support uses slotted pipe anchors, resin anchors, or anchor cables, with the length of the anchor or the length of the anchored section not less than the thickness of the direct top plate.

9. A method of continuous mechanized mining of a dipping thin ore body as claimed in claim 1, wherein, The flexible retaining wall consists of rubber pads and a steel frame. The thickness of the flexible retaining wall is 0.15 to 0.30 meters. The remote-controlled scraper is a low-profile device.

10. A method of continuous mechanized mining of a dipping thin ore body as claimed in claim 1, wherein, No permanent or temporary pillars are set in the mining area. Roof stability is controlled by filling, smooth blasting or pre-splitting blasting and active support.

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