Flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection

Abstract

The present application belongs to the field of mining technology, and provides a flat-bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection, comprising the following steps: S1, determining the stope layout form according to the occurrence form of deep and thick ore bodies, ground stress conditions, stope size and development project location, dividing the stope and determining the target stope; S2, constructing an upper stope connecting tunnel and a rock drilling tunnel from the upper part of the target stope, and the upper stope connecting tunnel is connected to the rock drilling tunnel; constructing a lower stope connecting tunnel and a mine exit tunnel from the lower part of the target stope, and the lower stope connecting tunnel is connected to the mine exit tunnel; the beneficial effect of the present invention is that by gradually reducing the depth of the first downward fan-shaped blasthole from the first cutting groove to the end of the target stope, a blasting excavation face inclined toward the first cutting groove area and adapted to the natural repose angle of the collapsed ore rock is formed, so that the collapsed ore is gathered toward the mine exit tunnel under the action of gravity and explosive force, thereby improving the mine exit efficiency and controlling the ore output of the remote-controlled scraper.

Description

Technical Field

[0001] The present application belongs to the field of mining technology, and specifically relates to a flat-bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection. Background Art

[0002] Open-stop and subsequent backfill mining has gradually become the mainstream method for mining thick and large metal ore bodies in my country, due to its advantages of minimal surface damage, high production efficiency, high resource recovery intensity, and minimal mining and cutting workload. The mine floor structure primarily utilizes a "V"-shaped trench and a "fishbone" ore flow. This presents challenges such as extensive mining preparation, complex processes, difficulty recovering peach-shaped pillars, severe damage to the brow line of the ore access route, and difficulty in supporting the mine. Furthermore, the exit tunnels from the second-step stope must be located within the backfill, which is inherently weak. This, combined with the impact of residual ore, results in low tunneling efficiency, difficulty in construction, and high costs and safety risks, making the exit tunnels difficult to excavate and support. While a flat-bottom structure can effectively address these issues, it requires the use of remote-controlled scrapers for ore removal, resulting in low ore extraction efficiency and insufficient capacity to meet mine production needs. Therefore, controlling the output of these scrapers and improving stope extraction efficiency remains a key technical challenge for the flat-bottom structure. At the same time, the traditional bottom structure has blind spots for mining, and some collapsed ores are in a static state in the early mining stage. For mining of ore bodies that are prone to compaction, such as sulfur-containing deposits, the ore will become compacted, resulting in a large amount of residual ore piles in the mining area.

[0003] With the depletion of shallow resources, deep mining has become an important part of my country's mining industry. The mining of thick and large ore bodies of deep metal ores is carried out in a special environment of "three highs and one disturbance". When downward vertical medium-deep hole drilling is adopted, the drilling chamber mining project is large and the exposed area of ​​the chamber roof is large, which can easily cause the collapse of the drilling chamber roof in the mining area. It has the disadvantages of difficulty in controlling ground pressure and poor drilling safety, making it difficult to adapt to deep mining. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] In order to solve the above problems, the present application provides a flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection, comprising the following steps:

[0006] S1. Determine the stope layout, divide the stopes and identify the target stope based on the occurrence morphology of the deep, thick ore body, ground stress conditions, stope size and development project location;

[0007] S2. Constructing an upper stope connecting tunnel and a rock drilling tunnel from the upper part of the target stope, wherein the upper stope connecting tunnel is connected to the rock drilling tunnel; constructing a lower stope connecting tunnel and a mine-discharging tunnel from the lower part of the target stope, wherein the lower stope connecting tunnel is connected to the mine-discharging tunnel; constructing a bottom cross tunnel connected to the mine-discharging tunnel from the target stope, and forming a first cutting groove in the target stope with the bottom cross tunnel as the initial free surface and compensation space, wherein the first cutting groove is connected to the rock drilling tunnel and the bottom cross tunnel;

[0008] S3. Determine a blasting excavation face in the target stope, construct a first downward fan-shaped blasthole downward in the rock drilling roadway until the blasting excavation face, wherein the depth of the first downward fan-shaped blasthole decreases from the first cutting groove toward the end of the target stope; construct an upward fan-shaped blasthole from the mining roadway until the blasting excavation face, wherein the depth of the upward fan-shaped blasthole increases from the first cutting groove toward the end of the target stope;

[0009] S4, loading explosives into the first downward fan-shaped blasthole and the upward fan-shaped blasthole, sequentially blasting the first downward fan-shaped blasthole and the upward fan-shaped blasthole, and sequentially unloading the collapsed ore through the unloading roadway;

[0010] S5. Filling the goaf formed in the target stope.

[0011] Optionally, constructing an upper stope junction and a rock drilling tunnel from the upper portion of the target stope, wherein the upper stope junction is connected to the rock drilling tunnel, comprises:

[0012] Upper stage tunnels are opened on both sides of the upper part of the target stope, the upper stope connecting tunnel is constructed from the upper stage tunnel to the target stope, and the rock drilling tunnel is arranged on the upper part of the target stope along the target stope mining direction.

[0013] Optionally, constructing a lower stope connecting tunnel and a mine-discharging tunnel from the lower part of the target stope, wherein the lower stope connecting tunnel is connected to the mine-discharging tunnel, includes:

[0014] Lower stage tunnels are opened on both sides of the lower part of the target stope, the lower stope connecting tunnel is constructed from the lower stage tunnel to the target stope, and the mining tunnel is arranged at the lower part of the target stope along the mining direction of the target stope.

[0015] Optionally, constructing a bottom cross lane connected to the mining roadway from the target stope, and constructing a first cutting groove in the target stope using the bottom cross lane as an initial free surface and compensation space, wherein the first cutting groove connects the rock drilling roadway and the bottom cross lane, includes:

[0016] The bottom cross tunnel is constructed at the lower part of the target mining area in a direction perpendicular to the mining tunnel, a second downward fan-shaped blast hole is opened in the rock drilling tunnel, explosives are loaded in the second downward fan-shaped blast hole, and the first cutting groove is formed by layered blasting with the bottom cross tunnel as the initial free surface and compensation space.

[0017] Optionally, the width of the bottom cross tunnel is 3m-5m, and the length is the width of the target stope.

[0018] Optionally, the inclination angle of the blasting excavation surface is equal to the natural repose angle of the collapsed ore bulk.

[0019] Optionally, the distance between the bottom of the first downward fan-shaped blasthole and the top of the mining tunnel is not less than 5m.

[0020] Optionally, the method includes loading explosives into the first downward fan-shaped blasthole and the upward fan-shaped blasthole, sequentially blasting the first downward fan-shaped blasthole and the upward fan-shaped blasthole, and sequentially unloading the collapsed ore through the ore-unloading roadway, including:

[0021] After loading explosives into the first downward fan-shaped blastholes, the first downward fan-shaped blastholes are detonated in stages and sequentially to side-collapse the ore body in the target stope located above the blasting excavation face, with the collapsed ore falling through the first cutting groove and being transported out through the ore discharge tunnel until the ore is completely discharged;

[0022] After the ore body located above the blasting excavation surface in the target mining area is mined, explosives are loaded into the upward fan-shaped blastholes, and the upward fan-shaped blastholes are detonated in sequence in sections to side-collapse the ore body located below the blasting excavation surface in the target mining area, and the collapsed ore is transported out through the mining tunnel until the mining is completed.

[0023] Optionally, filling the goaf formed in the target stope includes:

[0024] The filling pipeline is lowered into the goaf through the rock drilling tunnel, and the filling material is filled into the goaf through the filling pipeline.

[0025] Optionally, a long anchor cable and anchor rod support system is used to provide pre-support for the upper stope joint tunnel, the rock drilling tunnel, the lower stope joint tunnel and the mine exit tunnel.

[0026] Beneficial effects

[0027] The flat-bottom mining method based on fan-shaped hole blasting and gravity-assisted ore collection provided in the embodiments of the present invention has the advantages of a simple stope structure, a small mining workload, high mining efficiency, high ore recovery rate, easily controlled ground pressure, and favorable backfill load. By gradually decreasing the depth of the first downward fan-shaped blasthole from the first cutting groove toward the end of the target stope, a blasting excavation face is formed that is inclined toward the first cutting groove area and adapted to the natural repose angle of the collapsed ore. This allows the collapsed ore to gather toward the mine exit tunnel under the action of gravity and explosive force, thereby improving the stope's ore extraction efficiency and controlling the ore output of the remote-controlled scraper. In addition, the blasting excavation surface inclined toward the first cutting groove area keeps the collapsed ore in a flowing state under the disturbance of mining and gravity, thus avoiding the compaction of the ore. The first downward fan-shaped blasthole is used instead of the vertical medium-deep hole for blasting the ore, so that the top of the target mining area is changed from a rectangular structure to an arched structure, which reduces the stress concentration of the target mining area roof, facilitates ground pressure control, and reduces the amount of mining engineering. The arched structure at the top is conducive to the bearing of the filling body, reducing the requirements for the filling top. People construct in the well-supported mining area rock drilling tunnel and mining tunnel, which is safe. Compared with the traditional "V"-shaped trench mining structure, it has the advantage of simple mining engineering design, avoids the problem of tunnel excavation in the filling body for two-step mining, and improves the production efficiency of the mine. The mining method of the present invention avoids the setting of peach-shaped pillars, reduces ore loss, and has good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flow chart of the present invention;

[0029] Figure 2 This is a schematic diagram of the cross-sectional structure of the target stope of the present invention;

[0030] Figure 3 For the present invention Figure 2 Middle DD cross-sectional structure diagram;

[0031] Figure 4 This is a structural diagram of the first cutting groove blasting sequence of the present invention;

[0032] Figure 5 For the present invention Figure 2 Middle AA cross-sectional structural diagram;

[0033] Figure 6 For the present invention Figure 2 Middle BB cross-sectional structure diagram;

[0034] Figure 7 For the present invention Figure 2 Middle CC cross-sectional structure diagram;

[0035] Figure 8 This is a schematic diagram of the target stope ore collapse sequence of the present invention.

[0036] The reference numerals indicate:

[0037] 1. Target stope; 2. Upper stope connecting tunnel; 3. Rock drilling tunnel; 4. Lower stope connecting tunnel; 5. Mine exit tunnel; 6. Bottom cross tunnel; 7. First cutting groove; 8. Blasting excavation face; 9. First downward fan-shaped blasthole; 10. Upward fan-shaped blasthole; 11. Upper stage tunnel; 12. Lower stage tunnel; 13. Second downward fan-shaped blasthole. DETAILED DESCRIPTION

[0038] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0040] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; they can refer to mechanical connection or electrical connection; they can refer to direct connection or indirect connection through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0041] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0042] See also Figures 1-8 As shown, according to an embodiment of the present application, a flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection is provided, comprising the following steps:

[0043] S1. Determine the stope layout based on the occurrence form of deep and thick ore bodies, ground stress conditions, stope size and development project location, divide the stopes and determine the target stope 1.

[0044] Specifically, in the mining of deep, thick and large ore bodies, it is necessary to scientifically determine the stope layout, reasonably divide the stopes and select the target stopes1. This process requires comprehensive consideration of core factors such as the ore body occurrence form, ground stress conditions, stope size and development project location, and to build an efficient and safe mining system through systematic analysis.

[0045] S2. Construct the upper mining field connecting tunnel 2 and the rock drilling tunnel 3 from the upper part of the target mining field 1, and the upper mining field connecting tunnel 2 is connected to the rock drilling tunnel 3; construct the lower mining field connecting tunnel 4 and the mining tunnel 5 from the lower part of the target mining field 1, and the lower mining field connecting tunnel 4 is connected to the mining tunnel 5; construct the bottom cross tunnel 6 connected to the mining tunnel 5 from the target mining field 1, and construct the first cutting groove 7 for the target mining field 1 with the bottom cross tunnel 6 as the initial free surface and compensation space, and the first cutting groove 7 connects the rock drilling tunnel 3 and the bottom cross tunnel 6.

[0046] Specifically, the construction of the upper stope connecting tunnel 2 is the prerequisite for ensuring the smooth implementation of the rock drilling operation in the target stope 1. Through the opening of the upper stope connecting tunnel 2, a rock drilling tunnel 3 is opened on the upper part of the target stope 1, and the target stope 1 is connected to the upper stage tunnel 11 to form a closed ventilation, construction and transportation circuit; the lower stope connecting tunnel 4 and the mining tunnel 5 are opened at the lower part of the target stope 1, which can provide scrapers, remote-controlled scrapers and other mining equipment with smooth passage for ore transportation and mining; The bottom cross tunnel 6 connected to the mining tunnel 5 takes the bottom cross tunnel 6 as the initial free surface and compensation space, and forms the first cutting groove 7 connecting the rock drilling tunnel 3 and the bottom cross tunnel 6 through the VCR layered directional blasting technology. The opening of the first cutting groove 7 can provide the initial free surface and compensation space for subsequent blasting, improve the blasting effect, and at the same time provide a collection space for the subsequent blasting falling ore, so that the collapsed ore is concentrated in the first cutting groove 7, which is convenient for ore discharge from the mining tunnel 5 and improves the mining efficiency of the mining field.

[0047] S3. Determine the blasting excavation face 8 in the target stope 1, and construct the first downward fan-shaped blasthole 9 downward in the rock drilling tunnel 3 until the blasting excavation face 8, with the depth of the first downward fan-shaped blasthole 9 decreasing from the first cutting groove 7 to the end of the target stope 1; construct the upward fan-shaped blasthole 10 from the mining tunnel 5 until the blasting excavation face 8, with the depth of the upward fan-shaped blasthole 10 increasing from the first cutting groove 7 to the end of the target stope 1.

[0048] Specifically, the first downward fan-shaped blasthole 9 is constructed downward from the rock drilling tunnel 3, and its depth decreases from the first cutting groove 7 to the ends on both sides of the target stope 1 to ensure that after blasting, the ore forms a blasting excavation surface 8 that tilts upward from the first cutting groove 7 to the ends on both sides of the target stope 1. Near the first cutting groove 7, the blasthole depth is relatively deep. As it extends toward the end of the target stope 1, the blasthole depth gradually becomes shallower. This arrangement of decreasing depth makes the excavation surface after blasting tilt toward the first cutting groove 7, making it easier for the ore to naturally slide and gather in the area of ​​the first cutting groove 7 under the action of gravity and explosive force, reducing the accumulation of ore in the target stope 1 and improving the ore discharge efficiency. The scraper can directly load the blasted ore in the ore discharge tunnel 5.

[0049] Upward fan-shaped blastholes 10 are constructed upward from the mining roadway 5, with the depth increasing from the first cutting groove 7 toward the end of the target stope 1. They complement the first downward fan-shaped blastholes 9, ensuring that all ore in the target stope 1 is effectively blasted and crushed, avoiding the generation of large blasted chunks and ensuring the blasting effect of the stope. As the blasting advances toward the target stope 1, the ore blasted by the upward fan-shaped blastholes 10 is gathered toward the mining roadway 5 under the action of the explosive force and gravity, achieving all-round crushing and efficient transportation of the ore in the target stope 1, reducing ore residue and improving ore recovery rate.

[0050] The first downward fan-shaped blasthole 9 replaces the traditional vertical medium-length borehole for blasting ore drop. The rock drilling tunnel 3 replaces the traditional top rock drilling chamber, reducing the exposed roof area and facilitating ground pressure control. Drilling operations are performed safely within the rock drilling tunnel 3. The goaf, instead of the rectangular structure formed by traditional blasting, is transformed into an arched structure, alleviating stress concentration, facilitating ground pressure control, and reducing the mining workload. The arched structure also improves the bearing capacity of the fill after mining is completed, reducing the requirements for fill roof connection.

[0051] S4. Explosives are loaded into the first downward fan-shaped blasthole 9 and the upward fan-shaped blasthole 10, and the first downward fan-shaped blasthole 9 and the upward fan-shaped blasthole 10 are blasted in sequence, and the collapsed ore is discharged through the ore discharge tunnel 5 in sequence.

[0052] Specifically, the amount of explosives and the loading method are calculated based on the depth, angle, and rock properties of the first downward fan-shaped blasthole 9 and the upward fan-shaped blasthole 10. For the first downward fan-shaped blasthole 9, since its blastholes are relatively dense, it is advisable to adopt spaced charging to reduce the powder ore rate. In order to reduce the blasting of large pieces, it is advisable to adopt micro-difference bottom hole detonation. Considering that the upward fan-shaped blasthole 10 is close to the mining tunnel 5, in order to avoid damage to the tunnel structure caused by blasting, the blasthole should adopt uncoupled charging and spaced filling, and reserve an air gap between the blasthole wall and the explosives to reduce the impact of the explosion stress wave on the tunnel. During the loading process, the safety operating procedures are strictly followed, and special charging equipment is used to ensure that the explosives are evenly distributed in the blasthole to prevent blockage, discontinuous charging, etc., to create good conditions for subsequent blasting. The ore after blasting enters the mining tunnel 5 through the first cutting groove 7 for mining.

[0053] S5. Fill the goaf formed in the target stope 1.

[0054] Specifically, after the mining is completed, the goaf can be filled by methods such as tailings filling, tailings cemented filling, waste rock filling, and waste rock cemented filling according to the production technical conditions of the mine.

[0055] Combine Figure 1 、 Figure 2 、 Figure 5 As shown, in the embodiment of the present application, an upper stope tunnel 2 and a rock drilling tunnel 3 are constructed from the upper part of the target stope 1, and the upper stope tunnel 2 is connected to the rock drilling tunnel 3, including:

[0056] Upper stage tunnels 11 are opened on both sides of the upper part of the target stope 1, upper stope connecting tunnels 2 are constructed from the upper stage tunnels 11 to the target stope 1, and rock drilling tunnels 3 are arranged on the upper part of the target stope 1 along the mining direction of the target stope 1.

[0057] Specifically, the upper stage tunnels 11 on both sides of the upper part of the target mine 1 are constructed in the direction of the target mine 1 to form the upper mine tunnel 2, connecting the target mine 1 and the mine development system, forming a closed ventilation and transportation circuit, and providing an engineering foundation for workers to enter the rock drilling tunnel 3 for construction. After the upper mine tunnel 2 is formed, the rock drilling tunnel 3 is constructed along the upper mining direction of the target mine 1. The space after its construction directly affects the construction quality and blasting effect of the first downward fan-shaped blasthole 9. Before arrangement, the space of the rock drilling tunnel 3 is calculated according to the parameters of the first downward fan-shaped blasthole 9 designed for mining in the target mine 1. At the same time, sufficient space is reserved in the rock drilling tunnel 3 for arranging rock drilling equipment, water conduits and cable lines, creating a working environment for the subsequent construction of the first downward fan-shaped blasthole 9.

[0058] Combine Figure 1 、 Figure 2 、 Figure 3 、 Figure 5As shown, in the embodiment of the present application, the lower stope connecting tunnel 4 and the mine-exit tunnel 5 are constructed from the lower part of the target stope 1, and the lower stope connecting tunnel 4 is connected to the mine-exit tunnel 5, including:

[0059] Lower stage tunnels 12 are opened on both sides of the lower part of the target stope 1, lower stope connecting tunnels 4 are constructed from the lower stage tunnels 12 to the target stope 1, and a mining tunnel 5 is arranged at the lower part of the target stope 1 along the mining direction of the target stope 1.

[0060] Specifically, the lower stage tunnels 12 on both sides of the lower part of the target stope 1 are constructed in the direction of the target stope 1 to form the lower stope connecting tunnel 4. This construction method, which relies on the existing development project, greatly reduces the mining engineering workload and construction costs. The mining tunnel 5 is constructed along the lower mining direction of the target stope 1. Before construction, the size of the mining tunnel 5 is calculated by comprehensively considering factors such as the thickness of the ore body, mining methods, and the performance of the mining equipment to ensure that the size of the mining tunnel can meet the production capacity requirements of the mine. The layout of facilities such as cables, air and water pipes, and drainage pipes is reasonably planned in the mining tunnel 5, and sufficient space is reserved for the operation and maintenance of the mining equipment. Lighting, communication, and monitoring equipment are also installed to create a safe and convenient environment for mining operations.

[0061] After blasting, the ore is collected in the mining tunnel 5 and then transferred to the main transport tunnel through the lower stope tunnel 4 and the lower stage tunnel 12, and finally transported to the ore processing plant. Remote-controlled scrapers and other mining equipment can enter the mining tunnel 5 through the lower stope tunnel 4, thereby improving the mining efficiency.

[0062] Combine Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 As shown, in the embodiment of the present application, a bottom cross tunnel 6 connected to the mining roadway 5 is constructed from the target stope 1, and the bottom cross tunnel 6 is used as the initial free surface and compensation space to form a first cutting groove 7 in the target stope 1. The first cutting groove 7 connects the rock drilling roadway 3 and the bottom cross tunnel 6, including:

[0063] A bottom cross tunnel 6 is constructed at the lower part of the target mining area 1 in a direction perpendicular to the mining tunnel 5, a second downward fan-shaped blast hole 13 is opened in the rock drilling tunnel 3, explosives are loaded in the second downward fan-shaped blast hole 13, and layered blasting is carried out with the bottom cross tunnel 6 as the initial free surface and compensation space to form the first cutting groove 7.

[0064] Specifically, the bottom cross tunnel 6 is constructed and formed in the lower part of the target mining area 1 along a direction perpendicular to the mining tunnel 5, ensuring that the first cutting groove 7 formed subsequently can be smoothly connected to the mining tunnel 5, while providing sufficient free surface and compensation space for the layered blasting excavation of the first cutting groove 7. In the rock drilling tunnel 3, a second downward fan-shaped blast hole 13 is opened according to the position of the bottom cross tunnel 6 and the designed shape of the first cutting groove 7. The second downward fan-shaped blast hole 13 is filled with explosives, and the VCR layered blasting method is adopted. The blasting is carried out in sequence from bottom to top. After the rock is broken, it collapses in the direction of the bottom cross tunnel 6, gradually forming the first cutting groove 7 of a predetermined shape and size. This layered blasting method not only effectively controls the impact of blasting vibration on the surrounding rock of the mining area, but also ensures the forming accuracy of the first cutting groove 7, avoids over-excavation or under-excavation, and avoids the construction of a cutting shaft. It has the advantages of high construction efficiency and good safety.

[0065] gather Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 As shown, in the embodiment of the present application, the width of the bottom cross tunnel 6 is 3m-5m, and the length is the width of the target stope 1.

[0066] Specifically, by setting the bottom cross tunnel 6 to a width of 3m-5m, the wider tunnel can meet the flexible operation and parallel operation of large construction equipment such as drilling rigs and loading machinery, especially under deep and complex geological conditions, which is convenient for the equipment to quickly adjust its position and respond to emergencies, thereby improving construction efficiency; the setting of the length being consistent with the width of the target mining area 1 ensures that the bottom cross tunnel 6 can completely cover the bottom horizontal area of ​​the target mining area 1, providing sufficient free surface and compensation space for the first cutting groove 7 formed subsequently, ensuring that the ore can be evenly crushed and smoothly converge to the mining tunnel 5 when the blasting falls.

[0067] Combine Figure 1 、 Figure 2 As shown, in the embodiment of the present application, the inclination angle of the blasting excavation surface 8 is equal to the natural repose angle of the collapsed ore bulk.

[0068] Specifically, when the inclination angle of the blasting excavation face 8 is equal to the natural repose angle of the collapsed ore, the collapsed ore is in a critically stable state under the action of gravity. The natural repose angle is the maximum stable angle that can be formed between the slope of the ore and the horizontal plane when the ore is accumulated without external interference. At this point, under the action of gravity, the blasted ore only requires minimal external force (such as the residual explosive force generated by the blasting and the mutual collision force between the ore) to begin sliding downward along the blasting excavation face 8, allowing the ore to converge toward the mining roadway 5, reducing the ore's residence time and accumulation in the stope, and greatly improving mining efficiency. At the same time, this stable ore flow state avoids the impact force caused by sudden sliding or collapse of the ore, reduces pressure fluctuations on the roof and sidewalls of the target stope 1, helps maintain the stability of the stope's surrounding rock, and creates a safe environment for subsequent operations.

[0069] Combine Figure 5 、 Figure 6 、 Figure 7 As shown, in the embodiment of the present application, the distance between the bottom of the first downward fan-shaped blasthole 9 and the top of the mining tunnel 5 is not less than 5m.

[0070] Specifically, by setting the distance between the bottom of the first downward fan-shaped blasthole 9 and the top of the mining tunnel 5 to be no less than 5m, this distance setting effectively reduces the risk of impact damage to the mining tunnel 5 caused by blasting operations. During the blasting process, the stress waves and impact energy generated by the explosion of the explosives will propagate to the surroundings. If the bottom of the first downward fan-shaped blasthole 9 is too close to the top of the mining tunnel 5, the strong impact energy may cause the rock mass at the top of the tunnel to break and crack, and even cause the tunnel to collapse. When the distance is no less than 5m, there is enough rock medium to buffer and attenuate the stress wave during propagation, which greatly reduces the energy intensity transmitted to the top of the mining tunnel 5. At the same time, this distance also reserves sufficient safety thickness for the mining tunnel 5. Even if part of the rock mass is cracked due to blasting, it can rely on its own structural strength and support measures to maintain stability, thereby ensuring the safety of equipment operation and personnel operations in the mining tunnel 5. In addition, in the subsequent mining process, if the blasting causes abnormal ore collapse near the bottom of the hole, a larger distance can also prevent the ore from directly impacting the top of the mining tunnel 5, preventing the ore from damaging the equipment and facilities in the tunnel and reducing the possibility of safety accidents.

[0071] Combine Figure 1 、 Figure 2 、 Figure 5 、 Figure 6 、 Figure 7 As shown, in the embodiment of the present application, explosives are loaded into the first downward fan-shaped blasthole 9 and the upward fan-shaped blasthole 10, and the first downward fan-shaped blasthole 9 and the upward fan-shaped blasthole 10 are sequentially blasted, and the collapsed ore is sequentially discharged through the ore discharge tunnel 5, including:

[0072] After loading explosives into the first downward fan-shaped blasthole 9, the first downward fan-shaped blasthole 9 is detonated in sequence in sections to side-collapse the ore body in the target mining area 1 located above the blasting excavation surface 8. The collapsed ore falls through the first cutting groove 7 and is transported out through the mining tunnel 5 until the mining is completed.

[0073] After the ore body above the blasting excavation face 8 in the target mining area 1 is mined, explosives are loaded into the upward fan-shaped blastholes 10, and the upward fan-shaped blastholes 10 are detonated in sequence in sections to side collapse the ore body below the blasting excavation face 8 in the target mining area 1. The collapsed ore is transported out through the mining tunnel 5 until the mining is completed.

[0074] Specifically, the explosives loading, sequential blasting and ore removal operations of the first downward fan-shaped blastholes 9 and the upward fan-shaped blastholes 10 are important processes for achieving efficient ore extraction and safe transportation. The order is as follows: first, explosives are loaded into the first downward fan-shaped blastholes 9 on one side of the first cutting groove 7, and then the first downward fan-shaped blastholes 9 are detonated row by row in the order from the first cutting groove 7 to the end of the target mining area 1, so that the ore slides toward the first cutting groove 7 under the action of the explosive force and gravity, enters the mining tunnel 5, and the ore is unloaded through the mining tunnel 5 by a scraper. After the mining is completed; the first downward fan-shaped blastholes 9 on the other side of the first cutting groove 7 are loaded with explosives, and then the first downward fan-shaped blastholes 9 are detonated row by row in the order from the first cutting groove 7 to the end of the target mining area 1, so that the ore slides toward the first cutting groove 7 under the action of the explosive force and gravity, enters the mining tunnel 5, and passes through the mining tunnel 5. A scraper is used to unload the ore. After unloading, explosives are loaded into the upward fan-shaped blastholes 10 on one side of the first cutting groove 7. Subsequently, the upward fan-shaped blastholes 10 are detonated row by row in the order from the first cutting groove 7 to the end of the target stope 1, so that the ore enters the unloading tunnel 5 under the action of explosive force and gravity. The ore is unloaded through the unloading tunnel 5 using a remote-controlled scraper. After unloading, explosives are loaded into the upward fan-shaped blastholes 10 on the other side of the first cutting groove 7. Subsequently, the upward fan-shaped blastholes 10 are detonated row by row in the order from the first cutting groove 7 to the end of the target stope, so that the ore enters the unloading tunnel 5 under the action of explosive force and gravity. The ore is unloaded through the unloading tunnel 5 using a remote-controlled scraper.

[0075] In the embodiment of the present application, filling the goaf formed in the target stope 1 includes:

[0076] The filling pipeline is lowered to the goaf through the rock drilling tunnel 3, and the filling material is filled into the goaf through the filling pipeline.

[0077] Combine Figure 1 、 Figure 2 As shown, in the embodiment of the present application, a long anchor cable and anchor rod support system is used to provide pre-support for the upper stope tunnel 2, the rock drilling tunnel 3, the lower stope tunnel 4 and the mine tunnel 5.

[0078] Specifically, after the construction of the upper mining area connecting tunnel 2, the rock drilling tunnel 3, the lower mining area connecting tunnel 4 and the mining tunnel 5 is completed, long anchor cables and anchor rod support systems are used for pre-support to ensure the stability of the tunnels and the safety of mining operations. Steel mesh can be laid on the tunnel surface and concrete can be sprayed to form a combined support system of "long anchor cables + anchor rods + steel mesh + sprayed concrete" to enhance the impact resistance of the tunnel surface and prevent rock blocks from falling.

[0079] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application. The above are merely preferred embodiments of the present application. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present application, and such improvements and variations shall also be considered within the scope of protection of the present application.

Claims

1. A flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection, characterized in that: The following steps are involved: S1. Determine the stope layout according to the occurrence form of deep and thick ore bodies, ground stress conditions, stope size and development project location, divide the stopes and determine the target stope (1); S2, constructing an upper stope joint tunnel (2) and a rock drilling tunnel (3) from the upper part of the target stope (1), wherein the upper stope joint tunnel (2) is connected to the rock drilling tunnel (3); constructing a lower stope joint tunnel (4) and a mining tunnel (5) from the lower part of the target stope (1), wherein the lower stope joint tunnel (4) is connected to the mining tunnel (5); constructing a bottom cross tunnel (6) connected to the mining tunnel (5) from the target stope (1), and constructing a first cutting groove (7) in the target stope (1) with the bottom cross tunnel (6) as an initial free surface and compensation space, wherein the first cutting groove (7) is connected to the rock drilling tunnel (3) and the bottom cross tunnel (6); S3, determining a blasting excavation face (8) in the target stope (1), constructing a first downward fan-shaped blast hole (9) downward in the rock drilling tunnel (3) until the blasting excavation face (8), the depth of the first downward fan-shaped blast hole (9) decreasing from the first cutting groove (7) to the end of the target stope (1); constructing an upward fan-shaped blast hole (10) from the mining tunnel (5) until the blasting excavation face (8), the depth of the upward fan-shaped blast hole (10) increasing from the first cutting groove (7) to the end of the target stope (1); S4, loading explosives into the first downward fan-shaped blasthole (9) and the upward fan-shaped blasthole (10), blasting the first downward fan-shaped blasthole (9) and the upward fan-shaped blasthole (10) in sequence, and sequentially unloading the collapsed ore through the unloading tunnel (5); S5. Filling the goaf formed in the target stope (1).

2. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 1 is characterized in that: An upper stope connecting tunnel (2) and a rock drilling tunnel (3) are constructed from the upper part of the target stope (1), wherein the upper stope connecting tunnel (2) is connected to the rock drilling tunnel (3), comprising: Upper stage tunnels (11) are opened on both sides of the upper part of the target stope (1), the upper stope connecting tunnel (2) is constructed from the upper stage tunnel (11) to the target stope (1), and the rock drilling tunnel (3) is arranged on the upper part of the target stope (1) along the mining direction of the target stope (1).

3. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 2 is characterized in that: A lower stope connecting tunnel (4) and a mine-exit tunnel (5) are constructed from the lower part of the target stope (1), wherein the lower stope connecting tunnel (4) is connected to the mine-exit tunnel (5), comprising: Lower stage tunnels (12) are opened on both sides of the lower part of the target stope (1), the lower stope connecting tunnel (4) is constructed from the lower stage tunnel (12) to the target stope (1), and the mining tunnel (5) is arranged at the lower part of the target stope (1) along the mining direction of the target stope (1).

4. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 3 is characterized in that: A bottom cross tunnel (6) connected to the mining roadway (5) is constructed from the target stope (1), and a first cutting groove (7) is constructed on the target stope (1) using the bottom cross tunnel (6) as an initial free surface and compensation space, wherein the first cutting groove (7) connects the rock drilling roadway (3) and the bottom cross tunnel (6), comprising: The bottom cross tunnel (6) is constructed at the lower part of the target mining area (1) in a direction perpendicular to the mining tunnel (5), a second downward fan-shaped blast hole (13) is opened in the rock drilling tunnel (3), explosives are loaded in the second downward fan-shaped blast hole (13), and layered blasting is performed with the bottom cross tunnel (6) as the initial free surface and compensation space to form the first cutting groove (7).

5. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 4 is characterized in that: The bottom cross tunnel (6) has a width of 3m-5m and a length equal to the width of the target stope (1).

6. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 1 is characterized in that: The inclination angle of the blasting excavation surface (8) is equal to the natural repose angle of the collapsed ore body.

7. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 1 is characterized in that: The distance between the bottom of the first downward fan-shaped blasthole (9) and the top of the mining tunnel (5) is not less than 5m.

8. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 1 is characterized in that: The method comprises: loading explosives into the first downward fan-shaped blasthole (9) and the upward fan-shaped blasthole (10), sequentially blasting the first downward fan-shaped blasthole (9) and the upward fan-shaped blasthole (10), and sequentially unearthing the collapsed ore through the unearthing tunnel (5), comprising: After explosives are loaded into the first downward fan-shaped blastholes (9), the first downward fan-shaped blastholes (9) are detonated in sequence in sections to side-collapse the ore body of the target stope (1) located above the blasting excavation surface (8), and the collapsed ore falls through the first cutting groove (7) and is transported out through the ore discharge tunnel (5) until the ore discharge is completed; After the ore body above the blasting excavation surface (8) in the target stope (1) is mined, explosives are loaded into the upward fan-shaped blastholes (10), and the upward fan-shaped blastholes (10) are detonated in sequence in sections to side-collapse the ore body below the blasting excavation surface (8) in the target stope (1), and the collapsed ore is transported out through the mining tunnel (5) until the mining is completed.

9. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 1 is characterized in that: Filling the goaf formed in the target stope (1) comprises: A filling pipeline is lowered into the goaf through the rock drilling tunnel (3), and filling materials are filled into the goaf through the filling pipeline.

10. The flat bottom structure mining method based on fan-shaped hole blasting force-gravity coordinated ore collection according to claim 1, characterized in that: Long anchor cables and anchor rod support systems are used to provide pre-support for the upper stope joint tunnel (2), the rock drilling tunnel (3), the lower stope joint tunnel (4) and the mine exit tunnel (5).

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