Mining method for steeply inclined, broken, thick and large ore bodies

Abstract

The present invention relates to a mining method for a metal mine, and provides a mining method for a steeply inclined, broken, thick and large ore body, comprising the following steps: S1, arranging the stope perpendicular to the ore body trend, and segmenting the stope in height; S2, arranging the mining and cutting engineering of the stope of the pre-controlled top small segment filling method; S3, supporting and reinforcing the upper plate broken surrounding rock and the stope roof; S4, constructing multiple rows of long upward anchor cables outside the vein with the same inclination as the ore body in the vein outside tunnel near the upper plate boundary of the ore body, vertically downwardly constructing multiple rows of long downward anchor cables outside the vein with the same inclination as the ore body in the vein outside tunnel near the upper plate boundary of the ore body, and vertically upwardly constructing long upward anchor cables inside the vein vertically upwardly constructing the ore body trend in the rock drilling tunnel; S5, mining the pre-controlled top small segment stope, and performing filling operations after mining. The present invention can reduce the amount of excavation engineering, ensure the safety of the stope, and improve the production efficiency of the stope.

Description

Technical Field

[0001] The invention relates to a metal mine mining method, in particular to a steeply inclined, broken, thick and large ore body mining method. Background Art

[0002] In the field of metal mineral mining, steeply inclined, broken, thick and large ore bodies are common ore bodies. The surrounding rock of the upper plate is broken and unstable, and the roof is also unstable, so the safety of mining is low. It has always been a problem for steeply inclined, broken, thick and large ore bodies with complex mining conditions. The segmented filling method has the characteristics of large production capacity, low depletion loss rate and high safety. Compared with the horizontal tunnel excavation of the approach filling method and the upward horizontal layered filling mining method, the segmented filling method can use medium and deep holes for mining, and the process is simple. The segmented filling method is a good choice for mining steeply inclined, broken, thick and large ore bodies with complex conditions. However, the upper plate broken surrounding rock and the roof of the mining area need to be supported and reinforced to ensure the safety of mining. At present, long anchor cable grouting support is a widely used support method, which is often used in civil engineering and mining engineering. The support effect is obvious, which is of great significance for the mining of this kind of ore body.

[0003] Therefore, it is necessary to study a steeply inclined, broken, thick and large ore body mining method and system. First, the grouting long anchor cable technology is used to pre-control the top support of the upper plate broken surrounding rock and the mine roof to improve the stability of the upper plate surrounding rock and the mine roof, ensure the safe recovery of the ore and rock, and improve the production capacity and efficiency of the mine.

[0004] Prior art CN110566255B discloses a design and construction method for long anchor cable grouting in the upper plate of the mine room method in the stage of segmented rock drilling, and develops a mine room method for segmented rock drilling stage supported by long anchor cable grouting in the upper plate. This method arranges a long anchor cable measure tunnel in the upper plate of the ore body, and constructs grouting long anchor cables in the broken zone area through the long anchor cable measure tunnel to maintain the stability of the upper plate broken zone during the ore body recovery process, mainly using upward and downward grouting long anchor cables for support. However, this method requires the construction of multiple measure tunnels in the surrounding rock of the upper plate. Although it has an effect on the stability of the upper plate broken zone, the newly added tunnel excavation project is large and the excavation cost is expensive, and the ore recovery rate of the bottom structure of the mining site is low, which is also easy to lead to the loss of economic benefits of the mine. In addition, the anchor cable support amount is large, the construction period is long and the difficulty is high, which will also increase the support cost. In the actual production process, it is difficult to ensure the safety of the mine. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a steeply inclined, broken, thick and large ore body mining method, which can reduce the amount of excavation engineering while ensuring the safety of the mining site and improve the production capacity and production efficiency of the mining site.

[0006] In order to solve the above technical problems, the present invention provides a steeply inclined, broken, thick and large ore body mining method, comprising the following steps:

[0007] S1. Arrange the stope vertically along the ore body and divide the stope into sections in height;

[0008] S2. Arrange the mining and cutting engineering of the small-segment filling method stope with pre-controlled top;

[0009] S3. Support and reinforce the broken surrounding rock of the upper plate and the roof of the mining area;

[0010] S4, constructing multiple rows of long upward anchor cables outside the vein with the same inclination angle as the inclination angle of the ore body in the outer-vein tunnel near the upper wall boundary of the ore body, vertically and vertically downwardly constructing multiple rows of long downward anchor cables outside the vein in the outer-vein tunnel near the upper wall boundary of the ore body, and vertically and vertically and vertically upwardly constructing long upward anchor cables inside the vein in the rock drilling tunnel, vertically and vertically and vertically and vertically constructing the ore body;

[0011] S5. Mining is carried out in small sections of the pre-controlled top, and backfilling is carried out after mining is completed.

[0012] Specifically, the installation mesh of the long upward anchor cable in the vein is D, which is calculated by the following formula:

[0013]

[0014] Among them, a is the width of the rock drilling tunnel, r is the density of the ore rock contained in the ore body, R is the breaking force of the anchor cable, m is the safety factor, k is the unevenness coefficient, and f is the Pu coefficient.

[0015] Preferably, in step S4, 3 to 4 rows of the long upward anchor cables outside the vein are constructed, and 3 to 4 rows of the long downward anchor cables outside the vein are constructed, wherein at least 1 row of the long upward anchor cables outside the vein is constructed in the ore body.

[0016] Preferably, the outer-vein upward long anchor cable in the ore body is at least 0.5 m away from the boundary of the upper wall of the ore body.

[0017] Optionally, in step S4, the long anchor cable support construction includes the following steps:

[0018] a. Use rock drill to construct anchor holes;

[0019] b. flushing the anchor hole with high pressure water;

[0020] c. Bundle the exhaust pipe on the steel strand and push them together into the bottom of the anchor hole to fix the steel strand at the center of the anchor hole, and install the plug with the grouting pipe and the exhaust pipe at the plugging position;

[0021] d. Use a single-cylinder piston mortar pump for grouting;

[0022] e. Install the anchor after the initial setting period of the cement slurry.

[0023] Specifically, in step S1, the mining length is the thickness of the ore body, the mining width is 8 to 10 m, the mining stage height is 50 to 60 m, the mining segment height is 12 to 15 m, the number of segments at the mining height is 4 to 5, the pre-controlled top layer height is 3 to 4 m, and the small segment height is 8 to 9 m.

[0024] Optionally, in step S2, the rock drilling tunnels, segmented horizontal tunnels, chute, vein transport tunnels, cutting skylights, cutting cross tunnels and the extra-vein tunnels are arranged, wherein the extra-vein tunnels are arranged at intervals, and the rock drilling tunnels corresponding to the extra-vein tunnels are excavated toward the boundary of the ore body to form the extra-vein tunnels.

[0025] Specifically, the net cross-sectional specifications of the rock drilling tunnel, the segmented horizontal tunnel and the vein-crossing transport tunnel are in the range of 3.0 to 4.0 m×3.0 m, the net cross-sectional specifications of the cutting skylight are 2.0 m×2.0 m, the net cross-sectional specifications of the cutting cross tunnel are 2.0 m×3.0 m, the net cross-sectional specifications of the chute are 3.0 m×3.0 m, the length of the extra-vein tunnel beyond the boundary of the ore body ranges from 3.0 to 4.0 m, and the net cross-sectional specifications of the extra-vein tunnel are in the range of 3.0 to 4.0 m×3.0 m.

[0026] Preferably, in step S5, the mining is carried out in an alternate mining manner, with medium-deep holes used for downward blasting, 2 to 3 rows of blasting each time, and the downward blast holes in adjacent rows are staggered.

[0027] Preferably, in step S5, the stope filling is carried out in stages, and the strength of the filling body is selected according to the stope interval and location.

[0028] Through the above scheme, the beneficial effects of the present invention are as follows:

[0029] The steeply inclined, broken, thick and large ore body mining method of the present invention adopts a pre-controlled top small segment filling method for mining, by constructing multiple rows of long upward anchor cables outside the vein with the same inclination as the ore body in an outer vein tunnel near the upper wall boundary of the ore body vertically upward in the ore body direction, and constructing multiple rows of long downward anchor cables outside the vein vertically downward in the outer vein tunnel near the upper wall boundary of the ore body vertically in the ore body direction, so as to support and reinforce the surrounding rock of the upper wall, while ensuring the stability of the surrounding rock of the upper wall, no additional outer vein support tunnels and chambers are added, thereby reducing the amount of excavation engineering, and vertically constructing long upward anchor cables inside the vein vertically upward in the rock drilling tunnel vertically in the ore body direction to ensure the stability of the mining field roof, thereby ensuring the production capacity and production efficiency of the mining field.

[0030] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 It is a flowchart of a specific embodiment of the steeply inclined crushing thick ore body mining method of the present invention;

[0033] Figure 2 It is a schematic diagram of the principle of a specific embodiment of the steeply inclined crushing thick ore body mining method of the present invention;

[0034] Figure 3 yes Figure 2 Sectional view at AA;

[0035] Figure 4 yes Figure 2 Sectional view at the middle BB;

[0036] Figure 5 yes Figure 2 Sectional view at CC;

[0037] Figure 6 It is a structural schematic diagram of a specific implementation method of an upward long anchor cable in a vein;

[0038] Figure 7 It is a structural schematic diagram of a specific implementation method of a long upward anchor cable outside the vein;

[0039] Figure 8 It is a structural schematic diagram of a specific implementation method of a long downward anchor cable in a vein;

[0040] Fig. 9 It is a schematic diagram of the principle of a specific implementation method of long anchor cable support construction;

[0041] Fig.10 It is a flowchart of a specific implementation method of long anchor cable support construction.

[0042] Description of Reference Numerals

[0043] 1 Middle transport tunnel 2 Sectional level tunnel

[0044] 3 rock drilling tunnel 4 chute

[0045] 5 Downward blasthole 6 caving ore

[0046] 7 Filling body 8 Transit tunnel

[0047] 9. Long anchor cable downward outside the vein 10. Long anchor cable upward outside the vein

[0048] 11. Long upward anchor cable in vein 12. Tunnel outside vein

[0049] 13 Exhaust pipe 14 Cement slurry

[0050] 15 Grouting pipe 16 Hole plug

[0051] 17 anchor hole 18 steel strand DETAILED DESCRIPTION

[0052] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and the protection scope of the present invention is not limited to the following specific embodiments.

[0053] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "formed", "provided with", "set", "connected" and the like should be understood in a broad sense. For example, the connection can be a direct connection or an indirect connection through an intermediate medium, a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate connector, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In the present invention, unless otherwise specified, the orientation or positional relationship indicated by the directional words "upper" and "lower" etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; the orientation terms of the present invention should be understood in conjunction with the actual installation status.

[0055] The present invention provides a steeply inclined, broken, thick and large ore body mining method, see Figure 1-5 , the method mainly comprises the following steps:

[0056] S1. Arrange the stope vertically along the ore body and divide the stope into sections in height;

[0057] S2. Arrange the mining and cutting engineering of the small-segment filling method stope with pre-controlled top;

[0058] S3. Support and reinforce the broken surrounding rock of the upper plate and the roof of the mining area;

[0059] S4, construct multiple rows of long upward anchor cables 10 outside the vein with the same inclination angle as the ore body in the outer vein tunnel 12 near the upper wall boundary of the ore body, vertically upward in the direction of the ore body, construct multiple rows of long downward anchor cables 9 outside the vein in the outer vein tunnel 12 near the upper wall boundary of the ore body, and vertically upward in the direction of the ore body in the inner vein long anchor cables 11;

[0060] S5. Mining is carried out in small sections of the pre-controlled top, and backfilling is carried out after mining is completed.

[0061] The mining method of the present invention is mainly applied to steeply inclined thick ore bodies (the thickness of the ore body ranges from 15 to 50m, and the inclination of the ore body is greater than 55°). The mining is carried out by adopting a pre-controlled top small segment filling method, and a long upward anchor cable 10 with the same inclination as the ore body is constructed in a vein outer tunnel 12 near the boundary of the upper plate of the ore body, that is, the long upward anchor cable 10 with the same inclination as the ore body is parallel to the boundary of the upper plate of the ore body, which has a good support and reinforcement effect on the broken surrounding rock of the upper plate of the ore body with a large inclination, and can strengthen the broken surrounding rock of the upper plate. While the surrounding rock is supported and reinforced, the length of the outer-vein tunnel 12 is shortened, thereby reducing the excavation volume of the outer-vein tunnel 12, and there is no need to add additional outer-vein support tunnels and chambers, further reducing the excavation volume, and constructing the outer-vein downward long anchor cable 9 in the outer-vein tunnel 12 to further reinforce the upper plate broken surrounding rock, and constructing the inner-vein upward long anchor cable 11 in the rock drilling tunnel to reinforce the mine roof and ensure the stability of the mine roof, thereby ensuring the production capacity and production efficiency of the mine.

[0062] The specific embodiment of the steeply inclined crushing thick ore body mining method of the present invention is described below in conjunction with a domestic gold mine:

[0063] The average thickness of the ore body in a domestic gold mine is 40m, with a dip angle of 63 to 80°. It is mainly composed of steeply inclined thick ore bodies, and the mining conditions of the ore bodies in the mine are complex. The upper plate crushed surrounding rock carbonaceous slate is Class V rock body, the ore body is Class IV rock body, and the lower plate tuff is Class IV rock body. The overall stability of the ore rock is unstable, and the overall ore rock joints in the mine are well developed and relatively broken. The upper plate surrounding rock is Class V carbonaceous slate. Mining disturbance can easily cause local collapse, bringing challenges and difficulties to safe production.

[0064] In step S1, the stope is arranged perpendicular to the ore body, the stope length is the ore body thickness, the stope width is 8 to 10 m, the stope stage height is 50 to 60 m, the stope segment height is 12 to 15 m, the stope height is divided into 4 to 5 segments for rock drilling and mining, a panel area is composed of 6 stopes, the pre-controlled top layer height is 3 to 4 m, the small segment height is 8 to 9 m, and the stope structure parameters are arranged reasonably to improve work efficiency.

[0065] In step S2, see Figure 2-5, arrange rock drilling tunnels 3, segmented horizontal tunnels 2, chute 4, vein transport tunnels 8, cutting skylights (not shown in the figure), cutting cross tunnels (not shown in the figure) and vein tunnels outside the vein 12, complete the layout of the mining and cutting project, solve the problems of pedestrian, ventilation, transportation, filling and other issues of the mining unit, and form the necessary mining space. Among them, since the long upper anchor cable 10 outside the vein and the long lower anchor cable 9 outside the vein are constructed simultaneously in the vein tunnel outside the vein 12, the upper wall surrounding rock above and below the vein tunnel outside the vein 12 can be supported. Therefore, under preferred circumstances, the vein tunnels outside the vein 12 are arranged at intervals to further reduce the number of vein tunnels outside the vein 12, reduce the amount of excavation work and consumables, and reduce construction costs. The vein tunnels outside the vein 12 are formed by excavating the corresponding rock drilling tunnels 3 toward the boundary of the ore body. Specifically, see Figure 4 There are 4 small sections for rock drilling from bottom to top. Extra-vein tunnels 12 are arranged at the end of the second rock drilling tunnel 3 and the end of the fourth rock drilling tunnel 3 from bottom to top. Only two extra-vein tunnels 12 can complete the support of the upper surrounding rock of the mining area here.

[0066] In the layout of the mining and cutting project, the net cross-sectional specifications of the rock drilling tunnel 3, the segmented horizontal tunnel 2, and the cross-vein transport tunnel 8 are in the range of 3.0 to 4.0 m×3.0 m, the net cross-sectional specifications of the cutting skylight are 2.0 m×2.0 m, the net cross-sectional specifications of the cutting cross tunnel are 2.0 m×3.0 m, the net cross-sectional specifications of the chute 4 are 3.0 m×3.0 m, the length of the extra-vein tunnel 12 exceeding the boundary of the ore body ranges from 3.0 to 4.0 m, and the net cross-sectional specifications of the extra-vein tunnel 12 range from 3.0 to 4.0 m×3.0 m. It should be noted that the above net cross-sectional specifications range is width × height, and the length of the extra-vein tunnel 12 is preferably 3 m.

[0067] Since the mining height of the pre-controlled top small segment filling method reaches 8 to 9 meters, its safety mainly depends on the support quality and support effect of the pre-controlled top layered roof, and the broken surrounding rock and the mining area roof need to be supported and reinforced. Specifically, it is necessary to determine the design grid of the anchor cable installation, where the installation grid of the long upward anchor cable 11 in the vein is D, which is calculated by the following formula:

[0068]

[0069] Among them, a is the width of the rock drilling tunnel 3, r is the density of the ore rock contained in the ore body, R is the breaking force of the anchor cable, m is the safety factor, k is the unevenness coefficient, and f is the Pu coefficient.

[0070] In a domestic gold mine where the steeply inclined crushing thick ore body mining method of the present invention is applied, the stope length is the average thickness of the ore body 40m, the stope width is 10m, and the total length of the rock drilling tunnel 3 is the stope length, wherein the width of the rock drilling tunnel 3 is 3-4m, and 4m is taken, then a=4m; the density of the ore rock contained in the ore body r=2.9t / m3 , the general coefficient f = 4, the non-uniform coefficient k = 0.2, and combined with relevant mining experience, the diameter of the anchor cable project is 17.8mm, the breaking force is 300KN, that is, R = 30t, and the value range of the safety factor m is 1.0~1.5. Substituting each parameter into the calculation, it is found that the value range of the installation mesh D of the long upward anchor cable 11 in the vein is 1.9×1.9m~2.4×2.4m. In order to facilitate on-site construction operations and ensure the safety of the roof, the installation mesh D is 2.0×2.0m, and the anchor cable row spacing and spacing are both 2.0m. In addition, the installation mesh of the anchor cables in the outer vein tunnel 12 (the outer vein upward long anchor cable 10 and the outer vein downward long anchor cable 9) is 1.8×1.8m to ensure the support of the broken surrounding rock of the upper plate.

[0071] It should be noted that the length of the anchor cable must be determined so that the length of the long anchor cable on the tunnel roof should be greater than the maximum height of the roof falling. According to the pre-controlled roof sub-segment height (8-9m), the thickness of the unstable rock layer on the roof is 8-9m. Based on the suspension theory, the design length L of the long anchor cable is calculated by the following formula:

[0072] L=L a +L b +L c +L d

[0073] Among them, L a L is the length of the long anchor cable that needs to be exposed, which is 0.5m. b is the thickness of the anchor, tray and metal mesh, which is 0.15m; L c The thickness of the unstable rock layer that needs to be suspended is 8 to 9 meters; L d The anchoring length of the long anchor cable deep into the stable rock formation is 0.5-2.0m. Substituting the above parameters, we can get L is 9.15-11.65m. Considering the on-site ore and rock exposure, rock drilling equipment, safety factor and other factors, the design length of the long anchor cable is determined to be 10-12m. Specifically, the length of the long anchor cable 10 outside the vein, the long anchor cable 9 outside the vein and the long anchor cable 11 inside the vein is 12m.

[0074] When reinforcing the broken surrounding rock and the roof of the stope with long anchor cables, see Figure 4 Preferably, first, 3 to 4 rows of extra-vein upward long anchor cables 10 with the same inclination as the ore body are constructed vertically in the extra-vein tunnel 12 near the upper wall boundary of the ore body, and at least 1 row of extra-vein upward long anchor cables 10 are constructed inside the ore body to ensure that the ore body and the upper wall surrounding rock can be anchored into a whole.

[0075] Further preferably, the long upward anchor cable 10 outside the vein in the ore body needs to be at least 0.5 m away from the boundary of the upper wall of the ore body to ensure the support strength of the long upward anchor cable 10 outside the vein.

[0076] Secondly, 3 to 4 rows of long downward anchor cables 9 are constructed vertically downward in the vein tunnel 12 near the boundary of the ore body, perpendicular to the ore body. Figure 4 The long downward anchor cable 9 outside the vein is passed through the ore body and anchored together with the surrounding rock of the upper plate to form a whole, ensuring the support and reinforcement of the broken surrounding rock of the upper plate. Among them, the installation mesh of the long upward anchor cable 10 outside the vein and the long downward anchor cable 9 inside the vein are both 1.8×1.8m, and the length of the anchor cable is 12m.

[0077] While constructing long anchor cables in the outer-vein tunnel 12 for support and reinforcement, the inner-vein upward long anchor cables 11 are constructed vertically upward in the rock drilling tunnel 3 perpendicular to the ore body, and full-length anchor cables are used for support in the rock drilling tunnel 3. The installation mesh of the inner-vein upward long anchor cables 11 is 2.0×2.0m, and the anchor cable length is 12m. It should be noted that the mesh of the long anchor cables is appropriately adjusted according to the rock conditions of the exposed roof during excavation of the rock drilling tunnel 3. For example, in the case of unstable ore and rock on the top of the mining area, the installation mesh of the inner-vein upward long anchor cables 11 can be appropriately reduced to 1.8×1.8m to strengthen the support and reinforcement effect on the upper plate broken surrounding rock and the mining area roof.

[0078] See also Figure 6-8 The same row of long upward anchor cables 10 outside the vein, long downward anchor cables 9 outside the vein and long upward anchor cables 11 inside the vein are all fanned out. According to the different construction tunnels and support functions, the long upward anchor cables 10 outside the vein and the long downward anchor cables 9 inside the vein constructed in the tunnel outside the vein 12 are arranged in a row with 5 long anchor cables, so as to have a good support and reinforcement effect on the surrounding rock of the upper plate; the long upward anchor cables 11 inside the vein constructed in the rock drilling tunnel 3 are arranged in a row with 4 long anchor cables, which ensures the support effect on the top plate of the rock drilling tunnel 3 while reducing the use of long anchor cables, shortening the project time and saving construction costs.

[0079] Also, see Figure 9-10 In step S4, the long anchor cable support construction includes the following steps:

[0080] a. Use a YGZ-90 rock drill to construct the anchor hole 17. Specifically, the diameter of the drill hole is 60-65 mm. Before construction, place the center line on site, draw the line on the side wall, and adjust the angle according to the design drawing for construction. If obstacles such as anchor rods are encountered during construction, the drilling position of the anchor hole 17 can be appropriately adjusted forward and backward;

[0081] b. After the anchor hole 17 is constructed, before the drill rod is withdrawn, the anchor hole 17 is flushed with high-pressure water to flush away the mineral powder on the hole wall to avoid blocking the hole and affecting subsequent installation;

[0082] c. Bundle the exhaust pipe 13 onto the steel strand 18, and push them together into the bottom of the anchor hole 17 to fix the steel strand 18 at the center of the anchor hole 17, and install the hole plug 16 with the grouting pipe 15 and the exhaust pipe 13 inserted at the blocking position; wherein, it is necessary to make the anchor cable in advance, that is, to process the steel strand 18. Preferably, a steel strand 18 with a diameter of 17.8 mm, a tensile strength of 1860 MPa and a breaking force of 300 KN is selected, and the steel strand 18 is cut into segments according to the actual hole depth, and ensure that the length of each segment of the steel strand 18 is the actual hole depth plus 0.5 m. In addition, it should be noted that the exhaust pipe 13 is tied to the steel strand 18 with black tape, and is tied every 2m. The air outlet of the exhaust pipe 13 is 5-10cm away from the top of the steel strand 18 (the end close to the bottom of the anchor hole 17). When the steel strand 18 is fed into the anchor hole 17, steel wires are tied to the steel strand 18 at intervals of 2m to form a cross bracket so that the steel strand 18 can be fixed at the center of the anchor hole 17, that is, the central axis of the steel strand 18 coincides with the central axis of the anchor hole 17. The exhaust pipe 13 is preferably a Φ8mm plastic pipe, and the grouting pipe 15 is preferably a 28mm plastic pipe.

[0083] d. Use ZKHB-3 single-cylinder piston mortar pump for grouting, with a water-cement mass ratio of (0.2-0.3):1. When grouting the upward anchor hole 17, forward grouting is used. Specifically, the grouting pipe 15 is inserted into the plug 16 by about 0.2m, and the mortar is injected into the hole by the pressure of the grouting pump. When water comes out of the exhaust pipe 13, the grouting is stopped. The grouting pressure of the upward anchor hole 17 is 3MPa;

[0084] e. After the initial setting period of cement slurry 14 is over, the anchor is installed. Generally, the initial setting period is over one day after grouting and curing. When installing the anchor, the support plate is preferably made of steel plate with a length, width and thickness of 200mm×200mm×20mm. The lock is fixed to the support plate and steel strand 18 by a tensioner, and the tensioning force range of the tensioner is 60~80MPa.

[0085] After the roof support work in the rock drilling tunnel 3 is done well, the pre-controlled top small segmented stope is mined. In step S5, the alternate mining method is adopted. First, the hole network is arranged. In the rock drilling tunnel 3, starting from the end (the end of the rock drilling tunnel 3 close to the outer vein tunnel 12), a down-the-hole drilling trolley is used to drill a downward vertical medium-deep hole to form a downward blasthole 5, thereby adopting a medium-deep hole downward collapse, wherein the blasthole diameter is ф76mm, the blasthole row spacing range is 1.8-2.0m, the hole bottom distance range is 1.8-2.0m, and the downward blastholes 5 of adjacent rows are staggered to have a good blasting effect; segmented blasting is adopted, 2-3 rows are blasted each time, the depth of the downward blasthole 5 is 8-9m, and the hole interval charging is adopted. The height of each layer of charging is 1.5m, and the next layer of explosives is loaded at an interval of 0.6m. The hole mouth blocking height of the downward blasthole 5 is 0.6m.

[0086] See also Figure 4 After the blasting is completed, collapsed ore 6 is formed in the rock drilling tunnel 3, and mining starts from the end of the stope (the side of the cutting shaft), adopting a backward mining method. The collapsed ore 6 in the segmented stope is first shoveled out of the rock drilling tunnel 3 by a manually driven scraper, and the remaining collapsed ore 6 is shoveled out from the rock drilling tunnel 3 into the empty area of ​​the stope by a remote-controlled scraper, and transported to the chute 4. The ore is transported to the middle transport tunnel 1 through the vein transport tunnel 8, and the ore is pulled out of the ground by a dump truck.

[0087] It should be noted that in order to ensure ventilation of the mining area, fresh air flows from the segmented horizontal tunnel 2 of the mining area into the rock drilling tunnel 3 of this segment. After flushing the working face in the mining area, the polluted air enters the rock drilling tunnel 3 of the previous segment and is discharged to the segmented horizontal tunnel 2 of the upper segment, and then discharged to the surface through the return air tunnel.

[0088] In step S5, the filling of the mining area is carried out in stages, and the strength of the filling body 7 is selected according to the mining area interval and position. Specifically, the strength and proportion of the filling body 7 are different in different intervals and positions of the mining area. High-strength filling bodies 7 are used at the bottom and top plates of the segmented mining area, and the strength of the filling body 7 can be appropriately reduced in the middle of the mining area. At the beginning of the filling operation, the rising height of the primary material surface should be strictly controlled to ensure the stability of the retaining wall. After the filling begins, the primary filling height is controlled within 1m, and the filling can be continued only after the filling body 7 solidifies. After the filling surface exceeds the highest point of the filling retaining wall, the primary filling height is controlled at 2m, with the principle that there is no water accumulation on the surface of the filling body 7. In addition, the adjacent mine room can only be mined after the filling body 7 reaches a certain strength to reduce the vibration damage to the filling body 7 caused by blasting, and the ore blocks shall not be mined on both sides of the filling body 7 at the same time.

[0089] It should be noted that, first of all, the stope should be sealed before filling, so that the entire stope is separated from all the shafts and tunnels outside to prevent the loss and pollution of the filling materials. Secondly, appropriate water filtering facilities should be installed on the partition wall to prevent the water accumulation in the stope and reduce the pressure at the bottom of the stope. Among them, the filling retaining wall is preferably made of brick or steel structure.

[0090] In addition, the mining sequence in the middle section is to mine each section from bottom to top, and fill the section after each section is mined. After the filling is completed, the next section will be mined. In addition, the long anchor cable support of the upper broken surrounding rock and the roof of the mining area must be mined at least one section in advance.

[0091] The steeply inclined, broken, thick and large ore body mining method of the present invention adopts the long anchor cable grouting pre-controlled top support technology, optimizes the support parameters, ensures the safety of the mining site, and can excavate a new short-length extra-vein tunnel 12 on the basis of the original tunnel, without the need for additional excavation of extra-vein support tunnels and chambers along the direction of the ore body, which can not only reduce the excavation engineering workload but also ensure the safety of the mining site. The medium-deep hole mining is adopted to improve the overall safety of the mining site and the comprehensive production capacity of the entire mining site, accelerate production efficiency, shorten the operation cycle time of the mining site, and make the mining site layout more flexible and simple, the on-site organization and management are simple, and it is easy to improve the operation efficiency; the pre-controlled top small-segment filling mining method is adopted for mining, which can also improve the overall recovery rate of the mining site and reduce the ore loss rate.

[0092] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0093] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0094] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A steeply inclined, broken, thick and large ore body mining method, It is characterized in that The following steps are involved: S1. Arrange the stope vertically along the ore body and divide the stope into sections in height; S2. Arrange the mining and cutting engineering of the small-segment filling method stope with pre-controlled top; S3. Support and reinforce the broken surrounding rock of the upper plate and the roof of the mining area; S4, constructing multiple rows of long upward anchor cables (10) perpendicular to the strike of the ore body in an outer-vein tunnel (12) near the upper wall boundary of the ore body, with the same inclination as that of the ore body, and constructing multiple rows of long downward anchor cables (9) perpendicular to the strike of the ore body in an outer-vein tunnel (12) near the upper wall boundary of the ore body, and constructing long upward anchor cables (11) perpendicular to the strike of the ore body in a rock drilling tunnel (3); S5. Mining is carried out in small sections of the pre-controlled top, and backfilling is carried out after mining is completed.

2. The steeply inclined, broken, thick and large ore body mining method according to claim 1, It is characterized in that The installation mesh of the long upward anchor cable (11) in the vein is D, which is calculated by the following formula: Wherein, a is the width of the rock drilling tunnel (3), r is the density of the ore rock contained in the ore body, R is the breaking force of the anchor cable, m is the safety factor, k is the non-uniformity coefficient, and f is the Pu coefficient.

3. The steeply inclined, broken, thick and large ore body mining method according to claim 1, It is characterized in that In step S4, 3 to 4 rows of the above-mentioned long upward anchor cables (10) outside the vein are constructed, and 3 to 4 rows of the above-mentioned long downward anchor cables (9) outside the vein are constructed, wherein at least one row of the above-mentioned long upward anchor cables (10) outside the vein is constructed inside the ore body.

4. The steeply inclined, broken, thick and large ore body mining method according to claim 3, It is characterized in that The outer-vein upward long anchor cable (10) in the ore body is at least 0.5 m away from the upper wall boundary of the ore body.

5. The steeply inclined, broken, thick and large ore body mining method according to claim 1, It is characterized in that In step S4, the long anchor cable support construction includes the following steps: a. Using a rock drill to construct the anchor hole (17); b. flushing the anchor hole (17) with high pressure water; c. Bundle the exhaust pipe (13) onto the steel strand (18), and push them together into the bottom of the anchor hole (17), so that the steel strand (18) is fixed at the center of the anchor hole (17), and the plugging plug (16) with the grouting pipe (15) and the exhaust pipe (13) inserted is installed at the plugging position; d. Use a single-cylinder piston mortar pump for grouting; e. After the initial setting period of the cement slurry (14) has ended, the anchor is installed.

6. The steeply inclined, broken, thick and large ore body mining method according to claim 1, It is characterized in that In step S1, the stope length is the thickness of the ore body, the stope width is 8 to 10 m, the stope stage height is 50 to 60 m, the stope segment height is 12 to 15 m, the number of segments at the stope height is 4 to 5, the pre-controlled top layer height is 3 to 4 m, and the small segment height is 8 to 9 m.

7. The steeply inclined, broken, thick and large ore body mining method according to claim 1, It is characterized in that In step S2, the rock drilling tunnel (3), segmented horizontal tunnel (2), chute (4), vein-crossing transport tunnel (8), cutting skylight, cutting cross tunnel and the outer-vein tunnel (12) are arranged, wherein the outer-vein tunnels (12) are arranged at intervals, and the rock drilling tunnel (3) corresponding to the outer-vein tunnel (12) is excavated toward the boundary of the ore body to form the outer-vein tunnel (12).

8. The steeply inclined, broken, thick and large ore body mining method according to claim 7, It is characterized in that The net cross-sectional specifications of the rock drilling tunnel (3), the segmented horizontal tunnel (2), and the vein-crossing transport tunnel (8) are in the range of 3.0 to 4.0 m×3.0 m, the net cross-sectional specifications of the cutting skylight are 2.0 m×2.0 m, the net cross-sectional specifications of the cutting cross tunnel are 2.0 m×3.0 m, the net cross-sectional specifications of the chute (4) are 3.0 m×3.0 m, the length of the extra-vein tunnel (12) beyond the boundary of the ore body is in the range of 3.0 to 4.0 m, and the net cross-sectional specifications of the extra-vein tunnel (12) are in the range of 3.0 to 4.0 m×3.0 m.

9. The steeply inclined, broken, thick and large ore body mining method according to claim 1, It is characterized in that In step S5, the mining is carried out in an alternate mining mode, and medium-length holes are used for downward blasting. Two to three rows are blasted each time, and the downward blast holes (5) in adjacent rows are arranged staggered with each other.

10. The steeply inclined, broken, thick and large ore body mining method according to claim 1, It is characterized in that In step S5, the stope filling is carried out in stages, and the strength of the filling body (7) is selected according to the stope interval and position.

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