Mining method suitable for broken ore body

Abstract

The invention discloses a mining method for a broken ore body. The mining method comprises the following steps: 1, horizontally constructing an artificial false roof at the position of 234m to 230m of the ore body, and analyzing the maximum main stress, the minimum main stress, roof settlement, anchor cable stress and deformation conditions of the artificial false roof under the condition that the stope width is 8m, 10m and 12m by adopting a numerical model construction means; 2, after the artificial roof and the roof are supported, the test stope adopts a sublevel open stope subsequent filling mining method to carry out mining from bottom to top, sublevel rock drilling, sublevel ore removal and sublevel filling; 3, ore removal from a stope; 4, ventilating the stope; 5, a stope filling process is tested, in order to guarantee stope stability, after concentrated ore removal is finished, the goaf needs to be filled in time, and the 28-day strength of a stope filling body is designed to be not lower than 3 MP; sixthly, the maximum section explosive loading amount is determined; the conditions of loosening deformation and small collapse caused by roof collapse due to crushing mining are avoided, and the stability of the stope roof can be guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of mining, and in particular to a mining method for crushing an ore body. Background Art

[0002] Mining is the technology and science of extracting mineral resources from the earth's crust and surface. In a broad sense, mining also includes the mining of coal and oil. The mining industry is an important raw material industry. Metal ores are the main raw materials for the smelting industry, and non-metallic ores are important chemical raw materials and building materials.

[0003] A Chinese patent with publication number CN116378664A discloses a mining method suitable for crushing ore bodies, which divides the ore body into stages vertically and into alternatingly arranged mine rooms and pillars along the strike direction; the mine room is divided into multiple stopes along the strike direction and into layers for mining from bottom to top along the vertical direction. Middle and segmented lanes outside the vein are arranged in the lower plate of the ore body, and mining access roads and rock drilling access roads are constructed from the middle and segmented lanes to the ore body respectively; mining access roads are constructed along the strike direction of the ore body through the mining access roads, and the mining access roads are formed into mining structures at the bottom of the mine room through the top picking; rock drilling chambers are constructed outside the vein of the lower plate of the ore body through the rock drilling access roads; horizontal blast holes are constructed in the rock drilling chambers toward the upper plate of the ore body, and explosives are loaded in the blast holes for blasting; after blasting, the ore is transported to the middle section chute outside the vein through the bottom mining structure and mining access roads. After mining of each layer in the mine room is completed, the empty area is uniformly top-filled. The present invention realizes rock drilling outside the vein and ore extraction inside the vein by optimizing the arrangement of the rock drilling chamber and the ore extraction structure, thereby ensuring safe and efficient recovery of the broken ore body.

[0004] As mentioned above, the patent provides a mining method suitable for broken ore bodies. It optimizes the arrangement of rock drilling chambers and ore-exit structures to achieve drilling outside the vein and ore-exit inside the vein, ensuring safe and efficient recovery of the broken ore bodies. However, when the mining area width is designed to be greater than 5m during mining, loosening, deformation and small landslides may occur within a few days or months, and the stability of the mining area operation needs to be improved. Summary of the invention

[0005] The present invention provides a mining method for crushing an ore body to solve the problems raised in the background technology.

[0006] In order to solve the above problems, the present invention provides a mining method for crushing an ore body, comprising the following steps:

[0007] The first step is to construct an artificial false roof horizontally at -234m to -230m of the ore body and use multiple 8m anchor cables and multiple 15m anchor cables to support the roof of the mining area in advance. The maximum and minimum principal stresses of the artificial false roof, the settlement of the roof, the stress and deformation of the anchor cables are analyzed by means of numerical model construction when the mining area width is 8m, 10m and 12m. The lower plate transportation tunnel and ramp are arranged along the direction of the ore body. The ramp is connected with the lower plate transportation tunnel, and a penetration is also arranged. The access road passes through the ore body, and the ore chute is arranged outside the lower plate transportation road. The ore chute is connected with the lower plate transportation road through the access road. The upper plate return air road and return air skylight are arranged on the upper plate of the ore body. The return air skylight is connected with the upper plate return air road. The ore loading access road is constructed from the access road, and the trench is arranged at the end of the ore loading access road. The cutting level road is constructed from the trench bottom roadway end. A first-step rock drilling road is arranged directly below the first-step mining site, and a second-step rock drilling road is arranged directly below the second-step mining site.

[0008] Step 2: After the artificial false roof and roof support are completed, the test stope adopts the sub-level open-pit and subsequent filling mining method to mine from bottom to top, with sub-level rock drilling, sub-level ore extraction, and sub-level filling;

[0009] Step 3: The ore is unloaded from the mining area, and the ore falls into the trench. After the mining area is ventilated for 30 minutes, the ore can be unloaded and transported;

[0010] Step 4: Ventilation of the mining area. Fresh air flows from the lower wall transport tunnel into the access road, passes through the mine exit tunnels at the bottom of the mining area, and enters the upper wall return air tunnel. The polluted air is discharged from the return air shaft located in the upper wall into the upper wall return air tunnel, and finally discharged to the surface.

[0011] Step 5: Test the filling process of the stope. To ensure the stability of the stope, the empty area should be filled in time after the concentrated mining is completed. The design requires that the strength of the stope filling body should not be less than 3MPa after 28 days.

[0012] Step 6: Determine the maximum charge amount. The formula for the vibration attenuation of iron ore blasting is:

[0013] Where: V—peak vibration velocity of the particle, cm / s;

[0014] Q—explosive quantity, total charge quantity for simultaneous blasting, maximum charge quantity for millisecond delay blasting, kg;

[0015] R—the distance between the protected object and the explosion source center, m;

[0016] K—coefficient related to rock properties, blasting methods and other factors, i.e., site coefficient;

[0017] α—seismic wave attenuation index related to geological conditions;

[0018] The mine roof is taken as 15cm / s with reference to the allowable safety standard for blasting vibration in mine tunnels, R is taken as 30m, and the calculated maximum segment charge is 98Kg. In order to ensure the safety of the mine roof, the maximum segment charge during the blasting process in the test mine cannot be greater than 98kg.

[0019] Preferably: in the second step, the mining area width is set to 10m, the segment height is 20m, a hydraulic drilling trolley is used to drill a first-step drilling tunnel, slot holes are arranged at the end of the mining area, the slot holes are blasted to form a cutting groove, and the ore is collapsed laterally with the cutting groove as the free surface. The collapsed ore is shoveled out from the bottom loading access road, and the ore blocks are filled immediately after the mining is completed. The first-step mining blocks are filled with tailings cementation, and the second-step mining blocks are filled with non-cemented or low-grade cementation.

[0020] Preferably, the maximum allowable size of the ore mined in the third step is 850 mm, the ore discharge port of the chute needs to be screened, and unqualified large pieces are crushed for the second time using a breaker hammer.

[0021] Preferably, the filling process in the sixth step includes arranging filling boreholes, hanging filling pipes and setting up drainage wells.

[0022] Compared with the prior art, the present invention provides a mining method suitable for crushing ore bodies, which has the following beneficial effects:

[0023] The present invention designs an artificial false roof to be constructed at the level of -234m--230m and uses a plurality of 8m anchor cables and a plurality of 15m anchor cables to support the roof of the mining field in advance, and adopts the means of constructing a numerical model to analyze the maximum and minimum principal stresses of the artificial false roof, the settlement of the roof, the stress and deformation of the anchor cables when the mining field width is 8m, 10m and 12m. Finally, it is determined that the structural parameters of a single mining field are 60m×10m×20m, the thickness of the artificial false roof is 4m, the strength is 5MPa, the strength of the mining field filling body is 3MPa, the maximum section charge is 98Kg, the mining method is a segmented empty field followed by filling mining method from bottom to top, segmented rock drilling, segmented ore extraction and segmented filling, so as to avoid the situation that the roof collapses due to crushing mining and causes loosening, deformation and small landslides, and ensure the stability of the mining field roof.

[0024] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 It is a front view of the segmented chamber mining method of the present invention.

[0027] Figure 2 It is a side view of the segmented chamber mining method of the present invention.

[0028] Figure 3 It is a top view of the segmented chamber mining method of the present invention.

[0029] Among them: 1. Lower plate transport tunnel; 2. Access connecting road; 3. Ore chute; 4. Ramp; 5. Upper plate return air tunnel; 6. Artificial false roof; 7. Ore loading access road; 8. One-step rock drilling tunnel; 9. Two-step rock drilling tunnel. DETAILED DESCRIPTION

[0030] The following is combined with Figures 1 to 3 The principles and features of the present invention are described, and the examples given are only used to explain the present invention and are not used to limit the scope of the present invention. In the following paragraphs, the present invention is described in more detail by way of example with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0031] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0033] like Figures 1 to 3 As shown, in this embodiment, a mining method for crushing an ore body comprises the following steps:

[0034] Step 1: construct artificial false roof 6 horizontally at -234m to -230m of the ore body and support the roof of the mine in advance with multiple 8m anchor cables and multiple 15m anchor cables, and use the means of numerical model construction to analyze the maximum and minimum principal stresses of artificial false roof 6, roof settlement, anchor cable stress and deformation when the mine width is 8m, 10m and 12m; and arrange the lower plate transportation tunnel 1 and ramp 4 along the direction of the ore body, the ramp 4 is connected with the lower plate transportation tunnel 1, and the access road 2 and access road 2 that penetrate the ore body are also arranged. Connecting all the mine access routes, it has auxiliary ventilation, escape and other functions. The ore chute 3 is arranged outside the lower plate transport tunnel 1. The ore chute 3 is connected with the lower plate transport tunnel 1 through the access connecting road 2. The upper plate return air tunnel 5 and the return air skylight are arranged on the upper plate of the ore body. The return air skylight is connected with the upper plate return air tunnel 5. The ore loading access 7 is constructed from the access connecting road 2. A trench is arranged at the end of the ore loading access 7. The cutting level tunnel is constructed from the end of the trench bottom tunnel. A first-step rock drilling tunnel 8 is arranged directly below the first-step mining site, and a second-step rock drilling tunnel 9 is arranged directly below the second-step mining site.

[0035] Step 2: After the artificial false roof 6 and the roof support are completed, the test stope adopts the sub-level empty site and subsequent filling mining method to mine from bottom to top, with sub-level rock drilling, sub-level ore extraction, and sub-level filling;

[0036] Step 3: The ore is unloaded from the mining area, and the ore falls into the trench. After the mining area is ventilated for 30 minutes, the WJ-3 rock loader can be used to transport the ore. The ore is poured into the chute in the mining area and loaded into the mine car through the vibrating ore-discharging machine;

[0037] Step 4: Ventilation of the mining area. Fresh air flows from the lower wall transport tunnel 1 into the access road 2, passes through the mine exit tunnels at the bottom of the mining area, and enters the upper wall return air tunnel 5. The polluted air is discharged from the return air shaft located in the upper wall into the upper wall return air tunnel 5, and finally discharged to the surface.

[0038] Step 5: Test the filling process of the stope. To ensure the stability of the stope, the empty area should be filled in time after the concentrated mining is completed to avoid the collapse of the surrounding stope or filling body due to long exposure time, which will affect the depletion index. The design requires that the strength of the stope filling body should not be less than 3MPa after 28 days.

[0039] Step 6: Determine the maximum charge amount. The formula for the vibration attenuation of iron ore blasting is:

[0040] V = 358 × (Q 1 / 3 / R) 1.696

[0041] Where: V—peak vibration velocity of the particle, cm / s;

[0042] Q—explosive quantity, total charge quantity for simultaneous blasting, maximum charge quantity for millisecond delay blasting, kg;

[0043] R—the distance between the protected object and the explosion source center, m;

[0044] K—coefficient related to rock properties, blasting methods and other factors, i.e., site coefficient;

[0045] α—seismic wave attenuation index related to geological conditions;

[0046] The mine roof is taken as 15cm / s with reference to the allowable safety standard for blasting vibration in mine tunnels, R is taken as 30m, and the calculated maximum segment charge is 98Kg. In order to ensure the safety of the mine roof, the maximum segment charge during the blasting process in the test mine cannot be greater than 98kg.

[0047] Through the above technical scheme, it is designed to construct artificial false roof 6 at the level of -234m--230m and use multiple 8m anchor cables and multiple 15m anchor cables to support the roof of the mining area in advance. The maximum and minimum principal stresses of artificial false roof 6, roof settlement, anchor cable stress and deformation are analyzed by numerical simulation when the mining area width is 8m, 10m and 12m. The following points should be noted when constructing the numerical model:

[0048] First, the rock mass is regarded as a quasi-homogeneous and isotropic medium. The excavation of the goaf is one-time, and the filling operation is also completed in one time. Both do not consider the time effect.

[0049] Second, only the excavation effect of the empty area is considered, that is, the influence of the surrounding rock moving toward the exposed surface on the roof and surface deformation, without considering the influence of the Quaternary permeability coefficient and the hydrostatic pressure of the aquifer;

[0050] Third, when the model was established, the average thickness of the Quaternary system was 71.76m, and the thickness of the weathering layer was about 50m. For safety reasons, the ore bodies with intercalation smaller than the ore body thickness were considered to be mined together;

[0051] Fourth, the simulated stopes were uniformly arranged along the strike direction, with a stope width of 10m, a length equal to the thickness of the ore body, and a middle section height of 20m. The simulated excavation was carried out with the stopes of each step as units;

[0052] Fifth, the simulation adopts the excavation steps of "mining one every two sections", dividing the ore body into three layers from bottom to top, and each layer is mined and filled in three steps until the mining and filling of the simulated ore section is completed;

[0053] Sixth, the mine has experienced surface collapse near Line 2. In this simulation, a 30m isolation pillar is left south of the collapse pit, and the isolation pillar will not be mined;

[0054] Seventh, the bottom of the model in the Z direction is at the -950m level. The model is extended to a certain extent in the X and Y directions, roughly covering the possible movement influence range of the surface. It is not reflected in the underground mining tunnel model. The model boundary is taken as 3 to 5 times the size of the mining area.

[0055] It was finally determined that the structural parameters of a single mining area are 60m×10m×20m, the thickness of the artificial false roof 6 is 4m and the strength is 5MPa; the strength of the mining area filling body is 3MPa, the maximum section charge is 98Kg, and the mining method is the segmented empty site and subsequent filling mining method from bottom to top, segmented rock drilling, segmented ore extraction, and segmented filling. This method uses an artificial false roof and determines that its dimensions can meet the construction scenario, and then is supported by an artificial false roof. This can avoid the collapse of the roof due to crushing mining, which may lead to loosening, deformation, and small landslides, and can ensure the stability of the mining area roof.

[0056] Furthermore, in the second step, the mining field width is set to 10m, the segment height is 20m, a hydraulic drilling trolley is used to drill a first-step drilling tunnel 8, slot holes are arranged at the end of the mining field, the slot holes are blasted to form a cutting groove, and the ore is collapsed laterally with the cutting groove as the free surface. The collapsed ore is shoveled out from the bottom loading access road 7, and the ore blocks are filled immediately after the mining is completed. The first-step mining blocks are filled with tailings cementation, and the second-step mining blocks are filled with non-cemented or low-grade cementation; in the third step, the maximum allowable size of the mined ore is 850mm, the chute unloading port needs to be screened, and unqualified large blocks are crushed for the second time with a breaker; in the sixth step, the filling process includes filling drilling arrangement, hanging filling pipes and setting up drainage wells.

[0057] Through the above technical scheme, during the filling process, when arranging the filling boreholes, in order to ensure timely filling, the filling boreholes are designed to be constructed in advance. The filling boreholes are arranged at the -230m level and suspended in the filling pipe. After the mining and support operations are completed, the anchor steel ring hanging method is adopted. The seam is cut at one end of the 500mm long anchor, and the wedge is prepared. The other end is welded and fixed with the steel ring; then the anchor steel ring is anchored into the anchor eye at the center of the top plate, with a hook spacing of 3m to 4m. In order to prevent the slurry from sinking after grouting and causing insufficient top connection, two filling pipes are used, one of which is used for the final top connection filling. When setting up the drainage well, in order to facilitate the dehydration and solidification of the filling body, the self-penetrating vein arranges the drainage well in the disk area mining field, and the drainage area of ​​each drainage well does not exceed 200m 2 , cross-sectional dimensions: 2.0×2.0m.

[0058] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A mining method for crushing an ore body, characterized in that: The following steps are involved: The first step is to construct an artificial false roof (6) horizontally at -234m to -230m of the ore body and use multiple 8m anchor cables and multiple 15m anchor cables to support the roof of the mining area in advance. The maximum and minimum principal stresses of the artificial false roof (6) when the mining area width is 8m, 10m and 12m, the settlement of the roof, the stress and deformation of the anchor cables are analyzed by means of numerical model construction. A lower plate transport tunnel (1) and a ramp (4) are arranged along the direction of the ore body. The ramp (4) is connected with the lower plate transport tunnel (1). An access road (1) that penetrates the ore body is also arranged. 2), the ore chute (3) is arranged outside the lower plate transport tunnel (1), the ore chute (3) is connected with the lower plate transport tunnel (1) through the access road (2), the upper plate return air tunnel (5) and the return air skylight are arranged on the upper plate of the ore body, the return air skylight is connected with the upper plate return air tunnel (5), the ore loading access road (7) is constructed from the access road (2), a trench is arranged at the end of the ore loading access road (7), and the cutting level tunnel is constructed from the end of the trench bottom tunnel, a first-step rock drilling tunnel (8) is arranged directly below the first-step mining area, and a second-step rock drilling tunnel (9) is arranged directly below the second-step mining area; Step 2: After the artificial false roof (6) and the roof support are completed, the test stope adopts the sub-level open-pit and subsequent filling mining method to mine from bottom to top, with sub-level rock drilling, sub-level ore extraction, and sub-level filling; Step 3: The ore is unloaded from the mining area, and the ore falls into the trench. After the mining area is ventilated for 30 minutes, the ore can be unloaded and transported; Step 4: Ventilation of the mining area. Fresh air flows from the lower wall transport tunnel (1) into the access road (2), passes through the mine exit tunnels at the bottom of the mining area, and enters the upper wall return air tunnel (5). The polluted air is discharged from the return air shaft located in the upper wall into the upper wall return air tunnel (5), and finally discharged to the surface. Step 5: Test the filling process of the stope. To ensure the stability of the stope, the empty area should be filled in time after the concentrated mining is completed. The design requires that the strength of the stope filling body should not be less than 3MPa after 28 days. Step 6: Determine the maximum charge amount. The formula for the vibration attenuation of iron ore blasting is: V=358×(Q 1 / 3 / R) 1.696 Where: V—peak vibration velocity of the particle, cm / s; Q—explosive quantity, total charge quantity for simultaneous blasting, maximum charge quantity for millisecond delay blasting, kg; R—the distance between the protected object and the explosion source center, m; K—coefficient related to rock properties, blasting methods and other factors, i.e., site coefficient; α—seismic wave attenuation index related to geological conditions; The mine roof is taken as 15cm / s with reference to the allowable safety standard for blasting vibration in mine tunnels, R is taken as 30m, and the calculated maximum segment charge is 98Kg. In order to ensure the safety of the mine roof, the maximum segment charge during the blasting process in the test mine cannot be greater than 98kg.

2. A mining method for a crushed ore body according to claim 1, characterized in that: In the second step, the width of the mining area is set to 10m, the segment height is set to 20m, a hydraulic drilling trolley is used to drill a first-stage drilling tunnel (8), slot holes are arranged at the end of the mining area, and the slot holes are blasted to form a cutting groove. The cutting groove is used as the free surface for lateral ore collapse, and the collapsed ore is shoveled out from the bottom loading access road (7). After the ore block is recovered, it is immediately filled. The first-stage mining blocks are filled with tailings cementation, and the second-stage mining blocks are filled with non-cemented or low-grade cementation.

3. A mining method for a crushed ore body according to claim 1, characterized in that: The maximum allowable size of the ore mined in the third step is 850mm. The ore unloading port of the chute needs to be screened, and unqualified large pieces are crushed for the second time using a breaker.

4. A mining method for a crushed ore body according to claim 1, characterized in that: The filling process in the sixth step includes arranging the filling boreholes, hanging the filling pipes and setting up the drainage wells.

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