Pre-splitting blasting drill hole arrangement method for layer mining remaining coal pillar

Abstract

The invention provides a pre-splitting blasting drill hole arrangement method for a layer mining remaining coal pillar, and the method comprises the following steps: determining the geological conditions of the coal pillar and the vicinity, determining the drilling construction parameters according to the detected top coal thickness and the geological parameters of a top plate, determining the drilling construction frequency and hole number according to the lithology of the top plate, high-position, middle-position and low-position drilling parameters are determined, the high-position drilling hole is located in the basic top, the middle-position drilling hole is located in the immediate top, the low-position drilling hole is located in the upper split coal pillar, the inclination angle of the low-position drilling hole is larger than that of the high-position drilling hole, the inclination angle of the high-position drilling hole is larger than that of the middle-position drilling hole, and the explosive loading amount is determined according to the length of the drilling holes. According to the pre-splitting blasting drill hole arrangement method for the layered mining remaining coal pillar, the safety and efficiency of coal mining can be improved, resource waste is reduced, and meanwhile environmental damage caused by mining is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of coal pillar blasting drilling, and in particular to a method for arranging pre-splitting blasting drilling of coal pillars left over from stratified mining. Background Art

[0002] In coal mining, due to the different thickness of coal seams, most coal seams cannot be mined in one go due to equipment and geological conditions, so stratified mining is adopted. In the first stratified mining, due to the lack of technical theory and field experience, a wide coal pillar is left between adjacent working faces. In the later mining, the coal pillar cannot be crushed due to its large width, forming a residual coal pillar in the goaf, and the roof in the residual coal pillar area has not fully collapsed.

[0003] In the related technology, a drilling rig is used to construct deep hole blasting in the remaining coal pillar above the heading. Because the upper part is the goaf of the first layer working face, the drilling hole cannot be constructed into the roof above the remaining coal pillar due to the angle, and the drilling hole is easy to enter the goaf above, causing gas leakage from the upper layer. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention proposes a method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining. The method can improve the safety and efficiency of coal mining, reduce waste of resources, and reduce environmental damage caused by mining.

[0006] The method for arranging pre-splitting blasting drilling holes for coal pillars left over from layered mining according to an embodiment of the present invention comprises the following steps:

[0007] S1. Determine the coal pillar and nearby geological conditions;

[0008] S2. Determine drilling construction parameters based on the detected top coal thickness and roof geological parameters;

[0009] S3. Determine the drilling construction frequency and the number of holes according to the lithology of the roof, wherein the construction frequency includes: multiple cyclic mining stages, and eight holes are constructed in each cyclic mining stage, wherein each cyclic mining stage takes four days, and one cyclic mining stage includes two mining stages, one mining stage takes two days, and four holes are constructed in each mining stage;

[0010] S4. Determine the parameters of high-position, middle-position and low-position drilling holes, wherein the high-position drilling hole is located at the basic top, the middle-position drilling hole is located at the direct top, the low-position drilling hole is located at the upper residual coal pillar, and the inclination angle of the low-position drilling hole is greater than the inclination angle of the high-position drilling hole, and the inclination angle of the high-position drilling hole is greater than the inclination angle of the middle-position drilling hole.

[0011] S5. Determine the charge amount according to the drilling length.

[0012] The pre-splitting blasting drilling arrangement method for the coal pillars left over from layered mining in the embodiment of the present invention can effectively control the blasting range by reasonably arranging the high, middle and low drill holes, avoiding the risk of gas leakage and roof collapse. And according to the position layout of the high, middle and low drill holes, it can help to reduce the supporting force of the coal pillars in layers, and gradually achieve the crushing and collapse of the coal pillars.

[0013] Therefore, the pre-splitting blasting drilling arrangement method for stratified mining legacy coal pillars according to the embodiment of the present invention can improve the safety and efficiency of coal mining, reduce the waste of resources, and reduce the environmental damage caused by mining.

[0014] In some embodiments, step S1 also includes the following steps: using a peep device to observe the collapse of the coal pillar and the nearby roof, and using a hydraulic drill to drill holes under the coal pillar of the working face to detect the thickness of the top coal and the rock properties of the roof in the coal pillar area.

[0015] In some embodiments, in step S2, the drilling construction parameters include the drilling construction position, depth, inclination and charge amount.

[0016] In some embodiments, in step S3, in a cyclic pushing and mining stage, the pushing and mining stage direction is consistent with the mining direction, and multiple cyclic pushing and mining stage construction drilling holes are arranged at intervals along the extension direction of the mining working face.

[0017] In some embodiments, the first mining stage of a mining cycle includes: a high-position drilling hole, a middle-position drilling hole and a low-position drilling hole, and there are two low-position drilling holes. The high-position drilling hole is located between the two low-position drilling holes in the length direction of the mining working face, and the middle-position drilling hole and the low-position drilling hole are arranged at intervals.

[0018] In some embodiments, the second mining stage of a mining cycle includes: a high-position drilling hole, a middle-position drilling hole and a low-position drilling hole. There are two low-position drilling holes, and the two low-position drilling holes are located between the high-position drilling hole and the middle-position drilling hole in the length direction of the mining working face.

[0019] In some embodiments, in step S4, the final hole position of the high-position drilling hole is located in a region above 2 / 3 of the basic top height.

[0020] In some embodiments, the drilling depth of the high-level borehole is less than or equal to 70 meters.

[0021] In some embodiments, in step S4, the final hole position of the mid-level borehole is adjacent to the area below the immediate top, and the vertical position of the mid-level borehole coincides with the step length of the leading stress peak of the working face.

[0022] In some embodiments, in step S4, the low-level drill hole includes a low-level fracture high hole and a low-level fracture low hole, the inclination angle of the low-level fracture high hole is greater than the inclination angle of the low-level fracture low hole, and the low-level fracture high hole is located above the low-level fracture low hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a top view schematic diagram of the construction of a pre-splitting blasting drilling arrangement method for stratified mining remaining coal pillars according to an embodiment of the present invention.

[0024] Figure 2 It is a first cross-sectional schematic diagram of the construction of a pre-splitting blasting drilling arrangement method for stratified mining remaining coal pillars according to an embodiment of the present invention.

[0025] Figure 3 It is a second cross-sectional schematic diagram of the construction of the pre-splitting blasting drilling arrangement method for stratified mining remaining coal pillars according to an embodiment of the present invention.

[0026] Reference numerals:

[0027] 1. Mining working face,

[0028] 2. Mining face drift,

[0029] 3. Promotion and procurement stage,

[0030] 4. Mining coal body,

[0031] 5. The coal pillars left over from the upper division,

[0032] 6. Directly push up.

[0033] 7. Basic top,

[0034] 801, the first round of high-position drilling, 802, the second round of high-position drilling,

[0035] 901, first round of median drilling, 902, second round of median drilling,

[0036] 101, first round low position high hole, 102, first round low position low hole, 103, second round low position high hole, 104, second round low position low hole,

[0037] 11. Circular promotion stage,

[0038] 12. Mining direction,

[0039] 13. Upper layer mining face drift,

[0040] 14. Upper layer goaf,

[0041] 15. Bottom plate,

[0042] 16. Bottom coal. DETAILED DESCRIPTION

[0043] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0044] like Figure 1-Figure 3 As shown, the method for arranging pre-splitting blasting drilling holes for the coal pillars left over from layered mining according to an embodiment of the present invention comprises the following steps:

[0045] S1. Determine the geological conditions of the coal pillar and its vicinity. It is understandable that, in some embodiments, step S1 also includes the following steps: using a peep instrument to observe the collapse of the coal pillar and the nearby roof, and using a hydraulic drill to drill holes under the coal pillar of the working face to detect the thickness of the top coal in the coal pillar area and the lithology of the roof.

[0046] It is understandable that through real-time observation of the peep instrument, the collapse of the coal pillar and the nearby roof can be accurately grasped, providing accurate data support for subsequent mining and blasting work. The use of hydraulic drilling rigs can directly explore the thickness of the top coal in the coal pillar area and the lithology of the roof without destroying the coal pillar, increasing the understanding of geological conditions.

[0047] That is to say, the observed data, including the collapse range, collapse speed, and roof status after collapse, can be recorded using a peephole, and by analyzing the observed data, the stability of the coal pillar and the collapse characteristics of the roof can be evaluated. The drilling of a hydraulic drill can collect data during the drilling process, such as drilling resistance, rock type, rock hardness, etc. Based on the drilling data and observation data, the stability of the coal pillar and the geological conditions of the roof can be further analyzed. In this way, the coal pillar and the nearby address conditions can be determined, and full preparations can be made for subsequent drilling and blasting.

[0048] It should be noted that the thickness of the top coal is determined based on the change in the color of the water produced in the hole during the geological drilling construction process (such as black water is coal, white water is rock), and the number of construction drill rods is counted. The thickness of the top coal is determined based on the number of construction drill rods and the inclination of the borehole. The thickness of the direct top 6 and basic top 7 is determined based on data such as the geological drilling column chart and the expected profile of the mining working face 1.

[0049] S2. Determine drilling construction parameters according to the detected top coal thickness and roof geological parameters. In some embodiments, in step S2, the drilling construction parameters include the drilling construction position, depth, inclination and charge amount.

[0050] It is understandable that the spacing and number of drilling construction are determined according to the width of the coal pillars left in the upper layer. According to the basic experimental data of roof lithology, density, elastic modulus, cohesion and tensile strength, it can be calculated that the radius of the blasting crack zone of φ75mm drilling and φ65mm emulsion explosive under the original rock stress state is about 1m to 3m. Preferably, in order to ensure the fracturing effect, the amount of explosive can be increased according to the thickness of the direct roof 6, and the fracturing length can be increased, thereby increasing the fracturing range.

[0051] In addition, the high-level drilling fracturing depth is determined according to the thickness of the top coal, basic roof 7 and direct roof 6 to ensure that it enters the middle and upper part of the direct roof 6. The high-level drilling construction depth is determined according to the optimal inclination angle of the drilling rig, the hole opening position and the thickness of the overlying rock layer; the final hole position of the medium-level advance fracturing hole is determined based on the analyzed distribution range of the advance stress field of the working face, thereby determining the construction position, inclination and drilling depth of the borehole; the low-level drilling construction depth and angle (generally set in the middle and upper part of the top coal) are determined according to the top coal thickness, coal density and hardness of the coal pillar area of ​​the working face to increase the recovery of the top coal in the coal pillar area.

[0052] Preferably, the charge amount is determined based on the drilling length, but on the premise of ensuring 1 / 3 of the sealing length, the charge length is determined based on the remaining hole depth and the position where fracturing is required, and the charge amount is determined based on the type parameters of the explosive used and the uncoupling coefficient.

[0053] S3. Determine the frequency and number of drilling holes according to the rock properties of the roof. The construction frequency includes: multiple cyclic mining stages 11, and eight holes are constructed in each cyclic mining stage 11, wherein each cyclic mining stage 11 takes four days, and one cyclic mining stage 11 includes two mining stages 3, one mining stage 3 takes two days, and four holes are constructed in each mining stage 3.

[0054] It is understandable that if Figure 1-Figure 3 As shown in the figure, dividing the mining plan into two stages helps to better manage time and ensure that the work is carried out in an orderly manner. Each stage has a clear time limit, which helps to monitor and evaluate work efficiency. And by planning the number of holes to be drilled in advance, human resources, equipment and materials can be allocated more effectively to avoid waste and redundancy of resources. In addition, dividing the drilling construction into stages helps to disperse the risks during the construction process. If problems occur at a certain stage, the plans for the subsequent stages can be adjusted in time to reduce the impact on the overall work.

[0055] In some embodiments, in step S3, in a cyclic pushing and mining stage 11, the direction of the pushing and mining stage 3 is consistent with the mining direction 12, and the construction drilling holes of multiple cyclic pushing and mining stages 11 are along the extension direction of the mining working face 1 (such as Figure 1 The mining direction 12) shown is arranged at intervals.

[0056] In some embodiments, the first mining stage 3 of a mining cycle 11 includes: a high-level borehole, a middle-level borehole and a low-level borehole, and there are two low-level boreholes. The high-level borehole is located between the two low-level boreholes in the length direction of the mining face 1, and the middle-level borehole and the low-level borehole are arranged at intervals.

[0057] It is understandable that if Figure 1-Figure 3 As shown, the pushing direction is consistent with the recovery direction 12, making the drilling and pushing work process simpler and more intuitive, reducing the complexity of operation. In addition, due to the consistent direction, the extra time and labor cost caused by the direction change can be avoided, and the mining efficiency is improved.

[0058] like Figure 1-Figure 3 As shown, a cycle of pushing and mining stage 11 includes eight boreholes, among which the first pushing and mining stage 3 includes four boreholes, namely the first round high-position borehole 801, the first round low-position high borehole 101, the first round low-position low borehole 102 and the first round middle-position borehole 901; the second pushing and mining stage 3 includes another four boreholes, namely the second round high-position borehole 802, the second round low-position high borehole 103, the second round low-position low borehole 104 and the second round middle-position borehole 902.

[0059] It should be noted that the high-position drill hole needs to penetrate the coal pillar and enter the roof to prevent the top coal body from being crushed due to mining, which makes charging difficult. Therefore, it is arranged in the middle of the two low-position drill holes.

[0060] In some embodiments, the second mining stage 3 of a mining cycle 11 includes: a high-position borehole, a middle-position borehole and a low-position borehole, there are two low-position boreholes, and the two low-position boreholes are located between the high-position borehole and the middle-position borehole in the length direction of the mining face 1.

[0061] It is understandable that if Figure 1-Figure 3 As shown, in the second mining stage 3, the high-position borehole, the middle-position borehole and the low-position borehole are arranged in sequence, and the low-position borehole is located between the high-position and middle-position boreholes, which can form a better blasting superposition effect and improve the blasting and crushing efficiency. Through the arrangement of the low-position borehole, a crushing zone can be formed in the middle area of ​​the coal pillar, which helps to improve the stability of the coal pillar and reduce the deformation and collapse risks of the coal pillar.

[0062] In other words, through the layered arrangement of high, medium and low-position boreholes, the coal seams can be blasted layer by layer, the stress of the coal seams can be gradually reduced, and the safety of mining can be improved. The arrangement of boreholes at different positions helps to control the propagation direction and range of the blasting and avoid damage to the surrounding areas.

[0063] S4. Determine the parameters of high-position, middle-position and low-position drilling holes, wherein the high-position drilling hole is located at the basic top 7, the middle-position drilling hole is located at the direct top 6, and the low-position drilling hole is located at the upper residual coal pillar 5, and the inclination angle of the low-position drilling hole is greater than the inclination angle of the high-position drilling hole, and the inclination angle of the high-position drilling hole is greater than the inclination angle of the middle-position drilling hole.

[0064] In some embodiments, in step S4, the final hole position of the high-position drilling is located at an area above 2 / 3 of the height of the basic top 7. Preferably, the drilling depth of the high-position drilling is less than or equal to 70 meters to ensure the effectiveness of the drilling and avoid the construction difficulty and cost increase caused by excessively deep drilling.

[0065] It is understandable that if Figure 1-Figure 3 As shown, the final hole position of the high-position drilling hole is located in the area above 2 / 3 of the height of the basic roof 7, ensuring that the drilling hole can penetrate into the basic roof 7 and effectively control the stability of the upper layered coal pillar.

[0066] In some embodiments, in step S4, the final hole position of the mid-position borehole is adjacent to the area below the immediate top 6, and the vertical position of the mid-position borehole coincides with the step length of the leading stress peak of the working face.

[0067] It is understandable that if Figure 1-Figure 3 As shown in the figure, the final hole position of the middle hole is close to the area below the direct roof 6, which can avoid the collapse of the direct roof 6 and is also conducive to controlling the leading stress peak in front of the working face. The vertical position of the middle hole is consistent with the leading stress peak step of the working face, ensuring that the drilling can effectively affect and control the area of ​​stress concentration.

[0068] In some embodiments, in step S4, the low-level drill hole includes a low-level fracture high hole and a low-level fracture low hole, the inclination angle of the low-level fracture high hole is greater than the inclination angle of the low-level fracture low hole, and the low-level fracture high hole is located above the low-level fracture low hole.

[0069] It is understandable that if Figure 1-Figure 3 As shown in the figure, by arranging the low-position drill holes in layers, the upper residual coal pillar 5 can be gradually broken, reducing the risk of coal pillar collapse. The inclination angle of the low-position fracture high hole is greater than that of the low-position fracture low hole, which is conducive to gradually releasing the stress of the low-position coal pillar and improving the stability of the coal pillar. The inclination angle design of the high-position drill hole, the middle-position drill hole and the low-position drill hole is conducive to the effective transmission of blasting energy and improves the blasting effect.

[0070] Preferably, the inclination angle of the high-position drill hole is determined according to the maximum angle that is conducive to construction and charging.

[0071] S5. Determine the charge amount according to the length of the drill hole. Adjusting the charge amount according to the length of the drill hole can ensure the effective use of blasting energy and avoid waste of resources due to excessive charge or poor blasting effect due to insufficient charge. It also helps to improve the safety and effectiveness of blasting and reduce damage to the surrounding rock mass.

[0072] In summary, the pre-splitting blasting drilling arrangement method for the coal pillars left over from layered mining in the embodiment of the present invention can effectively control the blasting range by reasonably arranging high, middle and low drill holes, avoiding the risk of gas leakage and roof collapse. And according to the position layout of the high, middle and low drill holes, it can help to reduce the supporting force of the coal pillars in layers, and gradually achieve the crushing and collapse of the coal pillars.

[0073] Therefore, the pre-splitting blasting drilling arrangement method for stratified mining legacy coal pillars according to the embodiment of the present invention can improve the safety and efficiency of coal mining, reduce the waste of resources, and reduce the environmental damage caused by mining.

[0074] In the description of the present invention, it is to 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”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0075] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0076] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0077] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0078] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0079] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining, characterized in that: The following steps are involved: S1. Determine the coal pillar and nearby geological conditions; S2. Determine drilling construction parameters based on the detected top coal thickness and roof geological parameters; S3. Determine the drilling construction frequency and the number of holes according to the lithology of the roof, wherein the construction frequency includes: multiple cyclic mining stages, and eight holes are constructed in each cyclic mining stage, wherein each cyclic mining stage takes four days, and one cyclic mining stage includes two mining stages, one mining stage takes two days, and four holes are constructed in each mining stage; S4. Determine the parameters of high-position, middle-position and low-position boreholes, wherein the high-position borehole is located at the basic roof, the middle-position borehole is located at the direct roof, the low-position borehole is located at the upper residual coal pillar, and the inclination angle of the low-position borehole is greater than the inclination angle of the high-position borehole, and the inclination angle of the high-position borehole is greater than the inclination angle of the middle-position borehole; S5. Determine the charge amount according to the drilling length.

2. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 1, characterized in that: In step S1, the following steps are also included: using a peep instrument to observe the collapse of the coal pillar and the nearby roof, and using a hydraulic drill to drill holes under the coal pillar of the working face to explore the top coal thickness and roof lithology in the coal pillar area.

3. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 2, characterized in that: In step S2, the drilling construction parameters include the drilling construction position, depth, inclination and charge amount.

4. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 3 is characterized in that: In step S3, in one cyclic pushing and mining stage, the pushing and mining stage direction is consistent with the mining direction, and multiple cyclic pushing and mining stage construction drilling holes are arranged at intervals along the extension direction of the mining working face.

5. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 4, characterized in that: The first mining stage of a mining cycle includes: high-position drilling, middle-position drilling and low-position drilling, and there are two low-position drilling holes. The high-position drilling hole is located between the two low-position drilling holes in the length direction of the mining face, and the middle-position drilling hole and the low-position drilling hole are arranged at intervals.

6. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 5, characterized in that: The second mining stage of a mining cycle includes: high-position drilling, middle-position drilling and low-position drilling. There are two low-position drilling holes, and the two low-position drilling holes are located between the high-position drilling hole and the middle-position drilling hole in the length direction of the mining face.

7. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 1, characterized in that: In step S4, the final hole position of the high-position drilling is located in a region above 2 / 3 of the basic top height.

8. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 7, characterized in that: The drilling depth of high-position drilling is less than or equal to 70 meters.

9. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 7, characterized in that: In step S4, the final hole position of the mid-level borehole is adjacent to the area below the immediate roof, and the vertical position of the mid-level borehole is consistent with the step distance of the leading stress peak of the working face.

10. The method for arranging pre-splitting blasting drilling holes for coal pillars left over from stratified mining according to claim 1, characterized in that: In step S4, the low-position drill hole includes a low-position fracture high hole and a low-position fracture low hole, the inclination angle of the low-position fracture high hole is greater than the inclination angle of the low-position fracture low hole, and the low-position fracture high hole is located above the low-position fracture low hole.

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