Method for continuous and sequential mining of a single roadway by converting an auxiliary roadway with double roadway layout into a "negative coal pillar"

Abstract

The present invention relates to a mining method for underground coal mines, and particularly to a method for continuous and sequential mining of a "negative coal pillar" by converting an auxiliary roadway in a double roadway layout. Considering the limitations existing in the traditional double roadway layout, tunneling, and gob-side entry driving technologies with extremely long advancing distances, such as low recovery rate, much coal loss, prone to isolated working faces, and inability to solve problems such as ventilation and material transportation. Accordingly, a method for continuous and sequential mining of a "negative coal pillar" by converting an auxiliary roadway in a double roadway layout that is applicable to a new double roadway layout with extremely long advancing distances and meets the requirements of ventilation and auxiliary transportation is proposed. The present invention is applicable to the longwall mining of thick coal seams with extremely long advancing distances, requiring double roadway layout and tunneling, and the coal seam longitudinally can meet the layout conditions of the upper and lower roadways; the hydrogeological conditions are simple to avoid a large amount of water inrush in the subsequent working face; in mines with hard coal quality, high gas content, and dynamic disaster problems in the coal seam and roof, the function of "one roadway for multiple uses" can be fully realized.

Description

Technical Field

[0001] The present invention relates to a mining method for underground coal mines, and particularly to a method for continuous and sequential mining of a "negative coal pillar" in a single roadway by converting an auxiliary roadway with double roadway layout. Background Art

[0002] An ultra-long advancing distance working face usually refers to a working face advancing a distance of one kilometer or more along the strike. And within a certain range, extending the advancing distance of the working face can achieve high-yield and high-efficiency production, efficiency increase and staff reduction in the underground working face, and promote the development of highly centralized coal mine production. However, at the same time, when the advancing distance is too long, it is difficult for air ducts and local fans to meet the underground ventilation requirements; for material transportation, as the length of the roadway increases, it becomes more difficult to transport the required materials.

[0003] Using the traditional double roadway driving technology, such as Figure 1 As shown, a number of connecting roadways 7 are arranged in the reserved coal pillar 6. During the driving process, an air flow circuit can be formed; for driving ventilation, the air enters from roadway 2, passes through the connecting roadway 7, and finally returns from roadway 3; for driving and material transportation, roadway 4 is responsible for transporting materials, and roadway 5 is responsible for transporting the coal and gangue produced by driving. The material transportation and waste discharge do not interfere with each other, solving the problem of interference between transportation and driving. Therefore, for an ultra-long advancing distance working face, double roadway layout needs to be adopted to meet the requirements of ventilation and auxiliary transportation.

[0004] Using the traditional double roadway driving technology, although it can solve the problems of ventilation and auxiliary transportation. However, during its driving process, a relatively large-sized coal pillar needs to be reserved between the two mining roadways. This coal pillar is affected by the mining of the first working face and then needs to serve the second working face. Therefore, the influence of multiple mining movements needs to be considered. Generally, a 30m coal pillar or even a larger-sized coal pillar is reserved between the double roadway drivings, resulting in problems such as low recovery rate of coal resources in the mining area and a large amount of coal loss.

[0005] A gob-side roadway is a mining roadway driven along the gob of the upper section working face. Gob-side entry driving has the characteristics of high recovery rate, easy maintenance and driving of the roadway, and is widely promoted and used in China. This technology has currently been successfully applied to mines under conventional and complex conditions such as isolated working faces, deep coal seam groups, and impact-prone coal seams, including thin, medium-thick, and thick coal seams. If the gob-side entry driving technology is adopted, the movement of the overlying strata usually lasts for one year or even longer. Therefore, skip mining is required, that is, first mining the coal seam at a long distance, and then returning to mine the adjacent gob area after the overlying strata of the gob are stable. If directly mining in sequence, that is, directly driving the mining roadway along the gob of the previous working face and carrying out mining, it will be affected by the movement of the overlying strata of the previous gob, and it is difficult to ensure the safety of the gob-side roadway.

[0006] In summary, when the traditional double - roadway driving technology is used in the working face with an extremely long advancing distance, if large - sized coal pillars are left, problems such as low recovery rate and a large amount of coal loss will occur; if small - sized coal pillars are left, although the recovery rate of coal resources is increased, after being affected by multiple mining operations, during the driving and mining periods, the roadway maintenance is extremely difficult, and it may even lead to the inability to be used normally, which is not conducive to efficient underground production. If the gob - side entry driving technology is used, not only is skip - mining required, and isolated working faces are likely to appear, but also the ventilation and transportation of materials cannot be guaranteed.

[0007] In summary, aiming at the limitations of the traditional double - roadway layout and driving in the extremely long advancing distance, as well as the fact that the gob - side entry driving technology cannot be applied in the mining of the working face with an extremely long advancing distance. Therefore, based on solving the above problems, in order to form technological innovation and achieve the goals of "continuous" and "sequential" mining, this invention patent proposes a continuous and sequential mining method for converting the auxiliary roadway in the double - roadway layout into a "negative coal pillar" single - roadway. The proposed mining method successfully solves the problems such as low recovery rate and a large amount of coal loss caused by leaving large - sized coal pillars during the period of ensuring the safe, high - yield and efficient service of the roadway in the traditional double - roadway layout; the gob - side roadway can be used as a pressure - relief roadway, a gas drainage roadway and for pressure - relief of the top coal, realizing "one roadway with multiple uses"; the floor roadway can continue to be used as the mining roadway of the subsequent working face, showing a different spatial layout from the traditional "double - roadway layout and driving", achieving a major breakthrough. Summary of the Invention

[0008] Aiming at the above - mentioned technical problems, the purpose of the present invention is to propose a continuous and sequential mining method for converting the auxiliary roadway in the double - roadway layout into a "negative coal pillar" single - roadway to solve the technical limitation problems existing in the prior art.

[0009] To achieve the above - mentioned purpose, the present invention adopts the following technical solutions:

[0010] The continuous and sequential mining method for converting the auxiliary roadway in the double - roadway layout into a "negative coal pillar" single - roadway includes the following processes:

[0011] a. On one side of the first - mined working face in the mining area or panel, a double - roadway layout is adopted, and a large - sized coal pillar is reserved between the two roadways; the roadway close to the working face is arranged along the coal seam floor, and the roadway far from the working face is arranged along the coal seam roof. The floor roadway and the roof roadway are connected by connecting inclined roadways at a certain interval to form a double - roadway layout method for an extremely long advancing distance;

[0012] b. The connecting inclined roadways slope up at 3°, 6°, 9°, 12°, 15°(n sections), 12°, 9°, 6°, 3°, 0°. The key parameter n of the height of the sloping section depends on the difference in height between the coal thickness and the roof roadway;

[0013] c. During the driving process of the floor roadway and the roof roadway on one side of the first - mined working face, the floor roadway undertakes the functions of intake air, transporting the excavated coal and gangue, and the roof roadway undertakes the functions of return air and feeding materials;

[0014] d. When the cutting roadway of the first mining face is opened, the roadway on the other side of the working face first cuts the roadway along the floor part, and then refers to the chute lifting process of patent protection right b to slope up until it penetrates through the roadway along the roof. At this time, a spatial relationship across the roadway is formed between the cutting roadway and the auxiliary haulage roadway along the floor;

[0015] e. During the mining of the first mining face, double roadway layout is also adopted on the other side of the subsequent working face with reference to patent protection right a, and a large-sized coal pillar is reserved between the double roadways; the roadway close to the working face side is arranged along the coal seam floor, and the roadway far from the working face side is arranged along the coal seam roof. The roadway along the floor and the roadway along the roof are connected by connecting inclined roadways at a certain interval; the process of the connecting inclined roadway is determined with reference to patent protection right b;

[0016] f. In the subsequent working face, after the double roadways are driven to the mining boundary, the roadway along the roof cuts a roadway towards the gob side of the first mining face until it penetrates through the auxiliary haulage roadway along the floor of the first mining face to form a cutting roadway;

[0017] g. In the subsequent working face, the production system is arranged by using the cutting roadway formed by the auxiliary haulage roadway along the floor of the first mining face and the roadway along the roof of the subsequent working face. The auxiliary haulage roadway along the floor of the first mining face can continue to be used as the return roadway for the subsequent working face;

[0018] h. During the mining of the working face formed by the roadway along the roof and the auxiliary haulage roadway along the floor of the first mining face in the subsequent working face, the roadway along the roof of the first mining face can still be used as a measure roadway, such as a gas drainage roadway, a top coal weakening or pressure relief roadway, to achieve the effect of "multiple uses of one roadway" for the roadway along the roof.

[0019] i. The auxiliary roadway with double roadway layout is used as the return roadway to continue to serve the subsequent working face, thus forming a continuous and smooth mining technology in which the auxiliary haulage roadway with double roadway layout along the floor is converted into a "negative coal pillar" single roadway for the subsequent working face.

[0020] According to the method of the present invention, preferably, it is applicable to the continuous and sequential mining method of converting the auxiliary roadway with double roadway layout into a "negative coal pillar" single roadway.

[0021] Specifically, in step a, double roadway layout is adopted on one side of the first mining face of the mining area or panel area, and a large-sized coal pillar is reserved between the double roadways; the roadway close to the working face side is arranged along the coal seam floor, and the side far from the working face is arranged along the coal seam roof. The roadway along the floor and the roadway along the roof are connected by connecting inclined roadways at a certain interval to form a double roadway layout with an ultra-long advancing distance.

[0022] In step b, the connecting inclined roadway slopes up according to 3°, 6°, 9°, 12°, 15° (n sections), 12°, 9°, 6°, 3°, 0°. The key parameter n of the height of the sloping section depends on the height difference between the coal thickness and the roadway along the roof.

[0023] In step c, during the driving of the bottom roadway and the top roadway along one side of the first mining face, the bottom roadway undertakes the functions of intake air, transporting the excavated coal and gangue, and the top roadway undertakes the functions of return air and feeding.

[0024] In step d, when cutting the starting cut of the first mining face, the roadway on the other side of the face first cuts the starting cut along the floor part, and then refers to the chute lifting process of patent protection right b to slope up until it penetrates through the top roadway. At this time, a cross-roadway spatial relationship is formed between the starting cut and the bottom auxiliary transportation roadway.

[0025] In step e, during the mining of the first mining face, a double roadway layout is also adopted on the other side of the subsequent working face with reference to patent protection right a, and a large-sized coal pillar is reserved between the double roadways; the roadway close to the working face side is arranged along the coal seam floor, and the roadway far from the working face side is arranged along the coal seam roof. The bottom roadway and the top roadway are connected by connecting inclined roadways at a certain interval; the connecting inclined roadway process is determined with reference to patent protection right b.

[0026] In step f, in the subsequent working face, after the double roadway driving reaches the mining boundary, the top roadway cuts a starting cut towards the goaf side of the first mining face until it penetrates through the bottom auxiliary transportation roadway of the first mining face to form a starting cut.

[0027] In step g, in the subsequent working face, a production system layout is carried out using the starting cut formed by the bottom auxiliary transportation roadway of the first mining face and the top roadway of the subsequent working face. The bottom auxiliary transportation roadway of the first mining face can continue to be used as the mining roadway of the subsequent working face.

[0028] In step h, during the mining of the working face formed by the top roadway and the bottom auxiliary transportation roadway of the first mining face in the subsequent working face, the top roadway of the first mining face can still be used as a measure roadway, such as a gas drainage roadway, a top coal weakening or pressure relief roadway, to achieve the effect of "multiple uses of one roadway" for the top roadway.

[0029] In step i, the auxiliary roadway with double roadway layout is used as the mining roadway to continue to serve the subsequent working face, thereby forming a continuous and smooth mining technology of converting the bottom auxiliary transportation roadway with double roadway layout into a "negative coal pillar" single roadway of the subsequent working face.

[0030] The continuous and sequential mining method of converting the auxiliary roadway with double roadway layout into a "negative coal pillar" single roadway provided by the present invention has the following advantages:

[0031] (1) High recovery rate. The bottom roadway can be completely arranged along the goaf, canceling the coal pillar, roadway and the part of the end that does not release the top coal, realizing "continuous" and "sequential" mining; the top roadway is used to pre-loosen the top coal to solve the problem of low recovery rate of top coal caving mining, and the maximization of the recovery rate can be achieved;

[0032] (2) High roadway utilization rate. The roadway along the roof can pre-pressure and loosen the top coal of the subsequent working face in advance, with the characteristics of a technological measure roadway; the roadway along the bottom of the first mining working face continues to be used as the mining roadway of the subsequent working face, showing a different spatial layout from the traditional "double roadway layout and driving", but the roadway along the bottom as the mining roadway of the subsequent working face has achieved a major breakthrough;

[0033] (3) High safety. The roadway along the roof can be used as a technological measure roadway of the subsequent working face to pre-drain gas, loosen and depressurize the top coal, etc.; the roadway along the bottom, combined with the function of the roadway along the roof as a mining roadway, can achieve the maximum extraction rate, which is beneficial to the prevention of spontaneous combustion. Description of the Drawings

[0034] Figure 1 Schematic diagram of the traditional double roadway layout and driving for a working face with an extremely long advancing distance

[0035] Figure 2 Schematic diagram of the double roadway layout for the mining working face and one side of the subsequent working face in the mining method of the present invention

[0036] Figure 3 Schematic diagram of the A-A cross-section of the double roadway layout for the mining working face and one side of the subsequent working face in the mining method of the present invention Detailed Embodiment

[0037] The detailed embodiment of the present invention will be described with reference to the accompanying drawings.

[0038] In this embodiment, in the first step, a double roadway layout is adopted on one side of the first mining working face of a mining area or panel. A large-sized coal pillar 12 is reserved between the two roadways; the roadway 5 is arranged along the coal seam floor near the working face side, and the roadway 6 is arranged along the coal seam roof far from the working face side. The bottom auxiliary transportation roadway 5 and the roadway 6 along the roof are connected by a connecting inclined roadway 9 at a certain interval to form a double roadway layout with an extremely long advancing distance.

[0039] In the second step, the connecting inclined roadway 9 slopes at 3°, 6°, 9°, 12°, 15° (n sections), 12°, 9°, 6°, 3°, 0°. The key parameter n of the slope section height depends on the height difference between the coal thickness and the roadway 6 along the roof.

[0040] In the third step, during the driving process of the bottom auxiliary transportation roadway 5 and the roadway 6 along the roof on one side of the first mining working face, the bottom auxiliary transportation roadway 5 undertakes the functions of intake air, transporting the excavated coal and gangue, and the roadway 6 along the roof undertakes the functions of return air and feeding materials.

[0041] Step 4: When the open-off cut 10 of the first mining face is being formed, the roadway 4 on one side of the face first forms the open-off cut along the floor part, and then, according to the chute lifting process in Step 2, slopes up until it penetrates through the top roadway 6. At this time, a cross-roadway spatial relationship is formed between the open-off cut formed by the roadway 4 on one side of the face and the top roadway 6 and the bottom auxiliary haulage roadway 5.

[0042] Step 5: During the mining of the first mining face, double roadway layout is also adopted on one side of the subsequent working face in the same way as in Step 1, and a large-sized coal pillar 12 is reserved between the double roadways; a roadway 7 is arranged along the coal seam floor near the working face side, and a roadway 8 is arranged along the coal seam roof far from the working face side. The bottom auxiliary haulage roadway 7 and the top roadway 8 are connected through liaison inclined roadways at a certain interval; the process of the liaison inclined roadways is determined according to Step 2.

[0043] Step 6: In the subsequent working face, after the bottom auxiliary haulage roadway 7 and the top roadway 8 are driven to the mining boundary, the top roadway 7 cuts an open-off cut 11 towards the gob side of the first mining face until it penetrates through the bottom auxiliary haulage roadway 5 of the first mining face to form an open-off cut.

[0044] Step 7: In the subsequent working face, a production system is arranged by using the open-off cut 11 formed by the bottom auxiliary haulage roadway 5 of the first mining face and the top roadway 8 of the subsequent working face, and the bottom auxiliary haulage roadway 5 of the first mining face can continue to be used as the extraction roadway of the subsequent working face.

[0045] Step 8: During the mining of the working face formed by the top roadway 8 and the bottom auxiliary haulage roadway 5 of the first mining face in the subsequent working face, the top roadway 6 of the first mining face can still be used as a measure roadway, such as a gas drainage roadway, a top coal weakening or pressure relief roadway, to achieve the effect of "multiple uses of one roadway" for the top roadway.

[0046] Step 9: The auxiliary roadway in the double roadway layout is used as the extraction roadway to continue to serve the subsequent working face, thereby forming a continuous and smooth mining technology in which the bottom auxiliary haulage roadway 5 in the double roadway layout is converted into a "negative coal pillar" single roadway of the subsequent working face.

Claims

1. Method for continuous and sequential mining of double - roadway layout auxiliary roadway turning into "negative coal pillar" single roadway, Characterized in that, It includes the following processes: a. Double - roadway layout is adopted on one side of the first - mined working face in the mining area or panel. A large - sized coal pillar is reserved between the double roadways. The roadway closer to the working face is arranged along the coal seam floor, and the roadway farther from the working face is arranged along the coal seam roof. The bottom - along roadway and the top - along roadway are connected by connecting inclined roadways at a certain interval to form a double - roadway layout with an extremely long advancing distance; b. The connecting inclined roadways slope at 3°, 6°, 9°, 12°, 15°(n sections), 12°, 9°, 6°, 3°, 0°. The key parameter n of the height of the sloping section depends on the height difference between the coal thickness and the top - along roadway; c. During the driving process of the bottom - along roadway and the top - along roadway on one side of the first - mined working face, the bottom - along roadway undertakes the functions of intake air, transporting the excavated coal and gangue, and the top - along roadway undertakes the functions of return air and feeding; d. When the open - off cut of the first - mined working face is made, the roadway on the other side of the working face first makes an open - off cut along the bottom part, and then refers to the chute lifting process in step b to slope until it is connected with the top - along roadway, forming a spatial relationship across the roadway between the open - off cut and the bottom - along auxiliary transportation roadway; e. During the mining period of the first - mined working face, on the other side of the subsequent working face, double - roadway layout is also adopted with reference to step a, and a large - sized coal pillar is reserved between the double roadways; the roadway closer to the working face is arranged along the coal seam floor, and the roadway farther from the working face is arranged along the coal seam roof. The bottom - along roadway and the top - along roadway are connected by connecting inclined roadways at a certain interval, and the process of the connecting inclined roadway is determined with reference to step b; f. In the subsequent working face, after the double - roadway driving reaches the mining boundary, the top - along roadway makes an open - off cut towards the gob - side of the first - mined working face until it is connected with the bottom - along auxiliary transportation roadway of the first - mined working face to form an open - off cut; g. In the subsequent working face, the production system is arranged by using the open - off cut formed by the bottom - along auxiliary transportation roadway of the first - mined working face and the top - along roadway of the subsequent working face. The bottom - along auxiliary transportation roadway of the first - mined working face can continue to be used as the mining roadway of the subsequent working face; h. During the mining period of the working face formed by the top - along roadway and the bottom - along auxiliary transportation roadway of the first - mined working face in the subsequent working face, the top - along roadway of the first - mined working face can be used as a gas drainage roadway, a top - coal weakening or pressure - relief roadway, achieving the effect of "multiple uses of one roadway" for the top - along roadway; i. Using the double - roadway layout auxiliary roadway as the mining roadway to continue to serve the subsequent working face, thus forming a continuous and sequential mining technology of the double - roadway layout bottom - along auxiliary transportation roadway turning into the "negative coal pillar" single roadway of the subsequent working face.

Images