Turning mining method for large-dip-angle turning working face

Abstract

The invention relates to a coal mining technology, in particular to a turning mining method for a large-dip-angle turning working face. The turning mining method for the large-dip-angle turning working face is provided by analyzing the change of the inclined length and the inclined dip angle of the working face and the change of the trend dip angle of the working face, and comprises the following steps of: S100, detecting basic parameters of a coal seam top plate and a coal seam bottom plate; s200, characteristic parameters of a turning section are determined; and S300, a turning mining scheme is formulated and adjusted.

Description

Technical Field

[0001] The invention relates to coal mining technology, in particular to a turning mining method for a large-angle turning working face. Background Art

[0002] Coal mining technology has been a hot topic in recent years. In order to achieve turning mining in a large-angle turning working face, it is necessary to accurately determine the changes in the inclined length and inclination angle of the working face at the turning point and the changes in the strike angle of the working face, and formulate an appropriate mining method to ensure that the recovery rate of corner coal is improved, the loss of coal pillars is reduced, and the equipment investment is reduced.

[0003] In view of the above problems, this paper proposes a turning mining method for a large-angle turning working face. The turning mining plan is determined mainly through the changes in the inclined length and dip angle of the working face and the changes in the strike angle of the working face. Specifically, the basic parameter detection of the roof and floor of the coal seam; determining the characteristic parameters of the turning section; and finally formulating a turning mining plan and making adjustments.

[0004] The use of turning mining in large-angle turning working faces can reduce coal pillar losses, increase the recovery rate of corner coal, reduce the amount of tunnel preparation work, reduce equipment investment, avoid geological structures and adapt to complex geological conditions. Summary of the invention

[0005] The present invention provides a method for turning mining of a large-angle turning working face by analyzing the changes in the inclined length and the inclination angle of the working face and the changes in the strike angle of the working face.

[0006] The present invention adopts the following technical scheme: a method for turning mining in a large-angle turning working face, comprising: S100: Basic parameter detection of coal seam roof and floor; S200: Determine characteristic parameters of the turning section; S300: Develop a turning mining plan and make adjustments.

[0007] In some embodiments, in step S100, the basic parameters of the coal seam roof and floor include main lithology, uniaxial compressive strength, elastic modulus, tensile strength, strength reduction cohesion and internal friction angle, as well as basic working face conditions such as gas, coal dust explosiveness, coal seam spontaneous combustion tendency, geothermal hazards and ground pressure.

[0008] In some embodiments, in step S200, the characteristic parameters of the turning of the working face include the length, width, height and net cross-sectional area of ​​the return air chute and the transport chute, as well as the changes in the inclined length and inclination angle of the turning working face and the changes in the strike angle of the turning section working face; In order to analyze the changes in the inclined length and inclination angle of the turning working face and the changes in the strike angle of the turning section working face, the turning working face is divided into n sub-areas, and each sub-area is analyzed one by one; According to the relationship between various parameters of the large-angle working surface, the formula for calculating the oblique length can be obtained as follows: s'=s / cosα Where: s' - oblique length of working surface; s—horizontal distance between two chute of working face; α—Working surface design inclination α=arccos(h 1 -h 2 ) / s Where: h 1 —Elevation of the drift on the working surface; h 2 —Elevation of the drift below the working face; s—horizontal distance between two chute of working face; For the turning and downward mining section of the working face, the strike distances of the return wind chute and the headwind chute at different strike angles are counted, and the vertical descent distances of the two chute in the turning area of ​​the working face are calculated in turn.

[0009] In some embodiments, in step S300, the turning and dipping mining of the working face is mainly controlled by closely following the bottom plates of the two chute tunnels to lower the working face layer. It is required to refer to the layer control parameters of the two chute layers, formulate the layer control parameters of the return air chute layer of the turning section of the working face, so as to smoothly transition and recover the middle section of the working face, formulate the corresponding large-angle turning working face turning mining plan, and analyze and adjust each sub-area one by one to ensure that all the supports are in a straight line; During the turning and downward mining of the working face, the length of the working face increases first and then decreases, the working face angle also changes continuously, and the number of working face supports also changes accordingly. Therefore, during mining, attention should be paid to ensuring mining safety by increasing or decreasing working face supports; During the process of adjusting the support, since the inclination angle of the working face above the arc section is large and the support is heavy, as the coal is released and leaked, the support sometimes slides down and tilts; the support with double-sided double-active large stroke, large push side guard plate, bottom adjustment beam and dovetail anti-skid device, as well as jacks connected between frames are used to achieve the requirements of top connection and anti-skid adjustment at any time for narrow upper and wide lower parts; at the same time, according to the changes in the bottom plate of the working face, the pseudo-slope is adjusted in time to ensure the consistency of the slope of the working face and prevent the support from tipping over at local slope change points. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is the relationship diagram of various parameters of the large-angle working face; Figure 2 Diagram for determining working surface position. DETAILED DESCRIPTION

[0011] The present invention provides a method for turning mining at a large-angle turning working face. The principle of the method is to detect the basic parameters of the coal seam roof and floor, determine the characteristic parameters of the turning section, formulate a turning mining plan and make adjustments. The above-mentioned purpose of the present invention is achieved through the following technical solutions.

[0012] S100: Basic parameter detection of coal seam roof and floor; the basic parameters detected include main lithology, uniaxial compressive strength, elastic modulus, tensile strength, strength reduction cohesion and internal friction angle, as well as basic working face conditions such as gas and coal dust explosiveness, coal seam spontaneous combustion tendency, geothermal hazards and ground pressure.

[0013] S200: Collect basic parameters of the turning working face; the basic parameters include the length, width, height, net cross-sectional area, changes in inclined length and inclination angle of the return air chute and the transport chute, and changes in the strike inclination angle of the turning section working face.

[0014] For the calculation of the changes in oblique length and dip angle, the turning mining face is divided into zones according to the return air chute and transport chute of the turning tunnel of the working face, and the turning mining working face is divided into n sub-areas to analyze the changes in oblique length and dip angle of the working face in each sub-area and the changes in strike angle of the working face in the turning section section by section.

[0015] According to the relationship between various parameters of the large-angle working surface, the formula for calculating the oblique length can be obtained as follows: s'=s / cosα Where: s' - oblique length of working surface; s—horizontal distance between two chute of working face; α—Working surface design inclination α=arccos(h 1 -h 2 ) / s Where: h 1 —Elevation of the drift on the working surface; h 2 —Elevation of the drift below the working face; s—Horizontal distance between the two drifts of the working face.

[0016] For the turning and downward mining section of the working face, the strike distances of the return wind chute and the headwind chute at different strike angles are counted, and the vertical descent distances of the two chute in the turning area of ​​the working face are calculated in turn.

[0017] The oblique length and inclination angle of the working face are calculated every 10m in each area. When calculating, the lower opening is 6m ahead of the upper opening. Since the return air chute and the transport chute in the turning section are not parallel, the working face cannot be perpendicular to the direction of the two chute at the same time. Any point of the return air chute of the working face is perpendicular to the transport chute, and the foot of the vertical extends forward 6m. After connecting the two points, the oblique length projection of the working face at this position is obtained, and the oblique length and angle of the turning section of the working face are obtained.

[0018] S300: Develop a turning mining plan and make adjustments.

[0019] Since the turning and inclined mining of the working face is mainly controlled by following the bottom plates of the two drift tunnels and lowering the working face layer, the layer control parameters of the two drifts are formulated so that the middle section of the working face can be smoothly transitioned and mined.

[0020] When turning mining is carried out in a large-angle turning working face, the main method of turning mining is to add a deflection cutter on the working face. Therefore, each sub-area should be discussed separately in order to formulate a coal cutting and frame moving plan for each area.

[0021] For each sub-area, the turning point is first determined, and according to the turning point, an alternating coal cutting method is formulated to complete the turning mining. According to the length and inclination of the cut before and after the turning, the supports are increased or decreased, and pushed forward and moved backward, and finally all the supports are ensured to be in a straight line.

[0022] When turning mining, the front scraper conveyor is mainly prevented from slipping by using the anti-skid cylinder mounting hole at the front base of the hydraulic support. Every 20 pairs of hydraulic supports use Ø28mm40 type chains to fix one pair of ZFQ50Q-02 hydraulic support guard jacks. The other end uses Ø28mm40 type chains to connect the top of the jacks with the corresponding hydraulic support front scraper conveyor push rod "I" head, and the front end of the hydraulic support where the jack is installed is connected to the jack inlet and return pipeline to ensure the jack's sensitive movement. Before pulling and moving the hydraulic support from top to bottom on the working surface, the preset jacks in front of each hydraulic support frame should be tightened in time, the front scraper conveyor should be pulled, and finally the hydraulic support should be pulled and moved with pressure. The rear scraper conveyor has a bottom anti-skid guide groove and a dovetail plate to cooperate with anti-skid, which can meet the anti-skid requirements.

[0023] The reset of the scraper conveyor is mainly done by pulling it upward with the inclined jack. The tunnel adopts a pseudo-inclined layout with the machine tunnel ahead and the air tunnel lagging behind. The working face is advanced obliquely during mining, and the main processes of moving the frame, pushing the chute, and placing the top coal are carried out in order from bottom to top, which improves the sliding state of the front and rear scraper conveyors and effectively prevents the sliding of the working face equipment.

[0024] During the turning and downward mining of the working face, the length of the working face first increases and then decreases, the working face angle also changes continuously, and the number of working face supports also changes accordingly. Therefore, during mining, attention should be paid to adjusting the mining plan by adding or reducing working face supports to ensure mining safety.

[0025] During the process of adjusting the support, due to the large inclination angle of the working surface above the arc section and the heavy support, the support sometimes slides down and deflects as the coal is released and leaked. The support with double-sided double-active large stroke, large push side guard plate, bottom adjustment beam and dovetail anti-skid device, as well as the jacks connected between the frames are used to achieve the requirements of top connection and anti-skid adjustment at any time. At the same time, according to the changes in the bottom plate of the working surface, the pseudo-slope is adjusted in time to ensure the consistency of the slope of the working surface and prevent the support from tipping over at the local slope change point.

Claims

1. A method for turning mining at a large-angle turning working face, characterized in that: include: S100: Basic parameter detection of coal seam roof and floor; S200: Determine characteristic parameters of the turning section; S300: Develop a turning mining plan and make adjustments.

2. The method for turning mining at an inclined turning working face according to claim 1, characterized in that: In step S100, the basic parameters of the coal seam roof and floor include main lithology, uniaxial compressive strength, elastic modulus, tensile strength, strength reduction cohesion and internal friction angle, as well as basic working face conditions such as gas and coal dust explosiveness, coal seam spontaneous combustion tendency, geothermal hazards and ground pressure.

3. The method for turning mining at an inclined turning working face according to claim 1, characterized in that: In step S200, the characteristic parameters of the turning of the working face include the length, width, height and net cross-sectional area of ​​the return air chute and the transport chute, as well as the changes in the inclined length and inclination angle of the turning working face and the changes in the strike angle of the turning section working face; In order to analyze the changes in the inclined length and inclination angle of the turning working face and the changes in the strike angle of the turning section working face, the turning working face is divided into n sub-areas, and each sub-area is analyzed one by one; According to the relationship between various parameters of the large-angle working surface, the formula for calculating the oblique length can be obtained as follows: s'=s / cosα Where: s' - oblique length of working surface; s—horizontal distance between two chute of working face; α—Working surface design inclination α=arccos(h1-h2) / s Where: h1—the elevation of the trench on the working surface; h2—Elevation of the chute below the working face; s—horizontal distance between two chute of working face; For the turning and downward mining section of the working face, the strike distances of the return wind chute and the headwind chute at different strike angles are counted, and the vertical descent distances of the two chute in the turning area of ​​the working face are calculated in turn.

4. The method for turning mining at an inclined turning working face according to claim 1, characterized in that: In step S300, the turning and dipping mining of the working face is mainly controlled by following the bottom plates of the two chute tunnels closely to lower the working face layer. It is required to refer to the layer control parameters of the two chute tunnels, formulate the layer control parameters of the return air chute tunnel of the turning section of the working face, so as to smoothly transition and recover the middle section of the working face, formulate the corresponding turning mining plan of the large-angle turning working face, and analyze and adjust each sub-area one by one to ensure that all the supports are in a straight line; During the turning and downward mining of the working face, the length of the working face increases first and then decreases, the working face angle also changes continuously, and the number of working face supports also changes accordingly. Therefore, during mining, attention should be paid to ensuring mining safety by increasing or decreasing working face supports; During the process of adjusting the support, since the inclination angle of the working face above the arc section is large and the support is heavy, as the coal is released and leaked, the support sometimes slides down and tilts; the support with double-sided double-active large stroke, large push side guard plate, bottom adjustment beam and dovetail anti-skid device, as well as jacks connected between frames are used to achieve the requirements of top connection and anti-skid adjustment at any time for narrow upper and wide lower parts; at the same time, according to the changes in the bottom plate of the working face, the pseudo-slope is adjusted in time to ensure the consistency of the slope of the working face and prevent the support from tipping over at local slope change points.

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