A method for coal mining with coal pillar filling and water conservation in stratified mining section of extra-thick coal seam working face

Abstract

The present invention belongs to the technical field of coal mining, and specifically relates to a method for filling and water-preserving coal mining in a stratified mining section of an extra-thick coal seam working face, comprising the following steps: adopting a downward mining method for extra-thick coal seams; leaving a section coal pillar between adjacent working faces; arranging a grouting pipeline on the roadway floor close to the section coal pillar; arranging a grouting borehole in the connecting roadway of the section coal pillar, and arranging two grouting boreholes in the goaf of adjacent working faces; when the lower stratified working face passes through the upper stratified section coal pillar connecting roadway, grouting is performed through the grouting borehole to form a filling body; the upper and lower stratified working faces coordinate operations until the water-preserving coal mining operation of the entire extra-thick coal seam working face is completed. The present invention provides a new idea for water-preserving mining of extra-thick coal seams, and the method can effectively protect the surface ecological water level and aquifers with water supply value. The method is safe and reliable, highly innovative, and has obvious effects, high economy and practicality, and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mining, and in particular relates to a method for coal mining with coal pillar filling and water conservation in a stratified mining section of an extra-thick coal seam working face. Background Art

[0002] The contradiction between coal mining and ecological environment protection has always been an urgent problem to be solved in the development of my country's coal mining technology. According to incomplete statistics, every ton of coal mined will destroy about 2m 3 Water resources: The coal mining process directly destroys the structure of groundwater aquifers, changes the recharge, runoff and discharge methods of groundwater aquifers, affects the water circulation conditions of groundwater aquifers, forms groundwater funnels and causes great damage to regional water resources.

[0003] Water-preserving mining in extremely thick coal seams has always been a technical bottleneck in the high-quality development of coal in my country's ecologically fragile mining areas in western China.

[0004] Therefore, how to rationally and efficiently utilize solid waste products such as coal gangue in mining areas to maximize the recovery rate of extra-thick coal seams while achieving water resource protection (water-saving mining) is a difficult problem that coal science and technology workers urgently need to solve. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned problems existing in the traditional technology and to provide a method for coal mining with coal pillar filling and water conservation in the stratified mining section of the working face of an extra-thick coal seam.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] The present invention provides a method for coal mining by filling coal pillars and retaining water in a stratified mining section of an extra-thick coal seam working face, comprising the following steps:

[0008] S1. For extremely thick coal seams, the downward mining method is adopted;

[0009] S2. Dig the upper layer coal transportation tunnel and return air tunnel according to the comprehensive mechanized coal mining tunnel layout mode, open the cut when the coal transportation tunnel and return air tunnel reach the boundary of the working face, and arrange coal mining and support equipment in the cut at the same time;

[0010] S3. Leave section coal pillars between adjacent working faces;

[0011] S4. Arrange the grouting pipeline on the roadway floor close to the section coal pillar;

[0012] S5. Arrange a grouting borehole in the connecting lane of the section coal pillar, and arrange two grouting boreholes in the goaf of the adjacent working face;

[0013] S6. Dig the next layered coal transportation tunnel and return air tunnel according to the comprehensive mechanized coal mining tunnel layout mode, and open a cut when the coal transportation tunnel and return air tunnel reach the boundary of the working face, and arrange coal mining and support equipment in the cut at the same time;

[0014] S7, the lower layer working face carries out normal mining operation, when advancing through the upper layer section coal pillar connecting lane, the grouting pipeline arranged beside the upper layer section coal pillar starts grouting from the grouting boreholes in the upper layer connecting lane and the working face goaf to form a filling body;

[0015] S8. Repeat steps S2 to S7 until the water-preserving coal mining operation of the entire extra-thick coal seam working face is completed.

[0016] Furthermore, in the above-mentioned coal pillar filling and water-preserving coal mining method in the stratified mining section of the extra-thick coal seam working face, the coal pillar in the upper stratified section should be designed to be located in the middle position in the inclination direction of the lower stratified working face.

[0017] Furthermore, in the above-mentioned method for coal mining with coal pillar filling and water conservation in the stratified mining section of the extra-thick coal seam working face, the advancement direction of the lower stratified working face is consistent with the length direction of the coal pillar in the upper stratified section.

[0018] Furthermore, in the above-mentioned method for coal pillar filling and water-preserving coal mining in the stratified mining section of the working face of the extra-thick coal seam, the spacing D between the grouting boreholes in the upper stratified connecting tunnel and the working face goaf is 10 to 20 m.

[0019] Furthermore, in the above-mentioned method for coal pillar filling and water-preserving coal mining in the stratified mining section of the extra-thick coal seam working face, the specific value of the spacing D is related to the length S of the filling body.

[0020] Furthermore, in the above-mentioned method for coal mining with coal pillar filling and water conservation in the stratified mining section of the working face of the extra-thick coal seam, the height H of the filling body formed after grouting filling is more than 80% of the mining height.

[0021] Furthermore, in the above-mentioned method for coal mining with pillar filling and water conservation in the stratified mining section of the extra-thick coal seam working face, the coal mining equipment includes a coal mining machine and a scraper conveyor, and the support equipment includes a fully mechanized hydraulic support.

[0022] Furthermore, in the above-mentioned method of coal pillar filling and water-preserving coal mining in the stratified mining section of the extra-thick coal seam working face, after adopting the method of coal pillar filling and water-preserving coal mining in the stratified mining section of the extra-thick coal seam working face, the impact of mining will not damage the overlying aquifer with ecological protection or water supply value.

[0023] The beneficial effects of the present invention are:

[0024] The present invention provides a method for water-preserving coal mining with coal pillar filling in the stratified mining section of an extra-thick coal seam working face, which can provide a new idea for water-preserving mining of extra-thick coal seams. The method can effectively protect the surface ecological water level and aquifers with water supply value. The method is safe and reliable, highly innovative, and has obvious effects. It is highly economical and practical, and has broad application prospects.

[0025] Of course, any product implementing the present invention does not necessarily need to achieve all of the above advantages at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0027] Figure 1 is a front view of the mining structure of the present invention;

[0028] Figure 2 is a top view of the mining structure of the present invention;

[0029] Figure 3 It is a partial enlarged diagram of the principle of the method of the present invention;

[0030] Figure 4 It is a numerical simulation curve of the water-conducting fracture zone height development law of the present invention;

[0031] In the accompanying drawings, the reference numerals of the various components are as follows:

[0032] 1-topsoil layer; 2-aquifer; 3-grouting borehole; 4-filling body; 5-upper layer section coal pillar; 6-grouting pipeline. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The present invention provides a method for coal mining by filling coal pillars and retaining water in a stratified mining section of an extra-thick coal seam working face, comprising the following steps:

[0035] S1. For extremely thick coal seams, the downward mining method is adopted;

[0036] S2. Dig the upper layer coal transportation tunnel and return air tunnel in accordance with the comprehensive mechanized coal mining tunnel layout. Open a cut when the coal transportation tunnel and return air tunnel reach the boundary of the working face. Arrange coal mining and support equipment in the cut at the same time. Coal mining equipment includes coal mining machines and scraper conveyors, and support equipment includes fully mechanized hydraulic supports.

[0037] S3, leaving a section coal pillar 5 between adjacent working faces;

[0038] S4, arranging the grouting pipeline 6 on the roadway floor near the section coal pillar 5;

[0039] S5, arrange a grouting borehole 3 in the connecting lane of the section coal pillar 5, and arrange two grouting boreholes 3 in the goaf of the adjacent working face;

[0040] S6. Dig the next layered coal transportation tunnel and return air tunnel according to the comprehensive mechanized coal mining tunnel layout, and open a cut when the coal transportation tunnel and return air tunnel reach the boundary of the working face. Arrange coal mining and support equipment in the cut at the same time; coal mining equipment includes coal mining machines and scraper conveyors, and support equipment includes comprehensive mining hydraulic supports.

[0041] S7, the lower layer working face performs normal mining operation. When advancing through the upper layer section coal pillar 5 connecting lane, the grouting pipeline 6 arranged beside the upper layer section coal pillar 5 starts grouting from the upper layer connecting lane and the grouting borehole 3 in the goaf of the working face to form a filling body 4;

[0042] S8. Repeat steps S2 to S7 until the water-preserving coal mining operation of the entire extra-thick coal seam working face is completed.

[0043] In the present invention, the upper layer section coal pillar 5 should be designed to be located in the middle of the inclined direction of the lower layer working face. The advancing direction of the lower layer working face is consistent with the length direction of the upper layer section coal pillar 5.

[0044] In the present invention, the spacing D between the upper layer connection tunnel and the grouting boreholes 3 in the working face goaf is 10 to 20 m. The specific value of the spacing D is related to the length S of the filling body.

[0045] In the present invention, the height H of the filling body formed after grouting filling is more than 80% of the mining height.

[0046] In the present invention, after adopting the coal pillar filling and water-preserving coal mining method in the stratified mining section of the extra-thick coal seam working face, the mining impact does not damage the overlying aquifer 2 with ecological protection or water supply value.

[0047] The relevant specific embodiments of the present invention are:

[0048] Embodiment 1

[0049] The designed production capacity of a mine in a certain mining area is 5.00Mt / a, and the main coal seam is 3# coal. The coal seam is buried at a depth of 150m, and the average thickness of the 3# coal seam is 9m. The surface aquifer overlying the coal seam is highly water-rich. Considering the requirements for surface vegetation and ecological environment protection, as well as reducing the amount of water inflow and potential disasters of water inrush during mining at the working face, water-saving coal mining operations need to be carried out. Combined with the coal pillar filling water-saving coal mining method for the stratified mining section of the working face of a particularly thick coal seam of the present invention, the specific steps are described as follows:

[0050] 1) According to the layout of comprehensive mechanized coal mining tunnels, the upper layer coal transportation tunnels and return air tunnels are excavated. When the coal transportation tunnels and return air tunnels are excavated to the boundary of the working face, a cut is made. The main coal mining and support equipment such as coal mining machines, scraper conveyors and fully mechanized hydraulic supports are arranged in the cut. The designed working face length L is 200m, the mining height is 3m, and mining is divided into 3 layers;

[0051] 2) A section coal pillar 5 is reserved between adjacent working faces in the upper layer, and the width W of the section coal pillar 5 is designed to be 20m. The grouting pipeline 6 is arranged on the ground close to the section coal pillar 5; a grouting borehole 3 is arranged in the connecting lane of the section coal pillar 5, and two grouting boreholes 3 are arranged in each adjacent working face. The spacing D of the grouting boreholes 3 is designed to be 15m, and the length of the filling body is designed to be 90m;

[0052] 3) Dig the next layered coal transportation roadway and return air roadway according to the comprehensive mechanized coal mining roadway layout mode, and open a cut when the coal transportation roadway and return air roadway are dug to the boundary of the working face. Arrange the main coal mining and support equipment such as coal mining machine, scraper conveyor and fully mechanized hydraulic support in the cut at the same time. The section coal pillar 5 between the upper layer fully mechanized mining working faces is arranged in the middle position of the lower layer fully mechanized mining working face;

[0053] 4) The lower layer working face carries out normal mining operation. When advancing through the connecting tunnel of the coal pillar 5 in the upper layer section, the grouting pipeline 6 arranged beside the coal pillar 5 in the upper layer section starts to grout from the grouting borehole 3 in the connecting tunnel and the working face to form a gangue, fly ash, and cement cementing filling body 4. According to the numerical simulation analysis results of the height development law of the water-conducting fracture zone, as shown in Figure 4 As shown; the height H of the filling body 4 is designed to be 2.7m;

[0054] 5) Repeat the above steps to complete the water-preserving coal mining operation of the entire extra-thick coal seam working face.

[0055] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for coal mining with coal pillar filling and water conservation in the stratified mining section of an extra-thick coal seam working face, characterized in that: The following steps are involved: S1. For extremely thick coal seams, the downward mining method is adopted; S2. Dig the upper layer coal transportation tunnel and return air tunnel according to the comprehensive mechanized coal mining tunnel layout mode, open the cut when the coal transportation tunnel and return air tunnel reach the boundary of the working face, and arrange coal mining and support equipment in the cut at the same time; S3. A section coal pillar (5) is left between adjacent working faces. The upper section coal pillar (5) should be designed to be located in the middle of the inclination direction of the lower section working face. The advancing direction of the lower section working face is consistent with the length direction of the upper section coal pillar (5). S4, arranging the grouting pipeline (6) on the roadway floor near the section coal pillar (5); S5, arranging a grouting borehole (3) in the connecting lane of the section coal pillar (5), and arranging two grouting boreholes (3) in the goaf of adjacent working faces; S6. Dig the next layered coal transportation tunnel and return air tunnel according to the comprehensive mechanized coal mining tunnel layout mode, and open a cut when the coal transportation tunnel and return air tunnel reach the boundary of the working face, and arrange coal mining and support equipment in the cut at the same time; S7, the lower layer working face performs normal mining operations. When advancing through the connecting lane of the coal pillar (5) of the upper layer section, the grouting pipeline (6) arranged beside the coal pillar (5) of the upper layer section starts grouting from the grouting boreholes (3) in the upper layer connecting lane and the working face goaf to form a filling body (4); S8. Repeat steps S2 to S7 until the water-preserving coal mining operation of the entire extra-thick coal seam working face is completed.

2. The method for coal mining with coal pillar filling and water conservation in the stratified mining section of the extra-thick coal seam working face according to claim 1 is characterized by: The spacing D between the grouting boreholes (3) in the upper layer connection tunnel and the goaf of the working face is 10 to 20 m.

3. The method for coal mining with coal pillar filling and water conservation in the stratified mining section of the extra-thick coal seam working face according to claim 2 is characterized by: The specific value of the spacing D is related to the length S of the filling body.

4. The method for coal mining with coal pillar filling and water conservation in the stratified mining section of the extra-thick coal seam working face according to claim 1 is characterized by: The height H of the filling body formed after grouting is more than 80% of the mining height.

5. The method for coal mining with coal pillar filling and water conservation in the stratified mining section of the extra-thick coal seam working face according to claim 1 is characterized by: Coal mining equipment includes coal mining machines and scraper conveyors, and support equipment includes fully mechanized hydraulic supports.

6. The method for coal mining with coal pillar filling and water conservation in the stratified mining section of the extra-thick coal seam working face according to claim 1 is characterized by: When the coal pillar filling and water-preserving mining method is adopted in the stratified mining section of the extra-thick coal seam working face, the mining impact does not damage the overlying aquifer with ecological protection or water supply value (2).

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