A method for filling high-position waste rock in the collapse zone of a longwall working face

Abstract

The present invention discloses a method for filling high-position gangue in the collapse zone of a longwall working face. The present invention sets a directional drilling site on the ground, and on the basis of determining the height of the collapse zone of the coal seam in the mining area, uses a directional drilling machine to construct a horizontal branch filling borehole from the surface to the high position of the collapse zone, and fills the high-position filling space of the collapse zone of the longwall working face. The present invention can effectively solve the problem of time and space interference between the filling and mining of the collapse zone of the longwall working face, and fills from top to bottom, fully reinforces the accumulation body of the collapse zone, can improve the overall bearing capacity of the collapse zone, and is conducive to the control of surface settlement.

Description

Technical Field

[0001] The invention relates to a coal mine gangue filling technology, in particular to a method for filling high-position gangue in a collapse zone of a longwall working face. Background Art

[0002] Longwall mining is a highly productive, efficient and safe method that is most commonly used in my country. However, it is also associated with shallow water leakage and surface subsidence due to mining disturbance. The filling mining method that inputs filling materials into the post-mining voids and pores can effectively hinder and control surface subsidence, and effectively dispose of the gangue in the mining area, which has significant social, environmental and development benefits. Analyzing from the gangue filling layer, the current low-level collapse zone in my country has failed to effectively solve the on-site problems such as the temporal and spatial interference between filling and mining operations, the high technical requirements for dehydration and flow blocking of the working face, and the insufficient reinforcement of the collapse zone. In addition, the separation zone grouting filling technology and the post-mining goaf grouting technology have alleviated the coordination problems of mine mining and filling processes to a certain extent, but they are faced with the problems of small grouting space, difficult to determine the grouting layer and delayed control of surface subsidence. Therefore, it is imperative to develop a grouting technology that can carry out mining and filling in parallel without interfering with each other, inject grout in time, and directly control the collapse zone, so as to break the existing filling process with poor adaptability, high cost and low output. Summary of the invention

[0003] In view of the shortcomings of the existing collapse zone filling technology, the purpose of the present invention is to provide a method for filling high-position gangue in the collapse zone of a longwall working face, so as to achieve efficient collapse zone filling while carrying out mining operations on the working face, and improve the collapse zone filling technology system of the longwall working face.

[0004] To achieve the above object, a method for filling high-position gangue in a collapse zone of a longwall working face of the present invention comprises the following steps:

[0005] S1: Use ground directional drilling technology to construct the main hole and secondary inclined hole within the mining area, and leave a feeding hole connected to the main hole on the ground;

[0006] S2: Directional drilling horizontal boreholes are constructed in the high-level filling layer, and then filling flower pipes are arranged in the horizontal boreholes;

[0007] S3: The working face is mined. Before the direct roof reaches the limit span, the primary high-position filling space is formed. Through the feeding hole set on the ground, the gangue filling material is injected into the primary high-position filling space through the directional drilling main hole, the secondary inclined hole, and the horizontal drilling hole in turn to fill the primary high-position filling space;

[0008] S4: The working face continues to advance forward, and the unbroken basic roof above the high-level filling body bends and sinks, gradually compacting the high-level filling body. The filling flower pipe is cut off under the action of its own weight and mine pressure. Before the basic roof above the collapse zone reaches the limit span, a periodic high-level filling space is formed, and waste rock filling materials are injected into the periodic high-level filling space to enrich the periodic high-level filling space. The parallel operation of backfilling and collapse zone high-level filling is continuously carried out until the mining line is stopped to complete the high-level filling work of this working face.

[0009] Furthermore, before step S1, the method further includes the following steps: high-level filling suitability determination, including: the height H2 of the unbroken basic top and the height H 1 The difference H 3 The following formula must be satisfied:

[0010] ,

[0011] In the above formula, H 1 Using formula

[0012] ,

[0013] The coal seam mining thickness is M, the drilling radius is R 1 , the direct top expansion coefficient K p , by collecting the volume V i The complete direct top rock is then crushed and the volume V of the accumulation formed after the surrounding rock is crushed is tested by the sand filling method. ii , determine the surrounding rock expansion coefficient K p =V ii / V i .

[0014] Furthermore, before step S1, the method further includes the step of determining basic parameters for high-level filling, including:

[0015] Height of high filling layer H c Satisfy the following formula:

[0016] ,

[0017] Among them, R 1 is the drilling radius, the value is determined by the directional drilling rig equipment;

[0018] The high filling width of the collapsed zone and the filling width of the collapsed zone W 1 The ratio of the working face inclination distance W 2 Decision, namely:

[0019] ,

[0020] Height of high filling body H gSatisfy the following formula:

[0021] .

[0022] Further, in step S2, if the mining area strike length L a <Inclination length L b When the horizontal drilling is carried out, the horizontal drilling holes are arranged in a dip direction; otherwise, the horizontal drilling holes are arranged along the layers.

[0023] Furthermore, in step S2, the spacing L between the horizontal holes is z , the criteria are as follows:

[0024] Expansion of waste rock filling material d k At 350mm~450mm, the horizontal branch hole spacing L z 60m~70m;

[0025] Expansion of waste rock filling material d k At 250mm~350mm, the horizontal branch hole spacing L z 50m~60m;

[0026] Expansion of waste rock filling material d k In the range of 150mm~250mm, the horizontal branch hole spacing L z It is 40m~50m.

[0027] Furthermore, after step S4, the method further includes the step of: repeatedly executing step S4 until the mining of the mining area and the high-position filling operation of the caving zone are completed.

[0028] In summary, the method for filling high-position gangue in the collapse zone of a longwall working face described in the present invention has the following advantages:

[0029] 1. It has innovated a new green mining mode of longwall working face mining-backfilling parallel operation. This method does not require the use of special backfilling supports. Mining and backfilling are carried out in parallel without interfering with each other, which is conducive to improving the production and backfilling efficiency of the mine;

[0030] 2. This method has clear filling layers. Through the ground directional drilling technology, the filling arrangement of the mining area of ​​"one well with multiple surfaces" is realized, which can save drilling volume and is conducive to filling cost control;

[0031] 3. This method can fully cement the broken rocks in the collapse zone from top to bottom, improve the bearing capacity of the broken rocks in the collapse zone, fully connect the direct top rock layer, inhibit the development height of the water-conducting fracture zone and reduce ground subsidence, which is conducive to green mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the high-position filling process plane of the collapsed zone of the long wall working face of the present invention;

[0033] Figure 2 This is a cross-sectional view of the high-level filling trend of the lower long wall working face collapse zone formed by the initial high-level filling space of the present invention;

[0034] Figure 3 It is a cross-sectional view of the high-position filling trend of the lower longwall working face collapse zone formed by the periodic high-position filling space of the present invention;

[0035] Figure 4 This is a cross-sectional view of the inclined direction of the high-position filling of the lower long wall working face collapse zone formed by the initial high-position filling space of the present invention;

[0036] Figure 5 It is a cross-sectional view in the inclined direction of the high-position filling of the collapse zone of the lower long wall working face formed by the periodic high-position filling space of the present invention.

[0037] In the figure: 1-ground filling pump station; 2-directional drilling vertical drilling; 3-directional drilling inclined section; 4-directional drilling horizontal branch drilling; 5-collapse zone; 6-direct top; 7-basic top; 8-high-position filling body; 9-hydraulic support; 10-coal mining machine; 11-working face advancement direction; 12-stop mining line. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution, implementation steps and advantages of the present invention clearer, the implementation methods and steps of the present invention are further described in detail below with reference to the accompanying drawings and implementation cases.

[0039] See also Figure 1-5 The embodiment of the present invention provides a method for filling high-position gangue in the collapse zone of a longwall working face, and the specific steps are as follows:

[0040] Step 1: Combine the coal seam mining thickness M and basic top height H of the production mine 2 , direct top rock expansion coefficient K p , to judge the applicability of the high-position filling method in the collapsed zone.

[0041] Height of high filling space H 3 Use the unbroken basic top height H 2 , the height of the collapse zone H 1 , Directional drilling horizontal drilling radius R 1 Parameters to judge:

[0042] ,

[0043] In the above formula, H 1 Using formula

[0044] ,

[0045] The direct top expansion coefficient Kp , the collection volume is V i The complete direct top rock is then crushed and the volume V of the accumulation formed after the surrounding rock is crushed is tested by the sand filling method. ii , determine the surrounding rock expansion coefficient K p =V ii / V i .

[0046] Step 2: Combine the strike length L of the mining area a , inclined length L b Layout parameters to determine the layout of high-position filling drilling holes.

[0047] If the strike length of the mining area is L a <Inclination length L b When the horizontal drilling is in the direction of the seam, the horizontal drilling is arranged in the direction of the seam. Otherwise, the horizontal drilling is arranged along the seam. a ≥Inclination length L b When the backfill drilling is adopted, the strike arrangement is adopted; otherwise, the backfill drilling is adopted in the layer-by-layer arrangement.

[0048] Step 3: Determine the high-level filling process parameters, including the high-level filling layer Hc, high-level filling width W1, high-level filling body height H g method of determination.

[0049] Combined with the height of the collapse zone H 1 , the height of the high-level filling space H 3 , Directional drilling horizontal drilling radius R 1 , the layer height of high filling H c Satisfy the following formula:

[0050] ,

[0051] High filling width of collapsed zone: Filling width of collapsed zone W 1 The distance W from the working surface 2 Decision, namely:

[0052] ,

[0053] The height Hg of the high-position filling body satisfies the following formula:

[0054] ,

[0055] Step 4: Determine the spacing of directional drilling horizontal holes based on the expansion of the waste rock filling material.

[0056] Using concrete Expansion meter, to measure the expansion of gangue filling material k Laboratory k Measurement work, based on numerical modeling The surface settlement law under different filling material widths was determined by simulation method, and then the The method for determining the horizontal branch hole spacing Lz is as follows:

[0057] Expansion of waste rock filling material d k At 350mm~450mm, the horizontal branch hole spacing L z 60m~70m;

[0058] Expansion of gangue filling material d k At 250mm~350mm, the horizontal branch hole spacing L z 50m~60m;

[0059] Expansion of waste rock filling material d k In the range of 150mm~250mm, the horizontal branch hole spacing L z 40m~50m;

[0060] Furthermore, the ground directional drilling technology is used to construct the main hole and secondary inclined hole within the mining area, the directional drilling horizontal borehole is constructed in the high-level filling layer, and the filling flower pipe is arranged in the horizontal borehole.

[0061] Step 4: Determine the implementation method for parallel operations of high-level filling and working face mining.

[0062] After the working face is arranged and the cut-eye is completed, the mining operation begins. Before the direct roof reaches the limit span, the initial high-position filling space is formed, and the gangue filling material is injected into the initial high-position filling space, and the initial high-position filling space is filled;

[0063] As the working face continues to advance, the unbroken basic roof above the high-level filling body bends and sinks, gradually compacting the high-level filling body. The filling flower pipe is cut off under the action of its own weight and the mine pressure. Before the basic roof above the collapse zone reaches the limit span, a periodic high-level filling space is formed, and waste rock filling materials are injected into the periodic high-level filling space, so that the periodic high-level filling space is filled;

[0064] Continuously carry out the parallel operation of mining and high-position filling in the collapsed zone until the mining stop line is reached, and the filling work of this working face is completed; continuously carry out the operation of mining and high-position filling until mining is carried out to the mining stop line, and the high-position filling operation of this working face is completed.

[0065] When the next working face is mined, repeat step 4 until the mining of this mining area is completed.

[0066] A method for filling high-position gangue in the collapsed zone of a longwall working face of the present invention is provided with reference to an embodiment of a specific mine: the main mining area is the upper coal seam 3, with an average thickness of 2m and a dip angle of 0°. The immediate roof is muddy sandstone, the basic roof lithology is medium-grained sandstone, the height is 15m, the strike length of a mining area is 2200m, the dip length is 1355m, there are 6 working faces in total, the working faces are arranged in a strike manner, the strike length is 2000m, the dip length is 200m, the width of the return air chute and the transport chute are 5m respectively, and the radius of the horizontal drilling hole of the directional drill is 54mm.

[0067] The specific steps include:

[0068] Step 1: According to the basic roof height, coal seam mining thickness, and direct roof expansion coefficient, the applicability of the high-position filling method in the collapsed zone is judged through theoretical formulas.

[0069] Collect rock samples from the collapsed zone of the mine where the working face is to be arranged, put them into the crusher to crush them, and naturally pile the broken rocks in a measuring cylinder with a diameter of 0.5m and a height of 1m. When the measuring cylinder is full of broken rocks, slowly pour in fine sand with a particle size of ≤0.2mm. After the broken rocks are completely immersed in the sand, record the volume of the sand in the measuring cylinder (0.18m 3 Finally, the broken rock and sand in the measuring cylinder are separated, and the broken rock expansion coefficient is 1.2.

[0070] The basic top height is 15m, the direct top rock type is muddy sandstone, the indoor test shows that the expansion coefficient is 1.2, the high position of the caving zone is 12, and the radius of the directional drilling is 54mm. Therefore, according to the judgment formula, high-position filling is feasible, and the high-position filling layer is 14m.

[0071] The second step is to design the process parameters for high-position filling. The strike length of the mining area is greater than the inclined length, so the directional drilling adopts a strike arrangement.

[0072] The third step is to use the above-mentioned high-position filling design parameters and the expansion of the gangue filling material to be 400 mm, so the spacing of the horizontal directional drilling holes is 60 m.

[0073] The fourth step is to construct high-level filling directional drilling based on the construction high-level filling parameters. During the drilling process, if the flushing fluid leaks and no grouting occurs, the drilling is stopped and grouting is performed. When the cracks are blocked and no more grouting occurs, the drilling of the hole is continued, and the operation of "drilling → grouting when the flushing fluid leaks → continue drilling after the cracks are blocked" is repeated during the drilling process. The grouting plugging material is a mixture of cement slurry and cement mortar, cement-water glass slurry, and acrylic slurry, with a ratio of 1:1.

[0074] The fifth step is to implement mining and high-level filling operations in the collapsed zone in the first mining area.

[0075] After the first mining face of the first mining area is arranged and cut, the mining operation begins. Before the direct roof reaches the limit span, the initial high-level filling space is formed, and the gangue filling material is injected into the initial high-level filling space, and the initial high-level filling space is filled;

[0076] As the working face continues to advance, the unbroken basic roof above the high-level filling body bends and sinks, gradually compacting the high-level filling body. The filling flower pipe is cut off under the action of its own weight and the mine pressure. Before the basic roof above the collapse zone reaches the limit span, a periodic high-level filling space is formed, and waste rock filling materials are injected into the periodic high-level filling space, so that the periodic high-level filling space is filled;

[0077] Continue to carry out the mining-high-level filling operation until the mining line is stopped, that is, the mining and high-level filling operation of the first mining face is completed. According to the working face mining plan, repeat the mining-high-level filling steps of the first mining face until the remaining working faces in this mining area are completed and the mining and high-level filling operation is completed.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for filling high-position gangue in the collapse zone of a longwall working face, characterized in that: The following steps are included: S1: Use ground directional drilling technology to construct the main hole and secondary inclined hole within the mining area, and leave a feeding hole connected to the main hole on the ground; S2: Directional drilling horizontal boreholes are constructed in the high-level filling layer, and then filling flower pipes are arranged in the horizontal boreholes; S3: The working face is mined. Before the direct roof reaches the limit span, the primary high-position filling space is formed. Through the feeding hole set on the ground, the gangue filling material is injected into the primary high-position filling space through the directional drilling main hole, the secondary inclined hole, and the horizontal drilling hole in turn to fill the primary high-position filling space; S4: The working face continues to advance forward, and the unbroken basic roof above the high-level filling body bends and sinks, gradually compacting the high-level filling body. The filling flower pipe is cut off under the action of its own weight and mine pressure. Before the basic roof above the collapse zone reaches the limit span, a periodic high-level filling space is formed, and waste rock filling materials are injected into the periodic high-level filling space to enrich the periodic high-level filling space. The parallel operation of backfilling and collapse zone high-level filling is continuously carried out until the mining line is stopped to complete the high-level filling work of this working face.

2. A method for filling high-position waste rock in a longwall working face collapse zone according to claim 1, characterized in that: Before step S1, the method further includes the step of judging the suitability of high-position filling, including: the difference H3 between the height H2 of the unbroken basic top and the height H1 of the collapse zone must satisfy the following formula: ， In the above formula, H1 adopts the formula ， The coal seam mining thickness M, the drilling radius R1, and the direct top expansion coefficient K p , by collecting the volume V i The complete direct top rock is then crushed and the volume V of the accumulation formed after the surrounding rock is crushed is tested by the sand filling method. ii , determine the surrounding rock expansion coefficient K p =V ii / V i .

3. A method for filling high-position waste rock in a longwall working face collapse zone according to claim 2, characterized in that: Before step S1, the method further includes the step of determining basic parameters for high-level filling, including: Height of high filling layer H c Satisfy the following formula: ， Where R1 is the drilling radius, and its value is determined by the directional drilling rig equipment; The ratio of the high filling width of the collapse zone to the filling width W1 of the collapse zone is determined by the working face inclination distance W2, that is: ， Height of high filling body H g Satisfy the following formula: 。 4. A method for filling high-position waste rock in a longwall working face collapse zone according to claim 1, characterized in that: In step S2, if the mining area strike length L a <Inclination length L b When the horizontal drilling is carried out, the horizontal drilling holes are arranged in a dip direction; otherwise, the horizontal drilling holes are arranged along the layers.

5. The method for filling high-position waste rock in the collapse zone of a longwall working face according to claim 1 is characterized in that: In step S2, the spacing L between the horizontal holes is z , the criteria are as follows: Expansion of waste rock filling material d k At 350mm~450mm, the horizontal branch hole spacing L z 60m~70m; Expansion of waste rock filling material d k At 250mm~350mm, the horizontal branch hole spacing L z 50m~60m; Expansion of waste rock filling material d k In the range of 150mm~250mm, the horizontal branch hole spacing L z It is 40m~50m.

6. A method for filling high-position waste rock in a longwall working face collapse zone according to claim 1, characterized in that: After step S4, the method further includes the step of: repeatedly executing step S4 until the mining of the mining area and the high-position filling operation of the caving zone are completed.

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