WO2013102309A1

WO2013102309A1 - Longwall working face, non-pillared mining method

Info

Publication number: WO2013102309A1
Application number: PCT/CN2012/070109
Authority: WO
Inventors: 何满潮; 张国锋; 孙晓明; 杨晓杰
Original assignee: He Manchao; Zhang Guofeng; Sun Xiaoming; Yang Xiaojie
Priority date: 2012-01-06
Filing date: 2012-01-06
Publication date: 2013-07-11
Also published as: PL2801697T3; EP2801697A1; EP2801697B1; EP2801697A4

Abstract

Disclosed is a longwall working face, non-pillared mining method, comprising the following steps: 1. Excavating a headentry (2) and a tailentry (3); 2. Reinforcing a top panel (5) of the headentry (3) and drilling on the top panel an energy collecting hole (7) for pre-splitting blasting; 3. Extracting until a goaf is formed; 4. Blasting at a position corresponding to the energy collecting hole and forming a kerf on the top panel; 5. The mining face collapsing to become a new tunnel; 6. Taking the original tailentry as the headentry of the next mining face, and excavating a tailentry relative to the headentry, to form a new mining face; and 7. Repeating steps 2-6, and continuing to mine coal until the coal seam mining is completed. The present method involves continuity between every two mining faces, non-pillared support, a short process for forming roadways, and high efficiency of mining and forming roadways.

Description

Long-wall working face without coal pillar opening method

The invention relates to a method for mining coal seams, in particular to a coal seam mining method for longwall working faces. Background technique

With the increase of coal mining depth, longwall mining usually uses the method of leaving coal pillars to protect the upper channel. When the roadway is deep, the width of the retained coal pillars increases due to the rapid increase of ground stress. Traditional longwall mining work In the deep mining process, there is a large amount of roadway engineering, high mining efficiency, low production efficiency, serious waste of resources, and gas outburst caused by leaving coal pillars, frequent impact pressure, Safety hazards such as air leakage in goaf have become major problems that have plagued and affected coal mine safety and efficient mining.

At present, the research on coal-free pillar mining in major coal mining countries at home and abroad mainly focuses on two aspects: roadway along the goaf and roadway along the goaf. The roadway along the empty road is completed after the mining of the previous working face, and the roof of the stope is fully collapsed. The meteorite is squeezed and compacted, and the overburden rock pressure appears to stop. After the surrounding rock is stabilized, it forms in the goaf and the coal body. A pressure relief belt, re-drilling a new roadway in the pressure relief belt. The roadway along the empty road must be completed in the upper section of the working face. The roof of the stope can be completed and compacted before the road can be excavated. Therefore, it takes a long time to make the production success of many mines in China very difficult. .

The retaining lane along the empty space is to use the relevant technology to retain the lower chute in the working face during the mining process of the working face, as the upper trough of the next working face. In the current roadway retaining technology, the inner support has developed wooden sheds, I-steel sheds, shrinkable brackets, anchor nets, etc. The roadside support has developed rafts, dense pillars, gangue belts, and concrete blocks. , paste filling and high water material filling technology. Although some achievements have been made, there are still many shortcomings and problems: Neglecting the supporting role of the coal body in the lane, the application of the active support technology in the lane is less, the roadside support and the surrounding rock deformation are not coordinated, and the support design is not systematic. Summary of the invention

SUMMARY OF THE INVENTION The object of the present invention is to improve the deficiencies of the background art and to provide a coal pillarless mining method for a longwall working face which is reliable in support, high in mining efficiency, and which does not require a coal pillar.

In order to achieve the above object of the present invention, the present invention adopts the following technical solutions: A method for mining a longwall working face without coal pillars, comprising the following steps:

(1) Excavating two roadways connected in the coal seam as the upper and lower channel roadway of the first mining face; (2) reinforcing the roof of the lower channel, and drilling a plurality of collecting holes for pre-cracking on the side of the working face of the lower channel;

(3) Carry out the mining until the formation of the goaf, and the lane disappears;

(4) blasting at the corresponding gathering hole position of the top plate at the position of the goaf in the goaf, and forming an directional slit extending along the entire original grooved roadway on the side of the top plate near the mining face;

(5) The pressure from the deep rock formation in the upper part of the goaf causes the roof of the mining face to sag and sink, and the original downhole roadway position is re-established as a roadway;

(6) The roadway automatically formed by the position of the original channel is used as the upper channel of the next mining face, and the lower channel of the upper channel is excavated to form a new mining face;

(7) Repeat the steps (2) - (6) to continuously mine the coal until the coal seam is mined.

In order to further achieve the above object of the present invention, the step (2) further includes the steps of: installing a sensor on the top plate of the lower channel, and transmitting it to the ground by wire, and performing remote real-time monitoring on the state of the lower channel. In the step (2), the constant resistance large deformation anchor is used to reinforce the roof of the roadway as the lower channel. In the step (4), the directional slitting is performed by the two-way energy pre-splitting blasting method. In the steps (1) and (6), it is also necessary to perform a leakproof fireproof treatment on the roadway. The sensor in the step (2) includes a top plate isolating device and a bolt force measuring device.

Compared with the prior art, the present invention has the following outstanding substantive features and significant progress: in the present invention, a collecting hole for pre-cracking blasting is drilled on the top plate on the side of the working face of the lower channel, and is correspondingly aggregated. The position of the hole can be blasted, and a slit extending along the direction of the original down channel is formed on the side of the top plate near the mining face, and the goaf is fell along the slit, so that the position of the original down channel is automatically formed into a lane, and the The roof of the roadway will not be affected by the fall of the goaf, and it can maintain a good state. Then the next round of mining will continue with the roadway as the upper channel of the next mining face, and the flow between each two mining faces is continuous. Compared with the prior art, the utility model has the outstanding substantive features; the invention realizes the coal pillarless support, has a high mining rate, and does not need to wait for a long time in the lane forming process, and reduces the continuousness under the premise of safety. The time to mine the coal seams is a significant improvement over the prior art. DRAWINGS

1 is a top plan view of a mining face structure in a coal pillarless mining method for a longwall working face according to the present invention.

2 is a front view showing the structure of a mining face in a coal pillarless mining method for a longwall working face according to the present invention.

FIG. 3 is a schematic view showing the reinforcement and drilling structure of the first mining face in the longwall working face without coal pillar mining method according to the present invention. 4 is a schematic view showing the structure of a goaf formed in the first mining face in the longwall working face non-coal mining method of the present invention. FIG. 5 is a schematic view showing a collapsed structure of a goaf in a longwall working face without coal pillar mining method according to the present invention.

FIG. 6 is a schematic view showing the structure of a constant resistance large deformation anchor rod in a longwall working face non-core pillar mining method according to the present invention.

DESCRIPTION OF REFERENCE NUMERALS: 1-first mining face, 2-upper grooved roadway, 3-lower grooved roadway, 4-recovery face, 5-top plate, 6-constant resistance large deformation anchor, 7-concentration hole, 61 - nut, 62-ball pad, 63-tray, 64-constant resistance device, 65-connecting sleeve, 66-rod body

The specific structural details and installation and use process of a floating pipe floating body of the present invention will be described in detail below with reference to the accompanying drawings. The coal-free column mining method used in the present invention first needs to form the first mining face. As shown in Fig. 1 and Fig. 2, the method of forming the first mining face 1 is the same as the existing method, and the first mining position is established on the edge of the coal seam mining, where two parallel roadways are excavated by the S100A type final machine. 2, 3, two parallel roadways 2, 3 are connected at the tail through the roadway 4. The roadway 2 near the edge is the upper channel, and the roadway 3 near the continuous mining face is the lower channel, and the roadway connecting the upper channel 2 and the lower channel 3 is the recovery face 4 . Each mining face must form two roadways. The upper channel is used for material transportation roadway, and the lower channel is used for return air. In actual mining, mining is carried out from the recovery face 4 until all the coal in the area between the smoothing roadway 2 and the lower smoothing roadway 3 is mined, and then mining of the next mining face is carried out.

Then, as shown in Fig. 3, the lower channel 3 of the first mining face 1 is supported. The support includes passive support and active support. The passive support is placed in the lower channel 3 to passively withstand the force of the lower roof of the lower channel 3, which is high in cost and high in cost. The support effect is limited. The active support is to install a bolt on the top plate 5 of the lower channel, to reinforce the top plate 5. The anchor rod 6 is generally 5-10 meters in length, and is connected to the upper and lower channel by connecting the upper layer of relatively stable rock layers. 3's top plate 5. The conventional anchor has a small amount of deformation and is easily broken. In the present invention, a constant-resistance large-deformation anchor is used for reinforcement. The patent of the publication No. CN101858225B has disclosed the constant-resistance large-deformation anchor in detail. The constant resistance large deformation anchor 6 is evenly distributed on the top plate 5 of the lower channel 3 of the first mining face 1, and the spacing is set at 2-5 meters as needed.

As shown in Fig. 6, the constant-resistance large-deformation anchor 6 is a bolt designed specifically for large-deformation roadways and high-stress roadways, which can maintain a constant resistance and maintain an extension by a mechanical sliding device. The constant resistance large deformation anchor 6 includes a nut 61, a ball pad 62, a tray 63, a constant resistance device 64, a connecting sleeve 65 and a rod body 66. The constant resistance device 64 has a cylindrical structure, is fitted to the tail portion of the rod body 66, the tray 63 and the nut. 61 is sequentially placed at the tail of the constant resistance device 64, wherein a middle portion of the tray 63 is provided with a hole for the constant resistance device 64 to pass through, a nut 61 is screwed to the constant resistance device 64, and a buffer ball is mounted between the nut 61 and the tray 63. Pad 62, the connecting sleeve is mounted on the other end of the constant resistance device 64. When the constant resistance large deformation anchor rod 6 is applied to the roadway, when the deformation of the surrounding rock of the roadway can exceed the range that the anchor rod can bear, the constant resistance device 64 and the anchor rod body 66 provided with the thread structure on the joint surface thereof are provided. The relative displacement is generated, that is, the anchor rod 6 exhibits a large deformation in the radial direction as the surrounding rock is largely deformed. After the large deformation of the surrounding rock, its energy is released, and the constant resistance large deformation anchor 6 can maintain a constant working resistance after stretching, and the deformation energy of the surrounding rock is smaller than the constant working resistance of the constant resistance large deformation anchor 6. When the constant resistance device 64 is restored to the original shape and tightly fitted on the rod body 66, the roadway will be in a stable state again, realizing the stability of the roadway and eliminating the safety hazard such as the impact of the roof. The constant resistance large deformation bolt 6 has a bearing capacity of 15~20KN, and the extension can reach 300~600mm. It has a large deformation capacity to adapt to the large deformation capacity of the roadway along the roadway.

In addition, on the top plate 5 on the side of the first mining face 3 which is close to the first mining face 1 on the first mining face, the MQT-120J drilling machine is used to sequentially drill upwardly arranged collecting holes 7 on the top plate 5 to facilitate the passing of the gathering. The hole 7 can be blasted to achieve directional slitting. The gathering holes 7 are spaced 2 to 5 meters apart, which is determined according to the actual rock formation characteristics. At the same time, it is necessary to spray urine aldehyde plastic foam on each roadway 2, 3, 4 to prevent leakage of fire.

In the present invention, the top plate isolating device and the anchor force measuring device are also installed on the top plate 5 of the down channel roadway 3 as the first mining face, and the shape position sensor can also be installed at the corresponding position on the side wall and the bottom surface of the lower channel roadway 3 . The top plate is installed on the top plate 5, and the relative displacement change of the determined near point relative to the determined far point is detected to monitor the falling state of the top plate 5; the anchor force gauge is mounted on the top plate 5 through the anchor rod 6, The pressure of the top surface of the tray 63 of the constant resistance large deformation anchor 6 is detected to monitor the change of the falling pressure of the top plate 5; the shape position sensors are respectively installed on the top plate 5, the bottom surface and the two side walls of the lower channel 3; The shape change of the section of the lower channel is monitored. The signals monitored by the top plate isolators, anchor force gauges and shape position sensors are transmitted to the ground through the line, data is converted on the ground, and the converted data is transmitted remotely through Ethernet or the like. The personnel can remotely monitor and analyze the data to realize remote real-time monitoring of the state of the lower channel.

After the above work is completed, the mining face is gradually extracted until the goaf is formed. As shown in Fig. 4, after the goaf is formed, the side wall of the lower channel of the first mining face 1 disappears, and the goaf is connected to form a piece, and the roadway disappears.

After the first mining face 1 forms a goaf, a two-way energy pre-splitting blasting device is installed on the top plate 5 of the original down channel roadway 3 corresponding to the collecting energy hole, and the blasting lead is connected, and the top plate 5 is blasted and pre-splitted. A pre-cracking surface is formed on the side of the top plate 5 of the original channel 3 adjacent to the gob, and the pre-cracking surface is a slit extending in the direction of the original lower groove 3 on the side of the top plate 5 close to the mining surface, That is, the directional slit is realized on the top plate 5 of the original roadway 3 . The patent number of the two-way energy pre-splitting blasting method is ZL200610113007X, which can realize the pre-cracking effect on the surrounding rock of the roof plate 5, and at the same time protect the roof plate 5 from the blasting damage, easy to use, good blasting effect, cost Low cost and easy to operate. The blasting technology constructs the blasthole on the pre-cracking line, and uses a two-way concentrating device to charge the drug, and the direction of the collecting energy corresponds to the pre-cracking direction of the rock mass. The detonation product will form a concentrated energy flow in two set directions, and generate a concentrated tensile stress, so that the pre-cracking blasthole penetrates in the direction of the collecting energy to form a pre-cracking surface. Since the rock between the boreholes is broken, the unit consumption of the blasting explosives will be greatly reduced. At the same time, due to the protection of the surrounding rock by the energy collecting device, the damage of the rock mass around the drilling hole is greatly reduced, so the technology can achieve the pre-cracking. At the same time, it can protect the purpose of the roof along the empty roadway. The two-way energy collecting device is processed by a pipe (including two kinds of PVC pipe and metal pipe) with a certain strength (uniaxial compressive strength of 1.6 MPa to 2.0 MPa); the diameter of the collecting device varies according to the diameter of the blasthole, The value of the value is determined according to the charge coupling coefficient of the specific rock mass; the shape of the energy collecting hole on the two-way tensile energy collecting device is various, and may be circular, elliptical, square, rectangular, etc., and the parameters are based on lithology and explosives. Determine; the size of the pores of the energy-generating pores on the two-way tensile energy gathering device, the spacing of the holes and the lithology, the rock mass structure and the stress state of the original rock of the construction rock mass, etc., need to establish a corresponding functional relationship, and design according to the relevant calculation results. .

In the goaf, under the influence of the directional slit and the deep stratum pressure above the goaf, the goaf collapses, as shown in Figure 5. Since the top plate 5 of the original roadway under the original mining face has been oriented with a directional slit, the goaf will not take down the top plate 5 of the original roadway under the original first mining face, and the fallen goaf will be down. The pre-cracking side of the channel roadway 3 forms the side gang of the lower channel roadway 3 along the pre-cracking surface (ie, the A area in Fig. 5), and the original position of the roadway 3 is re-established as the roadway. The side of the newly formed upper channel 3 is sprayed with plain concrete to prevent harmful gases such as gas and CO from entering the newly formed upper channel 3, so that the original first face is under The laneway 3 is retained for reuse as the upper channel of the second working face. Similarly, when the third working face is recovered, the lower working channel of the second working face is used as the upper working channel of the third working face by the process of the present invention.

Finally, the roadway 3 automatically formed by the position of the roadway under the original first mining face is used as the upper channel of the next mining face, and the lower channel of the upper channel is excavated, and a new mining face is formed. At the same time, it is necessary to spray urethane foam on each lane to prevent fire leakage.

The above mining steps are repeated to continuously mine the coal until the coal seam is mined. The coal-free column mining of the longwall working face was realized.

In the present invention, a collecting hole 7 for pre-split blasting is drilled on the top plate 5 on the side of the working face of the lower channel 3, and blasting is performed at the position of the corresponding collecting hole, and is formed on the side of the top plate 5 close to the mining face. A slit extending along the direction of the original laneway 3, the goaf is fell along the slit, so that the original lower channel 3 is automatically formed into a lane, and the roof 5 of the lane 3 is not subject to the fall of the goaf. The effect can be maintained in a good state, and then the next round of mining is continued with the roadway 3 as the upper channel of the next mining face. The flow between each two mining faces is continuous, without coal pillar support, which is related to the existing Compared with technology, it has outstanding substantive features. Industrial applicability

The invention realizes the support without coal pillars, has a high mining rate, and does not have to wait for a long time in the process of forming a lane, and reduces the time for continuously mining the coal seam under the premise of safety.

Claims

Rights request

A method for mining a longwall working face without coal pillars, comprising the steps of:

(1) Excavating two roadways connected in the coal seam as the upper and lower channel roadway of the first mining face;

(2) reinforcing the roof of the lower channel, and drilling a plurality of collecting holes for pre-cracking on the side of the working face of the lower channel;

(4) performing blasting at the position of the corresponding collecting hole of the top plate at the position of the gob in the goaf, and forming an directional slit extending along the entire original grooved roadway on the side of the top plate near the mining face;

(5) The pressure from the deep rock formation in the upper part of the goaf causes the roof of the mining face to sag and sink, and the original downhole roadway position becomes a new roadway;

2 . The method according to claim 1 , wherein the step ( 2 ) further comprises the steps of: installing a sensor on the top plate of the lower channel and transmitting the wire to the ground. 2 . , Remote real-time monitoring of the state of the next channel.

The non-coal pillar mining method for a longwall face according to claim 1, wherein in the step (2), the top plate of the roadway as the lower channel is reinforced by a constant resistance large deformation anchor.

The method according to claim 1, wherein the step (4) adopts a two-way energy pre-splitting blasting method to perform directional slitting.

The method according to claim 1, wherein in the step (1) and the step (6), the roadway is subjected to a leakproof fireproof treatment.

The method according to claim 2, wherein the sensor in the step (2) comprises a top plate isolating device and a bolt force measuring device.