AU2019435042A1 - Two-step grouting modified coal mining method under water-preservation for roof aquifer - Google Patents
Two-step grouting modified coal mining method under water-preservation for roof aquifer Download PDFInfo
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- 239000003245 coal Substances 0.000 title claims abstract description 77
- 238000005065 mining Methods 0.000 title claims abstract description 70
- 238000000034 method Methods 0.000 title claims abstract description 34
- 238000004321 preservation Methods 0.000 title claims abstract description 20
- 239000002002 slurry Substances 0.000 claims abstract description 55
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 48
- 238000005553 drilling Methods 0.000 claims abstract description 8
- 230000035699 permeability Effects 0.000 claims abstract description 5
- 238000012986 modification Methods 0.000 claims description 15
- 230000004048 modification Effects 0.000 claims description 15
- 239000007787 solid Substances 0.000 claims description 11
- 239000004568 cement Substances 0.000 claims description 8
- 235000019353 potassium silicate Nutrition 0.000 claims description 7
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 7
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 claims description 4
- 239000000463 material Substances 0.000 abstract description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000004891 communication Methods 0.000 abstract description 2
- 239000004927 clay Substances 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 239000013589 supplement Substances 0.000 description 2
- FGUUSXIOTUKUDN-IBGZPJMESA-N C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 Chemical compound C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 FGUUSXIOTUKUDN-IBGZPJMESA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011440 grout Substances 0.000 description 1
- 239000011268 mixed slurry Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
Classifications
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
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- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
The invention discloses a two-step grouting modified coal mining method under water
preservation for a roof aquifer. A coal seam and an aquifer located above the coal
seam are included. The method includes the following specific implementation steps:
obtaining parameters; calculating to obtain a first space range; arranging a plurality of
first grouting boreholes; injecting a first slurry into a bottom of the aquifer and
normally recovering; calculating using parameters to obtain a second space range into
which a second slurry is injected; drilling a second grouting borehole; then injecting
the second slurry with high strength and low permeability. The beneficial effects are:
the method injects slurries of different materials into the roof aquifer before and after
mining, and on the one hand, it increases a thickness of an aquiclude before mining,
and reduces the disturbance on the roof aquifer caused by coal mining; and on the
other hand, it can also prevent the communication between the aquifer and a goaf
caused by a diversion fissure after mining, thereby realizing mining under water
preservation.
Description
[0001] The invention relates to a coal mining method under water preservation in the field of mining, and in particular to, a two-step grouting modified coal mining method under water preservation for a roof aquifer.
[0002] During mine mining, the overlying stratum moves and deforms to form a water diversion channel, which communicates a roof aquifer to a goaf, resulting in great loss of water resources, and even posing safety hazards to a mining space such as a working face of a coal seam and a roadway. For mines in western China, with scarce water resources and fragile ecological environment, these problems are more serious. How to reduce the disturbance on the roof aquifer caused by coal mining and prevent the aquifer from communicating with the goaf is one of the key problems that must be solved to realize safe and water preservation mining.
[0003] At present, there have been many studies and practices on the treatment methods of aquifers, and good results have been achieved. For example, the water of roof aquifer is evacuated in advance through drilling to reduce the water abundance of the aquifer; and diversion fissures formed by mining are grouted to block the diversion fissures to prevent water inrush.
[0004] However, these methods have the following problems: (1) from the perspective of flood and waterlogging control of mines, evacuating the aquifer can reduce the potential safety hazards of mining, but causes great loss of water resources; (2) currently, grouting into the aquifer is mainly used for floor confined water flood disaster control, and there are few applications for the roof aquifer; (3) most of the previous research is to block the fissure appeared in the roof caused by mining to control roof water disasters, but a large amount of water has been lost already at this case; and (4) the protection for the roof aquifer is mostly achieved by sacrificing the resource recovery rate and recovery efficiency, such as increasing a thickness of left coal pillars, limiting a mining height, and adopting a stowing mining method.
[0005] Hence, in view of the limitation of the existing research, a two-step grouting modified coal mining method under water preservation for a roof aquifer is proposed.
Technical Problem
[0006] The invention is directed to provide a two-step grouting modified coal mining method under water preservation for a roof aquifer, to solve the problems proposed in the related art.
Technical Solution
[0007] To achieve the above objective, the invention provides the following technical solutions.
[0008] Provided is a two-step grouting modified coal mining method under water preservation for a roof aquifer. A coal seam and an aquifer located above the coal seam are included. The method further includes the following steps:
[0009] a. obtaining basic geological parameters and mining technical parameters of a working site, and calculating to obtain a first space range between the aquifer (4) and
an aquiclude (41) that needs to be modified before mining;
[0010] b. in the first space range in step a, arranging a plurality of first grouting boreholes at intervals from a surface to a bottom of the aquifer, wherein the first grouting borehole comprises a vertical borehole, a borehole deflecting section and a horizontal borehole fitting the bottom of the aquifer;
[0011] c. injecting, by a ground grouting pump station, a first slurry with flexibility and water-resisting property into the bottom of the aquifer in step b through the first grouting borehole, such that the aquifer is modified;
[0012] d. after the grouting modification is completed, normally recovering a working face of the coal seam;
[0013] e. after the mining of the working face of the coal seam is completed, calculating according to the parameters in step a to obtain a second space range into which a second slurry is injected; and
[0014] f. drilling a second grouting borehole from the surface to the second space range, and then injecting, by the ground grouting pump station, the second slurry with high strength and low permeability into a new diversion fissure that may be caused by unstable overlying stratum movement after mining in step d through the second grouting borehole and/or the first grouting borehole.
[0015] In an embodiment of the invention: the basic geological parameters and the mining technical parameters in step a include: a distance H between the aquifer and the coal seam, a dip angle a of the coal seam, a mining height m of a working face to be mined, a strike length 1, an incline length ', a stratum movement angle (strike 6, rise P, dip y), and a roof subsidence coefficient q; and further, a space size of the aquifer that needs to be modified is calculated as: along a strike direction of the working face, a thickness d=qmcosa from the bottom of the aquifer, a length L=l+2Hcot6, and along an incline direction of the working face, a length B=l'+H(cot+coty), and then a grouting modification range of the aquifer is a space area of LxBxd size from the bottom of the aquifer directly above working face.
[0016] In an embodiment of the invention: the first grouting borehole in step b also includes a plurality of horizontal branch boreholes divided from the horizontal boreholes.
[0017] In an embodiment of the invention: the first slurry in step c is a clay slurry.
[0018] In an embodiment of the invention: the grouting step of injecting the first slurry in step c is:
[0019] (1) first, using a dilute slurry to mainly block a fissure in a lower part of the aquifer and solidify lower water; and
[0020] (2) then, injecting a thick slurry, and adjusting a grouting pressure to ensure that the slurry fully fills an area to be grouted and is evenly distributed until reaching an expected modified thickness of the aquiclude.
[0021] In an embodiment of the invention: the second slurry in step e is a high-strength and low-permeability slurry formed by mixing water, a cement slurry and water glass.
[0022] In an embodiment of the invention: the second space range in step e is of a closed ring structure, and specific dimensions are as follows: in a strike direction of the working face, a width from directly above a coal wall to a solid coal side is Hcot6, and along an incline direction of the working face, a width at upper and lower ends and a width from directly above the coal wall to the solid coal side are Hcoty and Hcotj, respectively, forming a ring area.
Advantageous Effect
[0023] Compared with the prior art, the beneficial effects of the invention are as follows: the method injects slurries of different materials into the roof aquifer before and after mining, on the one hand, it increases a thickness of an aquiclude before mining, and reduces the disturbance on the roof aquifer caused by coal mining; and on the other hand, it can also prevent the communication between the aquifer and a goaf caused by a diversion fissure after mining, thereby realizing mining under water preservation.
[0024] FIG. 1 is a schematic diagram of a front structure of the invention;
[0025] FIG. 2 is a top view of an aquifer after modification of the invention;
[0026] FIG. 3 is a cross-sectional view at A-A in FIG. 2.
[0027] In drawings: 1 ground grouting pump station, 2 the first grouting borehole, 3 surface soil layer, 4 aquifer, 41 aquiclude, 5 coal seam, 6 working face, 7 first space, 8 goaf, 9 second space, 91 second grouting borehole.
[0028] The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0029] The technical problems to be solved by this application are detailed in the related art, that is, to propose a coal mining method that can both preserve water and increase the rate of output. The specific implementation may be as follows.
[0030] As shown in FIG. 1, a two-step grouting modified coal mining method under water preservation for a roof aquifer is provided. A coal seam 5 and an aquifer 4 located above the coal seam 5 are included. Generally, when the coal seam 5 is mined out, a damage fissure will appear in a stratum of an aquiclude 41 below the aquifer 4, and when the fissure continue to develop and communicate the aquifer to the coal seam, water inrush will form. Before using the method of this application, implementation needs to be performed according to the steps below.
[0031] As shown in FIG. 1, a, basic geological parameters and mining technical parameters of a working site are obtained. There are many ways to obtain the parameters, such as field surveys or data inquiries. The main parameters obtained include a distance H between the aquifer 4 and the coal seam, a dip angle a of the coal seam, a mining height m of a working face 6 to be mined, a strike length 1, an incline length ', a stratum movement angle (strike 6, rise P, dip y), and a roof subsidence coefficient q; and calculation is performed through such data to obtain a first space range between the aquifer (4) and an aquiclude (41) that needs to be modified before
mining. The space range here is specifically a space size of the aquifer that needs to be modified, which is: along a strike direction of the working face, a thickness d=qmcosa from a bottom of the aquifer 4, a length L=+2Hcot6, and along an incline direction of the working face, a length B='+H(cot+coty), and then a grouting modification range of the aquifer 4 is a space area of LxBxd size from the bottom of the aquifer directly above working face.
[0032] As shown in FIGs. 1and 2, b, in the first space 7 range in step a, a plurality of first grouting boreholes 2 are arranged at intervals from a surface to the bottom of the aquifer. The first grouting borehole includes a vertical borehole, a borehole deflecting section and a horizontal borehole fitting the bottom of the aquifer. Here, to ensure that the space area of LxBxd size at the bottom of the entire aquifer 4 is fully modified by the first slurry, it needs to drill one first grouting borehole 2 every a certain distance in the surface, and the interval distance can be specifically calculated from water permeability of the aquifer 4 on site.
[0033] Moreover, for the first grouting borehole 2 in step b, in order to make the first slurry more comprehensively modify the aquifer 4, the first grouting hole 2 may also include a plurality of horizontal branch boreholes divided from the horizontal boreholes. The horizontal branch boreholes here belong to the prior art in the drilling field and the descriptions thereof are omitted here.
[0034] c, the first slurry with flexibility and water-resisting property is injected, by a ground grouting pump station, into the bottom of the aquifer in step b through the first grouting borehole 2, such that the aquifer is modified.
[0035] The specific formula of the first slurry used may be a clay slurry. More specifically, the formula of the first slurry may be clay: water: cement=5:10:1.
[0036] In addition, in order to allow the first slurry to be better injected into a stratum of the aquifer 4, the following operation method may be used.
[0037] (1) First, a dilute slurry is used to mainly block a fissure in a lower part of the aquifer 4 and solidify lower water.
[0038] (2) Then, a thick slurry is injected, and a grouting pressure is adjusted to ensure that the slurry fully fills an area to be grouted and is evenly distributed until reaching an expected modified thickness of the aquiclude 41.
[0039] According to a capillary theory, the dilute first slurry can quickly diffuse into capillaries inside the aquifer 4, and the capillaries in the aquifer 4 can be completely blocked by using this diffusion, such that the aquifer 4 is modified into the aquiclude 41 in a disguised form. Then, the thick slurry is injected, which can block thicker capillaries. Through the method above, the purpose of modifying the aquifer 4 is achieved.
[0040] As shown in FIG. 3, d, after the grouting modification is completed, the working face 6 of the coal seam 5 is normally recovered, but since the aquifer 4 has been modified and has a certain anti-interference ability, it can be ensured that no water inrush occurs in the entire aquifer 4.
[0041] As shown in FIG. 3, the invention takes into consideration of roof subsidence of the working face, and the modified aquifer 4 has another more important role. That is a height of the modified aquifer 4 is just enough to supplement a depression area caused by subsidence.
[0042] As shown in FIGs. 2 and 3, although there is no water inrush in the aquifer 4 in step d, the subsidence of the roof of the working face will cause a new tensile fissure at an edge of the modified aquifer 4. Therefore, in order to eliminate potential hazards, in step e, after the mining of the working face of the coal seam is completed, the second space 9 range into which the second slurry is injected is calculated according to the parameters in step a. The specific range is as follows.
[0043] The second space 9 range is a closed ring structure. The specific dimensions are as follows: in a strike direction of the working face, a width from directly above a coal wall to a solid coal side is Hcot6, and along an incline direction of the working face, a width at upper and lower ends and a width from directly above the coal wall to the solid coal side are Hcoty and Hcot, respectively, forming a ring area. The specific working process is as step f: drilling a second grouting borehole 91 from the surface to the second space range, and then injecting, by the ground grouting pump station 1, the second slurry with high strength and low permeability into a new diversion fissure that may be caused by unstable overlying stratum movement after mining in step d through the second grouting borehole 91 and/or the first grouting borehole 2.
[0044] The second slurry may be formed by mixing water, cement slurry, and water glass, and specifically the ratio thereof is water: cement: water glass of 2:2:3.
[0045] The principle of the invention is roughly divided into 2 steps: the first step is to modify the bottom of the aquifer 4 into the aquiclude. Since the bottom of the aquifer 4 itself is above the original aquiclude 41, and because of the use of the clay slurry, the anti-disturbance ability is strong. Therefore, after the modification, on the one hand, when the original aquiclude 41 breaks, the first slurry used will act to block water; and on the other hand, after the modified aquifer 4 is superimposed on the aquiclude 41, a thickness of the aquiclude is increased, and this extra thickness will be used to supplement a height difference caused by subsidence of a goaf.
[0046] In addition, the role of the second step of the invention is to grout again to block the new fissure at the edge of the aquifer 4 after modification. In addition to blocking the fissure, the second step also has another role: to provide a pulling force at the edge of the modified aquifer 4 to make the modified aquifer 4 and the second slurry into a whole, which can ensure that a water source of the entire aquifer will not be exhausted. And, by using the method, all coal of the entire working face 6 can be mined, such that the output efficiency is improved.
[0047] The practical application of the invention will be described below in conjunction with a specific implementation.
[0048] The surface ecological environment of a mine in northwestern China is harsh and water resources are in short supply. According to the data provided by the miner, based on the research, the coal seam is a near horizontal coal seam with a coal seam dip angle of 7, a coal seam buried depth of 260 m, a minable coal seam thickness of 8 m, a working face advance length of 1800 m, and a working face length of 200 m. A method of longwall fully mechanized top coal mining on the strike is adopted for mining, and the roof is managed by a fully caving method. Based on geological exploration, there is an aquifer with a thickness of about 15 m at 165 m above the coal seam. The data show that under the conditions of this area, a mining subsidence coefficient is 0.6, and stratum movement angles are: a strike movement angle 650, a dip movement angle 55°, and a rise movement angle is 60°. With an original mining method, the water resource is seriously lost.
[0049] 1) The basic geological parameters and the mining technical parameters of the working face are obtained. By reviewing the basic data of the mine, the distance between the aquifer to the coal seam is H=165 m, the thickness of the aquifer is 15 m, the coal seam dip angle is a=7°, the coal seam buried depth is 260 m, the minable coal seam thickness m=8 m, the working face advance length 1=1800 m, the working face length l'=200 m, the mining subsidence coefficient q=0.6, and the stratum movement angles are: a strike movement angle 6=65, a dip movement angle P=55°, and a rise movement angle y=60°.
[0050] 2) Before mining the working face, grouting modification is performed on a range from the bottom of the aquifer. The specific steps are as follows.
[0051] (1) Before mining the working face, a pre-mining grouting modification range is determined by calculation according to the basic parameters: a thickness from the bottom of the aquifer d=qmcosa, a length L=l+2Hcot6 along the strike direction of the working face, and a length B=l'+H(cotj+coty) along the incline direction of the working face. Relevant parameters are substituted into the formula, obtaining the thickness from the bottom of the aquifer d=0.6x8xcos7°=4.8 m, the length along the strike direction of the working face L=1800+2x165xcot65°=1954 m, and the length along the incline direction of the working face B=200+165x(cot55°+cot65°)=411 m, and then the range that needs grouting is an area of 1954 mx4l1 mx4.8 m size from the bottom of the aquifer directly above the working surface, forming the first space 7 shown in FIG. 1.
[0052] (2) According to the position of the aquifer detected in 1) and the calculated grouting modification range, grouting boreholes are arranged in the aquifer by the ground grouting pump station, and the grouting hole is comprised of four parts, the vertical borehole, the borehole deflecting section, the horizontal borehole and the horizontal branch borehole. As shown in (2) in FIG. 1, the vertical borehole is drilled to a buried depth of 55 m, with the vertical distance to the aquifer of 20 m-30 m, which provides an enough bending space for subsequent drilling deflection; afterwards, the drilling deflection is performed to allow a main borehole to be driven horizontally into the lower part of the aquifer; the horizontal boreholes are arranged at the position of the modified aquiclude obtained by calculation, have a strike length of 1980 m, which is slightly larger than the strike length L of the aquiclude, and run through above the entire working face; and finally, by adjusting the position by a non-magnetic drill pipe, a plurality of branch boreholes are arranged in the grouting modification area of the aquifer, the length of the branch borehole is 420 m, and the branch boreholes are uniformly distributed to ensure that the injected slurry can be evenly distributed in the determined area to form the aquiclude with an expected thickness.
[0053] (3) The grouting slurry uses clay to solidify the slurry, the ratio is clay: water: cement=5:10:1, and an appropriate amount of water glass may be added according to the situation to appropriately increase the setting rate. The grouting sequence adopts the mode of dilute slurry first and then thick slurry. The thin slurry mainly plays a role of blocking the fissure in the lower part of the aquifer and solidifying the lower water, and then the thick slurry is injected, and the grouting pressure is adjusted to ensure that the slurry fully fills an area to be grouted and is evenly distributed until reaching an expected modified thickness of the aquiclude.
[0054] 3) After the pre-mining grouting modification is completed, the working face is normally recovered.
[0055] 4) After mining the working face, the modified aquiclude is affected by mining. Especially, overlying stratum deforms, which leads to tensile fissure appearance in some areas above the roof at the mining boundary, thus it needs to block those possible diversion fissures through grouting strength. The specific steps are as follows.
[0056] (1) After mining the working face, first, the second space 9 range of post-mining grouting is calculated according to the basic parameters: in the strike direction of the working face, the width from directly above the coal wall to the solid coal side is Hcot6, and along the incline direction of the working face, the width at upper and lower ends and the width from directly above the coal wall to the solid coal side are Hcoty and Hcot, respectively. Relevant parameters are substituted into the formula, obtaining that a width of the areas that need grouting on both sides of solid coal is Hcot6=165xcot65°=77 m; and along the incline direction of the working face, a width of a solid coal side at an upper end is Hcoty=165xcot60°=95 m, and a width of a solid coal side at a lower end is Hcot=165xcot55°=116 m. The grouting range is a ring area.
[0057] (2) As shown in FIG. 3, the boreholes are directly arranged from the ground to the area that needs grouting. Final holes of the boreholes are drilled into the bottom of the modified aquiclude, with a depth of 95 m, which are located at the center of the grouting range. One grouting hole is arranged every 50 m in the strike direction and the incline direction. For this working face, an incline grouting length is 411 m and a strike grouting length is 1954 m. Therefore, 8 grouting holes are arranged in each side of the incline direction and 40 grouting holes are arranged in each side of the strike direction.
[0058] (3) For a grouting material, it is recommended to use a high-strength and low-permeability slurry. In this example, a mixed slurry of the water glass and cement slurry is used as the grouting slurry, and the ratio is water: cement: water glass=2:2:3.
[0059] Although the embodiments of this application are already shown and described above, persons of ordinary skill in the art should understand that various changes, modifications, replacements and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is as defined by the appended claims and their equivalents.
Claims (8)
1. A two-step grouting modified coal mining method under water preservation for a roof aquifer, a coal seam (5) and an aquifer (4) located above the coal seam (5) being comprised, the method comprising:
a. obtaining basic geological parameters and mining technical parameters of a working site, and calculating to obtain a first space (7) range between the aquifer (4)
and an aquiclude (41) that needs to be modified before mining;
b. in the first space (7) range in step a, arranging a plurality offirst grouting boreholes (2) at intervals from a surface to a bottom of the aquifer, wherein thefirst grouting borehole (2) comprises a vertical borehole, a borehole deflecting section and a horizontal borehole fitting the bottom of the aquifer (4);
c. injecting, by a ground grouting pump station, a first slurry with flexibility and water-resisting property into the bottom of the aquifer (4) in step b through the first grouting borehole (2), such that the aquifer (4) is modified;
d. after the grouting modification is completed, normally recovering a working face (6) of the coal seam;
e. after the mining of the working face (6) of the coal seam is completed, calculating according to the parameters in step a to obtain a second space (9) range into which a second slurry is injected; and
f. drilling a second grouting borehole (91) from the surface to the second space (9) range, and then injecting, by the ground grouting pump station (1), the second slurry with high strength and low permeability into a new diversion fissure that may be caused by unstable overlying stratum movement after mining in step d through the second grouting borehole (91) and/or the first grouting borehole (2).
2. The two-step grouting modified coal mining method under water preservation for a roof aquifer according to claim 1, wherein the basic geological parameters and the mining technical parameters in step a comprise: a distance H between the aquifer (4) and the coal seam (5), a dip angle a of the coal seam (5), a mining height m of a working face (6) to be mined, a strike length 1, an incline length ', a stratum movement angle (strike 6, rise P, dip y), and a roof subsidence coefficient q.
3. The two-step grouting modified coal mining method under water preservation for a roof aquifer according to claim 2, wherein a space size of the aquifer that needs to be modified is: along a strike direction of the working face (6), a thickness d=qmcosa from the bottom of the aquifer (4), a length L=+2Hcot6, and along an incline direction of the working face (6), a length B='+H(cot+coty), and then a grouting modification range of the aquifer (4) is a space area of LxBxd size from the bottom of the aquifer (4) directly above working face (6).
4. The two-step grouting modified coal mining method under water preservation for a roof aquifer according to claim 1, wherein the first grouting borehole (2) in step b also comprises a plurality of horizontal branch boreholes divided from the horizontal boreholes.
5. The two-step grouting modified coal mining method under water preservation for a roof aquifer according to claim 1, wherein the first slurry in step c is a clay slurry.
6. The two-step grouting modified coal mining method under water preservation for a roof aquifer according to claim 1, wherein the grouting step of injecting the first slurry in step c is:
(1) first, using a dilute slurry to mainly block a fissure in a lower part of the aquifer (4) and solidify lower water; and
(2) then, injecting a thick slurry, and adjusting a grouting pressure to ensure that the slurry fully fills an area to be grouted and is evenly distributed until reaching an expected modified thickness of the aquiclude (41).
7. The two-step grouting modified coal mining method under water preservation for a roof aquifer according to claim 1, wherein the second slurry in step e is a high-strength and low-permeability slurry formed by mixing water, a cement slurry and water glass.
8. The two-step grouting modified coal mining method under water preservation for a roof aquifer according to claim 2, wherein the second space (9) range in step e is of a closed ring structure, and specific dimensions are as follows: in a strike direction of the working face (6), a width from directly above a coal wall to a solid coal side is Hcot6, and along an incline direction of the working face (6), a width at upper and lower ends and a width from directly above the coal wall to the solid coal side are Hcoty and Hcotj, respectively, forming a ring area.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2019102254927 | 2019-03-25 | ||
| CN201910225492.7A CN110242301B (en) | 2019-03-25 | 2019-03-25 | Two-step grouting modification water-retention coal mining method for roof aquifer |
| PCT/CN2019/108508 WO2020192055A1 (en) | 2019-03-25 | 2019-09-27 | Two-step grouting modified water-protective coal mining method for roof aquifers |
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| Publication Number | Publication Date |
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| AU2019435042A1 true AU2019435042A1 (en) | 2020-10-15 |
| AU2019435042B2 AU2019435042B2 (en) | 2021-10-07 |
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| AU2019435042A Active AU2019435042B2 (en) | 2019-03-25 | 2019-09-27 | Two-step grouting modified coal mining method under water-preservation for roof aquifer |
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Families Citing this family (27)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110242301B (en) * | 2019-03-25 | 2020-05-05 | 中国矿业大学 | Two-step grouting modification water-retention coal mining method for roof aquifer |
| CN111764960B (en) * | 2020-08-17 | 2021-11-12 | 六盘水师范学院 | Coal mining separation layer water damage prevention and control method |
| CN112377221B (en) * | 2020-10-30 | 2022-09-23 | 中煤科工集团西安研究院有限公司 | Method for inhibiting development of water guide crack belt by grouting before mining and building key layer of structure |
| CN112483172A (en) * | 2020-11-25 | 2021-03-12 | 中国煤炭地质总局水文地质局 | Method for artificially reconstructing water blocking boundary |
| CN112664192B (en) * | 2020-12-11 | 2023-07-18 | 中国矿业大学 | Method for improving coal mining upper limit in thin bedrock area |
| CN112695739B (en) * | 2020-12-18 | 2021-09-21 | 中国矿业大学(北京) | Grouting reinforcement method for thick flowing sand layer under mining influence area building structure group |
| CN112483040A (en) * | 2020-12-23 | 2021-03-12 | 莱芜莱新铁矿有限责任公司 | Mine water spraying treatment method |
| CN112746846B (en) * | 2021-02-05 | 2023-02-28 | 中煤科工集团西安研究院有限公司 | Non-settling coal mining method and device for mining and filling parallel with ground directional long drill hole |
| CN112814737B (en) * | 2021-03-10 | 2023-03-14 | 淮南矿业(集团)有限责任公司 | Collapse column advanced treatment method and system based on laminated multi-branch horizontal well |
| CN113006795B (en) * | 2021-04-09 | 2023-10-20 | 中国煤炭地质总局勘查研究总院 | Treatment method of dwarf coal field roof sandstone water |
| CN113062739B (en) * | 2021-04-15 | 2023-04-25 | 神华神东煤炭集团有限责任公司 | Goaf water disaster and strong mine pressure disaster cooperative treatment method |
| CN113175325B (en) * | 2021-04-25 | 2022-03-08 | 中国矿业大学 | Coal and intergrown sandstone type uranium ore coordinated mining method based on key layer protection |
| CN114033382A (en) * | 2021-08-17 | 2022-02-11 | 国家能源投资集团有限责任公司 | Water retention and dew mining process based on aquifer transformation |
| CN113982581B (en) * | 2021-10-26 | 2023-04-07 | 中国矿业大学 | Stability control method for overburden seepage isolation zone based on low-carbon mining |
| CN114233392B (en) * | 2021-11-03 | 2023-07-14 | 河南理工大学 | Underground low ecological damage working face mining parameter optimization method |
| CN114017106B (en) * | 2021-11-03 | 2023-10-27 | 中煤能源研究院有限责任公司 | Method for calculating filling capacity of underground ortho grouting of gangue |
| CN114109454B (en) * | 2021-11-10 | 2024-06-18 | 北京国电水利电力工程有限公司 | Method for treating grotto rock mass microcrack water damage |
| CN114218518B (en) * | 2021-12-16 | 2024-06-21 | 河南省地质局生态环境地质服务中心 | Method for measuring and calculating settling volume of goaf of coal mine |
| CN114414438B (en) * | 2022-01-24 | 2024-01-26 | 中国矿业大学 | Identification method for detecting grouting diffusion range based on proton magnetometer |
| CN114876403B (en) * | 2022-05-06 | 2023-04-21 | 河南理工大学 | Grouting repairing method for mining high-level fracture space |
| CN114934757A (en) * | 2022-05-31 | 2022-08-23 | 彬县水帘洞煤炭有限责任公司 | Water spraying treatment process for underground tunneling roadway of coal seam immediate roof aquifer |
| CN115419434A (en) * | 2022-07-31 | 2022-12-02 | 陕西正通煤业有限责任公司 | Coal seam roof pulse type high-pressure grouting working face water inrush prevention technology |
| CN115467639A (en) * | 2022-08-15 | 2022-12-13 | 中煤科工集团西安研究院有限公司 | Water interception and emission reduction method for directionally exploring and blocking ground |
| CN115791524B (en) * | 2022-11-01 | 2024-02-27 | 山东科技大学 | Measuring device and measuring method for measuring goaf grouting slurry properties |
| CN116147711B (en) * | 2023-04-17 | 2023-07-11 | 山西潞安环保能源开发股份有限公司 | Device and method for testing coal mine overburden stratum fracture space-time evolution law |
| CN117758772B (en) * | 2023-12-21 | 2024-07-02 | 中国矿业大学(北京) | Post-mining aquifer grouting restoration water retention method based on one-hole multipurpose coal mine area |
| CN117967277B (en) * | 2024-01-18 | 2024-08-02 | 中国矿业大学 | Measuring method for accurately measuring thickness of coal seam through bedding drilling |
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| US3999617A (en) * | 1975-09-29 | 1976-12-28 | Exxon Production Research Company | Self-supported drilling riser |
| US6158517A (en) * | 1997-05-07 | 2000-12-12 | Tarim Associates For Scientific Mineral And Oil Exploration | Artificial aquifers in hydrologic cells for primary and enhanced oil recoveries, for exploitation of heavy oil, tar sands and gas hydrates |
| CN101608552A (en) * | 2008-06-18 | 2009-12-23 | 郭国政 | The seat earth aquifer reinforces and protects the method for water barrier in reinforcing process |
| CN104481560B (en) * | 2014-12-09 | 2017-08-22 | 中煤第一建设有限公司 | Back water-bearing layer administering method |
| CN104989403B (en) * | 2015-06-02 | 2017-05-10 | 国投新集能源股份有限公司 | Method for reconstructing floor limestone aquifer into natural-artificial composite integrated aquiclude |
| CN106593445A (en) * | 2016-12-02 | 2017-04-26 | 淮北矿业（集团）有限责任公司 | Old goaf underlying close distance coal seam strata-overlying isolation grouting filling exploitation method |
| CN106907152B (en) * | 2017-04-06 | 2019-01-25 | 安徽理工大学 | A kind of soil type inlet well arrangement and grouting method |
| CN107740701A (en) * | 2017-11-27 | 2018-02-27 | 山东省邱集煤矿 | A kind of method of the accurate grout transformation of top plate thin layer limestone aquifer |
| CN108798589B (en) * | 2018-04-28 | 2020-07-28 | 安徽建筑大学 | Modification method of aquifer |
| CN108661644A (en) * | 2018-06-14 | 2018-10-16 | 陕西省地质环境监测总站 | A kind of water-protection coal-mining method reproducing clay pan using goaf negative pressure |
| CN110242301B (en) * | 2019-03-25 | 2020-05-05 | 中国矿业大学 | Two-step grouting modification water-retention coal mining method for roof aquifer |
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| CN110242301A (en) | 2019-09-17 |
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