CN110847955B - Method for upward repeated mining of empty coal seam by freezing accumulated water in room-and-column-type residual mining area - Google Patents
Method for upward repeated mining of empty coal seam by freezing accumulated water in room-and-column-type residual mining area Download PDFInfo
- Publication number
- CN110847955B CN110847955B CN201911121454.3A CN201911121454A CN110847955B CN 110847955 B CN110847955 B CN 110847955B CN 201911121454 A CN201911121454 A CN 201911121454A CN 110847955 B CN110847955 B CN 110847955B
- Authority
- CN
- China
- Prior art keywords
- room
- water
- freezing
- mining
- accumulated water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000005065 mining Methods 0.000 title claims abstract description 182
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 145
- 239000003245 coal Substances 0.000 title claims abstract description 131
- 238000007710 freezing Methods 0.000 title claims abstract description 90
- 230000008014 freezing Effects 0.000 title claims abstract description 88
- 238000000034 method Methods 0.000 title claims abstract description 39
- 239000011435 rock Substances 0.000 claims abstract description 22
- 238000009826 distribution Methods 0.000 claims abstract description 14
- 238000009825 accumulation Methods 0.000 claims abstract description 11
- 239000007791 liquid phase Substances 0.000 claims abstract description 5
- 238000005553 drilling Methods 0.000 claims description 17
- 239000012267 brine Substances 0.000 claims description 14
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims description 14
- 239000000498 cooling water Substances 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000004458 analytical method Methods 0.000 claims description 5
- 238000010586 diagram Methods 0.000 claims description 5
- 238000002347 injection Methods 0.000 claims description 5
- 239000007924 injection Substances 0.000 claims description 5
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 4
- 239000003507 refrigerant Substances 0.000 claims description 4
- 239000011780 sodium chloride Substances 0.000 claims description 4
- 238000005520 cutting process Methods 0.000 claims description 3
- 230000008093 supporting effect Effects 0.000 claims description 3
- 230000007774 longterm Effects 0.000 claims description 2
- 230000003014 reinforcing effect Effects 0.000 claims description 2
- 150000003839 salts Chemical class 0.000 claims description 2
- 239000000243 solution Substances 0.000 claims description 2
- 230000005641 tunneling Effects 0.000 claims description 2
- 238000001816 cooling Methods 0.000 claims 1
- 230000001174 ascending effect Effects 0.000 abstract description 4
- 229910052500 inorganic mineral Inorganic materials 0.000 abstract description 4
- 239000011707 mineral Substances 0.000 abstract description 4
- 238000005057 refrigeration Methods 0.000 abstract description 4
- 238000005516 engineering process Methods 0.000 abstract description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000011161 development Methods 0.000 abstract description 2
- 239000010410 layer Substances 0.000 description 9
- 238000012850 discrimination method Methods 0.000 description 6
- 238000010276 construction Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000009412 basement excavation Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 239000010721 machine oil Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000013475 authorization Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 238000010257 thawing Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F15/00—Methods or devices for placing filling-up materials in underground workings
- E21F15/005—Methods or devices for placing filling-up materials in underground workings characterised by the kind or composition of the backfilling material
-
- 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
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/001—Improving soil or rock, e.g. by freezing; Injections
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F15/00—Methods or devices for placing filling-up materials in underground workings
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Soil Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Remote Sensing (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The invention discloses a method for repeatedly mining a hollow coal seam by accumulated water in a freezing room column type residual mining area, and belongs to the field of coal mining. On the basis of judging the ascending mining feasibility of the kick-out coal seam, detecting the distribution conditions of a coal column group and a dead zone group in a room-and-pillar type residual mining zone, the water accumulation amount and the water accumulation range in the residual mining zone, freezing the accumulated water in the goaf by using an artificial refrigeration technology to enable the water in a liquid phase to be ice with certain bearing capacity, filling the room-and-pillar type residual mining zone, freezing the caving roof blocks, the left coal columns and the like in the goaf into ice blocks, filling the whole goaf with huge ice blocks formed by freezing the accumulated water, forming a whole with certain bearing capacity together with the roof and floor of the residual mining zone, the coal columns and surrounding rocks of the boundary of the goaf, and then carrying out the mining of the kick-out coal seam. The invention provides a more stable bottom plate environment for the working surface propulsion of the overlying and kicking-off coal seam, is beneficial to recovering mineral resources and promotes the sustainable development of the mineral resources.
Description
Technical Field
The invention relates to a method for freezing a room and column type residual mining area accumulated water ascending re-mining hollow coal seam, relates to the technical field of coal mining, and is mainly suitable for safe mining of the hollow coal seam covered on the room and column type residual mining area. Belongs to the technical field of coal mining.
Background
With the acceleration of the socialist modernization process, the contradiction between the limitless increase of the demand of coal and the limitless renewable resource is severe day by day, which requires that the resource recovery rate is improved and a saving-type mining area is built, so that the re-mining of residual coal is gradually paid attention to people.
Under the influence of early mining, some coalbeds capable of being mined are abandoned above a plurality of goafs in the existing production mining areas or mines, the abandoned coal reserves are considerable, and the upward mining of the residual mining areas of the coal mines becomes more and more the focus of attention of people along with the improvement of mining technologies. However, due to the influence of early mining, the integrity and stability of the goaf coal seam and the floor rock stratum in the residual mining area are damaged and destroyed in different degrees, which may cause mine disasters and affect safe production. Therefore, the precondition of the upward mining is that the feasibility evaluation and judgment are carried out on whether the safety mining can be carried out on the upward-stepping empty coal seam on the residual mining area, and besides the conventional upward mining feasibility judgment methods of the residual mining area, such as a three-belt judgment method, a surrounding rock balance method, a ratio judgment method and a mathematical analysis method, the CN101109283B quantitatively judges the feasibility of the upward mining of the upward-stepping empty coal seam from the perspective of the structure of the interbedded rock stratum; CN103147737A provides a detection method for an upgoing mining overburden rock damage rule, reveals a spatial and temporal evolution rule of overburden rock damage in the upgoing mining process, solves the problem of reasonably determining the layout of an upgoing mining working face and a roadway, and ensures the safety of upgoing mining. The upward mining feasibility judgment of each kick-off coal seam is based on the thickness and the stability of the interbed rock stratum, and the upward mining feasibility of the kick-off coal seam on the room and column type residual mining area is judged and evaluated in advance through calculation and analysis, so that engineering practice is guided.
The bottom coal layer is completely mined, and the top plate of the bottom coal layer collapses, so that the overlying rock layer of the bottom coal layer is changed inevitably, the stability of the top and bottom rock layers of the overlying and empty coal layers is influenced to a certain extent, and even the structure of the coal layer can be changed to a certain extent.
In addition, the room-and-column type residual mining area is gradually filled with accumulated water, the accumulated water in the goaf is reasonably treated in the traditional paste filling mining, then grouting filling is carried out, and in addition, the large-area goaf is filled, so that the cost is higher and the construction is difficult. Therefore, a method for reasonably solving the problem of water accumulation in the goaf and enhancing the stability of the pillars in the room-pillar type residual mining area underlying the pedaled-out coal seam is urgently needed to be found, and the safe mining of the pedaled-out coal seam is guaranteed.
Disclosure of Invention
The invention aims to provide a method for repeatedly mining a hollow coal seam by using accumulated water in a freezing room column type residual mining area.
On the basis of judging the ascending mining feasibility of the kick-out coal seam, detecting the distribution conditions of a coal column group and a dead zone group in a room-and-pillar type residual mining area, the water accumulation amount and the water accumulation range in the residual mining area, freezing the accumulated water in the goaf by using an artificial refrigeration technology to enable the water in a liquid phase to be an icing body with certain bearing capacity, filling the goaf of the room-and-pillar type residual mining area, freezing a roof block, a left coal column and the like which are collapsed in the goaf into a whole, filling the whole goaf with huge ice blocks frozen by the accumulated water, simultaneously forming the icing body, a roof plate, the coal column and surrounding rock of the boundary of the goaf into a whole with certain bearing capacity together, and then carrying out the mining of the kick-out coal seam.
The invention provides a method for repeatedly mining a hollow coal seam by seeper in a frozen room column type residual mining area, which comprises the following specific implementation method:
(1) judging the feasibility of upward mining of the overlying and empty coal seam on the room and column type residual mining area;
(2) combining the original geological and technical data of the mine and the distribution conditions of the coal pillar group and the goaf group, drawing a distribution form diagram of the coal pillar group and the goaf group in the room-and-pillar type residual mining area to guide safe production, and besides, exploring the accumulated water height, the accumulated water amount, the water quality and the like of the goaf;
(3) excavating a stoping roadway of the pedaled empty coal seam, arranging a pedaled empty coal seam cutting hole above a coal pillar at the end part of the explored room-and-column type residual mining area, and arranging a pedaled empty coal seam working face;
(4) drilling a series of vertical drill holes from top to bottom from a coal seam floor in the back mining roadway of the excavated goaf coal seam in the step (3) along the axial direction of the roadway, and putting down the drill holes into accumulated water in the goaf through the roadway and arranging freezing pipelines;
(5) arranging a freezing station in a mining roadway of the excavated empty coal seam in the step (3) to convey salt water in the roadway and erect loop pipelines;
(6) refrigerating by a freezing station arranged in the roadway in the step (5), replacing accumulated water heat by circulating brine through a freezing pipe loop placed in accumulated water of the room and column type residual mining area in the step (4), enabling the accumulated water in the room and column type residual mining area to enter an active freezing period, enabling the accumulated water to be gradually frozen, enabling the accumulated water to be fully connected to the roof while being frozen by utilizing the characteristics that the water is changed along with the shape of an accommodating body and the frozen volume of the water is expanded, and enabling the frozen ice in the residual mining area to serve as a filling body to play a role in supporting a floor rock stratum of a tunneling and treading coal seam;
(7) after water accumulation and subsequent water injection in the room and column type residual mining area are completely solidified and frozen, reducing the refrigerating capacity of each freezing station in the step (4), leading the freezing work to enter a negative freezing period, ensuring that ice blocks are not thawed, and maintaining the temperature of a frozen ice body to be constant at minus 8 ℃ to minus 10 ℃; when the accumulated water in the room and column type residual mining area is frozen and solidified, the locally collapsed stones and the left coal pillars in the room and column type residual mining area are frozen in the ice body to form a whole, and in addition, the ice body, the top floor of the residual mining area, the left coal pillars and the surrounding rocks form a whole together, so that a stable floor environment is provided for the pushing of the working surface of the overlying and kicking-off coal seam;
(8) then under the support of the ice body maintained by negative freezing, the working surface of the overlying and kicking-off coal seam starts to be pushed forward, and the coal resources are gradually mined;
(9) and in the process of pushing the empty coal seam, reinforcing the support of the roadway, starting to gradually stop the freezing work in the mining roadway along the working face pushing direction when the mining working face is pushed to the position of 150m before the mining stopping line, removing the freezing equipment, and removing the freezing pipeline after the frozen body is melted.
In the scheme, the accumulated water in the room and column type residual mining area is not communicated with the underground river, the long-term water volume of the accumulated water is basically unchanged, the accumulated water can be supplemented by a small amount of underground water and simultaneously flows off in a small scale, and the total water volume is in a dynamic stable state.
In the scheme, when each freezing pipeline is placed into the water in the room and column type residual mining area, a series of temperature sensors are placed along with the pipelines and are uniformly distributed in the water in the room and column type residual mining area, a real-time dynamic detection network is established, and the temperature of the water (frozen ice) in the goaf is detected in real time.
In the above scheme, the feasibility determination method in step (1) is as follows: the method combines the traditional three-belt discrimination method, the surrounding rock balance method, the ratio discrimination method, the mathematical analysis method and the quantitative discrimination method to comprehensively discriminate the feasibility of the upward mining of the overlying pedaled empty coal seam in the room and pillar type residual mining area.
In the scheme, the width and the height of the room and column type residual mining area empty area group and the coal column group under the pedaled empty coal bed are checked through investigating original geological and technical data of the mine in the step (2), the distribution direction, the size and the volume of the room and column type residual mining area empty area group are accurately detected by adopting a three-dimensional laser scanner, and the depth, the distribution range and the volume of accumulated water in the room and column type residual mining area are simultaneously detected.
In the scheme, the step (3) arranges the stoping roadway and the working face of the kick-out coal seam above the explored room-and-column type residual mining area, the stoping roadway is widened by 1.0-1.2 times on the basis of the design size meeting the mining requirement, and meanwhile, an auxiliary chamber is dug in the transportation roadway for arrangement of a subsequent freezing station to avoid influencing stoping work.
In the scheme, in order to reduce the drilling workload, the roadway drilling in the step (4) selects vertical drilling, wherein the number of the drilling is determined by the cold demand, the volume of accumulated water and the freezing radius of a freezing pipeline; a freezing pipeline is put into accumulated water in the room-and-column type residual mining area through drilling, and a group of closed loops are formed by the freezing pipes in the accumulated water in the goaf, so that brine circulation is carried out, heat in the accumulated water is replaced, and the accumulated water is frozen into ice.
In the scheme, the drilling position of the roadway in the step (4) is determined by the distribution form diagram of the room-and-pillar type residual mining area coal pillar group and the empty area group drawn in the step (2), and the drilling is carried out at the position of the residual mining area empty area right below the excavation roadway.
In the scheme, in the step (5), the type, the power and the number of the freezing devices of the freezing station are selected, the cold demand is determined according to the volume of the empty area of the room-and-column residual mining area and the volume of accumulated water in the empty area, which are detected in the step (2),selection of CaCl in brine circulating system2The solution is used as a refrigerant, and the cooling water circulation system is naturally cooled by the excavation water pool. After the freezing parameters are determined, the trial operation of the equipment is carried out, and the whole system is formally constructed after running without errors.
Further, in the step (5), the selection and arrangement of the freezing equipment refer to the construction experience of the conventional freezing method tunnel, and the equipment selection provides the following reference scheme:
the refrigerator selects an SKD136.1.H type screw unit, the working condition refrigerating capacity of a single unit is designed to be 116960Kcal/h, and the power of a single motor is 114 KW;
each refrigerator IS provided with a brine circulating pump (IS 150-125 and 315 are selected), and the flow rate of each refrigerator IS 200m3H, motor power 37 KW;
the cooling water circulating pump of the freezing station adopts an IS 150-125-315B type, and the flow of each cooling water circulating pump IS 173m3And h, the motor power is 18.5 KW.
Wherein, the equipment group of each freezing station needs to be additionally provided with a brine circulating pump and a cooling water circulating pump for standby.
The main parameter indexes related to freezing construction are as follows:
refrigerant: the preparation method of the Freon comprises the steps of R-22,
refrigerating machine oil: hanzhong HBR-B03 refrigerator oil (or other products with the same effect),
temperature of frozen brine: an active period: -20 ℃ to-25 ℃, dead time (maintenance time): the temperature is minus 15 ℃ to minus 20 ℃,
average temperature after accumulated water is frozen: at the temperature of minus 8 ℃ to minus 12 ℃,
freezing saline water conveying pipe: a low temperature resistant flexible metal tube.
In the scheme, the uniaxial compressive strength of the frozen accumulated water in the room and column type residual mining area in the step (6) is 3 MPa-6 MPa according to the actual measurement in a laboratory, the tensile strength is 1/2 of the compressive strength, and the strength is increased to a certain extent under the confining pressure action of surrounding rock in the underground goaf and is similar to the strength of a common gangue slurry filling material.
In the scheme, the volume of the water frozen in the step (6) is expanded, the volume of the frozen ice is 1.1 times of that of the original water, the water is accumulated in the goaf which is not connected with the roof in the goaf, and the frozen ice can be fully connected with the roof when the distance between the water surface and the roof reaches about 90% of the full height of the goaf; when the accumulated water is less and the roof cannot be fully connected after freezing, the ice accumulation amount is increased through manual water injection to enable the roof to be connected, the whole room and column type residual mining area is filled, the forward and pushing goaf coal seam floor rock stratum is supported, and in addition, solid ice has a certain lateral supporting effect on the room and column type residual mining area coal columns.
In the scheme, the passive freezing period in the step (7) refers to the freezing action of accumulated water in the room-column type residual mining area after the early active freezing period, the liquid-phase water is gradually and completely frozen, the freezing is basically finished, at the moment, the frozen ice body only needs to maintain the frozen state, the thawing is not guaranteed, the temperature of the circulating brine is increased within a small range (the temperature of the circulating brine is increased by 5-10 ℃), and the purposes of energy conservation and economy are achieved as much as possible.
According to the scheme, the coal pillar easy to recover in the lower goaf is excavated under the support of the frozen ice body on the lower layer while the upper pedaled coal seam is pushed to the mining working face.
The invention has the beneficial effects that:
(1) the upward mining feasibility of the pedaled empty coal seam is judged on the basis of mine production data and exploration data, accumulated water in a room-and-column type residual mining area is frozen by adopting artificial refrigeration, water in a liquid phase is frozen into solid ice, a slump top plate, stones and the like in the whole goaf are wrapped in the frozen ice to form a whole, filling materials are replaced, the whole goaf is filled in a full filling mode, a stable bottom plate condition is created for the overlying pedaled empty coal seam, pedaled empty coal resources are gradually mined, mineral resources are recovered, and sustainable development of the mineral resources is promoted;
(2) compared with the traditional paste filling mining, the method has the advantages that accumulated water in the dead area of the residual mining area does not need to be treated, a partition wall does not need to be built, a ground grouting material mixing station does not need to be set, the works such as mixing and pumping of filling slurry are carried out, and the like, so that great engineering quantity and equipment investment are saved;
(3) the accumulated water in the goaf is frozen into ice, and simultaneously, the collapsed roof and stones in the residual mining area are wrapped into the ice body to form a whole together with the roof and floor of the residual mining area and surrounding rocks, so that a common bearing body is formed, and a more stable floor environment is provided for the working surface propulsion of the overlying and kicking-off coal seam;
(4) and (3) pushing the stoping working surface of the overlying pedaled empty coal seam, and recovering part of the easy-to-mine coal pillars of the underlying goaf under the support of the frozen ice body of the lower layer while stoping the coal resources of the pedaled empty coal seam.
Drawings
FIG. 1 is a schematic diagram of a freezing pipeline in water accumulated in a roadway drilling and residual mining area;
FIG. 2 is a schematic view of a room and pillar type residual mining area during freezing (a-A direction cross section view);
FIG. 3 is a schematic view of the advancing of the stope face of the overlying and kicked-off coal seam under the support of the frozen ice body.
In the figure: 1-climbing an empty coal seam, 2-extracting a roadway, 3-freezing stations and 4-interlayer rock strata; 5-roadway drilling, 6-room-column type coal pillars in the residual mining area, 7-room-column type dead area, 8-freezing pipelines, 9-room-column type water and ice accumulation in the residual mining area, 10-treading empty coal seam goaf and 11-treading empty coal seam stoping working face.
Detailed Description
The following examples are intended to illustrate and explain the present invention without limiting its scope.
In order to clearly understand the technical objects, characteristics and effects of the invention, the method for upward repeated mining of the kick-off coal seam by the accumulated water in the frozen room and pillar type residual mining area is further described in detail with reference to the attached drawings.
In order to ensure the designed yield of a mine, a certain mine violates a conventional mining procedure, a production roadway is arranged in a 18 th thicker coal seam at the lower part, a 18 th coal seam 18403 working face is mined in a room and pillar type mining mode, the mine suffers from storage failure and mining imbalance as the 18403 working face approaches a mining stop line, the mine has to adopt up-run mining to complete a coal yield task, a 17 th coal seam with a thinner upper part and higher content of gangue is re-mined, the typical room and pillar type residual mining area is covered with a pedaled coal seam, the 18 th coal seam 18403 working face room and pillar type residual mining area is gradually filled with accumulated water, the accumulated water is not communicated with an underground river, and the water quantity is basically kept unchanged. The stability of the roof of the room-pillar type residual mining area of the working face of the No. 18 coal seam 18403 seriously restricts the safe running of the overhead resource ascending mining of the working face of the No. 17 coal seam 17705. In view of the above situation, the following describes the implementation process of the present invention in detail with reference to the accompanying drawings, and the implementation steps are as follows:
step one, a three-belt discrimination method, a surrounding rock balance method, a ratio discrimination method, a mathematical analysis method and a quantitative discrimination method (the authorization notice number can be referred to as CN 101109283B) are adopted to comprehensively discriminate the feasibility of the upward mining of the No. 17 pedaled empty coal seam 1, and the upward mining of the pedaled empty coal seam 1 on the room-pillar type residual mining area of the No. 18 coal seam is feasible.
Step two, according to the original geological and technical data of the mine, the strike length of the No. 18 coal seam 18403 room-column type residual mining area 7 is 441m, the inclined length is 202m, and the height is 6.9 m. The distribution position, the size and the volume of the room-and-column type residual mining area empty area group are accurately detected by adopting a three-dimensional laser scanner, and the distance between the water surface of the room-and-column type residual mining area accumulated water and the top plate is 0.8m by detecting the depth, the distribution range and the volume of the room-and-column type residual mining area accumulated water.
And step three, beginning to dig the stoping roadway 2, arranging a pedaled coal seam stoping working surface 11, properly widening the stoping roadway 2, and digging an auxiliary chamber in the transportation roadway for arrangement of a subsequent freezing station 3 to avoid influencing the stoping work.
Fourthly, arranging a freezing station 3 in a mining roadway 2 of the pedaled empty coal seam 1, and erecting a saline water pipeline in the roadway;
the parameters of the freezing station are selected as follows:
the refrigerator selects an SKD136.1.H type screw unit, the working condition refrigerating capacity of a single unit is designed to be 116960Kcal/h, and the power of a single motor is 114 KW;
each refrigerator IS provided with a brine circulating pump (IS 150-125 and 315 are selected), and the flow rate of each refrigerator IS 200m3H, motor power 37 KW;
the cooling water circulating pump of the freezing station adopts an IS 150-125-315B type, and the flow of each cooling water circulating pump IS 173m3And h, the motor power is 18.5 KW.
Wherein, the equipment group of each freezing station needs to be additionally provided with a brine circulating pump and a cooling water circulating pump for standby.
The main parameter indexes related to freezing construction are as follows:
refrigerant: the preparation method of the Freon comprises the steps of R-22,
refrigerating machine oil: hanzhong HBR-B03 refrigerator oil (or other products with the same effect),
temperature of frozen brine: an active period: -20 ℃ to-25 ℃, dead time (maintenance time): the temperature is minus 15 ℃ to minus 20 ℃,
average temperature after accumulated water is frozen: at the temperature of minus 8 ℃ to minus 12 ℃,
freezing saline water conveying pipe: a low temperature resistant flexible metal tube.
And fifthly, drilling a row of vertical roadway drill holes 5 from top to bottom from a top plate in the pedaled empty coal seam stoping roadway 2 along the axial direction of the roadway, putting the freezing pipes 8 into accumulated water in the room-and-pillar type residual mining area 7 through the roadway drill holes 5, and forming a group of closed loops in the accumulated water in the goaf by the freezing pipes.
Step six, the freezing station 3 arranged in the step four starts to refrigerate, the accumulated water in the room-and-column type residual mining area dead zone 7 enters an active freezing period, the accumulated water in the room-and-column type residual mining area dead zone 7 is frozen through the freezing pipeline 8 placed downwards in the step five, the volume expansion rate of the water is 110 percent due to the fact that the depth of the accumulated water in the room-and-column type residual mining area dead zone 7 is 6.1m and the distance between the accumulated water and the top plate is 0.8m, and therefore the water cannot be completely connected to the top when being frozen, proper supplementary water injection is carried out through the roadway drill holes 5 when the accumulated water in the residual mining area is frozen, the water is fully connected to the top when being frozen by utilizing the characteristics that the water changes along with the shape of the accommodating body and the volume of the frozen water, and the accumulated water-and ice-accumulated body;
and step seven, after the water accumulation and ice bodies 9 in the room and column type residual mining area are completely solidified and frozen, the freezing work in the step six reduces refrigeration, enters a negative freezing period, ensures that ice blocks are not thawed, and maintains the constant temperature of the frozen ice blocks at minus 10 ℃. When the accumulated water in the room-and-pillar type residual mining area dead zone 7 is solidified and frozen, the stones falling in the room-and-pillar type residual mining area are frozen in the accumulated water frozen body, and the ice body, the top bottom plate of the residual mining area, the left coal pillar and the surrounding rock form a whole together, so that a stable working environment is provided for the pushing of the upper pedal empty coal seam stope working face 11;
step eight, then under the support of the water accumulation and ice formation body 9 of the room-and-column type residual mining area which is maintained by negative freezing, the upper covering and kicking-off coal seam stoping working face 11 starts to advance, coal resources are gradually stoped, and after the stoping working face is advanced for 100m, the easy-to-mine coal pillars of the residual mining area which is shielded by the lower freezing ice body are recovered from the direction of the stoping line of the kicking-off coal seam;
and step nine, with the advance of the stoping working surface 11 of the overlying kicked-off coal seam, gradually filling the kicked-off coal seam goaf 10 with a caving roof, strengthening the support of the stoping roadway 2, starting to advance along the working surface in the stoping roadway along the advancing direction when the kicked-off stoping working surface 11 advances to a position 100m away from the stoping line, gradually stopping the freezing work, and removing the freezing equipment and the pipeline.
Claims (9)
1. A method for upward repeated mining of an empty coal seam by freezing accumulated water in a room-and-column type residual mining area is characterized by comprising the following steps:
(1) judging the feasibility of upward mining of the overlying and empty coal seam on the room and column type residual mining area;
(2) combining the original geological and technical data of the mine and the distribution conditions of the coal pillar group and the goaf group, drawing a distribution form diagram of the coal pillar group and the goaf group in the room-and-column type residual mining area to guide safe production, and besides, exploring the height of accumulated water, the accumulated water amount and the water quality of the goaf;
(3) excavating a stoping roadway of the pedaled empty coal seam, arranging cutting holes of the pedaled empty coal seam above the coal pillars at the end parts of the room-and-column type residual mining areas which are already found out, and arranging a working surface of the pedaled empty coal seam;
(4) drilling a series of vertical drill holes from top to bottom from a coal seam floor in the back mining roadway of the excavated goaf coal seam in the step (3) along the axial direction of the roadway, and putting down the drill holes into accumulated water in the goaf through the roadway and arranging freezing pipelines;
(5) arranging a freezing station in a mining roadway of the excavated empty coal seam in the step (3) to convey salt water in the roadway and erect loop pipelines; when each freezing pipeline is put into the water in the room and column type residual mining area, a series of temperature sensors are put down along with the pipelines, are uniformly distributed in the water in the room and column type residual mining area, and detect the water temperature in the goaf in real time;
(6) refrigerating by a freezing station arranged in the roadway in the step (5), replacing accumulated water heat by circulating brine through a freezing pipe loop placed in accumulated water of the room and column type residual mining area in the step (4), enabling the accumulated water in the room and column type residual mining area to enter an active freezing period, enabling the accumulated water to be gradually frozen, enabling the accumulated water to be fully connected to the roof while being frozen by utilizing the characteristics that the water is changed along with the shape of an accommodating body and the frozen volume of the water is expanded, and enabling the frozen ice in the residual mining area to serve as a filling body to play a role in supporting a floor rock stratum of a tunneling and treading coal seam;
(7) after water accumulation and subsequent water injection in the room and column type residual mining area are completely solidified and frozen, reducing the refrigerating capacity of each freezing station in the step (4), leading the freezing work to enter a negative freezing period, ensuring that ice blocks are not thawed, and keeping the temperature of a frozen ice body constant at-8 ℃ to-10 ℃; when the accumulated water in the room-and-column type residual mining area is frozen and solidified, the locally-collapsed stones and the left coal pillars in the room-and-column type residual mining area are frozen in the ice body, and in addition, the ice body, the top bottom plate of the residual mining area, the left coal pillars and the surrounding rock form a whole together, so that a stable bottom plate environment is provided for the pushing of the working surface of the overlying and kicking-off coal seam;
(8) then under the support of the ice body maintained by negative freezing, the working surface of the overlying and kicking-off coal seam starts to be pushed forward, and the coal resources are gradually mined;
(9) and in the process of pushing the empty coal seam, reinforcing the support of the roadway, starting to gradually stop the freezing work in the mining roadway along the working face pushing direction when the mining working face is pushed to the position of 150m before the mining stopping line, removing the freezing equipment, and removing the freezing pipeline after the frozen body is melted.
2. The method for upward repeated mining of the kick-off coal seam by accumulated water in the frozen room and pillar type residual mining area according to claim 1, which is characterized in that: the accumulated water in the room-and-column type residual mining area is not communicated with the underground river, the long-term water volume of the accumulated water is basically unchanged, the accumulated water can be supplemented by a small amount of underground water and simultaneously flows away in a small scale, and the total water volume is in a dynamic stable state.
3. The method for upward repeated mining of the kick-off coal seam by accumulated water in the frozen room and pillar type residual mining area according to claim 1, which is characterized in that: the feasibility judgment method in the step (1) comprises the following steps: the feasibility of the upward mining of the overlying pedaled empty coal seam in the room and pillar type residual mining area is comprehensively judged by combining a three-belt judgment method, a surrounding rock balance method, a ratio judgment method, a mathematical analysis method and a quantitative judgment method.
4. The method for upward repeated mining of the kick-off coal seam by accumulated water in the frozen room and pillar type residual mining area according to claim 1, which is characterized in that: and (2) the widths and the heights of the room and column type residual mining area empty area group and the coal column group below the kick-off coal seam are investigated and cleaned through the original geological and technical data of the mine, the distribution direction, the size and the volume of the room and column type residual mining area empty area group are accurately detected by adopting a three-dimensional laser scanner, and the depth, the distribution range and the volume of accumulated water in the room and column type residual mining area are simultaneously detected.
5. The method for upward repeated mining of the kick-off coal seam by accumulated water in the frozen room and pillar type residual mining area according to claim 1, which is characterized in that: and (3) arranging a back-mining roadway and a working face of the kick-out coal seam above the explored room-and-column type residual mining area, widening the back-mining roadway by 1.0-1.2 times on the basis of meeting mining requirements, and excavating an auxiliary chamber in a transportation roadway for arrangement of a subsequent freezing station to avoid influencing back-mining work.
6. The method for upward repeated mining of the kick-off coal seam by accumulated water in the frozen room and pillar type residual mining area according to claim 1, which is characterized in that: in the step (4), in order to reduce the drilling workload, vertical drilling is selected, and the number of the drilling holes is determined by the cold demand, the volume of accumulated water and the freezing radius of a freezing pipeline; putting a freezing pipeline into accumulated water in the room-and-pillar type residual mining area through a drill hole, forming a group of closed loops by freezing pipes in the accumulated water in the goaf, circulating saline water, and replacing heat in the accumulated water to freeze the accumulated water into ice; and (3) determining the drilling position of the roadway according to the distribution form diagram of the room-and-pillar type residual mining area coal pillar group and the empty area group drawn in the step (2), and drilling at the position of the residual mining area empty area right below the excavated roadway.
7. The method for upward repeated mining of the kick-off coal seam by accumulated water in the frozen room and pillar type residual mining area according to claim 1, which is characterized in that: in the step (5), the type, power and number of the freezing equipment of the freezing station are selected, the required cooling capacity is determined according to the volume of the dead zone of the room-and-column type residual mining area and the accumulated water volume of the dead zone, which are detected in the step (2), and the CaCl is selected by the brine circulation system2The solution is used as a refrigerant, and a cooling water circulating system is naturally cooled by a cutting water pool; after the freezing parameters are determined, the trial operation of the equipment is carried out, and the whole system is formally constructed after running without errors.
8. The method for upward repeated mining of the kick-off coal seam by accumulated water in the frozen room and pillar type residual mining area according to claim 1, which is characterized in that: the uniaxial compressive strength of the frozen accumulated water in the room and column type residual mining area in the step (6) is 3-6 MPa, and the tensile strength is 1/2 of the compressive strength; the water in the step (6) expands in volume after being frozen, the volume of the frozen ice body is 1.1 times of that of the original water, the water is accumulated in the goaf which is not connected with the roof in the goaf, and the ice body can be fully connected with the roof after being frozen when the distance between the water surface and the roof is 10% of the total height of the goaf; when the accumulated water is less and the roof cannot be connected after being frozen, the ice forming amount is increased through manual water injection so that the roof can be fully connected.
9. The method for upward repeated mining of the kick-off coal seam by accumulated water in the frozen room and pillar type residual mining area according to claim 1, which is characterized in that: the passive freezing period in the step (7) refers to the freezing action of accumulated water in the room-column type residual mining area in the early active freezing period, the liquid-phase water is gradually and completely frozen, the freezing is basically finished, at the moment, the frozen ice body only needs to be maintained in a frozen state, and the temperature of circulating brine is increased by 5-10 ℃; ensure that the frost is not melted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911121454.3A CN110847955B (en) | 2019-11-15 | 2019-11-15 | Method for upward repeated mining of empty coal seam by freezing accumulated water in room-and-column-type residual mining area |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911121454.3A CN110847955B (en) | 2019-11-15 | 2019-11-15 | Method for upward repeated mining of empty coal seam by freezing accumulated water in room-and-column-type residual mining area |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110847955A CN110847955A (en) | 2020-02-28 |
| CN110847955B true CN110847955B (en) | 2021-04-20 |
Family
ID=69600347
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911121454.3A Active CN110847955B (en) | 2019-11-15 | 2019-11-15 | Method for upward repeated mining of empty coal seam by freezing accumulated water in room-and-column-type residual mining area |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110847955B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112832769B (en) * | 2021-03-22 | 2023-03-14 | 中国矿业大学 | Outburst prevention mining method of coal seam floor high-pressure-bearing water freezing method |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101109283B (en) * | 2007-08-20 | 2013-04-03 | 太原理工大学 | Quantitative decision method for feasibility of mining above hollow |
| CN103147737A (en) * | 2013-02-22 | 2013-06-12 | 姚强岭 | Drilling detection method for disclosing law of overburden failure in ascending mining |
| CN104832174B (en) * | 2015-03-17 | 2016-10-19 | 太原理工大学 | The method that the other bilateral up second mining of whole filling of a kind of post pedals sky coal seam |
| CN104790952B (en) * | 2015-03-17 | 2016-11-02 | 太原理工大学 | The other unilateral up second mining of part filling of a kind of post pedals the method in sky coal seam |
| CN107313778B (en) * | 2017-08-11 | 2019-07-26 | 太原理工大学 | A kind of second mining super high seam stops the method for adopting line coal column |
-
2019
- 2019-11-15 CN CN201911121454.3A patent/CN110847955B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110847955A (en) | 2020-02-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104314573B (en) | A kind of hard rock tunnel construction method based on waterpower cutting | |
| CN105971606B (en) | A kind of thick sandstone coal wall recovery method | |
| AU2019376347B2 (en) | A method for coal mining based on frozen aquifer for underground longwall face under water-conservation condition | |
| CN104358572B (en) | Non-pillar mining technology by spontaneous caving filling roadway at large inclined angle steeply inclined seam | |
| CN113175325B (en) | Coal and intergrown sandstone type uranium ore coordinated mining method based on key layer protection | |
| CN112610218B (en) | Thick coal seam fully-mechanized top-tunneling top-cutting pressure relief automatic roadway forming method | |
| CN109098714A (en) | A kind of soft extremely irregularcoal seam fully mechanized coal face gob-side entry retaining method of high methane three | |
| CN104632221A (en) | Liquid carbon dioxide blasting induced caving mining method | |
| CN110761791B (en) | Method for upward repeated mining of hollow coal seam by accumulated water among coal pillars in freezing cutter pillar type residual mining area | |
| CN110847954B (en) | Method for re-mining empty coal seam by accumulated water in tool post type residual mining area with top plate being frozen in sections | |
| Li et al. | Trial of small gateroad pillar in top coal caving longwall mining of large mining height | |
| CN110847955B (en) | Method for upward repeated mining of empty coal seam by freezing accumulated water in room-and-column-type residual mining area | |
| CN113738367A (en) | Sublevel caving downward filling mining method for complex broken and steeply inclined thin vein | |
| CN103233739A (en) | Mining method for thick and large ore pillar under filling body package | |
| CN113006797B (en) | Mining method for partial filling loss reduction of coal bed under surface valley runoff | |
| CN112610212B (en) | Mining area unidirectional tunneling coal pillar-free mining method | |
| CN113217044B (en) | Upward and oblique scattering type grouting water plugging method for deep large fault tunnel | |
| CN110792471B (en) | Sublevel open stoping subsequent filling mining method for artificially freezing filling body | |
| CN114000882A (en) | Caving method and filling method collaborative mining method for same mining area | |
| CN108194083B (en) | Honeycomb mining and strategic oil storage combined implementation method | |
| CN214145491U (en) | Mine left-over pillar extraction system | |
| CN114109393B (en) | Underground tunnel underground excavation construction method combining beam-combination pipe curtain and pipe-jacking freezing | |
| RU2043501C1 (en) | Method for driving tunnels in unstable water-saturated rocks | |
| Qihua et al. | Progressive backfill mining technology with split and two wings | |
| CN113550751B (en) | Method for recovering near-surface caving ore body |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |