Patent ID: 12252972

DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical solutions in the embodiment of the present disclosure will be described clearly and completely with reference to the attached drawings. Apparently, the described embodiments are only a part of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by one of ordinary skill in the art without creative effort belong to the protection scope of the present disclosure.

In order to make the above objectives, features and advantages of the present disclosure clearer and easier to understand, the present disclosure will be further described in detail with the attached drawings and specific embodiments.

A fluidized coal mining method utilizing self-energy storage of a coal seam is provided, as shown inFIG.1, includes following steps.

A mine roadway is developed: a buried depth, a size and a dip angle of the coal seam1to be mined are detected and determined, and different mining zones and a mining sequence are delineated; and the coal seam1is drilled through a well drilling system to form a lifting shaft2; a roadway system is developed along a bottom of the lifting shaft2, and a ground equipment system is installed on a ground, the roadway system is arranged below the coal seam1.

Coal is uncovered actively: an explosive is sent to the roadway system through the lifting shaft2, a top of the lifting shaft2is sealed, the explosive is detonated to disturb the coal seam1so as to trigger a dynamic phenomenon of coal and gas outburst, and a fluid mixture formed by explosion is treated through the ground equipment system.

Fluidized coal mining: according to a position of an outburst hole6formed after the coal is uncovered actively, a position of a coal-mining drilling well is determined12on the ground, and the coal-mining drilling well12is drilled to an upper part of the roadway system through the well drilling system and then is stopped, a mining zone is formed; and the mining zone is mined.

A goaf is backfilled: after a first mining zone is mined, the goaf31is formed, and the goaf31is backfilled through the ground equipment system to enable the goaf31and the roadway system to form a gangue backfill zone32.

After the backfilling is completed, the above steps are repeated, and a next adjacent coal mining zone is mined in turn until the whole coal seam1is mined.

In the step of coal seam mining, the ground equipment system includes a gas filtering and compressing device9, a gas storage tank10, a settling pond20, a mixture separation device21, a gangue storage chamber22, a water storage tank23, a high-pressure pump24and a coal storage bunker25.

The gas filtering and compressing device9is hermetically connected to a gas drainage hole8opened at the top of the lifting shaft2; the gas filtering and compressing device9is hermetically connected to the gas storage tank10through a gas conveying pipeline.

One end of the mixture separation device21is connected to the settling pond20opened on the ground through a conveying pipeline, and the other end is in communication with the gangue storage chamber22, the water storage tank23and the coal storage bunker25through valves respectively, and the water storage tank23is hermetically connected to the high-pressure pump24through a water delivery pipeline.

In the step of coal seam mining, the well drilling system includes a coal-rock mixture conveying pipe28arranged in the lifting shaft2; a bottom end of the coal-rock mixture conveying pipe28is provided with a slurry suction pump26and a crushing and stirring device27, and a top end is connected to the settling pond20.

The top of the lifting shaft2is sealed by a wellhead sealing unit11.

In the step of fluidized coal mining, the well drilling system also includes a coal-mining drilling pipe13arranged in the coal-mining drilling well12; an inner cavity of the coal-mining drilling pipe13is hermetically connected to an output end of a high-pressure water pipe14, and an input end of the high-pressure water pipe14is in communication with the high-pressure pump24.

A bottom end of the coal-mining drilling pipe13is in transmission connection with a coal mining drill15, and a bottom of the coal-mining drilling pipe13is also provided with a rotation control device16, and a high-pressure ejector is fixedly installed on the rotation control device16through an injection distance telescopic rod18, and a hollow water passage is opened in the injection distance telescopic rod18, and the hollow water passage is in communication with the inner cavity of the coal-mining drilling pipe13.

The roadway system includes a coal-rock collection chamber3and a floor roadway4; a bottom end of the lifting shaft2is in communication with the coal-rock collection chamber3; the floor roadway4is excavated along the coal-rock collection chamber3, and the floor roadway4is connected to the coal seam through a cross-cut5.

In the step of uncovering coal actively, specific steps are: the explosive is sent to the cross-cut5at a bottom of the coal seam1through the lifting shaft2, and the top of the lifting shaft2is sealed through a wellhead sealing unit11, the explosive is detonated to disturb the coal seam1. The fluid mixture formed by the explosion enters the coal-rock collection chamber3through the floor roadway4and then is stored in the gas storage tank10through the gas drainage hole8, as shown inFIG.2.

As shown inFIG.3, in the step of fluidized coal mining, the coal-mining drilling well12is drilled to the upper part of the roadway system through the well drilling system specifically includes: the high-pressure pump24and the water storage tank23are arranged at a wellhead of the coal-mining drilling well12, the coal-mining drilling pipe13is extended into the coal-mining drilling well12, and the coal-mining drilling well12is developed through the coal mining drill15; and after the coal-mining drilling well12is drilled, continuing to drill a coal seam drilling section19towards the coal seam1until reaching an upper part of the cross-cut5, and the drilling is stopped.

In the step of fluidized coal mining, the mining zone is formed specifically includes: hydraulic cutting is performed to a loose coal seam around the outburst hole6by the high-pressure ejector17, and the coal-mining drilling pipe13is controlled to slowly retreat until the high-pressure ejector17retreats to a top end of the coal seam drilling section19to complete preliminary mining.

Lowering and resetting of the coal-mining drilling pipe13are controlled to enable the high-pressure ejector17to reach a lower limit position of the buried depth of the coal seam, the injection distance telescopic rod18is extended to increase an effective injection distance of the high-pressure ejector17and a water pressure is increased, so as to enlarge a hydraulic coal breaking radius, and the above steps are repeated cyclically until the first mining zone is mined.

In the step of fluidized coal mining, the mining zone is mined includes: after being cut in the mining zone, the coal-rock mixture is sent into the coal-rock collection chamber3along the floor roadway4, and lifted into the settling pond20by the slurry suction pump26and the crushing and stirring device27.

As shown inFIG.4, the goaf is backfilled includes: a plugging unit29is constructed in the floor roadway4neighbouring a bottom of the adjacent coal seam1adjacent to the goaf31, and the gangue in the gangue storage chamber22is transported to the goaf31for backfilling through the gangue conveying pipe30, so that the goaf31and a part, neighbouring the bottom of the goaf31, of the floor roadway4form the gangue backfill zone32.

After the backfilling is completed, the above steps are repeated, and a next adjacent mining zone is mined in turn until the mining of the coal seam1is completed, and the coal-rock collection chamber3and the lifting shaft2are backfilled.

In one embodiment of the disclosure, in the step of uncovering coal actively, the explosive is detonated to disturb the coal seam1to trigger a dynamic phenomena such as coal and gas outburst, so that a large amount of gas expansion energy, crustal stress energy and gravitational potential energy stored in the coal seam1are instantly released and act on the coal seam1itself to achieve the purpose of highly crushing the coal seam1, thereby completing the active coal uncovering and forming a fluid mixture of coal, rock, gas and water. The initial high crushing of the coal is realized, and the coal of the coal loosen zone7around the outburst hole is loosened, thereby improving the efficiency of subsequent fluidized coal mining and hydraulic coal mining.

In one embodiment of the present disclosure, the floor roadway4and the coal seam1both have a dip angle of 5°, ensuring that the coal-rock mixture with outburst and hydraulic coal breaking may be automatically transported to the coal-rock collection chamber3under the conditions of doing work through continuous expansion of gas and work through self-gravity so as to avoid the blockage of the floor roadway4.

Further, the coal-mining drilling well12is used to drill the outburst hole6, and the coal seam1around the outburst hole6is subjected to in-situ hydraulic cutting. The coal-rock mixture subjected to hydraulic cutting flows into the coal-rock collection chamber3along the floor roadway4, and is lifted up to the well by the slurry suction pump26to enter the settling pond20, thus realizing efficient fluidized coal mining.

In one embodiment of the present disclosure, gas is extracted synchronously during coal mining. Meanwhile, the coal-rock mixture lifted up to the well by the slurry suction pump26enters into the settling pond20, and is separated into coal, water and gangue by the mixture separation device21. The coal is transported to the coal storage bunker25, and the water is sent to the water storage tank23via water pipe for recycling. The gas released from the coal seam and broken coal particles during coal mining enters the gas filtering and compressing device9through the gas drainage hole8, purified and stored in the gas storage tank10, the separated water is returned to the water storage tank23for recycling in fluidized coal mining. And the gangue is used for backfilling the goaf31and the floor roadway4, realizing the full utilization of resources in the coal mining process.

In one embodiment of the present disclosure, by extending the injection distance telescopic rod18, the injection range of the high-pressure injector17may be effectively increased, and the dimension of the single mining zone is increased, so as to reduce the drilling construction project and improve the coal mining efficiency.

In one embodiment of the present disclosure, the mining zone is defined in advance according to the coal seam condition, and the goaf31and floor roadway4of the previous block are backfilled before mining this block to prevent the roof from collapsing in the subsequent mining, so there is no need to leave coal pillars in the subsequent mining process, which effectively improves the recovery rate of coal resources.

In one embodiment of the present disclosure, backfill is carried out in the mining zone adjacent to the goaf and the mining zone boundary33formed by the goaf; the mining zones adjacent to the goaf are mined in turn, and extend along the floor roadway4. The cross-cut5is formed at the bottom of the remaining mining zone. The floor roadway4at the bottom of the goaf and the cross-cuts5at the bottoms of remaining mining zones are cut off by the constructing the plugging unit.

In the description of the present disclosure, it should be understood that the terms “longitudinal”, “transverse”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, etc. indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, only for the convenience of describing the present disclosure, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the disclosure.

The above-mentioned embodiments only describe the preferred mode of the present disclosure, and do not limit the scope of the present disclosure. Under the premise of not departing from the design spirit of the present disclosure, various modifications and improvements made by one of ordinary skill in the art to the technical solution of the present disclosure shall fall within the protection scope determined by the claims of the present disclosure.