Abstract: Provided are a system and a method for monitoring bearing compression rate of a filler in a coal mine gob area. An ground information processing system, a vibration source control system, and a monitoring system are arranged on the ground according to a buried depth of the filler in the gob area. The vibration source control system generates vibration, and transmits a signal to the filler. The monitoring system on the ground receives different reflected waves according to different elasticities of the fillers under different compaction degrees. Final data is transmitted to the ground information processing system for data processing. The monitoring of the filler starts when the filler is filled in the gob area; the filler is gradually compacted. The filler is monitored until the thickness of the filler does not change. Finally, a bearing compression rate formula is utilized to calculate the bearing compression rate of the filler.

Abstract: Provided is a method for radially mining open-pit end slope pressed coal, including: L-shaped or U-shaped main tunnel arrangements, and radially mining; branch tunnels are formed by excavating tunnels in directions perpendicular to or obliquely crossing the main tunnel from the L-shaped or U-shaped main tunnel; In the mining method, a coal mining system and a transportation system both adopt a remote control mode, a tunneling machine excavates a tunnel to product coal; a rubber belt conveyor conveys coal; the main tunnel adopts an exhaust ventilation mode, the branch tunnels adopt a blowing ventilation mode; the lengths of the branch tunnels do not exceed a farthest control distance of a remote control system; the length of each main tunnel needs to ensure that all the end slope pressed coal is mined under the premise that the branch tunnels do not exceed the farthest control distance of the remote control system.

Abstract: Provided is a method for recovering room-type coal pillars by cemented filling of reserved roadways, which is especially suitable for safe and efficient recovery of left coal pillars in room-type mining faces in mining areas where the ecological system is fragile, such as in western China. In the method, by constructing reserved roadways in two adjacent rows of room-type goafs, excavating coal pillar roadways in room-type coal pillars, and finally interconnecting the reserved roadways with the coal pillar roadways to form a U-shaped working face, room-type left coal pillars are recovered. Thus, not only the workload of roadway excavation is reduced, but also the recovery ratio of the coal resources is maximized. The method provides a novel technical model for the recovery of room-type left coal pillars in mining areas, such as in western China.

Abstract: An internally injected replacement support room-type coal pillar recovery method is provided. During the recovery, the room-type coal pillars with an aspect ratio greater than 0.6 are divided into two parts: reserved coal pillars and pre-mined coal pillars. After the mining of the pre-mined coal pillars, a cemented filling material is injected into a goaf surrounded by the reserved coal pillars, and is stabilized to replace the coal pillars for support, and the reserved coal pillars are recovered. A mechanical model of the reserved coal pillars in a support overburden stage is established based on the Winkler beam theory, to obtain displacement and stress conditions of a roof of the reserved coal pillar in a support stage. A theoretical reserve-width of the reserved coal pillars is obtained according to a first strength theory of the roof and a criterion of ultimate strength of the reserved coal pillars.

Abstract: Provided is a method for recovering room-type coal pillars by cemented filling of reserved roadways, which is especially suitable for safe and efficient recovery of left coal pillars in room-type mining faces in mining areas where the ecological system is fragile, such as in western China. In the method, by constructing reserved roadways in two adjacent rows of room-type goafs, excavating coal pillar roadways in room-type coal pillars, and finally interconnecting the reserved roadways with the coal pillar roadways to form a U-shaped working face, room-type left coal pillars are recovered. Thus, not only the workload of roadway excavation is reduced, but also the recovery ratio of the coal resources is maximized. The method provides a novel technical model for the recovery of room-type left coal pillars in mining areas, such as in western China.

Abstract: A mine exploitation method based on stoping, separation and filling control is disclosed herein. The method includes deploying a gangue-less coal mining system; choosing a suitable coal and gangue separation method according to a separation requirement; choosing a suitable filling method according to mine geology, production conditions and rock stratum control requirement; reversely calculating a filling rate according to gangue discharge requirement and control indexes by utilizing theoretical calculation, simulation and experiment; determining a filling process and a separation process according to the filling rate; and feeding back and adjusting the filling process and separation process parameters by monitoring filling and control effect indexes.

Abstract: Provided are a system and a method for monitoring bearing compression rate of a filler in a coal mine gob area. An ground information processing system, a vibration source control system, and a monitoring system are arranged on the ground according to a buried depth of the filler in the gob area. The vibration source control system generates vibration, and transmits a signal to the filler. The monitoring system on the ground receives different reflected waves according to different elasticities of the fillers under different compaction degrees. Final data is transmitted to the ground information processing system for data processing. The monitoring of the filler starts when the filler is filled in the gob area; the filler is gradually compacted. The filler is monitored until the thickness of the filler does not change. Finally, a bearing compression rate formula is utilized to calculate the bearing compression rate of the filler.

Abstract: Provided is a method for radially mining open-pit end slope pressed coal, including: L-shaped or U-shaped main tunnel arrangements, and radially mining; branch tunnels are formed by excavating tunnels in directions perpendicular to or obliquely crossing the main tunnel from the L-shaped or U-shaped main tunnel; In the mining method, a coal mining system and a transportation system both adopt a remote control mode, a tunneling machine excavates a tunnel to product coal; a rubber belt conveyor conveys coal; the main tunnel adopts an exhaust ventilation mode, the branch tunnels adopt a blowing ventilation mode; the lengths of the branch tunnels do not exceed a farthest control distance of a remote control system; the length of each main tunnel needs to ensure that all the end slope pressed coal is mined under the premise that the branch tunnels do not exceed the farthest control distance of the remote control system.

Abstract: A multilevel deep well cooling and geothermal utilization system and process. The system has a deep well heat harnessing system, a shallow part heat-exchanging system, and a high-temperature water lifting system. The deep well heat harnessing system has a heat absorbing pipe, a thermally-conductive fluid lifting pipe, a thermally-conductive fluid lowering pipe, temperature sensors, and a water pump. The shallow part heat-exchanging system has a heat-dissipating pipe, a heat-storing water pool, a water intake pump, a water intake valve, a temperature sensor and a liquid level meter. The high-temperature water lifting system has a water discharging pump, a flowmeter, a water discharging valve, and a high-temperature water lifting pipe.

Abstract: A method of recovering a room-and-pillar coal pillar by using external replacement supports. In the recovery of a room-and-pillar coal pillar, a cement material wall is formed by performing pouring around a coal pillar having a width to height ratio of less than 0.6, by means of a single-pillar sack arrangement technique, such that a coal pillar resource may be mined while a wall made from a cement filling material supports an overlying stratum. After mining is complete, a coal pillar goaf region is filled with the cement filling material, and after the cement filling material solidifies and is stable, the single pillar can be recovered.

Abstract: The present invention discloses a mine exploitation, separation and filling and X exploitation mode, including four “exploitation, separation and filling and X” exploitation modes, namely an “exploitation, separation and filling and retaining” exploitation mode, an “exploitation, separation and filling and treatment” exploitation mode, an “exploitation, separation and filling and extraction” exploitation mode, and an “exploitation, separation and filling and control” exploitation mode. The selection of the “exploitation, separation and filling and X” exploitation mode is determined by actual engineering needs. A goaf filling rate is designed to meet the actual engineering needs of the mine, solve the technical problems in mine resource exploitation, and realize the objective of green, harmonious and safe exploitation of coal resources.

Abstract: Provided is a base mechanism of a single prop capable of being unloaded at reduced pressure, including a base bottom plate and two wedge-shaped support blocks, where one of the wedge-shaped support blocks serves as a fixed wedge-shaped support block and is welded onto the base bottom plate, and the other of the wedge-shaped support blocks serves as a movable wedge-shaped support block and is connected to the fixed wedge-shaped support block by using a screw rod and a nut. The present invention can effectively unload the single prop at reduced pressure or remove the single prop in a contracted manner, is of a simple structure, is convenient to operate, has a good use effect, overcomes the technical problem that it is difficult to unload a single prop at reduced pressure in this technical feature, and is widely applicable in this technical field.

Abstract: The present invention discloses a mine exploitation method based on stoping, separation and filling control. The design process comprises: deploying a gangue-less coal mining system; choosing a suitable coal and gangue separation method according to a separation requirement; choosing a suitable filling method according to mine geology, production conditions and rock stratum control requirement; reversely calculating a filling rate according to gangue discharge requirement and control indexes by utilizing theoretical calculation, simulation and experiment; determining a filling process and a separation process according to the filling rate; and feeding back and adjusting the filling process and separation process parameters by monitoring filling and control effect indexes.

Abstract: The present invention discloses a mine exploitation, separation, filling and treatment exploitation method, including main sources of gangue on a small-volume gangue exploitation working face and gangue reducing measures; system layout, equipment and separation technology for coal gangue separation; system layout, equipment and production technology for filling synergistic caving type coal efficient stoping; pretreatment and pre-control measures for environmental influence before and after gangue filling; and design principle and design steps of the mine “exploitation, separation, filling and treatment” exploitation method.

Abstract: An internally injected replacement support room-type coal pillar recovery method is provided. During the recovery the room-type coal pillars with an aspect ratio greater than 0.6 are divided into two parts: reserved coal pillars and pre-mined coal pillars. After the mining of the pre-mined coal pillars, a cemented filling material is injected into a goaf surrounded by the reserved coal pillars, and is stabilized to replace the coal pillars for support, and the reserved coal pillars are recovered. A mechanical model of the reserved coal pillars in a support overburden stage is established based on the Winkler beam theory, to obtain displacement and stress conditions of a roof of the reserved coal pillar in a support stage. A theoretical reserve-width of the reserved coal pillars is obtained according to a first strength theory of the roof and a criterion of ultimate strength of the reserved coal pillars.

Abstract: A method of recovering a room-and-pillar coal pillar by using external replacement supports. In the recovery of a room-and-pillar coal pillar, a cement material wall is formed by performing pouring around a coal pillar having a width to height ratio of less than 0.6, by means of a single-pillar sack arrangement technique, such that a coal pillar resource may be mined while a wall made from a cement filling material supports an overlying stratum. After mining is complete, a coal pillar goaf region is filled with the cement filling material, and after the cement filling material solidifies and is stable, the single pillar can be recovered.

Abstract: Provided is a base mechanism of a single prop capable of being unloaded at reduced pressure, including a base bottom plate and two wedge-shaped support blocks, where one of the wedge-shaped support blocks serves as a fixed wedge-shaped support block and is welded onto the base bottom plate, and the other of the wedge-shaped support blocks serves as a movable wedge-shaped support block and is connected to the fixed wedge-shaped support block by using a screw rod and a nut. The present invention can effectively unload the single prop at reduced pressure or remove the single prop in a contracted manner, is of a simple structure, is convenient to operate, has a good use effect, overcomes the technical problem that it is difficult to unload a single prop at reduced pressure in this technical feature, and is widely applicable in this technical field.

Abstract: The present invention discloses a method for determining internal stress of a solid filling material, comprising the following steps: step 1) acquiring stress data of the solid filling material, and fitting the stress-strain relationship of the solid filling material; step 2) calculating surface subsidence in the solid filling area on the basis of an equivalent mining height theory with a probability integration method; step 3) calculating the expansion height of fractured zones in the area under a solid-backfill coal mining condition; step 4) calculating the strain in the solid filling material at a distance L from the rear of the stope by combing with step 2) and step 3); step 5) calculating internal stress in the solid filling material at distance L from the rear of the working face. The present invention attains the following beneficial effects: the present invention provides a method for calculating the stress in filling mass for solid-backfill coal mining.

Abstract: A method for determining a physical similarity simulation material of a solid backfill body is provided. A compaction test is run on a gangue backfill body in a lab, to obtain a ?-? curve regarding the gangue backfill body in the compaction process. Backfill blocks are made by using a thin wood board, sponge, and a paper sheet in different proportions, and then an unconfined compression test is separately run on the backfill blocks used for physical similarity simulation, to obtain ?i-?i curves regarding the backfill blocks in the compression process. A sum of squared errors ?(?i??0)2 is introduced to separately calculate a sum of squared errors of the backfill block and that of the gangue backfill body, and accordingly an error between ?-? curves regarding the test block and the gangue backfill body is determined. Finally, a backfill block for which the sum of squared errors is less than 0.5 is determined as a physical similarity simulation material of the gangue backfill body.

Abstract: A method for recovering room-mining coal pillars by solid filling in synergy with artificial pillars. Solid materials and cementing materials on the ground are conveyed through a feeding well and a pipeline to a room-and-pillar goaf, a plurality of artificial pillars is cast at an interval in a coal room area, and gangue is cast to fill other regions of the coal room using a gangue casting machine. Under joint support by the artificial pillars and the coal room filler, coal pillars are recovered using a continuous coal mining machine, artificial pillars are cast in the original coal pillar area after recovery, and gangue is cast to fill the original coal pillar area using the gangue casting machine. A system for recovering room-mining coal pillars by solid filling in synergy with artificial pillars mainly includes a material conveying system, a joint support system, and a coal pillar recovery system.