The present disclosure relates to a technical field of coal mining, particularly to a method of no-pillar mining with gob-entry retaining adapted for fully-mechanized top coal caving in a thick coal seam, which comprises the following steps: reinforcing support on a roof and two sides of a roadway; performing roof slitting blasting to form a pre-splitting slit; erecting a temporary support device and a gangue retaining device in the roadway along the retained entry; performing no caving within a range of a preset distance at an end of the working face near the retained entry side; and removing the temporary support device in the roadway after entry forming stabilizes, and closing the goaf to complete entry retaining. The roof slitting blasting is more beneficial to collapse of strata in the goaf, so that the strata in the slit can better fill stoping space after collapse, and the roof of the retained entry forms a short arm beam structure laterally, which avoids forming a long suspended roof in the goaf, and improves the stress of surrounding rock of gob-side entry retaining; coal caving is not performed in a certain range at the end of the working face of the retained entry side, which further ensures the filling effect of the goaf on the retained entry side, effectively limits the rotary sinking of blocks of the main roof, and greatly reduces effect on the stability of the retained entry.

The present disclosure relates to a technical field of coal mining, particularly to a method of no-pillar mining with gob-entry retaining adapted for fully-mechanized top coal caving in a thick coal seam, which comprises the following steps: reinforcing support on a roof and two sides of a roadway; performing roof slitting blasting to form a pre-splitting slit; erecting a temporary support device and a gangue retaining device in the roadway along the retained entry; performing no caving within a range of a preset distance at an end of the working face near the retained entry side; and removing the temporary support device in the roadway after entry forming stabilizes, and closing the goaf to complete entry retaining. The roof slitting blasting is more beneficial to collapse of strata in the goaf, so that the strata in the slit can better fill stoping space after collapse, and the roof of the retained entry forms a short arm beam structure laterally, which avoids forming a long suspended roof in the goaf, and improves the stress of surrounding rock of gob-side entry retaining; coal caving is not performed in a certain range at the end of the working face of the retained entry side, which further ensures the filling effect of the goaf on the retained entry side, effectively limits the rotary sinking of blocks of the main roof, and greatly reduces effect on the stability of the retained entry.

A method for carrying out grouting between adjacent gateroads in internal-staggered split-level coal mining. A return air gateroad of a stoping face and an inlet air gateroad of a heading face are not on the same level. The return air gateroad of the stoping face is arranged along a roof of a coal seam. The inlet air gateroad of the heading face is arranged along a floor of the coal seam. There is a height difference between the return air gateroad and the inlet air gateroad in a vertical direction. During the construction process, the inlet air gateroad is excavated at a delay distance of 180-200 meters from the return air gateroad. The drilling and grouting are performed while excavating the roadway, where grouting holes are arranged in a single row. A device for implementing the method is also provided.

A method for carrying out grouting between adjacent gateroads in internal-staggered split-level coal mining. A return air gateroad of a stoping face and an inlet air gateroad of a heading face are not on the same level. The return air gateroad of the stoping face is arranged along a roof of a coal seam. The inlet air gateroad of the heading face is arranged along a floor of the coal seam. There is a height difference between the return air gateroad and the inlet air gateroad in a vertical direction. During the construction process, the inlet air gateroad is excavated at a delay distance of 180-200 meters from the return air gateroad. The drilling and grouting are performed while excavating the roadway, where grouting holes are arranged in a single row. A device for implementing the method is also provided.

A pit designing method is provided without coal-pillar leaving and laneway excavation. The method includes drilling a main shaft and an auxiliary shaft from a ground to a coal bed and exploiting in the coal bed first and second connection laneways. The first connection laneway is in communication with the main shaft, and the second connection laneway is in communication with the auxiliary shaft. The method further includes communicating the first and second connection laneways, and using a communication part between the first connection laneway and the second connection laneway as a first open-off cut; and by using a direction of the first open-off cut further away from the connecting line connecting the main shaft and the auxiliary shaft as a first direction, and exploiting by cutting a coal wall in the first direction using a coal mining machine.

A pit designing method is provided without coal-pillar leaving and laneway excavation. The method includes drilling a main shaft and an auxiliary shaft from a ground to a coal bed and exploiting in the coal bed first and second connection laneways. The first connection laneway is in communication with the main shaft, and the second connection laneway is in communication with the auxiliary shaft. The method further includes communicating the first and second connection laneways, and using a communication part between the first connection laneway and the second connection laneway as a first open-off cut; and by using a direction of the first open-off cut further away from the connecting line connecting the main shaft and the auxiliary shaft as a first direction, and exploiting by cutting a coal wall in the first direction using a coal mining machine.

A coal mining method is provided without coal-pillar leaving and without laneway excavation in a full mining area. The coal mining method includes drilling a main shaft, an auxiliary shaft and a return air shaft from a ground to a coal mining layer; by a coal mining machine, forming a first mining face with a first direction as an advance direction; by the coal mining machine, cutting out a first haulageway and a first return airway while cutting the coal wall at the first mining face, and preserving the first haulageway and the first return airway. In this method, the first haulageway and the first return airway are located on two sides of the first mining face, the first haulageway is in communication with both of the main and auxiliary shafts, and the first return airway is in communication with the return air shaft.

A coal mining method is provided without coal-pillar leaving and without laneway excavation in a full mining area. The coal mining method includes drilling a main shaft, an auxiliary shaft and a return air shaft from a ground to a coal mining layer; by a coal mining machine, forming a first mining face with a first direction as an advance direction; by the coal mining machine, cutting out a first haulageway and a first return airway while cutting the coal wall at the first mining face, and preserving the first haulageway and the first return airway. In this method, the first haulageway and the first return airway are located on two sides of the first mining face, the first haulageway is in communication with both of the main and auxiliary shafts, and the first return airway is in communication with the return air shaft.

A deep low-permeability high gassy seam drilling-slitting-sealing-fracturing drilling device includes a drilling control system, a high-pressure water power system, a water pressure grading control system and a fracturing and sealing control system. The drilling control system adjusts a drilling direction a water supply pressure of the drill rod, the high-pressure water power system supplies high-pressure water with different pressures to the device, and the water pressure grading control system ensures that a water pressure for flushing drill cuttings is less than 5 MPa, a water pressure for slitting in a direction perpendicular to a length of the drill rod is 25-35 MPa, a water pressure for sealing with a borehole sealing capsule is 35-40 MPa, and a water pressure for further pressure relief and permeability increasing of a coal seam is 40-50 MPa. The fracturing and sealing control system controls borehole sealing and hydrofracturing operations.

An automatic coal mining machine and a fluidized coal mining method are provided. A first excavation cabin is configured to cut coal seam to obtain raw coal and to be transported to a first coal preparation cabin for separating coal blocks from gangue. Then, the obtained coal blocks are transported to a first fluidized conversion reaction cabin. The first fluidized conversion reaction cabin converts the energy form of the coal block into liquid, gas or electric energy, which is transported to a first energy storage cabin for storing. Coal mining and conversion are carried out in underground coal mines, so it is not necessary to raise coal blocks to the ground for washing and conversion, thereby reducing the transportation cost of coal, improving the utilization degree of coal, and avoiding the pollution of the ground environment caused by waste in the mining and conversion process.