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:
In an inclined layered solid-filling mining method in an ultrathick coal layer, tunnels and equipment are arranged according to a solid-filling mining method. An artificial roof for a lower layer is formed by metal meshes and bamboo fences of a first layer a solid-filling mining method. The method is repeated, until the entire ultrathick coal layer is finished. The method is repeated forming additional roofs for subsequent layers.
Abstract:
The present disclosure relates to the field of mineral processing and separation, and in particular, to an underground coal hypergravity field separation system and a separation process. The separation system includes a grading hydrocyclone group, hypergravity field separators, feeding pumps, and conveying pumps. Coal collected underground is graded through a grading hydrocyclone first, then is fed into the hypergravity field separators for separation, and finally, is conveyed to a next link for dehydration through the conveying pumps. The separation system of the present disclosure has less supporting equipment, small floor area, and no complex pipeline, and is suitable for a downhole operation. In addition, the hypergravity field separators can provide a high-strength centrifugal acceleration, which can realize rapid separation of coal gangue particles in a radial direction and a tangential direction, and realize effective separation of fine coal gangue particles.
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:
An inclined layered solid-filling mining method in an ultrathick coal layer is applicable to exploitation in a “three-unders” ultrathick coal layer. In this method, the number of inclined layers is determined based on a principle of layered thickness from 2.5 m to 4.5 m, and a layered-exploitation downward-filling exploitation order is adopted. Tunnels and equipment are arranged according to a conventional solid-filling mining method. A cyclic order of mining, layout of metal meshes (14) and bamboo fences (24), and filling is adopted, so as to accomplish filling and exploitation of a first mining face and a first layer (21). Meanwhile, 4 months after the working face of this layer is finished, at a corresponding position in a second layer (22), under the cover of an artificial ceiling formed by the first layer (21), exploitation is performed by using the same filling mining method; such a cycle is repeated, and exploitation in a current layer is performed under the cover of an artificial ceiling fabricated by an upper layer, until the entire ultrathick coal layer is finished. When this method is adopted to exploit “three-unders” ultrathick coal layer resources, strata movement and earth surface subsidence may be effectively controlled; the method has a high extraction rate, high production efficiency, and low cost.
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 solid-filling coal mining feeding and conveying monitoring system, suitable for monitoring of a vertical feeding and conveying system in underground mine solid-filling mining. The monitoring system mainly consists of an industrial control computer, a PLC control box, an operating platform, a liquid crystal display, a color four-picture divider, two video optical receivers and loudspeakers, four cameras, uphole electronic belt scales, downhole electronic belt scales, a radar level meter, a coal level sensor, a vibration sensor, and various matching junction boxes and cables, the components being installed in positions such as a material field, a control room, upper and lower openings of a storage silo, and a gangue transportation lane. The system implements four main functions of a solid-filling material transportation and feeding process, the four main functions being status monitoring, a full silo alarm, centralized control, and recording and querying. The monitoring content of the system is comprehensive; operation of the system is simple; and the system is safe and reliable.
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:
A solid-filling coal mining feeding and conveying monitoring system, suitable for monitoring of a vertical feeding and conveying system in underground mine solid-filling mining. The monitoring system mainly consists of an industrial control computer, a PLC control box, an operating platform, a liquid crystal display, a color four-picture divider, two video optical receivers and loudspeakers, four cameras, uphole electronic belt scales, downhole electronic belt scales, a radar level meter, a coal level sensor, a vibration sensor, and various matching junction boxes and cables, the components being installed in positions such as a material field, a control room, upper and lower openings of a storage silo, and a gangue transportation lane. The system implements four main functions of a solid-filling material transportation and feeding process, the four main functions being status monitoring, a full silo alarm, centralized control, and recording and querying. The monitoring content of the system is comprehensive; operation of the system is simple; and the system is safe and reliable.