Plasma reduction method for thick hard roof and left coal pillar composite strong mine pressure

Abstract

The invention discloses a plasma reduction method for composite high mine pressure of a thick and hard roof and an abandoned coal pillar in a residual mining area. A T-shaped drilling well is drilledin the ground over the abandoned coal pillar in the residual mining area, the T-shaped drilling well is divided into a T-shaped drilling well vertical section and a T-shaped drilling well horizontal section, the T-shaped drilling well vertical section penetrates through the overlying coal bed thick and hard roof and an overlying coal bed to get into the abandoned coal pillar of the underlying residual mining area, the T-shaped drilling well horizontal section is parallel to the advancing direction of a working face in the overlying coal bed thick and hard roof, and then the thick and hard roofand the abandoned coal pillar in the residual mining area are cracked by a plasma device. According to the plasma reduction method, the characteristic that strong movement between ions generates hightemperature and high pressure instantaneously is fully utilized, the T-shaped drilling well is drilled in the ground, double purposes are achieved through the one well, shock waves are formed, cracksare generated in the overlying coal bed thick and hard roof and the abandoned coal pillar in the residual mining area and are extended, the purpose of reduction of the composite high mine pressure ofthe thick and hard roof and the abandoned coal pillar in the residual mining area is achieved, thus coal mine green mining is achieved, and production is safe.

Description

technical field [0001] The present invention relates to a plasma The invention discloses a method and device for reducing the combined strong mine pressure of thick and hard roofs and left coal pillars, belonging to the technical field of coal mining. Background technique [0002] The so-called ascending mining method means first mining the underlying coal seam and then mining the overlying coal seam. When the overlying coal seam is mined, it will pass through the thick and hard roof between the layers and the remaining coal pillars in the underlying residual mining area, and the coal mining work will be affected by the upper and lower composite strong mine pressure. [0003] Composite strong rock pressure mainly comes from: (a) thick and hard roof: Due to natural geological conditions, the overlying coal seams in many mining areas have thick and hard roofs with large thickness, high strength, no joints and fissures, and good integrity; (b) residual Remaining coal pillars ...

AI Technical Summary

Problems solved by technology

However, the technology of reducing composite strong mine pressure by plasma is very important in the field of coal mining technology (especially in the field of plasma ground " However, there are few applications in reducing the thick and hard roof and the composite strong mine pressure of the remaining coal pillars in the residual mining area.

Images