Method and device for plasma weakening of underlying coal seam mining with thick and hard roof and strong mine pressure

Abstract

The invention discloses a method and a device for weakening strong ore pressure of an underlying coal seam mining thick hard roof by plasma, and belongs to the field of coal mining. When an overlyingcoal seam is mined, the underlying coal seam thick hard roof is pre-cracked by a plasma device to weaken the strong ore pressure of the underlying coal seam mining thick hard roof in advance. According to the invention, a shock wave is formed by using the characteristics that high temperature and high pressure are produced at an instant of strong motion among ions to produce a crack and expand thecrack, which is convenient in operation and simple in method. A top suspension area of a goaf is reduced, the step pitch between first weighting and periodic weighting is shortened, the weighting strength is reduced, and so the damage of the thick hard roof to the safe production of a mine is reduced or eliminated and the safety of roof management is greatly improved. Compared with a conventionalsystem and method for weakening strong ore pressure of the underlying coal seam mining thick hard roof, the method and device of the invention are converted from an extensive type to a fine type andrealizes the green mining and safe production of coal mines.

Description

technical field [0001] The invention relates to a method and a device for plasma-weakened underlying coal seam mining with thick and hard roof and strong mine pressure, belonging to the field of coal mining. Background technique [0002] Most of the coal mines in my country use the downward mining method, that is, the overlying coal seam is mined first and the underlying coal seam is mined, and the underlying coal seam in many mining areas has thick and hard roofs with large thickness, high strength, no joints and fissures, and good integrity. When the working face continues to move forward, the suspended roof area of ​​the thick and hard roof in the stope will gradually increase without collapsing, and the initial / periodic pressing step distance of the thick and hard roof in the stope will also increase, and a large amount of Energy, when the thick and hard roof of the stope suddenly collapses, the accumulated energy will be released instantly, which will cause severe impac...

AI Technical Summary

Problems solved by technology

However, the technology of plasma weakening strong mine pressure is rarely applied in the field of coal mining technology (especially in the field of plasma advanced weakening of underlying coal seam mining thick and hard roof strong mine pressure)

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