Method for partial recovery of residual coal from wide coal pillar

Abstract

The invention discloses a method for partial recovery of residual coal from a wide coal pillar; the method is mainly applied to low gas mines or mines meeting ventilation requirement; the method comprises the following steps: (1) from a district gathering roadway, digging a mining preparatory roadway from a coal body on one side of the wide coal pillar and reserving a thin-coal-wall protection roadway; (2) rotating by a certain angle alpha when the mining preparatory roadway keeps a certain distance from the boundary of a mining area, and digging a mining roadway; (3) after digging to a coal pillar at the boundary of the mining area, arranging an inclined short-wall working surface in a manner of being parallel to the coal pillar at the boundary of the mining area; (4) mining along the direction of the mining roadway, and reserving a security coal pillar when keeping a certain distance with the mining roadway; (5) after the first short-wall working surface is mined out, recovering partial triangle coals along the end of the mining preparatory roadway by virtue of a fully-mechanized excavating machine; and (6) repeating steps (2)-(5) by spacing a security coal pillar along the mining preparatory roadway to arrange short-wall working surfaces in a parallel manner, so as to gradually recover the residual coal from the wide coal pillar sequentially.

Description

technical field [0001] The invention relates to the field of coal mining, in particular to a method for partially recovering residual coal from large coal pillars. Background technique [0002] With the depletion of coal resources, especially in the south where there are relatively few coal resources, it is urgent to increase the recovery rate of coal resources. The original large coal pillar with a width of tens of meters has caused a lot of waste of coal resources, and mining the residual coal of the large coal pillar can recover a large amount of coal resources and improve economic benefits. However, the large coal pillar is similar to the island working face, and the stress environment is relatively complex. Not only are both sides subjected to lateral abutment pressure, but also are subjected to advanced abutment pressure during mining, and the stress concentration factor is very high. Ordinary coal mining methods are difficult to guarantee the safe and efficient recov...

AI Technical Summary

Problems solved by technology

However, the large coal pillar is similar to the island working face, and the stress environment is relatively complex. Not only are both sides subjected to the lateral bearing pressure, but also the advanced bearing pressure during mining, and the stress concentration factor is very high.

Ordinary coal mining methods are difficult to ensure safe and efficient recovery of large coal pillars

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