The room and pillar method mainly relies on the stability of the surrounding rock and the remaining pillars for ground pressure management. If stability is poor roof slate stone, rock top plate may be installed by the pole, to increase its stability, if the local instability, may leave some areas in these pillars. This mining method is therefore more flexible.
The pillars left by the room column method are initially continuous pillars (also called mines), and the pillars are generally not recovered, as permanent losses. Later, with the development of mining technology, the continuous pillar will be changed to a discontinuous pillar, which can improve the ore recovery rate.
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