How does the single pillar mining face finish?
When the mining face is advanced to the prescribed stop line, it is time to move the face. At this point, it is necessary to finish the work: withdraw all the brackets and electromechanical equipment, and make the roof fall. This is a difficult job, and if it is not good, there will be a roof accident.
In order to prevent the loss of the monomer hydraulic (friction) pillars during recycling, generally two or three days before the closing, a new row of wooden columns is pushed for each row of the working face, and the replaced single pillars and top beams are removed from the lower slot. After the replacement is completed, the electromechanical equipment can be removed and the wooden column can be recovered from the bottom up by the column winch. This finishing method is suitable for the condition that the roof of the working face is stable. Because the working surface iron and wood column are mixed during the replacement process, and the shrinkage and supporting force of the two pillars are different, the roof is unevenly scattered, and the stepped crack is often formed, the roof is broken, and even the roof is collapsed. In order to avoid this phenomenon, some only advance in the recovery of a section of the support. Sporadic wood column.
The following safety measures should be taken when finishing the working face: when picking up the stop line, leave a minimum support top clearance space for pedestrians and transportation; use the girders and rafts to maintain the upper exit, after the guarantee The road is unblocked; the order of returning the column is from the goaf to the coal wall, from bottom to top; the working face with the working face and the middle roadway, if the angle of inclination is not large, can be recovered from the middle to the middle; the work of returning the column must be familiar with the nature of the roof Responsible and strong workers, one person to return to the column operation, must also have a special person to observe the roof, the pillars in the goaf should be recycled to the net; as the lower roof is blocked, if the working surface temperature rises, harmful gases accumulate, The return air duct should be equipped with a local fan to enhance ventilation, and so on.
If the angle of inclination is not large, it is also possible to carry out the withdrawal of the work surface from top to bottom. However, this method must pay special attention to the downward rolling of the falling rock of the roof, and it is necessary to formulate corresponding safety technical measures.
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