Plugging for Damaged Drainage Hole in the Fourth Aquifer of Qidong Coal Mine Unconsolidated Formation

To ensure the safety of Qidong Coal Mine 7131 working face, we need to plug 32^# drainge hole ar airway. However, the hole is unable to use the original casing to grout and plug due to the quality problems. Using hole casing, grouting and other methods to inject aggregate, we successfully plug the damaged drainage hole.