Research and Application of Pulverized Coal with Pressure Grouting Hole Sealing Technology

In order to make further understanding about the sealing performance and actual sealing effect of the new sealing technique of pulverized coal with pressure grouting hole sealing technology, in this paper, the methods of laboratory experiment and field experiment are used to make deep exploratory development to the pulverized coal with pressure grouting hole sealing technology, the results show that: the sealing material consisting of coal powder and additives has a certain micro-expansion characteristics, and with the decrease of water-cement ratio, the expansion of coal powder sealing material increases gradually; good sealing effect can be achieved by pulverized coal with pressure grouting hole sealing technology, and the gas extraction concentration of the closed borehole is similar to that of the hole sealed by the expansion cement sealing technology, but the sealing cost is reduced by about 70%.