Effectiveness analysis of methane-drainage by deep-hole controlled pre-splitting blasting for preventing coal and gas outburst

Abstract

In the study of the application effectiveness of deep-hole controlled pre-splitting blasting technology, it was found through laboratory micro test and field study on a mine in south China that under the technology, coal masses produce many irreversible cracks. After blasting, the nearer the distance from blasting hole, the larger the BET surface area and volume ratio of the infiltration pore are; they increased by 11.47% and 5.73%, respectively. The coefficient of air permeability is increased 4 times. After 3 months, the gas drainage rate was increased by 66%. In the first 15 days, the cumulative pumped gas was 1.93 times of blasting before. The average absolute gas emission decreased by 63.46%. Experimental results show that deep-hole controlled pre-splitting blasting not only prevents coal and gas outburst, but also gives good economic results.