Experimental Research on Rock Bench Blasting Method and Parameters in Hongtian Opencast Coal Mine

the big spherical conglomerate of about 2 m in diameter in quaternary and tertiary strata in Hungtian Coal Mine,which makes open-pit blasting hole be difficulty,was removed by using of small chamber blasting.After repeated calculation of blasting parameters and experiment,empirical formula of loading dose was derived,according which the consumption of explosives droped 40%.the blasting rock block is uniformity in shape and there are non-umbrella rocks on explosive pile,the shipment is facilitated,so economic efficiency of mine is improved.