Fractured directional blasting by hole in medium depth to improve drilling efficiency
GAO Qiu - sheng; LI Guo - sheng (Lujiatuo Branch of Kailuan Mining Group, Tangshan 063107, China)
It introduces the technological process of fractured directional blasting by holes in medium depth, and analyzes and compares the constructed results with that of the smooth - hole in medium depth blasting. This tech. has its advantage and remarkable economic benefits.