METHOD FOR REMOVAL OF HARD ROCK OVERBURDEN Russian patent published in 1994 - IPC

FIELD: mining industry. SUBSTANCE: overburden mass is selected into upper and lower zones. Mass of upper zone is relieved by successive action of impact loads of hydraulic percussive unit when it is moved over surface by longitudinal runs. Impact load is applied to zone surface in staggered manner. Distance between adjacent longitudinal runs of percussive unit and intervals between points of application of impact loads of one run is determined by relations given in invention description. After relieving upper zone rocks are loosened by successive runs parallel to runs of hydraulic percussive unit. Then, rocks are piled, and lower zone mass is worked by sawing, or splitting from block mass. EFFECT: reduced labor input and higher efficiency of overburden removal. 2 dwg