METHOD FOR ROCK MASS BREAKING Russian patent published in 1995 - IPC

FIELD: mining industry. SUBSTANCE: method for rock mass breaking includes drilling of rows of blastholes at preset base with subsequent action of breaking force on blasthole walls and excavation of broken mass. Two neighboring blastholes on one base of each row are drilled convergent with overdrill to a depth not in excess of 10-15% of length of convergent part. Then, alternately breaking force is acted on blasthole walls over their working length in direction of shortest distance between generating lines in neighboring blastholes in vertical plane and in counterdirection parallel to bottom hole plane between neighboring blastholes in horizontal plane. After excavation of outlined by cracks and broken part of rock mass, preparation is performed and breaking of next layer of rock mass by its drilling from blasthole sleeves is proceeded. EFFECT: higher efficiency. 4 dwg