METHOD FOR ROCK BREAKAGE Russian patent published in 1994 - IPC

FIELD: mining. SUBSTANCE: method includes drilling of blasthole, placing in it of outward-thrust member of hydraulic breaking device, pneumatic cartridge, and packer for sealing blasthole mouth. Then, pressure is built-up in hydraulic breaking device to form cracks. Pressure is raised until it starts dropping in outward-thrust member. Then, raising of fluid pressure is discontinued, and air pressure in pneumatic cartridge is raised up to its operation. Compressed air is supplied up to pressure stabilization in outward-thrust member, and is discontinued only after pressure drop in outward-thrust working member. EFFECT: higher efficiency.