Method and apparatus for small-charge blasting
AssigneeSandvik Mining and Construction Oy
InventorsErkki Ahola, Veikko Räisänen
Life of this patent
Estimating the term…
Abstract
A method of small-charge blasting, a rock drilling unit and a front guide to be used therein. By means of a rock drill machine provided in the rock drilling unit, a hole is first drilled into a material to be excavated and, subsequently, a drilling tool is pulled out of the hole. Next, one or more propellants comprising a propellant charge are fed to the bottom of the hole through a propellant feed channel provided in connection with a feed beam. Then, the hole is sealed and the propellant is ignited, whereupon a high gas pressure is generated, which causes fractioning in the material to be excavated. During the feeding and ignition of the propellant, the rock drill machine is kept in a parallel direction with respect to the hole.
Claims5
A rock drilling unit for small-charge blasting, the drilling unit comprising:
- a feed beam;
- a rock drill machine;
- a feed device which enables the rock drill machine to be moved on the feed beam in a feed direction and in a return direction;
- a drilling tool connected with the rock drill machine;
- a front guide which is located in a front part of the feed beam and through which the drilling tool is arranged;
- and
- a propellant feed channel which enables a propellant comprising a propellant charge to be fed into a hole,
- wherein the propellant feed channel is a separate member with respect to the drilling tool,
- wherein the propellant feed channel is arranged in the front part of the feed beam,
- wherein the propellant feed channel is a flexible tube, and
- wherein the drilling unit comprises at least one transfer device which enables the propellant feed channel to be pushed into the hole for feeding the propellant and further, the transfer device enabling the propellant feed channel to be pulled back out of the hole after the propellant has been fed.
Dependencies are inferred from the claim text.