Explosive blasting method and means
OwnerDavid S. Bowling, Roy N. Mooreinventors
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Abstract
An explosive blasting method and apparatus for producing rock fragmentation and substantially reducing the amplitude of seismic effects (ground vibration) in the vicinity of the blast. An embodiment of the invention utilizes an air gap method and apparatus for superheating the air surrounding the charge in a borehole thereby significantly raising the pressure therein coupled with the use of multiple detonation points along the borehole for the reduction of burn time thereby substantially reducing the quantity of explosives used along with a marked reduction of seismic shock, sound and dust effects to the surrounding area.
Claims12
A method of fragmenting structure surrounding a borehole comprising the steps of:
- placing a plurality of elongated explosive segments in end-to-end relationship within the borehole in which the diameter of the borehole is at least 2.5 times the diameter of the explosive segments;
- supporting the explosive segments centrally of the borehole, the annular area between the explosive segments and borehole being filled with a gas;
- placing at least one detonation in intimate contact with each said explosive segment;
- connecting a short lead wire to each said detonator;
- electrically connecting said lead wires in a parallel circuit;
- and
- substantially simultaneously detonating said detonators by a single electrical impulse.
An elongated explosive column for fragmenting rock or ore adjacent the wall of a borehole comprising:
- a plurality of elongated explosive segments in end-to-end relationship with the borehole, the diameter of the borehole being at least 2.5 times the diameter of the explosive segments;
- means to support said explosive segments centrally of the borehole, the annular area between the explosive segments and borehole being filled with a gas;
- at least one detonator positioned in intimate contact with each said explosive segment;
- a short lead wire connected to each said detonator;
- and means operably connected to said lead wire for connecting said detonators in parallel for simultaneous detonation thereof.
Dependencies are inferred from the claim text.