Abstract: An apparatus for the controlled refining of an emulsion explosive composition is shown. The apparatus includes a pump for pumping the pumpable explosive composition, a conduit for transporting the explosive composition away from the pump, and a refining or shear valve located in the conduit. Also provided is control instrumentation which allows the amount of refining to be monitored. The preferred control instrumentation comprises a first pressure indicator located on an upstream side of said valve, the second pressure indicator located on the downstream side of said valve, and an adjustor associated with the valve to allow the valve to be adjusted to produce a predetermined pressure difference between the first and second pressure indicators.

Abstract: An apparatus for the controlled refining of an emulsion explosive composition is shown. The apparatus includes a pump for pumping the pumpable explosive composition, a conduit for transporting the explosive composition away from the pump, and a refining or shear valve located in the conduit. Also provided is control instrumentation which allows the amount of refining to be monitored. The preferred control instrumentation comprises a first pressure indicator located on an upstream side of said valve, the second pressure indicator located on the downstream side of said valve, and an adjustor associated with the valve to allow the valve to be adjusted to produce a predetermined pressure difference between the first and second pressure indicators.

Abstract: A blasting explosive comprises an organic carbonaceous fuel, an inorganic oxidizing salt, a gelling agent and particulate filler material, wherein prior to exposing the particulate filler material and the inorganic oxidizing salt to the organic carbonaceous fuel and the gelling agent, from about 15 to about 60 wt % of the particulate filler material and the inorganic oxidizing salt are retained on a Tyler 10 sieve, from about 15 to about 60 wt % of the particulate filler material and the inorganic oxidizing salt are retained on a Tyler 14 sieve and from about 20 to about 60 wt. % of the particulate filler material and the inorganic oxidizing salt are retained on a Tyler 20 sieve.

Abstract: A blasting agent is disclosed for use in a borehole having a pressure resistant closure. The blasting agent is used in combination with a primary initiating system comprised of a detonator and an initiator for the detonator. The blasting agent is preferably a semi-fluid explosive material having a predetermined sensitivity. The sensitivity is related to the borehole diameter and the initiating system's strength, wherein the blasting agent upon initiation is transformed into explosive products by means of reaction front which consumes substantially all the blasting agent as the reaction front passes through the blasting agent. The reaction front has an average velocity of propagation of beween 200 meters/second and 1,000 meters/second for at least 30% of the total length of blasting agent located in the borehole. Another aspect of the invention is a method of blasting wherein the average velocity of propagation of the explosive front in the blasting agent is in a range of between 200 m/sec and 1,000 m/sec.

Abstract: A blasting agent is disclosed for use in a borehole having a pressure resistant closure. The blasting agent is used in combination with a primary initiating system comprised of a detonator and an initiator for the detonator. The blasting agent is preferably a semi-fluid explosive material having a predetermined sensitivity. The sensitivity is related to the borehole diameter and the initiating system's strength, wherein the blasting agent upon initiation is transformed into explosive products by means of reaction front which consumes substantially all the blasting agent as the reaction front passes through the blasting agent. The reaction front has an average velocity of propagation of between 200 meters/second and 1,000 meters/second for at least 30% of the total length of blasting agent located in the borehole. Another aspect of the invention is a method of blasting wherein the average velocity of propagation of the explosive front in the blasting agent is in a range of between 200 m/sec and 1,000 m/sec.

Abstract: An explosive composition comprising an explosive mixture of ammonium nitrate and fuel oil. The fuel oil is selected to provide an oil separation sufficiently low so that the explosive is detonatable. The fuel oil is also selected such that the viscosity of the explosive is sufficiently low so that the explosive may be loadable into a borehole. The explosive is substantially free of tackifying agents.

Abstract: A blasting explosive having improved water resistance comprises a particulate blend of from about 5 to about 27 wt. % of a slurry explosive and from about 73 to about 95 wt. % of a mixture of ammonium nitrate particles and a liquid hydrocarbon fuel based on the weight of the slurry, the ammonium nitrate particles and the fuel. The mixture of ammonium nitrate particles and a liquid hydrocarbon fuel contain from about 3.0 to about 6.0 wt. % hydrocarbon fuel based on the weight of the ammonium nitrate/fuel mixture. The blend is first coated with a gelling agent and subsequently coated with an anticaking agent.

Abstract: An improved connector for holding low energy detonating cord adjacent the percussion-actuation and surface of a detonator comprises a plastic tube having a detonator-receiving bore and one or more cord receiving transverse bores between a plastic end closure for the tube and the end of the bore of the tube. The transverse bore(s) form channels which permit the cord segments therein to span the actuation end surface of the detonator and result in improved reliability of initiation of the detonator.

Abstract: A primer assembly for use in the non-electric initiation of cap-insensitive explosives, especially of deck-loaded explosive charges by means of a single downline of low-energy detonating cord (LEDC), includes a percussion-actuated detonator seated in a cavity in a high-energy primer, and an explosive coupler in which a coupling explosive charge, housed in a plastic connecting block, is in initiating proximity to the detonator's percussion-sensitive ignition charge and sufficiently close to a cord-receiving perforation or conduit in or adjacent the primer as to be initiatable by the detonation of LEDC threaded therethrough. A preferred connecting block has means for engaging the detonator, and means for attaching the block to the primer. Preferably the explosive coupler is seated within a block-like cavity in the primer.

Abstract: An explosive primer unit in which the degree of energy coupling between a low-energy detonating cord (LEDC) and an explosive coupling element in a cast explosive primer is maximized; the unit contains (a) a substantially cylindrical charge of cast explosive having a perforation therein aligned substantially parallel to the charge's cylindrical axis, and sized to slidably receive a length of LEDC and (b) embedded in the cast explosive charge along the LEDC-receiving perforation, an explosive coupling element containing a shock-sensitive high-velocity detonating explosive having a tubular body having a wall that surrounds, and a bore that forms, the LEDC-receiving perforation over at least a portion of the perforation's length, the size of the bore of the coupling element's tubular body that forms the LEDC-receiving perforation in the cylindrical charge of cast explosive closely matching the outer diameter of a length of LEDC to be received therein.