Abstract: A switch connectable to an upper explosive device and a lower explosive device in a perforation gun train is provided. The switch comprises a circuit, a portion of the circuit being openable upon detonation of the lower explosive device, and the switch being changeable from a first position to a second position upon the opening of the portion of the circuit. In the first position, current can flow to the lower explosive device but not to the upper explosive device. In the second position, opposing current can flow to the upper explosive device but not to the lower explosive device.

Abstract: A system (10) for loading a flowable explosive into blast holes includes a mobile explosives supply unit (12) having at least one explosives feed line for feeding a flowable explosive from the supply unit (12) into a blast hole, a global positioning system (GPS) unit (14) operable to determine the position of a blast hole, and a blast hole identification processor (16) in communication with the GPS unit (14) operable to receive from the GPS unit (14) a blast hole co-ordinate position. The processor (16) is configured or programmed uniquely to identify the blast hole based on the co-ordinate position of the blast hole.

Abstract: A chemical detonator includes a housing, having an open end and a closed end; and a detonation element located in the housing, into which a shock tube for initiating the detonation element intrudes, wherein the housing and the shock tube are of plastics construction and the housing is substantially cylindrical cup shape, and wherein the shock tube intrudes into, and is welded to, the open end to hold the shock tube at a desired spacing from the detonation element. The detonator includes a detonation element that includes a series of charges.

Abstract: An open cast mining method includes sinking a blasting borehole (14) for receiving an explosive charge into a ground body (12) which is to be mined, taking an initial measurement of one or more borehole conditions, including at least a temperature inside a bottom half (14.1) of the borehole (14), and loading the borehole (14) with a base explosive charge (28) only if the initial measurement of all of the one or more measured borehole conditions are within predefined limits indicating that the borehole (14) will not be subject to uncontrolled detonation of the base explosive charge (28). The one or more borehole conditions, including at least said temperature, are further measured and monitored after the base explosive charge (28) has been loaded. An alarm signal external of the borehole (14) is provided if any of the one or more measured borehole conditions are not within predefined limits so that there is a risk of uncontrolled detonation of the explosive charge (28).

Abstract: A chemical detonator includes a housing, having an open end and a closed end; and a detonation element located in the housing, into which a shock tube for initiating the detonation element intrudes, wherein the housing and the shock tube are of plastics construction and the housing is substantially cylindrical cup shape, and wherein the shock tube intrudes into, and is welded to, the open end to hold the shock tube at a desired spacing from the detonation element. The detonator includes a detonation element that includes a series of charges.

Abstract: A method of manufacturing a pyrotechnic time delay composition includes admixing together a solid oxidizer, a solid fuel and water to form an aqueous slurry. The slurry is transformed into droplets. The droplets are gas-dried to form particles comprising the oxidizer and the fuel, with the particles thus constituting a pyrotechnic delay composition.

Abstract: A process for producing a pyrotechnic delay composition includes admixing an oxidizer, a fuel, a surfactant and a liquid, to form a paste or slurry. The paste or slurry is dried to remove the liquid and to obtain a solid product which, if necessary, is rendered into particulate form. Optionally, the solid particulate product is classified to obtain a pyrotechnic delay composition in particulate form.

Abstract: A method and apparatus for removing fluid from a container using a conventional shaped charge such as those used in well perforation; the charge being spaced from the container wall, and producing an explosive jet, the explosive jet directed by a diffuser disk to provide a vent or drain.

Abstract: A device for crimping the mouth of a detonator housing comprises a pair of opposed jaws reciprocally movable relative to each other, and a plurality of toothed segments on each jaw. The segments are moveable, are located in a jaw cavity, and together form a segmented ring. The side faces of each segment converge from a broad radially outer end towards a toothed radially inner narrow end. A resiliently stressable biasing element is provided between each adjacent pair of segments. The biasing elements act to space the segments of each pair apart when the jaws are spaced apart from each other, and also act to permit the segments, in response to movement of the moveable segments arising from the closing of the jaws, to abut against one another in series when the jaws are tightly in contact with each another, to form the segmented ring.

Abstract: A method and apparatus for removing fluid from a container using a conventional shaped charge such as those used in well perforation; the charge being spaced from the container wall, and producing an explosive jet, the explosive jet directed by a diffuser disk to provide a vent or drain.

Abstract: The invention provides a method of sensitizing a base emulsion of the water-in-oil type, and the invention provides also a sensitized emulsion explosive comprising an emulsion of the water-in-oil type when produced by the method. The method comprises dispersing, in the base emulsion, a sensitizing solution having a solvent which comprises at most 50% by mass water, the balance of the solvent being organic, and a solute which is a chemical sensitizing agent.

Abstract: The invention provides a method and apparatus (10) for loading a sensitized flowable explosive into a borehole. The apparatus (10) is portable and comprises containers 14, 16 which are pressurizable, for containing an explosive under pressure. Containers 14, 16 have closeable explosive inlets, closeable explosive outlets, and closable fluid inlets. In accordance with the method gas bubbles are dispersed into an explosive base to provide a sensitized explosive which is fed as a batch into the portable containers. The containers are pressurized to de-sensitize the explosive, after which the containers are conveyed to a borehole where the explosive is loaded from the apparatus into the borehole.

Abstract: The invention provides a method for the initiation of blasting. The method comprises the steps of initiating a detonation in an initial shock robe and causing the detonation to propagate along the interior of the shock robe. The detonation in the initial shock tube initiates a detonation in a high explosive charge in a connection device whereby the shock tube is connected to a plurality of further shock tubes. The detonation of the high explosive charge acts to transfer the detonation from the initial shock tube to the further shock tubes to initiate detonations therein. The transfer of the detonations from the initial shock tube to the further shock tubes is effected in a direction which is radial relative to the initial shock tube and radial relative to the further shock tube. The invention also provides a system for the initiation of blasting.

Abstract: The optically active .gamma.-lactone of (1R, cis)-2, 2-dimethyl-3-hydroxymethyl-cyclopropane-1-carboxylic acid, which is useful as an intermediate in the production of pyrethroid insecticides, may be made from optically active (-)car-3-en-5-one by a two stage oxidation process followed by hydrolysis of the intermediate obtained.

Abstract: A water-in-oil explosives composition comprising water, liquid or liquefiable carbonaceous fuel and inorganic oxidizer salt, optionally with gassing agent and/or thickening agent, and containing 0.02 to 2% of a stabilizer selected from organo-sulphur compounds, organic compounds containing quaternary nitrogen, phenolic compounds and substituted derivatives thereof, dihydroxybenzenes, quinones, unsubstituted and substituted aryl diazo compounds, unsubstituted and substituted aryl amines and salts thereof, and unsubstituted and substituted quinolines. Preferred stabilizers include thioureo, hydroquinone, anthraquinone, 1-phenylazo-2-naphthol, 1-[(4'-o-tolylazo)-o-tolylazo]-2-naphthol, N-phenyl-.alpha.-naphthylamine, N-phenyl-.beta.-naphthylamine, the condensation products of 1,4 dichloroanthraquinone with p-toluidine and 2,2,4-trimethyl-1,2-dihydroquinolines.

Abstract: Cyclic terpenes containing at least one unsubstituted methylene group adjacent to a double bond are converted into cyclic mono- and/or diketones by oxidation with oxygen in the presence of a transition metal catalyst.

Abstract: A process is disclosed for preparing a gelatine explosive composition comprising the steps of adding at least one dispersing agent to a mixture of liquid nitric esters and ortho-nitrotoluene, adding the resulting mixture to blasting soluble nitrocotton to form a gel and subsequently adding oxidizing salts, fuels, and when desired, a water-proofing agent such as tamarind seed flour or guar gum to form a homogeneous mixture.

Abstract: A new gelatine explosive composition is disclosed comprising mixtures of nitric esters, ortho-nitro-toluene, blasting soluble nitrocotton, oxidizing salts, fuels and at least one dispersing agent. Said gelatine explosive composition is markedly reduced in the quantities of liquid nitric esters and blasting soluble nitrocotton content.

Abstract: This invention describes a method of preparation of sensitized dry blasting agents comprising a mixture of granular/powder ammonium nitrate with or without Sodium Nitrate, Potassium Nitrate, Calcium Nitrate, etc. fuel(s), and at least one sensitizer. The aid sensitizer is selected from the group comprising nitrate, chlorate, perchlorate and an organic derivative of a metal, which can exhibit variable valency and whose oxides and hydroxides are weakly basic in nature, e.g., iron, cobalt, nickel, chromium, copper, lead, etc.Unlike the dry blasting agents known in prior art, the sensitized dry blasting agents can be detonated in small diameter boreholes with a generally available low strength detonator or specially made powerful detonator.