Abstract: A method is provided for the explosive welding together of sections of large diameter metal pipe of the kind used in the construction of high volume oil and gas pipelines. In the method, internal and external band charges of welding explosive are simultaneously detonated adjacent to overlapped telescoped pipe ends. The welding charges are detonated simultaneously by means of very high detonation velocity initiation explosive charges placed along a leading edge of each welding explosive charge. The initiating explosive charges are each set off by a single detonator means. The velocity of detonation of the initiating explosive is selected so that welding charges are simultaneously detonated around the pipes while maintaining the detonation fronts at superimposed locations and at a large angle to the pipe axis. This avoids unbalancing forces on the pipes and minimizes the collision of circumferential shock waves thus preventing pipe damage and imperfect welds.

Abstract: A nitrogen gas generating composition is provided which consists of a stoichiometric mixture of an alkali metal azide or an alkali earth metal azide and a doped iron oxide of high chemical reactivity. The doped iron oxide contains up to 1.0% by weight of another metal oxide impregnated into its particle lattice. The resulting composition has improved properties of ignition delay time, total burn time, filter-ability and reduced toxic by-products.

Abstract: A method is provided for the explosive welding together of sections of large diameter metal pipe of the kind used in the construction of high volume oil and gas pipelines. In the method, internal and external band charges of welding explosive are simultaneously detonated adjacent to overlapped telescoped pipe ends. The welding charges are detonated simultaneously by means of very high detonation velocity initiation explosive charges placed along a leading edge of each welding explosive charge. The initiating explosive charges are each set off by a single detonator means. The velocity of detonation of the initiating explosive is selected so that welding charges are simultaneously detonated around the pipes while maintaining the detonation fronts at superimposed locations and at a large angle to the pipe axis. This avoids unbalancing forces on the pipes and minimizes the collision of circumferential shock waves thus preventing pipe damage and imperfect welds.

Abstract: An apparatus is described for handling a continuous, stuffed, flexible casing and especially stuffed with explosives material. The apparatus includes pairs of split necking plates on either side of a casing path adapted for opposed reciprocal movement for engaging the casing in the path and necking the casing. The necking plates are mounted by a parallelogram linkage suspended from an overhead frame, and linkage means are provided for simultaneously moving the necking plates through said parallelogram linkage to neck the casing. Each pair of necking plates is adapted to move apart in a direction parallel to the axis of the path of the casing such that when the casing is necked by the necking plates, the neck so formed on the casing can be elongated by moving the plates apart.

Abstract: A mobile mixing and delivery apparatus for bulk slurry explosive compositions is provided. The apparatus comprises a vehicle body upon which is mounted a rotatable drum mixer. Explosive ingredients are fed into the mixer, mixed and then delivered close to the point of use where they are pumped through a hose into boreholes. Provision is made for the addition of thickness or other additives to the slurry during pumping.

Abstract: A slurry explosive composition is provided which has improved water resistance and thermal stability and resists segregation. The composition consists of an inorganic oxygen-supplying salt, a liquid carrier or solvent for the salt, a solid or liquid fuel and, as a thickener a sulfonated guar gum derivative.

Abstract: A novel method of excavating underground chambers in strong rock is provided which is particularly suitable for use in stope and pillar mining operations. The method takes advantage of blasting techniques and specifically the use of large diameter spherical explosive charges by locating a spherical charge in a cavity provided in the ceiling or roof of an underground chamber. Upon detonation of the charge, an optimum volume of cavity is produced in the chamber ceiling from which well fragmented ore rock is displayed by gravity to the floor of the chamber from where it is easily removed.

Abstract: A thickened, aqueous slurry explosive composition containing a soluble organic nitrate sensitizer is provided which has improved rheological properties. Use in the composition as a thickener, of a mixture of an unmodified guar gum and a hydroxypropyl-modified guar gum provides a composition which retains flowability for an hour or more for easy extrusion packaging yet achieves a high level of gel strength and cartridge rigidity within a day after packaging.

Abstract: Disclosed is a process for rejuvenating and reclaiming useful hydrocarbon oils from contaminated waste oils. The process comprises dehydrating the waste oil and thereafter dissolving the dehydrated oil in a selected amount of isopropanol or N-propanol at a temperature of from 45.degree. C. to 80.degree. C. The undissolved waste matter is separated and the residual oil/solvent fraction is distilled to recover the decontaminated oil and the solvent. The recovered oil can be further clarified by treatment with a bleaching clay or activated carbon at elevated temperatures. The process is more efficient and economic than those known heretofore resulting in high yields of reclaimed oil and more environmentally acceptable waste products.

Abstract: A foamed or aerated water gel explosive composition devoid of any self-explosive sensitizer is provided which is sensitive to detonation in charge diameters greater than 5.1 cm. The explosive composition retains sensitivity for long periods. The migration or collapse of air or gas entrained in the composition is substantially prevented by incorporating a blend of a foaming surfactant and a stabilizing surfactant in chosen proportions.

Abstract: A bag closure clip fabricated from an elongated double ply plastic strap, one end of which serves as a loop hanger, the closure being in the form of a noose made by passing the looped end of the strap through an aperture in the opposite strap end. The clip can replace the wire closure commonly employed for closing and carrying plastic bags containing blasting agents.

Abstract: A gas generating composition containing nickel oxide or iron oxide and an alkali metal or alkaline earth metal azide, preferably fabricated in the form of tablets or granules. Upon ignition the composition generates nitrogen gas. The gas generating reaction takes place at a relatively low temperature and the solid products of the reaction form a sinter that is readily retained by a filter. The composition is useful for inflating the bags of automobile passive restraint systems.

Abstract: A foamed or aerated explosive composition containing a water-soluble organic nitrate sensitizer is provided which retains sensitivity for long periods in small diameter cartridges. The dissipation or migration of entrained air or gas in the composition is substantially prevented by incorporating a blend of a foaming surfactant and a stabilizing surfactant in chosen proportions.

Abstract: A process for the production of alkali metal amides is provided wherein liquid ammonia is reacted with an alkali metal under moderate pressure in the presence of an alkali metal azide as catalyst.

Abstract: An apparatus is provided for determining the location of a liquid-liquid or a liquid-gas interface in tanks or cavities and has particular use in determining the position of the explosive collar level in boreholes charged with water gel explosives. The apparatus consists of a sensing element which may be lowered into a cavity. Air is exhausted from the sensing element into the surrounding medium. Any restriction to air flow caused by the surrounding medium causes an increase in air pressure which increase signals the presence of an interface.

Abstract: A process is provided for the continuous separation of suspended basic alkali metal azide particles from a liquid reaction medium by bringing the liquid reaction medium into contact with a non-reactive mineral oil whereby the suspended metal azide particles migrate into the mineral oil phase and are thereafter separated therefrom.