Abstract: The invention of the present application provides a method of controlled blasting comprising dispersing an explosive (9) within a blasthole (1) to form a dispersed explosive having a lower average bulk density than said explosive (9) prior to dispersion and detonating said dispersed explosive. Typically the explosive (9) is dispersed in air, however the explosive (9) may be dispersed in other matrices such as other gases or liquids or in gases comprising particulate matter. The explosive (9) may be dispersed using a number of different techniques such as, using a discharge of pressurised fluid or by detonation of a small propellant charge or by falling under gravity in the blasthole. The invention of the present application is particularly useful where a reduced concentration of explosive energy is required such as in perimeter control, presplitting or soft rock conditions, can be controlled by a method which involves dispersion the explosives composition (9) within a blasthole prior to initiating the blast.

Abstract: A shock tube initiator comprises a core charge having an oxidizer-rich fuel-oxidizer mixed particle system the mixed particle system containing co-mingled particles of finely comminuted organic dyestuff of the phthalocyanine family or a similarly thermally-stable organic dyestuff in sufficient quantity to impart a distinct color to the charge, the dyestuff being a material which does not decompose below 250.degree. C.

Abstract: A shock tube initiator comprises a plastics tubing having an unobstructed axial bore, said tubing having throughout its length an inner surface, and unconsolidated reactive materials provided upon said surface as a loosely adherent dusting of shock-dislodgeable particles at a core loading sufficiently low to avoid rupture of the tubing in use, wherein said reactive materials comprise fuel particles selected from the group consisting of metals, quasi-metals and non-metallic fuels, and, as oxidant, at least about 20% (by weight) of ammonium perchlorate, preferably up to about 99% (by weight) ammonium perchlorate.

Abstract: A shock tube initiator comprises a plastics tubing having an unobstructed axial bore, said tubing having throughout its length an inner surface upon which unconsolidated reactive materials are provided as a loosely adherent dusting of shock-dislodgeable particles at a core loading sufficiently low to avoid rupture of the tubing in use, wherein said reactive materials comprise flake metallic fuel particles having a surface colouring layer of pigment, e.g. Fe.sub.2 O.sub.3 whereby on firing of the core charge the residue is visibly of a different colour, hue, or shade.