Water-in-oil blasting composition

Abstract

A blasting composition is disclosed having bulk density and hence explosive energy superior to that of conventional ammonium nitrate fuel oil mixtures, e.g. 94% AN, 6% fuel oil mixtures, but of nearly comparable cost. It comprises two major constituents blended together, namely, (1) about 10 to 40% by weight of a water in oil emulsion which includes aqueous solution of a powerful oxidizer salt as the disperse or inner phase and an oil serving to provide oxygen balance as the external or continuous phase, this emulsion being mixed or blended with (2) a mass of essentially solid particulate oxidizer salt in proportions of 60 to 90% of the total. The emulsion, which may be also a slurry, is mixed to partially but not completely fill the pores or interstices in the solid particulate mass, thereby to increase bulk density, part of the spaces being left unfilled to provide aeration and active sites or 'hot spots' to facilitate detonation of the composition by standard detonation devices. Ammonium nitrate preferably constitutes most or all the particulate solid salts; the dissolved salts in the emulsion or slurry preferably comprise a mixture of AN with calcium nitrate to enhance solubility. Other salts such as nitrates, chlorates and perchlorates of ammonium, alkali metals and alkaline earth metals may be added or substituted, at least in part.