The engineering rheology of liquid explosives as highly concentrated emulsions

Abstract

Rheological properties of liquid explosives are summarized and discussed in this paper. Liquid explosives are highly concentrated emulsions by their physical nature. During the internal phase, it is an aqueous supersaturated solution of mainly ammonium nitrate which is a useful component of a multi-component system, and at the continuous phase it is a solution of emulsifier in hydrocarbon oils. Liquid explosives demonstrate a complex set of properties characteristic for highly concentrated emulsions, such as visco-plasticity, existence of the yield stress, thixotropy (or time-dependent behavior), non-Newtonian flow at stresses exceeding the yield stress. Rheological properties depend on the concentration of internal phase, size of droplets, and the nature of the used surfactant. Stability of these materials is determined mainly by the tendency of an aqueous solution to crystallization at prolonged storage, though shearing does not influence on phase separation. Wall slip is absent in flow of liquid emulsions through tubes. Therefore, it allows us to make reliable predictions on the output vs. pressure dependence for real technological practice.