The Influence of Time on the Density and Detonation Velocity of Bulk Emulsion Explosives – a Case Study from Polish Copper Mines

The basic method for emulsion matrix sensitisation is chemical reduction of the density by producing in situ gas bubbles. The mixing of the components takes place directly inside the loading hose, which is equipped with a mixing device. Due to the multi-component nature of the mixture, the precise dosing of individual components has a key influence on the detonation behaviour of the final product. Unfortunately, keeping the mixing and charging of UG mobile units in good working condition in underground mines is a considerable challenge. As a result, completely different detonation parameters may be observed when charging the same explosive into blast holes using two different units. The aim of the present study was to determine the behaviour of the mechanically loaded emulsion explosives used in Polish underground copper mines by tracking the changes in the density and detonation velocity over time. Samples of the explosives were collected from selected mobile units. In addition, the influence of the quantity of the sensitising agent on the changes in the emulsion density and VOD was studied.