Advances in the rheology of emulsion explosive

Abstract This review explores the rheology of emulsion explosive, especially the emulsion explosive matrix, through summarizing its flow, yield stress, viscoelasticity and effect on the assessment of stability and performance of emulsion explosive. The emulsion explosive matrix is defined as highly concentrated emulsion due to the volume fraction of dispersed phase exceed 74%. There are two important characteristics of microstructure for emulsion explosive matrix should be considered, that is the polydispersity and deformation of compassed dispersed droplets. This microstructure feature confers matrix good elasticity and solid-like rheological behavior. But, the rheological behavior of matrix will vary from elastic to sticky flow under strong shear stress, in which the deformed droplets will also undergo further deformation and even flow. Obviously, whether the droplet can return to its initial state after deformation or flow is very important for the stability and performance of explosive because the emulsion explosive must be experiencing a certain length of flow in the pipeline before blasting, and this ability is strongly attributed to the droplet size of matrix. Besides that, the main rheological properties of matrix, such as: yield stress, storage modulus, zero shear viscosity and so on, are highly dependent on the nature of emulsifiers and oil materials. The rheology of matrix is changed with the destroy of its microstructure in aging through experimental researches, thus some rheological parameters are considered to be used to assess the stability of matrix. These results will facilitate the further development of methods for predicting the performance and stability of emulsion explosive, as well as the exploration of rheological properties of other types of emulsion explosives, like packaged emulsion explosive and powdery emulsion explosive.