Engineering properties of highly concentrated emulsions depend on their refining behaviour. The refining of highly concentrated "water-in-oil" emulsions used as "liquid explosives" during emulsification was studied. It was shown that droplet size distribution during the emulsification process becomes narrower, although remains of the Gauss type and the average droplet size decreases. Fitting equations for this process were proposed. The energy consumption was treated as the determining factor in the refinement process. A number of surfactant types and concentrations were examined and their refining behaviour was compared. Expectedly, the increase of the refining efficiency with the increase of the surfactant concentration was observed. Droplet refinement is accompanied by the evolution of theological properties of emulsions that are visco-plastic materials. It was found that the droplet refinement occurs at high values of the Capillary Number lying above the stability curve. (C) 2010 Elsevier B.V. All rights reserved.