Experimental Study on Critical Detonation Diameter of Finished Emulsion Explosive

To address the absence of specialized explosives for mine presplitting blasting and excessive detonation velocity/power of conventional 32 mm emulsion explosives, this study proposed reducing the explosive diameter to moderate detonation characteristics. By combining critical diameter theory with numerical simulation analysis, a PVC tube charge model was developed in LS-DYNA. The detonation wave propagation was simulated using ignition-growth reaction-rate equations and fluid-solid coupling algorithms, with detonation-curve analysis verifying explosive stability. The BSS-1 intelligent ten-stage detonation velocity meter was employed to measure detonation velocities of emulsion explosives of different diameters, thereby enabling the determination of their critical diameter from experimental data. Results demonstrate strong agreement between simulations and experiments: stable detonation occurs at 14 mm diameter, while failure occurs at 12 mm, establishing the critical diameter range as 12 ~ 14 mm. Additionally, when the diameter exceeds 14 mm, the detonation velocity exhibits a positive correlation with diameter increase. This study, cross-validation of numerical simulations and field experiments, identifies the critical diameter range for industrial emulsion explosives in mining applications, offering empirical support for optimizing presplitting blasting parameters and enhancing safety management.