Numerical simulation study on the effect of delay time on blasting effectiveness in a uranium mine

Focusing on the geological characteristics of a uranium mine, this paper explores the impact of delay time on blasting effectiveness through numerical simulation methods. Utilizing LS-DYNA software and the SPH-FEM coupling algorithm, a finite element model of bench blasting is established to simulate the blasting process under different delay times. Through the analysis of rock mass damage cloud images, blast-induced fly rock displacement, and time-history analysis, the optimal delay parameters are determined. The results show that both longer and shorter delay times can reduce the effectiveness of rock blasting. When the hole-to-hole delay time is 25 ms and the row-to-row delay time is 65 ms, the rock fragmentation effect is relatively better. In addition, under this delay scheme, the blast heap is more concentrated, and the range of fly rock affected by blasting is relatively smaller. This research provides a theoretical basis and optimization guidance for the efficient and safe blasting mining of the uranium mine.