Research and Application on Parameter Optimization of Medium-deep Hole Bench Blasting with Millisecond Delay in Open-pit Mines

This study focuses on optimizing blasting parameters for millisecond blasting of medium-deep holes at the Jinduicheng Open-pit Molybdenum Mine, addressing its complex blasting conditions. Through numerical simulations, the research systematically examines how hole spacing, row spacing, and delay time influence blasting effectiveness. Field rock samples were prepared and tested to acquire actual in-situ rock mechanical parameters. Borehole acoustic data were analyzed using RSM acoustic logging software to determine rock wave impedance. A ten-segment detonation velocity meter measured explosive detonation velocity, enabling rock-explosive matching. Simulation parameters were established based on measured rock mechanical properties and explosive characteristics. LS-DYNA software was employed to construct numerical models with varying hole and row spacing, inter-hole and inter-row delay times.