Study on damage characteristics of iron ore under variable line density charge structure blasting

Blasting test research was conducted on iron ore specimens with variable line density charging structures. Computer tomography (CT), digital image processing, and three-dimensional model reconstruction techniques were used to analyze the damage characteristics of iron ore specimens after blasting based on the calculated number of box dimensions. The results show that increasing the variable line density section charge uncoupling coefficient reduces the overall damage to the specimen by up to 1.73%, indicating that the overall damage size negatively correlates with the size of the variable line density section charge uncoupling coefficient. The damage characteristics of iron ore specimens from different layers (uncoupled charging section, transition section, coupled charging section) have some variability; when the uncoupling coefficient of the uncoupled charging section was reduced, the uncoupled section of the center of the damaged layer increased and then reduced. In contrast, the transition section shows a trend of increase, and the coupled section shows a minor difference, fully demonstrating the change in the variable line density section of the uncoupling coefficient of the specimen blasting damage effects. This study concludes that in the actual blasting project, choosing a reasonable variable line charge density structure can make the release of explosive blast energy more uniform to efficiently and thoroughly use explosive power to improve the iron ore crushing effect.