Research on the Fragmentation Characteristics of Iron Ore Based on RHT Constitutive Model Calibration and Charge Structure Optimization

Damage to the back of mined ore body caused by the strong impact effect of blasting has always been a focus of scientific research workers. Based on the engineering background of parallel deep blasthole blasting in the Gongchangling underground mine of Anshan Iron and Steel Group, the blasting characteristics induced by blasting with different charge structures of the same charge are studied through theoretical analysis, numerical analysis, and field test. Firstly, the Riedel-Hiermaier-Thoma (RHT) model suitable for Gongchangling iron-rich ore was theoretically determined and verified by the Hopkinson test. Numerical simulations were performed for parallel deep blastholes with different charge structures of the same charge and the best charge structure suitable for parallel deep blasthole blasting in Gongchangling underground iron mine was obtained. The numerical results show that the RHT model can well reproduce the tensile failure behavior and three-dimensional fracture distribution of iron-rich ore samples. Through the combination of reasonable charge structure and delay time, the optimization scheme is applied to the upward parallel medium-deep blasthole blasting, which improves the blasting effect of parallel deep blasthole blasting and achieves a remarkable effect in the control of the damage to the remaining ore body caused by blasting.