Blastability evaluation for rock mass fragmentation in Iran central iron ore mines

In this research, we investigated the influence of rock mass properties, blast design parameters and explosive properties on blast fragmentation. Rock mass properties were evaluated in 51 blasting blocks using engineering geological mapping of 1961 meters of the scanline, experiments on intact rock samples and measuring P-wave velocity (Vp) for 1771 meters of seismic profiles. The results indicate that increasing spacing, persistence, opening, roughness, waviness of discontinuities, and Vp and uniaxial compressive strength (UCS) of intact rock as well as the increase of discontinuities angle with the bench face of blasting block will increase the size distribution of blasted rocks. In addition, evaluation of the influence of connector type, specific drilling and specific charge has shown that using the Nonel system will decrease the mean size of fragmentation. It is also demonstrated that increasing specific drilling and specific charge quantities will result in the increase of mean size of fragmentation.