Rock fragmentation has been a concern in hard-rock mining for the mining industry. Rock fragmentation distribution is an important index to measure the blasting effect. It not only affects the cost of drilling and blasting, but also affects the efficiency of subsequent operations, such as loading, transportation and secondary crushing.
Experiments show that blasting energy can be transferred more efficiently when the explosion wave impedance and rock wave impedance are in the best matching state. Traditional statistical methods of rock fragmentation size analysis are mainly based on manual measurement, but they are labor intensive, offer low efficiency and are susceptible to site conditions. Moreover, the statistical results are not sufficiently accurate. Inadequate unit consumption of explosive and stemming height, faulty drilling, unreasonable borehole density coefficient due to poor previous blast, mismatched explosive with rock acoustic impedance are the main factors affecting the blasting parameters. Furthermore, unknown geological conditions, such as original joint, weak seams, fissure and water have been identified as the major factors in rock fragmentation size distribution in opencast mines.
Due to the mismatching of explosive and rock wave impedance, high boulder yield often occurs, which affects the blasting effect. In this study, methods of measuring rock wave impedance, rock strength point loading, and detonation wave velocity were used to obtain more accurate input parameters.
Mining, Metallurgy & Exploration (2021) 38:1071–1080, https://doi.org/10.1007/s42461-021-00384-0