Analysis of the Effects of Blasting on Comminution Using Experimental Results and Numerical Modelling

From blasting to downstream, processes are linked through the continuous reduction of the size of the rock. The effect of blasting is traditionally limited to fragmentation, although effects on crushing and grinding are also recognized and examined in the paper. Fragmentation prediction methods are reviewed to identify issues that need to be addressed in engineering models to improve the accuracy of the predictions. Blastability and energy partition during the blast are key areas for improvement. Damage to the rock, in the form of microcracks, is discussed using experimental findings as well as computer calculations of damage. Experimental results have shown that grindability is affected by energy consumption, which is simplified by the powder factor and by the powder distribution in the blast. Damage calculations show that powder distribution as well as energy partition are important, while the geometry of the blast, borehole pressure, delay time and the complicated stress-wave interaction during the blast play a significant role. To derive a relationship between blasting and milling, analysis of field data, considering lithology, fracture network, detailed blasting parameters and mill performance are needed.