Lowering comminution energy cost through smarter blasting

Cost saving measures are at the very top of the list for industries dealing with high input costs and a volatile global commodities market. For mines dealing with increased demand and rapidly intensifying production constraints, saving on one of its biggest line items, namely energy consumption, can be the difference between a tight quarter and a cash-flush year.

More than half of a mine’s energy consumption going toward comminution – the crushing and grinding of rock to extract precious resources – making it the best operational segment to streamline and save big on. Energy consumption from drilling and blasting operations, on the other hand, hover around 2%, according to the Coalition for Energy Efficient Comminution, making it the best place to offset comminution spend.

By increasing efficiency and boosting production outcomes in relatively low-cost areas such as drilling and blasting, down-the-line costs associated with comminution, can be significantly lowered. In simpler terms: by shifting a portion of the workload back upstream, into the blast, the entire comminution circuit starts breathing easier.

How fragmentation quality decides mill power

Ultimately, chemical energy is far less expensive than electrical energy. By utilising advanced blasting techniques, and using the right explosives, detonators, and other blasting components best suited for the job, mines can optimise the run-of-mine produced for crushing and grinding.

Rock that reaches the primary crusher already cracked along grain boundaries require lower energy consumption to reach liberation size. Notably, researchers Workman and Eloranta found  that a 30% drop in crushing-and-grinding work index (the kilowatt hours needed to break rock into the ideal size) occurs when blasts are redesigned to drive microfractures through each fragment. Less resistance at the mill means lower power demand, slower liner wear, and a front-end throughput lift that rolls straight into revenue.

Designing blasts with more than breakage in mind

Optimisation starts with an accurate model of in-situ rock strength. Mining and Energy Acuity (MEA) engineers help clients log structural data, joint orientation, and stress fields, then map hole geometry to exploit natural weakness.

Micro-fracturing is particularly important when optimising fragmentation for comminution. Micro-fragmentation is the network of microscopic cracks created by smart blasting that leaves each rock fragment already weakened, so the crushers and grinders need much less power and operational time to finish the job.

To truly take advantage of this kind of advanced blasting technique, it must be combined with, for example, electronic delay detonators with millisecond timing that open free-faces in a controlled wave, driving extra cracks through each burden and reducing the energy the plant must spend later.

Furthermore, air-decking – which are decoupled charges that leave a gas cushion in the borehole – redistributes explosive energy, expands the fracture network, and trims powder use while delivering finer, softer muck.

Finally, add site or close-to-site storage and transportation options for maximum blasting efficiency. MEA delivers the correct quantities of bulk emulsions at the bench as a base matrix and sensitiser exactly when needed, giving crews the freedom to dial density up or down as vein hardness requires. The approach minimises over-break, cuts velocity of detonation mismatch, and slashes the number of truck-borne high-hazard consignments that must thread public roads. The end result is a leaner comminution circuit that achieves the same product size with fewer kilowatt-hours and longer liner life.

Blasting for comminution is, at the end of the day, less about brute force and more about preparation. A well-timed shot that seeds micro-cracks turns hard rock into mill-friendly feed that moves through the plant with less resistance. Operators see the benefit in three ways: power consumption gradually decreases, machinery wear slows, which in turn means fewer repairs and less downtime, and throughput edges upwards.