Fact or fiction? What you need to know about blasting misconceptions

Mining and Energy Acuity’s (MEA) team has heard every half-truth and misconception in the book:

“More explosives in the hole must mean better fragmentation.”

“Charging patterns that work in one place will work everywhere.”

“All you need for waterlogged conditions is a good emulsion explosive.”

“when in doubt, over charge and stand far away”

Whether seemingly trivial or dangerously misleading, any misconception in blasting practices can have serious consequences. In industries like mining, quarrying, and construction, even small errors rooted in false assumptions can quickly snowball into upwards of tens of thousands of rands in lost productivity and efficiency over time.

To dispel the untruths and make operations more profitable, here are five of the most common myths to look out for in your blasting operations:

1.     More energy in the hole always means better fragmentation

The assumption that increasing powder factor guarantees superior fragmentation is deeply misleading. Fragmentation quality is not determined by energy alone, but by a complex interplay between timing, burden, spacing, confinement, and rock strength and composition. Here, the timing between blast holes plays the most critical role, as precise delays control how energy interacts across the rock mass to achieve consistent, well-structured breakage.

Too much energy without the proper design principles needed to effectively direct force can result in suboptimal fractures, excessive fines, uncontrolled throw, or even damage to highwalls and pit floors. Instead of improving productivity, overcharging often adds to downstream inefficiencies by producing unusable material or destabilising excavation areas.

Leading blasting specialists like MEA stress precision over brute force. Energy must be distributed evenly across the rock mass, matched to geological features, and sequenced in ways that promote controlled breakage.

2.     Good fragmentation guarantees lower downstream costs

A commonly held belief is that quality fragmentation directly translates into productivity gains and streamlined operations down the line. While fragmentation is critical, the “perfect” size distribution in theory does not always translate into lower costs in practice. Factors like diggability, crusher design, haulage constraints, and mill throughput mean that fragmentation needs to be tuned to the whole value chain, not just the blast itself.

Additionally, what is optimal for one site may be inefficient for another. A slightly coarser fragmentation pattern, for example, might reduce the time it takes for shovels to load trucks, even if it increases crusher energy demand. Conversely, finer material may choke conveyors or reduce throughput in mills. Fragmentation is therefore a balancing act across the value chain rather than a one-size-fits-all target at the blast face.

3.     Standard charging patterns work everywhere

Borrowing a pattern from another operation may save time in the short-term, but geology never repeats itself exactly. Joints, bedding planes, groundwater conditions, and rock strength vary both between pits and, often, within the same bench. Using a standard pattern without adjustment risks overbreak, poor fragmentation, or dangerous flyrock events.

MEA’s expert blasting advisors work closely with operators to consistently adapt design to local ground conditions. This may mean adjusting burden, altering stemming depth, or modifying hole orientation. Templates that initially provide a good foundation for blasting operations must be supplemented with continuous customisation interventions to ensure each blast is as effective, or even more effective, than the one before.

4.     Detonator timing is a secondary consideration only

Charge quantity and hole placement often get the most attention, while delay timing is sometimes treated as a secondary priority. In reality, however, detonator timing is critical in determining how efficiently energy is released across the blast. Milliseconds matter, and fractions of time can change the blast’s vibration levels, the muck pile’s shape, and the transfer efficiency of energy.

Modern electronic detonators make timing as precise as charge design. When properly sequenced, delays minimise ground vibration, optimise rock displacement, and greatly enhance safety margins.

5.     Pumping or swapping to emulsions as a magic pill for waterlogged holes

The belief that water challenges can be eliminated simply by dewatering or switching to emulsions is misleading. Waterlogged holes affect far more than explosive choice – standing water on top of the main charge can raise the measure of confinement, increase velocity of detonation (VOD), decouple the charge from the borehole wall, and deliver very different results from what was expected.

Treating water as a minor inconvenience risks serious consequences like costly underperformance, and dangerous explosive remnants when blast designs are not adapted appropriately. Hole depth, stemming, initiation timing, and the overall blast design must be reconsidered to ensure the ongoing safety and reliability of operations.

Blasting remains as much an art as a science, and misconceptions that oversimplify complex blasting processes do more harm than good. By questioning long-held assumptions and further refining practices, operators protect both their people and their productivity. In the end, smart blasting is less about applying force, and more about how well that force is directed.