IN ROCK-breaking operations, blasting remains unmatched. It is the fastest and most effective method of fragmenting rock, outperforming mechanical and chemical alternatives in both speed and cost efficiency.
Where other methods are used in place of blasting, projects often become unnecessarily expensive. Yet the profitability of blasting goes beyond simply choosing the method itself. The selection of the right explosive is a critical component of blast design and overall operational performance.
While choosing the correct explosive does not guarantee a perfect blast, selecting the wrong one almost certainly leads to poor fragmentation, higher downstream costs and lost savings.
The modern explosives market is crowded and competitive. Products range from ammonium nitrate fuel oil (ANFO) and heavy ANFO to slurries, water gels, dry gels, emulsions and various blends. Each category contains multiple variations, making selection a complex and technical process.
Emulsions alone differ widely. Their appearance, often reflected in colour, depends on the type of oil used and the raw materials involved in manufacture. They also vary in rheology, sensitivity, reactivity and adhesion. Emulsives may be supplied in bulk, as bagged products or as cartridges, each form suited to different operating conditions.
No single explosive is universally superior. What works well at one site may fail at another. The key lies in understanding both the properties of the explosive and the conditions of the rock being blasted.
Understanding the selection process
Explosives selection is not a simple procurement decision. It requires a clear understanding of the interaction between explosive properties, geological conditions and the intended blast outcome.
Rock type, moisture content, hole diameter, confinement, desired fragmentation and allowable rock displacement all influence the choice. Equally important are operational constraints such as drilling accuracy, available equipment and ventilation capacity.
Safety remains the overriding consideration. At the same time, blasting must make economic sense. It is, ultimately, a business activity.
The chosen explosive must safely deliver optimum fragmentation and controlled displacement while meeting production targets. In some cases, spending more on a higher-performance product may generate substantial savings elsewhere along the mine-to-product value chain.
Blasting does not exist in isolation. Its performance affects loading, hauling, crushing, milling and even final product quality.
Safety considerations
No task is so important that it cannot be done safely. Handling energetic materials exposes people, property and the environment to significant risk, with the potential for catastrophic consequences.
Modern explosives manufacturers place strong emphasis on safety throughout the product lifecycle, from research and development to end use and disposal.
One of the most critical safety characteristics of an explosive is sensitivity. This refers to how easily a product can be initiated by friction, heat, static electricity or impact. Highly sensitive explosives present a greater risk of accidental detonation, placing workers and equipment in danger.
The industry’s shift away from nitroglycerine-based explosives towards blasting agents such as ANFO and emulsions was driven largely by safety concerns.
Older blasting products often generated toxic and asphyxiating gases, and many fatalities were historically linked to post-blast gassing incidents. Today, fume generation remains a key consideration, particularly in underground operations.
ANFO used in wet conditions can produce excessive nitrous fumes that are difficult to clear. In such environments, water-resistant, chemically balanced emulsions that generate fewer fumes are often preferable.
Some explosives can also cause skin irritation or longer-term health conditions if handled improperly. Appropriate controls, training and personal protective equipment are essential wherever such products are used.
Economic factors
Explosives selection must be assessed across the entire mining value chain. The cheapest option is rarely the most economical.
Savings achieved through lower explosive costs can quickly be erased by poor fragmentation, increased secondary breakage, higher drilling density or inefficiencies in crushing and milling.
Selecting a less effective explosive may result in larger fragment sizes, driving up downstream processing costs. In some cases, tighter drilling patterns are required to compensate, increasing overall blasting costs.
The objective is not to minimise explosive spend, but to optimise total operating cost from blast to finished product.
Making informed choices
There is no universal formula for explosive selection. Each site presents unique challenges that demand careful analysis and informed decision-making.
Technical data sheets, site trials and guidance from explosives suppliers and technical representatives remain essential tools in the selection process. Combined with sound engineering judgement, they enable operations to achieve safe, efficient and economically sound blast outcomes.
Blasting excellence is not achieved through shortcuts. It is built on understanding, discipline and informed choices, qualities that define modern, world-class mining operations.
