Slurry explosives are solving the problems ANFO can’t

Tight drill and blast timetables, lean budgets, and unforgiving production targets leave mining, quarrying, and construction crews no time for benches to drain after heavy rain, and low tolerance for fixed-density explosives that can’t be tuned to changing ground conditions.

Slurry explosives resolve many of the challenges these industries have been dealing with for years. Slurries are inherently water-resistant, so crews can load straight into wet or partially flooded holes instead of waiting for standing water to be pumped out. Moreover, on-bench blending lets operators change in-hole density and energy hole-by-hole as needed, which additionally limits exposure potential to fully active explosives, reducing the likelihood of accidental initiation.

It is also much safer to handle and transport. It’s shipped as an unsensitised emulsion, suspension, or gel. Importantly, an oxidiser can feed combustion but will not detonate under normal shock, friction, or static. Because the matrix is still an oxidiser, it may be kept in purpose-built tanks or ISO-compliant containers, and stock turns can extend for weeks without worrying about cartridge ageing.

Per-kilogram, bulk slurries often cost more than ANFO, but, critically, they eliminate the need for laborious dewatering procedures, cut misfire re-drills, and let crews load one product across wet and dry zones.

Finally, slurry explosive materials allow blasters to adjust in-hole density and energy in real-time to increase power for hard rock or lower it for softer overburden, and to introduce inert gaps to keep vibration within safety and regulatory limits.

Modern slurry’s edge over conventional explosives

Due to the many benefits associated with the use of slurry in blasting operations, the field has advanced substantially in the past few decades, making slurry a leading choice for most. Slurry has the advantage over other explosives under a few common conditions:

1.     Persistent groundwater or sudden inflow

High levels of groundwater shuts conventional dry blends down almost as soon as they come in contact with each other. Uncoated prills absorb moisture, slump, and then refuse to detonate, forcing crews to halt work while pumps chase inflow that never really stops.

Pumpable slurries, by contrast, stay cohesive in standing water. The water in the hole simply becomes part of the confinement, so the column keeps its density and delivers full energy. Crews load once, stem once, and fire on schedule, saving hours of dewatering delays that impact both production and morale.

2.     Reactive or acid-generating ore bodies

In ore bodies rich with sulphides or that generate acid on exposure, there are concerns around the exothermic reactions between ammonium nitrate and the host rock. Slurries keep the oxidiser locked inside a thickened matrix, separating it from reactive minerals until the moment of initiation.

That barrier curbs spontaneous heating, blocks nitrous fumes that can affect crews, and sharply lowers the risk of misfires blamed on acid-eaten primers. Where other products require costly inhibition packages or complete exclusion, slurries step in as the safer default.

3.     High-burden patterns that favour fewer holes

High-burden patterns favour fewer, larger holes to move the same tonnage with less drilling. Those wider spacings demand a charge that holds the velocity of detonation (VOD) and gas pressure right to the last collar.

With slurry columns, density can be dialled up to hit stubborn toes or dialled down where over-break is present. The result is consistent breakage across bigger blocks, with fewer redrills and a shorter pattern mark-up cycle.

4.     Sites constrained by vibration or fly-rock limits

Urban quarries and sites near heritage structures often face strict vibration and fly-rock thresholds. Slurries give engineers extra levers to pull: density can be stepped down to lower peak particle velocity, micro-air gaps can be introduced to damp shock transmission, and gassing profiles can be trimmed so gas pressure vents sooner. The column still fires cleanly, but the ground shake that reaches property lines stays beneath statutory limits.

5.     Extended supply lines and warm-storage requirements

Remote pits with hundred-kilometre supply lines live or die by material supply stability. Unsensitised bulk slurry ships as a pumpable fluid with a low-class rating until it meets a gasser on the bench. That lower hazard designation eases road restrictions and slashes escort costs.

Once on site, the blend tolerates wide temperature swings without caking or sweating oil. Warm-storage tanks keep it fluid for weeks, so a weather shutdown or border delay no longer strands crews without product.

Ultimately, slurry is a valuable addition to blasting operations’ toolkits, making it easier and less expensive to reach ore under certain circumstances. But knowing when to utilise it, and how best to apply slurry can be challenging. To ensure optimal application, as well as to maintain strict safety and security standards during storage and transportation, companies rely on the expertise of Mining and Energy Acuity (MEA).

MEA’s bespoke explosives management solutions include:

· Procurement – MEA is a fully licenced explosives dealer that sources directly from leading global manufacturers, guaranteeing certified products, steady supply, and cost savings for every blast programme.

· Border logistics – Dedicated cross-border teams secure permits, clear customs, and plot sub-Saharan Africa routes so consignments move from factory gate to remote shafts without hold-ups.

· Secure storage – MEA keeps explosives in SANS-compliant magazines across Gauteng and Limpopo, protected by 24-hour security and live digital inventory tracking, giving clients on-demand access without investing in their own bunkers.

· Technical services – Mobile crews provide on-bench pumping, prime-load-tie-up-shoot support, and VOD, vibration, and fragmentation monitoring, delivering measurable gains in breakage and cycle time.

· ESG compliance – Low-dust charging, noise-and-vibration control, and traceable inventory reporting help mines hit stringent ESG targets and avoid costly shutdowns.

For operators weighing the switch, the question is no longer “Will slurry work?” but “Who will make it work predictably?” That is where MEA stands apart. We design, ship, store, mix, and fire slurry charges across half a continent, closing the gap between chemistry and tonnes broken so our clients can keep the plant humming regardless of what the groundwater decides overnight.