In underground mining, common explosives include ANFO (Ammonium Nitrate Fuel Oil), emulsion explosives, and slurry explosives, often used in conjunction with detonators and blasting agents. These explosives are chosen for their ability to break rock effectively and safely within the confined space of a mine. The main explosives used in underground mines are presented in table 1.
| Explosive Type | Water Resistance | Typical Use | Safety Features | Cost/Efficiency |
| ANFO | Low | Hard rock, dry conditions | General safety, not for coal | High (low cost) |
| Emulsion | High | Wet conditions, hard rock | Low toxic gas, stable handling | High (bulk delivery) |
| Water Gel/Slurry | High | Wet conditions | Low toxic gas, stable handling | Moderate |
| Permissible Dynamite | Moderate | Coal mines, soft rock | Methane/coal dust safe | Lower strength |
| Gelatine Dynamite | Moderate | Hard rock, non-coal | Higher strength, regulated use | Moderate |
| Sheathed Explosive Unit | High | Coal mines, special tasks | Flame inhibiting, gas/dust safe | Specialized |
Why these explosives are used?
- Water resistance: Emulsion, water gel, and slurry explosives are chosen for wet conditions to ensure reliable detonation and minimize explosive loss.
- Safety: Permissible explosives and sheathed explosive units are specifically engineered to prevent ignition of flammable gases and coal dust, which is critical in coal mining.
- Cost and efficiency: Bulk emulsions and ANFO are favoured for their lower cost, ease of handling, and ability to be delivered in bulk, improving operational efficiency and reducing manual labor.
- Reduced toxic gas emissions: Modern underground explosives are formulated to produce minimal toxic fumes, protecting worker health and allowing quicker re-entry after blasting.
- Regulatory compliance: Only explosives approved as suitable for underground use, with appropriate oxygen balance and safety features, are permitted in underground mines.
