The full story
What is drilling and blasting?
Drilling and blasting is how almost every hard-rock mine breaks rock so it can be dug. A drill rig bores a pattern of holes into the rock, the holes are loaded with explosives, and a timed blast breaks the rock in place. Open pits do this bench by bench; underground mines blast the face of a tunnel to advance it, or blast big blocks of ore called stopes. Soft rock such as lignite or oil sand can be dug without blasting, by bucket wheel excavators and shovels.
The drill rigs
Open-pit blasthole rigs are tracked machines with a tall mast. Rotary rigs turn a large tricone bit under heavy downward force; down-the-hole rigs use a hammer just behind the bit; top-hammer rigs, used in quarries and smaller pits, strike the drill string from above. The largest rotary rigs, such as Epiroc's Pit Viper 351, drill holes 270 to 406 mm wide. Makers include Epiroc, Sandvik, Caterpillar and Komatsu. Many large mines run autonomous or remotely operated drills; Rio Tinto, for example, has expanded its fleet of autonomous drills in the Pilbara.
Explosives and initiation, at industry level
Most large mine blasts use bulk ammonium-nitrate-based products, delivered and mixed at the hole by specialist trucks. They are designed to be insensitive until fired by a detonator and booster. Initiation systems control the timing: electric detonators, non-electric shock tube with delays, and programmable electronic detonators, some now wireless. Timing holes a few milliseconds apart improves fragmentation and reduces vibration, which matters near towns. Everything about explosives is tightly licensed and regulated; this site gives an overview of the industry only and does not describe products, quantities or methods.
Who supplies the explosives
Mining blasting is mostly a service business. Suppliers such as Orica, Dyno Nobel, Enaex, MAXAM, AECI Mining, Austin Powder and Solar Industries make the products and detonators, run the delivery trucks and often design and load the blasts with their own crews. In the US, the USGS publishes yearly figures on explosives use, gathered by the Institute of Makers of Explosives, and coal mining has long been the largest user. Supplier names here are facts, not a ranking or investment advice.
Why it matters
- Nothing moves until the rock is broken: drilling and blasting sets the pace of the whole mine.
- Fragmentation drives cost downstream, in loading, hauling, crushing and grinding.
- Control matters as much as power: clean walls, low vibration and safe exclusion zones are part of every blast design.
More machines: all mining equipment, haul trucks and crushers. On reading drill results (exploration drilling, a different job): exploration drilling and drill core.
Questions people ask
Why do mines use explosives?
Hard rock is too strong to dig directly. Blasting breaks it into pieces small enough for shovels and excavators to load and for the crusher to take. How well a blast breaks the rock, called fragmentation, affects how fast it can be dug, hauled and crushed, and how much energy the mill uses later.
What is a blasthole drill?
A large rig, on tracks, that drills rows of vertical holes into a bench of the pit. Big rotary rigs such as Epiroc's Pit Viper 351 drill holes 270 to 406 mm wide and about 20 m deep in one pass. Many are now run by remote control or drill on their own.
How are mine blasts timed?
The holes are not fired at once. Detonators with built-in delays fire them a few milliseconds apart, row by row, so each row has room to move before the next goes. That breaks the rock better and cuts ground vibration and noise. Electronic detonators let each hole's delay be set individually.
What explosives do mines use?
Most large blasts use bulk ammonium-nitrate-based products, mixed on site by specialist trucks from ingredients that are not explosive until combined. They need a detonator and a booster to fire. Explosives are made, stored and used under strict licences; this site does not describe formulations or methods.
Who supplies mining explosives?
The largest suppliers include Orica, Dyno Nobel, Enaex, MAXAM, AECI Mining, Austin Powder and Solar Industries. Most provide a full service: products, detonators, delivery trucks, blast design and crews. This is a list of facts, not a ranking or advice.
