1. It’s the first step
Blasting is the very first step of the mining process. Explosives are placed deep in the ground (surface mining) or in the rock-face (underground mining), and detonated to release large quantities of mineral-bearing ore. Explosives are important, because it’s the only economical way to break up hard rock.
2. It goes back centuries
The use of explosives to blast open the earth for mining goes back to 1627 in Hungary, when gunpowder was used. It was followed by dynamite, which was invented in 1886. Common explosives used today are ANFO (Ammonia Nitrate/Fuel Oil), slurries and emulsions.
3. It’s dangerous
The explosives used in mining are fairly safe; it’s the process itself that is dangerous, which is why the blast area has to be cleared. In surface mining, most blast injuries and fatalities occur when miners are struck by flying rock; in underground mining, it’s from miners being too close to the blast, as well as from explosive fumes, misfirings and premature blasts.
4. It makes the ground shake
When there’s a blast at a mine – particularly a surface mine – everybody in the surrounding area knows. The sound and vibration can be felt not only in the mine buildings close by, but in homes and buildings several kilometres away. These effects are generated by ground vibration and airblast, and can last for three seconds or more.
5. It uses GPS technology
Mines in Zambia are starting to use a novel technology developed in Australia, called Blast Balls. These round plastic devices are equipped with a GPS transmitter, and are placed in strategically spaced holes in the blast pattern prior to blasting; after the blast, the balls help to track the movement of the ore and waste. The location of mineable ore can now be determined with far greater accuracy and in less time.
See also: How copper is produced
