Drilling and blasting are very important unit operations in the mining industry. Understanding the associated terms is crucial for any layman. Here are some useful terms for anyone operating or assisting in drilling and blasting operations.
Blasthole: a hole drilled into rock for the placement of explosives. Proper placement and sizing are critical for effective blasting.
Bench: the horizontal ledge or step in a quarry or mine face where holes are drilled; also refers to the horizontal surface created during excavation.
Jumbo: a large drilling machine equipped with multiple drilling units, commonly used for drilling multiple holes simultaneously.
Drifter Drill (Top Hammer): a type of drill where the piston and rotation components are integrated, transmitting energy to the drill bit for rock penetration.
Subdrilling: drilling holes deeper than the intended floor level to ensure complete rock breakage at the base and prevent uneven floors.
Blast: the operation of breaking rock using explosives; also referred to as a “shot”.
Blaster-in-Charge: the qualified person responsible for supervising and executing blasting operations.
Blasting Agent: a mixture of fuel and oxidizer (such as ANFO) that is not classified as an explosive unless confined and initiated properly.
ANFO: a common blasting agent made from ammonium nitrate and fuel oil.
Primer: an explosive unit containing a detonator, used to initiate other explosives or blasting agents.
Booster: a high-velocity explosive used to enhance the initiation of the main charge; must be cap sensitive.
Stemming: inert material (such as crushed rock) used to fill the top of a blasthole after loading explosives, helping to contain the blast energy.
Decking: separating charges within a single blasthole using stemming or air gaps to control the timing and effects of the blast.
Delay Blasting: using detonators or connectors to initiate charges at different times, improving fragmentation and reducing vibration.
Cushion Blasting: a controlled blasting technique using decoupled charges to produce a smooth excavation line and minimize damage to remaining rock.
Powder Factor: the amount of rock broken per unit of explosive, typically measured in tons or cubic yards per pound of explosive.
