Primary Explosive
Definition
A high explosive sensitive enough to detonate from friction, spark, percussion, or flame without confinement or a separate booster. Examples: mercury fulminate, lead azide, DDNP, lead styphnate. Used in detonator initiation trains.
- Sensitivity trigger
- Detonates from friction, spark, percussion, flame, heat, or electrostatic discharge
- Confinement required
- No confinement or booster needed to detonate
- Primary role
- Initiating charge in detonator trains
Common questions
What makes a primary explosive different from other explosives?+
Primary explosives are extremely sensitive to mechanical shock, friction, heat, electrostatic discharge, spark, percussion, or flame. They detonate without needing confinement or a separate booster, making them ideal for starting the detonation chain in devices.
Why are primary explosives used in detonators?+
Primary explosives ignite from small amounts of energy (a spark, friction, or electric discharge), so they reliably initiate detonation trains without requiring a large shock or booster. This controlled sensitivity makes them the standard choice for detonator caps and initiating charges.
What are some common primary explosives?+
Mercury fulminate, lead azide, DDNP, and lead styphnate are standard primary explosives. These are all highly shock-sensitive and used as initiating materials in detonator systems.
Related terms
- Brisance
- The shattering power of a detonating explosive, distinct from heave (bulk displacement). Measured by the Trauzl lead block test. High-brisance explosives (RDX,...
- Deflagration
- A subsonic combustion front propagating through an explosive by thermal conduction. Characteristic of low explosives such as black powder and smokeless powder;...
- Detonation
- A supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100...
- Secondary Explosive
- A high explosive insensitive to normal friction, spark, and percussion; requires a primary explosive shock or blasting cap to initiate detonation. Examples:...
- ANFO
- Ammonium nitrate fuel oil: 94% ammonium nitrate prills + 6% diesel fuel oil. Detonation velocity approximately 4,500-4,800 m/s. The most widely used...
- Chapman-Jouguet Velocity
- The minimum stable detonation velocity for a given explosive at a specific density, a thermodynamic property of the explosive composition. Used to...
- Deflagration-to-Detonation Transition (DDT)
- The acceleration of a deflagrating burn front to supersonic detonation velocity, triggered by confinement. Relevant to understanding how improvised devices using low...
- Ion Chromatography (IC)
- An analytical technique that separates and quantifies anions and cations in solution. In post-blast residue analysis, IC detects nitrate, nitrite, ammonium, and...
- Oxygen Balance
- A percentage expressing the surplus or deficit of oxygen in an explosive molecule relative to stoichiometric complete oxidation of carbon to CO2...
- PESO (India)
- Petroleum and Explosives Safety Organisation, the Indian government body under the Ministry of Commerce and Industry that administers the Explosives Act 1884...
- Smokeless Propellant
- A low explosive based on nitrocellulose (single-base), nitrocellulose plus nitroglycerin (double-base), or nitrocellulose plus nitroglycerin plus nitroguanidine (triple-base). Used as firearm propellant...
- Tertiary Explosive (Blasting Agent)
- An ammonium nitrate-based explosive formulation requiring both a primary and a booster charge for reliable initiation. ANFO is the globally dominant blasting...
Explained in these topics
- Explosives Classification: Low vs High, Primary vs SecondaryA high explosive sensitive enough to detonate from friction, spark, percussion, or flame without confinement or a separate booster. Examples: mercury fulminate...
- Explosives Classification: Low, High, Primary, Secondary, TertiaryAn explosive material highly sensitive to mechanical shock, friction, heat, or electrostatic discharge, used as an initiating charge. Examples: lead azide, mer...