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How do chemical explosives create rapidly expanding gases?
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explosive
A coal miner loading a drill hole with a water gel explosive called Tovex.
Chemical explosives create rapidly expanding gases through a chemical reaction characterized by extremely rapid decomposition or burning, which releases energy in an incredibly brief period.12
These explosives are categorized by how they produce this gas:
- Detonating (High) Explosives: These substances, such as TNT and dynamite, undergo an instantaneous, violent reaction. A shock wave passes through the molecules at supersonic speeds, causing them to displace and decompose almost simultaneously, resulting in high pressure.342
- Deflagrating (Low) Explosives: Materials like black and smokeless powders produce gas through fast burning. While this process is slower than detonation, the rapid expansion of gases under confinement creates sufficient pressure to break apart the containing vessel.42
In both cases, the fundamental mechanism is the conversion of a solid or liquid substance into a large volume of gas, which exerts immense pressure as it expands. Under specific conditions of confinement and quantity, some deflagrating explosives can be forced to detonate.12