Ammonium Nitrate

CAS RN: 6484-52-2

Explosive Limits / Potential

May explode under confinement and high temperatures.
In the pure state it requires a combination of an initiator and a high explosive. This combination is known as a reinforced detonator. ...In combination with nitro compounds, e.g., TNT, forms one of the major high explosives for military use.
Explosions of ammonium nitrate, involving relatively small quantities, have occurred during the preparation of nitrous oxide. In these cases (e.g., an explosion in 1977), the explosions of ammonium nitrate occurred as a result of excessively high temperatures and confinement during processing.
Ammonium nitrate will not explode due to the friction and impact found in normal handling, but it can be detonated under heat and confinement or severe shock. For example, in a fire, pools of molten ammonium nitrate may be formed and if the molten mass becomes confined (eg in drains, pipes, plant or machinery) it could explode, particularly if it becomes contaminated.
Explosions of stored ammonium nitrate are responsible for some of the worst chemical disasters on record. Several of these incidents, including two in Germany in 1921, occurred during attempts to break up large piles of solidified or caked ammonium nitrate and ammonium sulfate mixtures using explosives. In both cases, the initial blast intended to break up solid ammonium nitrate initiated an unintended general detonation of the ammonium nitrate or ammonium sulfate mixture.
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