What is "ammonal"

Ammonal \Am"mo*nal`\, n. [Ammonium + aluminium.] An explosive consisting of a mixture of powdered aluminum and ammonium nitrate.

n. an explosive made up of ammonium nitrate, trinitrotoluene, and aluminium powder

Ammonal is an explosive made up of ammonium nitrate and aluminium powder. Not to be confused with T-ammonal which contains trinitrotoluene as well to increase properties such as brisance.

The ammonium nitrate functions as an oxidizer and the aluminium as fuel. The use of the relatively cheap ammonium nitrate and aluminium makes it a replacement for pure TNT.

The mixture is affected by humidity because ammonium nitrate is highly hygroscopic. Ammonal's ease of detonation depends on fuel and oxidizer ratios, 95:5 ammonium nitrate and aluminum being fairly sensitive, however not very oxygen balanced. Even copper metal traces are known to sensitize bulk amounts of ammonium nitrate and further increase danger of spontaneous detonation during a fire, most likely due to the formation of tetramines. More oxygen balanced mixtures are not easily detonated, requiring a fairly substantial shock, though it remains more sensitive than trinitrotoluene and C-4.

The detonation velocity of ammonal is approximately 4,400 metres per second or 9,842 miles per hour.