Ammonal

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Ammonal
The explosion of 18,400 kilograms (40,600 lb) of ammonal under Hawthorn Ridge Redoubt, 1 July 1916
Type	Explosive
Place of origin	United Kingdom
Service history
Wars	World War I

Ammonal is an explosive made up of ammonium nitrate and aluminium powder. TNT is added to create T-ammonal which improves properties such as brisance. The mixture is often referred to as Tannerite, which is a brand of ammonal.

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 aluminium 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 14,000 feet per second.