Silver azide

Chemical Properties

orthorhombic, a=0.559 nm, b=0.591 nm, c=0.610nm; can be prepared by reacting silver nitrate solution with hydrazine or hydrazoic acid; sensitive to shock [KIR83] [CIC73]

Uses

It is used as a primary explosive, often as areplacement for lead azide. It may be usedin smaller quantities than lead azide as ainitiator.

Health Hazard

Silver azide is a highly toxic substance. Thetoxic effects have not been reported.

Fire Hazard

It is a primary explosive. It explodes violently upon thermal and mechanical shock. It requires lesser energy for initiation than lead azide and also fires with a shorter time delay. The heats of combustion and detonation are 1037 and 454 cal/g, respectively (i.e., 156 and 68 kcal/mol, respectively). The detonation velocity is 6.8 km/sec (at the crystal density 5.1 g/cm3). The pure compound explodes at 340°C (644°F) (Mellor 1967). The detonation can occur at much lower temperatures in an electric field when initiated by irradiation. Also, the presence of impurities can lower down the temperature of detonation. Such impurities include oxides, sulfides, and selenides of copper and other metals.
It reacts with halogens forming halogen azides, often producing explosions. It reacts explosively with chlorine dioxide, most interhalogen compounds, and many dyes. It reacts with acids forming heat- and shock-sensitive hydrazoic acid. When mixed with salt solutions of heavy metals, their azides are formed, which are sensitive to heat, impact and electric charge.

Safety Profile

Explodes when heated above 270°C or on impact. Pure silver azide explodes at 340℃. An electric field or irradiation by electron pulses can explode the crystals. Shock-sensitive when dry and has detonated @ 250℃. Solutions in aqueous ammonia explode above 100°C. Reacts to form more explosive products with iodine (forms iodine azide); bromine and other halogens. The presence of metal oxides or metal sulfides increases the azide's sensitivity to explosion. lMixtures with sulfur dioxide are explosive. When heated to decomposition it emits toxic fumes of NOx. See also AZIDES and SILVER COMPOUNDS.

Raw materials

Preparation Products