COMMON NAME – Lead Azide
NAME – Dextrinated Lead azide
CHEMICAL NAME – Lead Hexanitride
FOREIGN NAMES – Azoture de plomb (Belgium), Azide de plomb (France), Bleiazid (Germany), Acido di piombo (Italy), Chikkaen (Japanese Navy),
Chikka Namari (Japanese Army), Azid svintsa (Soviet Union), Azida de pl;ombo (Spain), Blyazid (Sweden), Bleiazid (Switzerland
TYPE – Primary explosive
DATE OF DISCOVERY – 1891
DATE FIRST USED AS AN EXPLOSIVE – 1907
COUNTRY OF ORIGIN – Germany
COMPOSITION – 93% Lead azide, 4% Lead hydroxide, 3% Dextrin
MOLECULAR FORMULA – Pb(N3)2
MOLECULAR WEIGHT – 291.258
DENSITY – 4.6 g per ml
NORMAL STATE – Needle shaped crystals
PHYSICAL APPEARANCE/COLOR – White to buff crystals, darkens on exposure to light
INITIATION – Flame or shock
SENSITIVITY – Very shock and friction sensitive, particularly in pure form. A fall of 15.2 cm (6 in) to a hard surface can detonate it.
STABILITY – Very stable in storage
DETONATION VELOCITY – 5,300 m/s (17,389 fps)
RE FACTOR (BRISANCE) [TNT=1.0] – 0.39
TOXICITY – No more toxic than other lead salts, inhalation of particles should be avoided
MELTING POINT – 190o C. (374o F.), Decomposes, 250o C. (482o F.) Detonates
SOLUBILITY – Insoluble in cold water, slightly soluble in hot water
APPLICATIONS – PRINCIPLE USES – Blasting caps, initiators, and primers
Lead azide came into prominence as a primary explosive shortly before World War I. It has greatly replaced Mercury fulminate as a primary explosive in blasting caps, detonators, and initiators since that time. It is sensitive to impact, but much less so than Lead styphnate. It is very sensitive to initiation by flame, more so that impact or friction, which makes it a good choice for inclusion in blasting caps. It is also very stable in storage and does not break down from heat as easily as other explosives. Lead azide does react with copper creating extremely sensitive salts of Copper azide so it is usually loaded into blasting caps made from aluminum. Reasonably powerful, a smaller amount of Lead azide is usually needed to initiate a high explosive. To lower the sensitivity of Lead azide to being handled, it is dextrinated. Dextrinated Lead azide has been mixed with 4 % Lead hydroxide and 3% Dextrin, making it much easier to handle than the pure azide without lowering its valuable properties.
