Cuprous Azide

The introduction of lead azide led to a difficulty in the choice of metal for the detonator tube. Under moist conditions, lead azide and copper can react to form cuprous azide on the inner wall of the tube and thus in a particularly dangerous position. Therefore with plain detonators, which cannot be sealed, copper cannot be used when lead azide is employed. Such detonators are usually made from aluminium tubes, or occasionally zinc. 

Cuprous Azide was first mentioned by T, Curtius in Ber 23, 3023, but was not properly investigated. History of later work is given in Vol 1 of Encycl, p A534... 

Black Powder 225 to 300, NC (13%N) 185, smokeless powder 185, NG 160, Nitrostarch 170, NH4N03 225, Tetryl 190, Mercury Azide 200, Silver Azide 200, Lead Azide 340 to 350, Cuprous Azide 210 to 350, Cupric Azide 245, Mercuric Fulminate 160 to 200, Silver Fulminate 200, Chedaite 200, blasting gelatin 207 to 211 and Picric Acid 225 to 350°... 

Ag Fulminate 5) Lead Azide 6) Cuprous Azide 7) Cuprous Fulminate 8) Mercurous Azide 9) Mercuric Fulminate 10) Tellurium Azide 11) Tellurium Fulminate... 

A plot of logio Ed against 1/1) is almost rectilinear. Therefore, Ea may be determined by equating (EJ4.57) with the slope of the straight line. Equation 3.3 holds good for a number of explosives such as lead azide, cuprous azide, mercury fulminate, lead styphnate, barium styphnate and metal picrates and metal picramates etc. [25-30]. Thus, it appears that the determination of Ea gives a more complete picture concerning the heat sensitivity of explosives than ED or ET. 

Cupric azide, Cu(N3)2, is of great practical significance since it can be formed in addition to cuprous azide by long term action of lead azide on copper or its alloys. 

Martin [126] prepared nickel, cobalt, zinc and manganese azides by the action of an ether solution of hydrazoic acid on the dry metal carbonate. Cuprous azide, CuN3, was obtained in the form of a light grey sediment by the reaction of sodium azide with a solution of cuprous sulphate. 

Martin carried out extensive research into the explosive properties of the azides of various metals (Table 33). The high sensitiveness of cuprous azide to impact is noteworthy. 

Cirulis (Ref 13) found that LA loaded into copper caps can form copper azide if moisture is present. Hydrazine and hydroxylamine reduce Cu(N3), to white, cuprous azide, CuN,... 

Cuprous azide is thus indicated to be an efficient initiator. For addnl info on prepn of cuprous azide see Refs 9 18... 

In a large variety of detonators, in which LA has been loaded into brass containers, cuprous azide is formed on the surface of containers stored under hot and humid con ditions. Extreme care should be exercised in handling cuprous azide or any components of ammunition in which it may be formed... 

Cuprous azide 1 A534—A535 expl properties 1 A534-A535 preparation and properties 1 A534... 

Cuprous Azide. See under AZIDES, INORGANIC Vol 1, p A534, p C 515-R... 

A recent study of the sensitivity of cuprous azide to heat and impact by Singh (Ref 20)... 

A recent study of the sensitivity of cuprous azide to heat and impact by Singh (Ref 20) confirms earlier investigations showing that sensitivity increases with an increase in cryst size. The activation energy involved in its thermal decompn has been established as 26.3 k cal (Ref 20). In addn to heat of deton, temp develpd on exp In, work density and loading density, Wohler Martin (Refs 6 7) also report the following info with respect to the initiating efficiency of CuNsi... 

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