Primary explosives lead azide

For the terrorist, TATP and HMTD offer easy sources of primary explosives. Consulting the do-it-yourself literature, it can be seen that there are two other commonly recommended primary explosives—lead azide Pb(N3)2 and mercury fulminate Hg(ONC)2, but these are difficult to prepare cleanly. The synthesis of diazodinitrophenol (DDNP) (Fig. 2.5), common in commercial detonators, is reported in such publications, but apparently is rarely attempted by clandestine chemists. Typically, the brisance of a primary is less than TNT, but the efficacy is the fact that a shock wave can result from a relatively mild insult. 

Thermal decomposition of pure explosives such as primary explosives lead azide, lead styphnate, mercury fulminate etc. [35], monomethylamine nitrate [36] and explosive mixtures RDX + HMX mixtures [37]. 

Primary explosives (also known as primary high explosives) differ from secondary explosives in that they undergo a very rapid transition from burning to detonation and have the ability to transmit the detonation to less sensitive explosives. Primary explosives will detonate when they are subjected to heat or shock. On detonation the molecules in the explosive dissociate and produce a tremendous amount of heat and/or shock. This will in turn initiate a second, more stable explosive. For these reasons, they are used in initiating devices. The reaction scheme for the decomposition of the primary explosive lead azide is given in Reaction 2.2. 

In early days Alfred Nobel already replaced mercury fulminate (MF, see above), which he had introduced into blasting caps, with the safer to handle primary explosives lead azide (LA) and lead styphnate (LS) (Fig. 1.17). However, the long-term use of LA and LS has caused considerable lead contamination in military training grounds which has stimulated world-wide activities in the search for replacements that are heavy-metal free. In 2006 Huynh und Hiskey published a paper proposing iron and copper complexes of the type [cat]2[Mn(NT)4(H20)2] ([cat]+ = NH4, Na+ M = Fe, Cu NT = 5-nitrotetrazolate) as environmentally friendly, green primary explosives (Fig. 1.17) [3]. 

Of interest are some correlations which Cook tentatively established between theoretical detonation and explosion results and the practical performance of explosives. For a group of primary and near-primary explosives (lead azide, mercury fulminate, and six CHNO explosives), he found a correlation between the probable order of ease of transition from deflagration to detonation and adiabatic explosion temperature. Moreover, he noted a rough correlation between the effectiveness of a primary explosive as a detonator (its ability to transfer detonation to a secondary explosive) and the C-J pressure [130]. 

The phenomenon of dead pressing is not common to aU primary explosives. Many azides, including lead azide, cannot be easily dead-pressed. On the other... 

Lead azide - Also used as a primary detonator, lead azide is a highly sensitive inorganic compound that is usually handled and stored under water in insulated rubber containers. It will explode after a fall of around six inches or in the presence of a static charge. A related compound, copper azide, is even more explosive and considered too sensitive to be used commercially. 

Only relatively few compounds can act as primary explosives and still meet the restrictive military and industrial requirements for reflabiUty, ease of manufacture, low cost, compatibiUty, and long-term storage stabiUty under adverse environmental conditions. Most initiator explosives are dense, metaHoorganic compounds. In the United States, the most commonly used explosives for detonators include lead azide, PETN, and HMX. 2,4,6-Triamino-l,3,5-triuitrobenzene (TATB) is also used in electric detonators specially designed for use where stabiUty at elevated temperatures is essential. 

Lead Azide. The azides belong to a class of very few useflil explosive compounds that do not contain oxygen. Lead azide is the primary explosive used in military detonators in the United States, and has been intensively studied (see also Lead compounds). However, lead azide is being phased out as an ignition compound in commercial detonators by substances such as diazodinitrophenol (DDNP) or PETN-based mixtures because of health concerns over the lead content in the fumes and the explosion risks and environmental impact of the manufacturing process. 

Mass effects due to some ions in salts. It is generally observed that there is a greater instability amongst compounds containing heavy atoms compared with elements in the first periods of the periodic tabie.This can be observed by analysing enthalpies of formation of ammonia, phosphine, arsine and stibine (see previous table for the last three). In the same way, it is easier to handle sodium azide than lead azide, which is a primary explosive for detonators. It is exactly the same with the relatively highly stable zinc and cadmium thiocyanates and the much less stable mercury thiocyanate. 

This primary explosive is created by adding lead acetate to a solution of sodium or ammonium azide. Lead azide has a good shelf life in dry conditions but is unstable in the presence of moisture, oxidizing agents, and ammonia. It is less sensitive to impact than mercury fulminate, but more sensitive to friction. Since lead azide is a nonconductor, it may be mixed with flaked graphite to form a conductive mixture for use in low-energy electronic detonators. 

Silver azide (AgN3) is a white-colored crystalline explosive. It requires less energy for initiation than lead azide, and fires with a shorter time delay. This primary explosive decomposes under the influence of ultraviolet radiation. If the ultraviolet... 

Primary explosives are sensitive to modest stimuli such as heat, spark, or friction application of the correct stimulus will lead to a detonation. The primary explosives used in detonators are typically extremely sensitive but not particularly powerful common examples are mercury fulminate, lead azide, and lead styphnate. In principle, the heavy metals present in most primary explosives should be a good cue for detection however, there are primary explosives that do not contain such elements. 

Lead azide is used in fuses and detonators as a primary explosive to initiate the booster. It also is used in shells and cartridges. 

This distinction is more in kind than in degree. Small quantities of primary or initiating explosives usually detonate when exposed to flames or high temperatures whiie secondary explosives usually burn or deflagrate under these conditions. However under slightly altered conditions primary explosives can be made to deflagrate and secondary explosives can be made to detonate. Examples of primary explosives are Lead Azide, Mercury Fulminate, DDNP, etc Examples of secondary explosives are PETN, RDX, HMX, Tetryl, TNT, as single HE compns and Comp B, Comp C, PBX 9404, Dynamite ANFO (Ammonium Nitrate/Fuel Oil) as HE mixtures... 

It is a primary explosive and is slightly more sensitive to impact than Lead and Silver Azides. It would require 0.25g of this explosive to detonate lg of TNT... 

Primary explosives can be ignited and will burn without detonating if they are essentially unconfined (Refs 4 6). Lead Azide appears to be an exception because its ignition results in detonation or at most a very short-lived combustion which almost instantaneously goes over into detonation (Ref 6). However, dextri-nated Lead Azide can be made to flash without detonating (Ref 5)... 

Primary high explosive, Extremely Lead azide... 

Examination of nitration acids 167—191 — Examination of finished products propellants, secondary expls and primary expls 192 — Examination of individual expls solid TNT, liquid TNT, Hexogen (RDX), Hexotol (Cyclotol), Hexotonal (RDX/TNT/A1, Torpex), Penthrite (PETN), Bofors Plastic Explosive (BPE), Bonocord, Tetryl, Lead Azide, Lead Styphnate, Mercury Fulminate, Silver Azide and Tetracene]... 

The erstwhile Explosives Research and Development Laboratory (ERDL), now High Energy Materials Research Laboratory (HEMRL), Pune, had undertaken a study on primary explosives with a view to synthesizing a series of new explosives, which are safer, powerful and free from the drawbacks of lead azide and MF. As a result of these sustained efforts, HEMRL has successfully synthesized and developed a new and safer initiatory explosive called basic lead azide (BLA). 

The testing and application of replacements for lead azide. Proc. Inti. Conference on Research in Primary Explosives, Vol.2 of 3, ERDE, Waltham Abbey, Essex, UK March 17-19, pp. 16/1-16/19. 

Group A Primary explosives, for example, mercury fulminate, lead azide, basic lead azide, styphnic acid, lead styphnate etc. 

Apart from mercury fulminate, lead azide is the most important primary explosive. 

Other data concerning the initiating properties of lead azide, as compared with the other primary explosives, are given in Table 32. 

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