Explosion ammonium nitrate

Nitrous gases originating from the combustion units in nitric acid plants carry small amounts of unreacted ammonia, NH3. The ammonia may react with the nitrous gas to form microscopic particles of ammonium nitrate that adhere to solid surfaces. Within a short time, there is a growing layer of ammonium nitrate salt covering the internal surface of the nitrous gas compressor (Figure 4-27). This layer can obstruct the flow passages because it tends to increase the power consumption, provoke excessive vibrations, and even present a safety hazard since ammonium nitrate explosions can occur. 

A mixture of 0.5% of potassium permanganate with an ammonium nitrate explosive caused an explosion 7 h later. This was owing to formation and exothermic decomposition of ammonium permanganate, leading to ignition. 

Code for the Storage of Ammonium Nitrate Explosive Materials Code... 

The 2001 massive ammonium nitrate explosion near Toulouse, France that led to 30 fatalities, 2500 injuries, damage to nearly a third of the city of Toulouse, and the permanent closing of the facility. Figure 1.1 shows the crater formed by the blast. 

CA 44, 7539(1950) (Character of the detonation break in powdered explosives) 7) Yu.B. Khariton, "On Detonating Capacity of Explosives A.F. Belyaev, "Influence of Physical Factors on Stability of Detonation in Ammonium Nitrate Explosives Ya.I. Leitman, "Influence of Fineness of Brisant Explosives on Sensitivity to Initiation . Series of papers in Russian, Vol 1 of the book "Problems of Theory of Explosives , IzdAkadNauk, Moscow(1947)... 

Spencer Chemical Co, "Ammonium Nitrate Explosives for Underwater Applications ,... 

Shoan bakuyaku. An AN (Ammonium Nitrate) explosive compn used in Army Substitute Demolition Charges AN 79, DNN (Dinitronaph-thalene) 10, sawdust 1 NaCl 10%. TNT could replace DNN (Ref 1, p 29 Ref 5, p 371)... 

Amatol, but was sensitive to bullet impact and was rendered very insensitive by compression. Its high mp (about 160°) made loading of shells or bombs by casting or extrusion impracticable, therefore the expl was thought to offer no particular promise Ref J.D. Hopper, Study Ammonium Nitrate Explosive Received from Kelbar Powder Company , PATR 1009 (Oct 1939)... 

Low Melting Ammonium Nitrate Explosives. See under Ammonium Nitrate Blasting Explosives, High Explosives and Propellants (AN High Explosives) in Encycl 1 (1960), A346-R to A348-L, A352-R... 

Frank Explosives. Ammonium Nitrate explosives, patented in 1895 in Germany, contd as an additive K permanganate and/or chromate... 

In mining, a No. 8 detonator is used for ammonium nitrate explosives, No. 6 and No. 3 for nitroglycerine explosives. 

Ohlsson and Norrbin [46] suggested another type of ammonium nitrate explosive for mining purposes (see p. 395). 

In military ammonium nitrate explosives containing aluminium even those in which the oxygen balance is negative, the main reaction is assumed to be that of oxidation of the aluminium by reaction with ammonium nitrate ... 

Chlorate explosives yield only a small amount of gaseous products since the major product of explosion is potassium chloride. The specific pressure / is therefore relatively low (the high temperatures do not compensate for the small volume of gases), hence the lead block expansion is low, but Cheddites without nitro compounds—type O No. 6 and S—give an even smaller lead block expansion 180-200 cm3. Some chlorate explosives, when detonated in the open, do not transmit detonation from cartridge to cartridge, differing in this respect from dynamites and ammonium nitrate explosives. In a confined space, however, they behave differently. Here the... 

The converse obviously applies to ammonium nitrate explosives, which must not contain any chlorates, since during storage a double exchange reaction may occur resulting in the formation of ammonium chlorate (p. 476, Vol. II), an unstable substance which decomposes spontaneously. A number of patents were taken out between 1880 and 1895, for explosives based on the use of ammonium chlorate or mixtures of ammonium nitrate with potassium or sodium chlorate. Many accidents which occurred through the spontaneous decomposition of these explosives proved the impossibility of using mixtures containing both chlorates and ammonium salts (Hantke [79]). 

In spite of their advantages, mixtures with potassium perchlorate as the chief constituent are not very often used since the latter is too expensive. Other disadvantages of such mixtures lie in their rather high sensitiveness to mechanical impulses, the relatively great difficulty of detonating them, and their fairly high ability for deflagration. Potassium perchlorate is therefore often employed simply as an additive to ammonium nitrate explosives (p. 264). 

Another constituent of perchlorate explosives, ammonium perchlorate, unlike ammonium chlorate, is stable. It is also dissimilar to potassium perchlorate in being an explosive in the pure state, like ammonium nitrate. The greater specific gravity of ammonium perchlorate gives to explosives with which it is mixed a greater power than that of similar ammonium nitrate explosives. The former are also more sensitive than chlorate explosives to friction and impact and to thermal ignition. 

Fig. 130. Flame from ammonium nitrate explosive (Ammoncarbonit). DurationO.33 millisec (according to Bichel [16]).

It was also found that mixtures containing a large amount of ammonium nitrate (ammonium nitrate explosives) ensure much greater safety than dynamites or chlorate and perchlorate explosives. 

Another method was to dip blackpowder pellets in paraffin wax. This rendered them waterproof, and also surrounded them with a cooling sheath . A blasting powder made in this form called Bobbinite was introduced in Great Britain. It will be discussed later. These half-measures brought little improvement and attention was centred on the use of ammonium nitrate explosives. 

Monobel—an ammonium nitrate explosive containing about 80% ammonium nitrate and 10% nitroglycerine, plus 10% wood meal which adsorbed the nitroglycerine. 

Faversham Powder—another type of ammonium nitrate explosive, without nitroglycerine, containing, for instance, 90% ammonium nitrate and 10% TNT. 

Cambrite—an ammonium nitrate explosive modelled on the German Car-bonits (see Table 124). It contained a small quantity of nitroglycerine, potassium or sodium nitrate and a considerable amount of carbonaceous material (e.g. wood meal, charcoal etc.). This material was added to prevent the complete combustion of the carbon included in the explosive (to carbon monoxide only), to reduce the heat of explosion and, in consequence, the temperature of the explosion. 

Thus, Payman found that a smaller charge of ammonium nitrate explosive (No. 2 Viking Powder, see Table 96) is more likely to explode the gas mixture than a larger one. This would be compatible with observation 1 on the other hand, on moving the charge nearer to the mouth of the shothole the flame is removed almost com-... 

The effect of solid particles. In his studies of the detonation products of explosives stemmed in different ways, Audibert [29, 32] paid attention to the fact that in charges insufficiently stemmed a certain amount of the explosive remains in the form of small particles which may undergo further explosive decomposition according to conditions, i.e., temperature and ambient pressure. If these particles are ejected into a space filled with a methane-air mixture they may lead to the explosion of this mixture. The possibility of the existence of particles of undecomposed explosive in ejected detonation products has been disputed by some authors (Segay [33]), but many others have proved that it can occur. T. Urbanski [34] found that a thin layer on the periphery of a cylindrical charge of ammonium nitrate explosive is... 

A partial misfire may have various causes. For instance, the charge may be contaminated by coal-dust, as described above. The incomplete detonation of hardened cartridges of ammonium nitrate explosive occurs widely. It is obvious that the incomplete detonation of damp explosives is also possible. 

The addition of aluminium to increase the heat of the explosion and, in consequence, the power of the explosive, as practised for some time, is now believed to be too dangerous. Ammonium nitrate explosives with aluminium are permitted only for rock work in opencast mining (e.g. quarries) or underground, where there is no methane. 

Ammonium nitrate explosives usually contain a certain amount of nitro compounds from mononitro (e.g. nitronaphthalene) to trinitro compounds (e.g. trinitrotoluene). 

Some ammonium nitrate explosives used in the U.S.S.R. contain a small amount of paraffin (0.5-1 %) to reduce the hygroscopicity of the ammonium nitrate. 

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