Ammonium nitrate military explosives

Secondary high explosive. Mixture of TNT and Ammonium nitrate. Military explosive Amatol... 

For civilian aircraft the facility for rapid starting is not important and cartridge operation is not often employed, particularly because it involves storing and handling explosives, even though the hazards of these explosives are those of fire and not of detonation. For military purposes, however, particularly for fighter aircraft which are best scattered on an airfield, a rapid start is of considerable importance. Therefore cartridge operated starters are much used for these aeroplanes. In Britain, development has been essentially with propellants based on ballistite, namely double base propellants of the solventless type, whereas in the United States composite propellants based on ammonium nitrate have proved more popular. 

The military explosives RDX and HMX are manufactured from the 3 components using the Bachman process. Some of the possible mixtures may lead to fires in open vessels and explosions under confinement, and the exothermic and other effects (some calculated by the CHETAH program) for a wide range of mixtures are presented as ternary diagrams. It was also found that acetic anhydride layered onto solutions of ammonium nitrate in nitric acid exploded, owing to formation of acetyl nitrate. 

Large quantities of explosives are used every year. In the United States, for example, the annual consumption exceeds over 2 million tonnes. Most are used for commercial purposes and are ammonium nitrate-based formulations. There are less than a dozen chemical explosives that are manufactured in bulk quantities, and most of these were discovered in the 50-year period between 1850 and 1900. New explosives have been synthesized but optimization of the formulations takes decades and is very expensive. Consequently, any new material has to offer very significant advantages, either in terms of unique performance for military applications or in terms of cost and safety for commercial applications. 

The most important nitrolysis reaction to date is the formation of RDX (3) and HMX (4) from the caged methylenediamine known as hexamine (104). These important military explosives were first mass manufactured by this route towards the end of the Second World War and they are still prepared by this route today. The process uses a mixture of acetic anhydride, ammonium nitrate and nitric acid. The nitrolysis of hexamine is one of the most widely studied reactions in the history of explosives. Many other cyclic and linear polynitramines have been isolated from these reactions and this rich chemistry is discussed in more detail in Section 5.15. 

Until the end of the First World War the main filling for mass ordnance was TNT and its mixtures with ammonium nitrate known as Amatols. During this period improved methods for the manufacture of RDX enabled its inclusion in munitions, usually in formulation with TNT in the form of the Cyclotols. RDX and its mixtures are still the most widely used explosives for military use. 

The nitrolysis of hexamine is a direct route to the military high explosives 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and l,3,5,7-tetranitro-13,5,7-tetraazacyclooctane (HMX). " The direct nitrolysis of hexamine with dinitrogen pentoxide in absolute ifitric acid provides RDX in 57 % yield. RDX prepared by this process is exceptionally pure, but other reagents, like ammonium nitrate-nitric acid-acetic anhydride, give much higher yields, partly because they use ammonium nitrate to supplement for ammonium nitrogen deficiency in the reaction. 

Before anything else can be said about IEs, some rudimentary chemistry is needed. From a cookbook perspective, all explosives (be they military, commercial, or improvised) require the same chemical building blocks, which consist of a fuel and an oxidizer. Some explosives have the fuel and oxidizer as part of the same molecule, such as trinitrotoluene (TNT), and some explosives are comprised of mixtures of separate fuels and oxidizers, such as ammonium nitrate-fuel oil (ANFO). The oxidizer employed by the vast majority of explosives tends to be the NO2 (nitro) group. It is so predominant as an explosive ingredient that the primary focus of detection methods traditionally has been to look for nitro-derived properties. IEs tend to utilize a more diverse range of oxidizers. Table 3.1 gives a list of the numerous oxidizer possibilities. 

CHEMICAL PRODUCTS Ammonium Nitrate special purified product for industrial chemical use, available in solution, prill, and grained form. Also high-density grained material for formulation of military explosive compositions Composition D-2 Wax a densensitizing compound containing wax, nitrocellulose, and a wetting agent used in military explosive formulations... 

Explosives Sensitivity Data. Card-gap and projectile sensitivity, data are presented by Watson (Ref 1) for a wide variety of expl compns tested at the USBurMines laboratories in more or less standard test geometries. The results of both tests are in good agreement in that they provide the same sensitivity ordering fbr different subclasses of expls. Least sensitive were homogeneous liquids that did not exhibit a tendency, to undergo low-velocity detonation, AN-FO (Ammonium Nitrate-Fuel Oil), and most cast military expls. Of intermediate sensitivity were pressed and powdered military expls, cast Pentolite, permissible and nonpetmissible water-based expls, and one commercial two-component expl. The most sensitive were permissible and nonpermissible Dynamites and expls susceptible to low-velocity detonations Refs I) R.W. Watson, 1 Card-Gap and Projectile Impact Sensitivity Measurements, A Compilation , USBurMines Information Circular 1C 8605(1973)... 

The preparation of infusible (loose powder) ammonium nitrate mixtures is usually carried out in the same way as the manufacture of composite mining explosives. Since the military explosives are not very sensitive to mechanical stimulants, and it is important to obtain a high density, mixing is usually performed by edge runner mills. 

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 ... 

Miedziankit was one of the most widely used non-military explosives in Germany, Russia and Poland before, during and immediately after World War I, when there was a need to economize in the nitrates, including ammonium nitrate, used for military purposes. 

Liquid explosives came into extensive use during World War I when nitro compounds and ammonium nitrate became scarce panclastites were most commonly used for military purposes and oxyliquits in the mining industry. During the World War II the Germans employed liquid mixtures for jet propulsion including a newcomer in this field—a mixture of concentrated (80-85%) hydrogen peroxide with hydrazine for the propulsion of V2 rockets. 

According to the U.S. Standards ammonium nitrate for production of military explosives should contain 99.0% of NH4N03, no more than 0.02% free nitric acid, 0.18% of water-insoluble material, 0.50% of ammonium sulphate and 0.5% of ammonium chloride. The product should be free from alkalis and metal nitrates. A substance of similar purity is used for the manufacture of mining explosives. 

Ammonium nitrate is used in explosives, and many commercial and military explosives contain ammonium nitrate as the major explosive ingredient. Ammonium nitrate is difficult to detonate, but, when sensitized with oil or mixed with other explosive materials, it can be detonated with a large booster-primer. Amatol is a mixture of trinitrotoluene (TNT) and granular ammonium nitrate and is a major conventional military explosive. The explosive ANFO is a mixture of ammonium nitrate and fuel oil. 

The demand for nitrogen in a chemically fixed form (as opposed to elemental nitrogen gas) drives a huge international industry that encompasses the production of seven key chemical nitrogen products ammonia, urea, nitric acid, ammonium nitrate, nitrogen solutions, ammonium sulfate and ammonium phosphates. Such nitrogen products had a total worldwide annual commercial value of about US 50 billion in 1996. The cornerstone of this industry is ammonia. Virtually all ammonia is produced in anhydrous form via the Haber process (as described in Chapter 2). Anhydrous ammonia is the basic raw material in a host of applications and in the manufacture of fertilizers, livestock feeds, commercial and military explosives, polymer intermediates, and miscellaneous chemicals35. 

Application. A mixture of the dinitronaphthalene isomers is used in explosive compositions with picric acid and ammonium nitrate for military and mining explosives (Vol. III). The mixture is often referred to as Dinal . It is also designated by the symbols DN or DNN. It is an explosive very difficult to detonate. The highest rate of detonation of Dinal, when using a very powerful detonator, is about 5100 m/sec (Calvet [32]). 

Ammonium nitrate will explode if the reaction is initiated by another primary explosive. Mixtures of NH4NO3 and TNT (2,4,6-trinitrotoluene) are known as AMATOL, a military explosive. Most ammonium salts can be decomposed by heating, but many solid compounds that contain the ammonium cation and an anion that is the conjugate of a weak acid decompose quite readily with only mild heating. Some examples are illustrated in the following equations ... 

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