Ammonium nitrate density

Oxidizers. The characteristics of the oxidizer affect the baUistic and mechanical properties of a composite propellant as well as the processibihty. Oxidizers are selected to provide the best combination of available oxygen, high density, low heat of formation, and maximum gas volume in reaction with binders. Increases in oxidizer content increase the density, the adiabatic flame temperature, and the specific impulse of a propellant up to a maximum. The most commonly used inorganic oxidizer in both composite and nitroceUulose-based rocket propellant is ammonium perchlorate. The primary combustion products of an ammonium perchlorate propellant and a polymeric binder containing C, H, and O are CO2, H2, O2, and HCl. Ammonium nitrate has been used in slow burning propellants, and where a smokeless exhaust is requited. Nitramines such as RDX and HMX have also been used where maximum energy is essential. 

When used in blasting, ammonium nitrate is mixed with fuel oil and sometimes sensitizers such as powdered aluminum. Lower density ammonium nitrate is preferred for explosive formulation, because it absorbs the oil more effectively. When detonated,these mixtures have an explosive power of 40 to 50% that of TNT (see Explosives and propellants). 

Figure 9.11. Poisoning of a coated V205/W03—TiOz SCR catalyst at various temperatures due to the formation of ammonium nitrate. Cell density 400 cpsi. Vcat = 7.5 cm3. Model gas 10% 02, 5% H20, 500ppm NO + 500ppm N02, 0-1500ppm NH3 and balance N2. GHSV = 52000 h 1.

As noted above (p. 36), the ammonium nitrate used for these explosives should be porous and should retain 7% of the oil without tendency to segregate on standing. A further requirement in modem practice is that the mixture, when blown into boreholes by compressed air, should break down to give a proportion of fine powder which increases both the density of loading and the sensitiveness of the mixture (see p. 141). 

It will be clear from the above that the optimum types of oxidising materials are those of highest density and dense forms of ammonium nitrate are always used. The combustibles can be dense also, although it is sometimes necessary to add at least a proportion of the combustible in an absorbent form to ensure adequate sensitiveness. Wheat flour may be regarded as typical of a dense combustible woodmeal is a useful and cheap combustible of intermediate properties. 

AN, ammonium nitrate DMNB, 2,3-dimethyl-2,3-dinitrobutane 2,4-DNT EGDN, ethylene glycol dinitrate HMX, C4H8N8O8 NG, nitroglycerin NM PETN, pentaerythritol tetranitrate RDX, C3H6N6O6 TATP, triacetone triperoxide TNT, trinitrotoluene UN, urea nitrate TMD, theoretical maximum density. 

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... 

For pure primary secondary explosives (except for border-line HE such as Ammonium Nitrate or Ammonium Perchlorate) dcr decreases as p0 increases until p0 approaches very close single crystal density when dcr may increase drastically. Thus if we limit ourselves to p0 < 0.9pcrySt, increases in p0 (according to Eq 8) should result in a greater sensitivity to impact. This is quite the opposite of what is found for shock initiation and will be examined more closely later on. At a fixed density, dcr increases as p. increases (see A B, p 90). This increase is fairly pronounced at small p (<0.2 mm) but levels off becomes almost asymptotic at large p (>0.4mm, except for cast TNT or TNT with 1% paraffin oil). Thus an increase in p, as expected, leads to a decrease... 

T. Soyama, F. Shimogori N. Otake, Ammonium Nitrate of Apparent Low Specific Density , JP 2153 (1959) CA53,22956 (1959)... 

Medard [20], for instance, recommends a mixture of 62% ammonium nitrate and 38 % trimethylolpropane trinitrate. Such a mixture has on oxygen balance corresponding to complete combustion. A charge with a diameter of 30 mm and a density of 1.50 detonates with a rate of 6150 m/sec, and a charge with a density of 1.10 detonates with a rate of 4230 m/sec. Its lead block expansion is 127.5 (taking picric acid as 100). 

A mixture of 40% ammonium nitrate and 60% trimethylolpropane trinitrate may be melted at 60°C and used as a poured filling for shells. The substance solidifies into a mass with a density of 1.36, giving a rate of detonation of 5200 m/sec. 

The explosive properties of nitrostarch mixtures (containing 12.7% of nitrogen) with ammonium or sodium nitrates have been studied by T. Urbanski et al. [48]. Values for rate of detonation of mixtures with a density of 1.0 are given in Fig. 71. They conform to Laffitte s rule that the variation in rate of detonation with the composition of mixtures with ammonium nitrate is almost rectilinear. 

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. 

Ammonium powder has the important disadvantage that ammonium nitrate occurs in various crystallographic forms with (Afferent specific gravities, one of the transitions taking place at + 32°C, i.e. only just above room or summer temperature (Vol. II). When a charge of ammonium powder is heated to this temperature a decrease in density occurs and in consequence there is an undesirable increase in rate of burning. 

These authors suggest the use of fusible mixtures containing ammonium nitrate (of the type described above—p. 253) from which the propellant grains are cast. The grains in the form of tubes have a high density and are suitable for rockets of small calibre. 

The transmission of detonation in a confined space (in a tube or shothole) is higher than in the open air. E.g. an ammonium nitrate explosive with 4% nitroglycerine which ordinarily has a transmission value of 10-15 cm, in a mortar gives the value 19-23 cm, according to T. Urbanski [70]. This author studied change of transmission as a function of density. The results for ammonium nitrate explosives are given in the diagram in Fig. 144. 

Type I—dynamites and rock explosives. The chief ingredients of the latter are ammonium nitrate, nitroglycerine and TNT. Their rate of detonation at a density of 1.1 is about 3800m/sec, their transmission distance 6 cm. 

V. Nitroglycerine low-density powder. This is a modification of Group IV. Low density (ca. 0.7) is obtained by incorporating vegetable fibre or peat. A low density form of ammonium nitrate and sodium chloride may also be used. A 1 Roun-kol is an example of an explosive of this group. Sheathed Rounkol has been replaced by Unikol. They are used for soft coal, for maximum lump production. Their water resistance is the same as that of Group IV. 

Another improvement consisted of preparing low density explosives (L.D. explosives) which contain ammonium nitrate in the form of bulky, porous crystals... 

Low density Ammonit No. 14 is a relatively new explosive — it was first tested in 1954. It contains low density ammonium nitrate and 7% nitroglycerine. Its properties are ... 

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