Ammonium nitrate dense

Precipitated or synthetic barium carbonate is the most commercially important of all the barium chemicals except for barite. Barium carbonate is an unusually dense material, that is almost kisoluble ki water and only slightly soluble ki carbonated water. It does dissolve ki dilute hydrochloric, nitric, and acetic acids and is also soluble ki ammonium nitrate and ammonium chloride solutions. 

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. 

This base is used to the minimum possible extent in the final explosive as the water it contains does not contribute to the power and indeed requires energy for its evaporation. All slurry explosives therefore contain further ammonium nitrate in solid form and also a fuel for combustion. The ammonium nitrate is usually in dense form similar to that used in nitroglycerine explosives as this gives the best physical properties. However, it is common practice to mix the explosive hot so that much or all of the solid ammonium nitrate results from crystallisation during cooling. 

The first and still successful dense slurry was sensitised with TNT and therefore consisted of a suspension of TNT and solid ammonium nitrate in a solution of ammonium and sodium nitrates gelled with cross-linked guar gum. The TNT is preferably in the form of small pellets. No further fuel than the TNT is essential but aluminium can be added for increased... 

In all explosives of this kind the fusible constituent of the mixture was ammonium nitrate with other nitrates, e.g. of sodium, potassium or calcium (with water of crystallization), of organic bases such as methylamine, ethylenediamine, guanidine etc. and urea. Since on Solidification these mixtures become very dense and detonate with great difficulty, PETN, cyclonite or TNT were usually added. The composition of some of these mixtures is given in Table 47. 

Dense ammonium nitrate crystals are formed by spraying droplets of molten ammonium nitrate solution (>99.6%) down a short tower. The spray produces spherical particles known as prills . These crystals are non-absorbent and used in conjunction with nitroglycerine. An absorbent form of ammonium nitrate can be obtained by spraying a hot, 95% solution of ammonium nitrate down a high tower. The resultant spheres are carefully dried and cooled to prevent breakage during handling. These absorbent spheres are used with fuel oil. 

The density of the prills is reduced substantially when much evaporation occurs with 0.2-0.5% water in the feed, ammonium nitrate prills have a specific gravity of 0.95, but with 3-5% water it falls to 0.75. Prilled granules usually are less dense than those made by layering growth in drum or fluidized bed granulators. The latter processes also can make larger prills economically. To make large prills, a tall tower is needed to ensure solidification before the bottom is reached. The size distribution depends very much on the character of the atomization but can be made moderately uniform. Some commercial data of cumulative % less than size are ... 

One of the more critical feed properties in the case of ammonium nitrate prilling is the moisture content of the melt. Evaporation of the melt to nearly 100% solids produces hard, non-porous prills. Larger water contents yield porous, less dense prills. 

Ammonium nitrate is hygroscopic and readily soluble in water (the saturated solution contains about 65% NH4N03). Transitions from one crystal form to another take place at + 125.2 °C = 257.4°F, +84.2 °C = 183.6°F, +32.3 °C = 90.1 °F and -16.9 °C = +1.6°F. The product shows a great tendency to cake. The difficulties therefore involved are avoided by transformation into Prills. Ammonium nitrate is marketed as dense prills and as porous prills. Both can be introduced in industrial explosives after milling except ANFO blasting agents, which need unmilled porous prills. 

Dense ammonium nitrate crystals are formed by spraying droplets of molten ammonium nitrate solution (>99.6 percent) slowly in a short... 

However, it has been observed experimentally that fast reactions can proceed at least transiently at rates that are significantly below those of a detonation in a dense medium, yet are too rapid to be treated as normal deflagrations. Some of the observations are evidently due to the low density of the sample in other cases, such as with ammonium nitrate, the propagation rates are limited by chemical kinetics. Such occurrences can be explained, at least conceptually, within the framework of hydrodynamic theory. However, two other regimes have been described for which well-conceived theories do not exist. These are low-velocity detonation and convective deflagration. 

The EMEP monitoring network of precipitation chemistry consists of about a hundred stations distributed in almost 30 countries across Europe.1 All of these measure inorganic ions as well as pH and conductivity. Figure 17.1 illustrates the concentration levels of sulfate (corrected for sea salt), nitrate, and ammonium in 2006. The monitoring sites of heavy metals and persistent organic pollutants (POPs) are less densely distributed 2 in 2006, there were around 50 for heavy metals such as lead... 

A 1-g. ampoule of osmium(VIII) oxide (ca. 0.004 mol) is broken into a 100-ml. Erlenmeyer flask, and 36 ml. of 47% hydrobromic acid is added immediately. The mixture is boiled under reflux for 2 hours. The solution is decanted from the portions of broken glass into a 125-ml. beaker, and the flask is rinsed with an additional 7 ml. of the hydrobromic acid solution. To the hot solution in the beaker, 3 g. of ammonium bromide (0.03 mol) is added. After the solid has dissolved completely, the mixture is cooled to room temperature, and 50 ml. of absolute ethanol is added with stirring. The dense black solid which forms is allowed to settle f and is then washed by decantation with absolute ethanol until the washings are nearly free from bromide ion. The residue is transferred to a sintered-glass filter and washed on the filter with absolute ethanol until the filtrate gives no turbidity with ethanolic silver nitrate solution. The product is then dried at 140°. 

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