Ammonium nitrate periodates

Sodium nitrate is used as a fertiliser and in a number of industrial processes. In the period from 1880—1910 it accounted for 60% of the world fertiliser nitrogen production. In the 1990s sodium nitrate accounts for 0.1% of the world fertiliser nitrogen production, and is used for some specific crops and soil conditions. This decline has resulted from an enormous growth in fertiliser manufacture and an increased use of less expensive nitrogen fertilisers (qv) produced from synthetic ammonia (qv), such as urea (qv), ammonium nitrate, ammonium phosphates, ammonium sulfate, and ammonia itself (see Ammonium compounds). The commercial production of synthetic ammonia began in 1921, soon after the end of World War I. The main industrial market for sodium nitrate was at first the manufacture of nitric acid (qv) and explosives (see Explosives and propellants). As of the mid-1990s sodium nitrate was used in the production of some explosives and in a number of industrial areas. 

A 500-ml, three-necked, round-bottomed flask fitted with a sealed mechanical stirrer and an outlet leading to a gas bubbler, is charged with a solution containing 4.0 g (0.0208 mole) of cyclobutadieneiron tricarbonyl2 [tricarbonyl( 4-l,3-eyclobutadiene)iron] and 2.0 g. (0.0185 mole) of freshly sublimed p-benzoquinone (2,4-cyclohexadiene-l,4-dione) (Note 1) in 72 ml. of acetone and 8 ml. of water. To the vigorously stirred, ice-cold solution, approximately 40-42 g of ceric ammonium nitrate [ammonium hexanitrocerate(IV)] (Note 2) is added portion-wise over a period of 10-12 minutes (Note 3), until the carbon monoxide evolution has ceased. The reaction mixture is then poured into 600 ml. 

Manufacturers take advantage of endothermic dissolution to produce cold packs that athletes can use to treat injuries. One type of cold pack contains water and a salt, such as ammonium nitrate, in separate compartments. When you crush the pack, the membrane that divides the compartments breaks, and the salt dissolves. This dissolution process is endothermic. It absorbs heat for a short period of time, so the cold pack feels cold. Figure 5.8 shows how a cold pack works. 

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. 

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. 

However, Feick and Hainer [18] consider most of the above figures of the energy of activation are not very accurate as in the period prior to explosion a considerable quantity of ammonium nitrate is evaporated. The authors suggest the following equations for ammonium nitrate thermal decomposition ... 

The authors drew attention to the induction period noticeable in both types of samples of pure ammonium nitrate and those with ammonium chloride. The time, length and character of the induction period does not seem to depend on the concentration of ammonium chloride in the samples. After the induction period the decomposition of ammonium nitrate with ammonium chloride becomes faster than that of the pure substance. Guiochon and L. Jacqud found that the samples became acid during the induction period. Free nitric acid, and in the samples with ammonium chloride free hydrochloric acid (and subsequently chlorine) are formed. By adding nitric acid or chlorine to the samples, a considerable reduction or suppression of the induction period was achieved. 

Fig. 170. Thermal decomposition of ammonium nitrate (pure and with varying quantities of ammonium chloride) at 200°C (broken line) and 250°C. —induction period in min, according to Guiochon and Jacque.

The data set treated in this study is a part of the above-mentioned measurements in the Struma River basin. The period of observation in this region was 10 years (1989-98), and the chemical indicators were pH, dissolved oxygen, BOD5, COD, conductivity, acidity, DISS, N-DISS, total hardness, chloride, sulfate, ammonium, nitrate, nitrite, iron, magnesium, and calcium. 

In the dual-pressure process, low to medium pressure gases (0.3 to 0.6 MPa) containing nitrogen oxides are compressed to 1.1 to 1.5 MPa for efficient absorption in water to make nitric acid. Because of the potential for unreacted ammonia from the converter to combine with nitric acid to form ammonium nitrate, additional operating and safety precautions are necessary to deal with the accumulation of ammonium nitrate solids. One reported solution is a periodic injection of steam to parts of the compressor (see Figure 9.3)104. 

In spite of its drawbacks, during World War I France, Russia, and the United States used commercial trinitroxylene as an explosive, mostly in mixtures with other nitro compounds, or with ammonium nitrate, when these countries were short of nitration grade toluene. In the period between the two World Wars trinitroxylene was manufactured in the U.S.S.R and France and on a small scale in Poland. 

The biomaterial was dispersed in a definite amount of water. Ceric ammonium nitrate and nitric acid are then to be added slowly to the reaction mixture. Then, the monomer acrylic acid should be added drop wise to the reaction mixture. The reaction flask is to be placed in a water bath at 10-85°C for various time periods under stirring by a magnetic stirrer. After a definite time period, the reaction mixture is to be filtered and the homo-polymer should be removed with excess water. The grafted sample is to be dried to a constant weight and used for sorption studies. From the increase in weight of the biomaterial, the percentage of grafting should be calculated as follows ... 

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