Calcium nitrate manufacturing

Calcium nitrate is used in explosives, matches and pyrotechnics. Other applications are in the manufacture of incandescent mantle and as an additive to diesel fuel for corrosion inhibition. 

Iodine.—During the Napoleonic wars, nitre beds were cultivated in various parts of France, and from these saltpetre was obtained artificially. About 1811, Bernard Courtois, a manufacturer of saltpetre, near Paris, used an aq. extract of varec or kelp for decomposing the calcium nitrate from the nitre beds he noticed that the copper vats in which the nitrate was decomposed were rapidly corroded by the liquid, and he traced the effects to a reaction between the copper and an unknown substance in the lye obtained by extracting the varec or kelp with water, B. Courtois isolated this new substance and ascertained its more obvious properties. In his paper entitled Dec uverte d une substance muvelle dans le vareck, and published about two years after his discovery,11 he said ... 

The calcium nitrate solution is treated with a calculated quantity of ammonium sulphate to precipitate calcium sulphate and ammonium nitrate is recovered from the resulting solution by evaporation, for use in the manufacture of explosives. 

In most cases air is used as the cooling medium but other gases or liquids may also be used. In the manufacture of lead shot, molten lead is prilled into water. The prilling of calcium nitrate into mineral oil has been described [5], Prilling into liquid medium requires shorter towers because of the improved cooling by liquids but an extra step to remove the liquid cooling medium is necessary. 

For the manufacture of ammonium nitrate from calcium nitrate see Section 2.1.2.4). 

Regarding the manufacture of ammonium nitrate from calcium nitrate the reader should consult the parents —Dyes, English Patent, 15,391, 1908 Nydegger and Wedekend, English Patent, 20,907, 1909. 

Sodium nitrate is also called Chile saltpeter. It occurs as a natural mineral in Chile saltpeter means salt of the rock. It is used in manufacturing sulfuric acid as well as other products. Calcium nitrate is used in explosives and as a corrosion inhibitor in diesel fuels. Both compounds are used in fertilizers and matches and in the manufacture of nitric acid. 

Magnesium nitrate is prepared by dissolving magnesium oxide, hydroxide, or carbonate in nitric acid, followed by evaporation and crystallization at room temperature. Impurities such as calcium, iron, and aluminum are precipitated by pretreatment of the solution with slight excess of magnesium oxide, followed by filtration. Most magnesium nitrate is manufactured and used on site in other processes. 

This subsection discusses the production of ammonia, urea, ammonium sulfate, ammonium nitrate (AN), calcium ammonium nitrate (CAN), and ammonium sulfate nitrate (ASN). The manufacture of nitric acid used to produce nitrogenous fertilizers typically occurs on site and is therefore included here. 

Pentaerythritol is made by mixing formaldehyde with calcium hydroxide in an aqueous solution held at 65-70 °C. Nitration of pentaerythritol can be achieved by adding it to concentrated nitric acid at 25-30 °C to form PETN. The crude PETN is removed by filtration, washed with water, neutralized with sodium carbonate solution and recrystallized from acetone. This manufacturing process for PETN results in 95% yield with negligible by-products. The process is summarized in Reaction 7.9 (overleaf). 

Another major manufacturer was the Eastern Dynamite Corporation, at Wilmington, Delaware, which developed the patents of Holmes [26]. The starch was nitrated by means of mixed nitric-sulphuric acid and then stabilized by prolonged boiling with water in the presence of calcium carbonate, for 75-100 hr. In later patents the addition of ammonium salts to the water was recommended. 

This is an endothermic reaction of non-explosive character. It is evident from reaction (6a) why ammonium nitrate becomes acid during storage. Owing to the presence of free nitric acid in ammonium nitrate, its admixture with nitroglycerine may cause the latter to decompose in the course of time. Hence a little calcium carbonate, e.g. 0.3%, is very often added to ammonium nitrate destined for the manufacture of explosives including nitroglycerine. 

The resulting AN solution may be handled in various ways103. It can be stored as a solution, used in down-stream plants or sold as a solution it can be formed into solid AN by prilling or granulation, or it can be mixed with a solid filler. The most common filler is calcium carbonate in the form of ground limestone, dolomite or by-product calcium carbonate. This product is known as Calcium Ammonium Nitrate (CAN) and can be prilled or granulated. Granular products that contain AN and either ammonium or calcium sulphate are also manufactured. 

J.P.Picard M.Blais A New Approach to the Synthesis of Calcium Cyanamide without Using Electrical PowerM> PATR 2261 (1955) (Conf) 14)Sax (1957), 426 WJ.P. Picard V.LSiele, "Mechanism of Formation of White Calcium Cyanamide by the Picatinny Process . PATR 2405 (1957) (Conf) l6)J.P. Picard et al, "Laboratory Pilot Plant Investigation of Picatinny Process for Producing White Calcium Cyanamide , PATR 2452 (1957) (Conf) 17)V.I.Siele et al, "Suitability of White Calcium Cyanamide for the Preparation of Guanidine Nitrate , PATR 2455 (1957) (Conf) 18)M.Blais J.P.Picard, "Effect of Various Physical Properties of Lime on the Purity of White Calcium Cyanmide Made by the Picatinny Process , PATR 2457 (1857) (Conf) 19)S. Chard et al, "The Manufacture of Calcium Cyanamide Via Carbon Monoxide, Ammonia and Reactive Lime Parti. Laboratory Work ERDE Rept 2/R/57 (1957) (Conf), and "Part II. An Assessment of the Possible Procedure... 

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