Ammonium carbonate, production from

Synthesis from Aldehydes and Ketones. Treatment of aldehydes and ketones with potassium cyanide and ammonium carbonate gives hydantoias ia a oae-pot procedure (Bucherer-Bergs reactioa) that proceeds through a complex mechanism (69). Some derivatives, like oximes, semicarbazones, thiosemicarbazones, and others, are also suitable startiag materials. The Bucherer-Bergs and Read hydantoia syntheses give epimeric products when appHed to cycloalkanones, which is of importance ia the stereoselective syathesis of amino acids (69,70). 

Synthetic manganese carbonate is made from a water-soluble Mn (IT) salt, usually the sulfate, by precipitation with an alkafl or ammonium carbonate. The desired degree of product purity determines the quaUty of manganese sulfate and the form of carbonate to be used. For electronic-grade material, where the content of K O and Na20 cannot exceed 0.1% each, the MnSO is specially prepared from manganese metal, and ammonium bicarbonate is used (26) (see Electronic materials). After precipitation, the MnCO is filtered, washed free of excess carbonate, and then, to avoid undesirable oxidation by O2, dried carefljlly at a maximum temperature of 120°C. 

Ammonium nitrate [6484-S2-2J, NH NO, formula wt 80.04, is the most commercially important ammonium compound both Hi terms of production volume and usage. It is the principal component of most iadustrial explosives and nonmilitary blasting compositions however, it is used primarily as a nitrogen fertilizer. Ammonium nitrate does not occur Hi nature because it is very soluble. It was first described Hi 1659 by the German scientist Glauber, who prepared it by reaction of ammonium carbonate and nitric acid. He called it nitrium flammans because its yeUow flame (from traces of sodium) was... 

Many plants outside of North America pfill or granulate a mixture of ammonium nitrate and calcium carbonate. Production of this mixture, often called calcium ammonium nitrate, essentially removes any explosion hazard. In many cases calcium nitrate recovered from acidulation of phosphate rock (see Phosphoric acid and the phosphates) is reacted with ammonia and carbon dioxide to give a calcium carbonate—ammonium nitrate mixture containing 21 to 26% nitrogen (23). 

Losses are kept to a minimum by carbonation of the mother Hquor with CO2 and recycle of the carbonated product back to the leach system. From acid solutions, uranium is usually precipitated by neutralization with ammonia or magnesia. Ammonia gives an acceptable precipitate, for which compositions such as (NH 2(U02)2S04(0H)4 were calculated. The ammonium salt is preferred if the product is to be used ia the manufacture of... 

Carbonates. Basic zirconium carbonate [37356-18-6] is produced in a two-step process in which zirconium is precipitated as a basic sulfate from an oxychloride solution. The carbonate is formed by an exchange reaction between a water slurry of basic zirconium sulfate and sodium carbonate or ammonium carbonate at 80°C (203). The particulate product is easily filtered. Freshly precipitated zirconium hydroxide, dispersed in water under carbon dioxide in a pressure vessel at ca 200—300 kPa (2—3 atm), absorbs carbon dioxide to form the basic zirconium carbonate (204). Washed free of other anions, it can be dissolved in organic acids such as lactic, acetic, citric, oxaUc, and tartaric to form zirconium oxy salts of these acids. 

The mauve colored cobalt(II) carbonate [7542-09-8] of commerce is a basic material of indeterminate stoichiometry, (CoCO ) ( (0 )2) H20, that contains 45—47% cobalt. It is prepared by adding a hot solution of cobalt salts to a hot sodium carbonate or sodium bicarbonate solution. Precipitation from cold solutions gives a light blue unstable product. Dissolution of cobalt metal in ammonium carbonate solution followed by thermal decomposition of the solution gives a relatively dense carbonate. Basic cobalt carbonate is virtually insoluble in water, but dissolves in acids and ammonia solutions. It is used in the preparation of pigments and as a starting material in the preparation of cobalt compounds. 

This ammonia is recycled to the reactor via a compressor and a heater. Liquid ammonia is used as reflux on the top of the absorber. The net amount of carbon dioxide formed in the reactor is removed as bottom product from the absorber in the form of a weak ammonium carbamate solution, which is concentrated in a desorber-washing column system. The bottom product of this washing column is a concentrated ammonium carbamate solution which is reprocessed in a urea plant. The top product, pure ammonia, is Hquefted and used as reflux together with Hquid makeup ammonia. The desorber bottom product, practically pure water, is used in the quench system in addition to the recycled mother Hquor. 

In a German patent issued in 1929, Bergs described a synthesis of some 5-substituted hydantoins by treatment of aldehydes or ketones (1) with potassium cyanide, ammonium carbonate, and carbon dioxide under several atmospheres of pressure at 80°C. In 1934, Bucherer et al. isolated a hydantoin derivative as a by-product in their preparation of cyanohydrin from cyclohexanone. They subsequently discovered that hydantoins could also be formed from the reaction of cyanohydrins (e.g. 3) and ammonium carbonate at room temperature or 60-70°C either in water or in benzene. The use of carbon dioxide under pressure was not necessary for the reaction to take place. Bucherer and Lieb later found that the reaction proceeded in 50% aqueous ethanol in excellent yields for ketones and good yields for aldehydes. ... 

Synthesis gas is a major source of hydrogen, which is used for producing ammonia. Ammonia is the host of many chemicals such as urea, ammonium nitrate, and hydrazine. Carbon dioxide, a by-product from synthesis gas, reacts with ammonia to produce urea. 

The novel highly substituted spiro[4.4]nonatrienes 98 and 99 are produced by a [3+2+2+2] cocyclization with participation of three alkyne molecules and the (2 -dimethylamino-2 -trimethylsilyl)ethenylcarbene complex 96 (Scheme 20). This transformation is the first one ever observed involving threefold insertion of an alkyne and was first reported in 1999 by de Meijere et al. [81]. The structure of the product was eventually determined by X-ray crystal structure analysis of the quaternary ammonium iodide prepared from the regioisomer 98 (Ar=Ph) with methyl iodide. Interestingly, these formal [3+2+2+2] cycloaddition products are formed only from terminal arylacetylenes. In a control experiment with the complex 96 13C-labeled at the carbene carbon, the 13C label was found only at the spiro carbon atom of the products 98 and 99 [42]. 

Benzenesulphonamide.—Finely powdered ammonium carbonate (10 g.) and benzenesulphonyl chloride (about 1 c.c.) are ground in a porcelain basin which is then warmed over a small flame until the odour of the sulphochloride has disappeared the mixture is well stirred meanwhile. After cooling, water is added and the product is collected at the pump, washed several times with water, and then crystallised from alcohol by adding hot water until a turbidity appears. Melting point 156°. 

Nickel and cadmium are used in the production of NiFe rechargeable batteries. Using the AmMAR concept, the main leaching procedure to dissolve these valuable metals from spent accumulator scrap and production waste is performed in a two-step procedure, first with an ammonium carbonate solution and second with diluted sulfuric acid to obtain very high leaching efficiency (Fig. 14.18). 

Metyrosine Metyrosine, (-)a-methyltyrosine (12.3.11), is synthesized in a few different ways, the simplest of which is the synthesis from 4-methoxybenzylacetone, which is reacted with potassium cyanide in the presence of ammonium carbonate to give the hydan-toin (12.3.9). Treating this with hydrogen iodide removes the methyl-protecting group on the phenyl hydroxyl group and the product (12.3.10) is hydrolyzed by barium hydroxide into a racemic mixture of a-methyl-D,L-tyrosine, from which the desired L-isomer is isolated (12.3.11) [83-86]. 

Sal Ammoniac. In the tenth century A D, Abu Musa Jabir ibn Hayyan prepared by distillation of blood or hair a volatile product which he called sal ammoniac from blood or sal ammoniac from hair. This was probably salt of hartshorn, or ammonium carbonate (23). 

The reactions involved in the preparation of ammonium carbamate are essentially either the union of carbon dioxide and ammonia, or the dehydration of ammonium carbonate. A. Basaroff prepared ammonium carbamate by passing the mixture of dried ammonia and carbon dioxide gases into well-cooled absolute alcohol. A copious crystalline precipitate is formed. This is separated by filtration from the mass of liquid, and heated with absolute alcohol in a hermetically sealed vessel to 100°-110° when the liquid on cooling deposits the salt in laminae. These are pressed between filter paper, and dried over potassium hydroxide. A. Mente says the process furnishes a highly pure product, but the cost is high. When the crystals are powdered, they attract moisture from the air, and if the mass is then dried over sulphuric acid or potassium hydroxide, the composition of the product is not quite the same as before. 

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