Soda, Ammonia crystals

The black product was extracted with water and the sodium carbonate in it was recovered by concentration and crystallization. The residue, chiefly calcium sulfide, known as galigu, was dumped on land and created an environmental nuisance for many years because it never hardened. The process was invented by N. Leblanc in France in 1789, in response to a competition organized by the French Academy of Sciences. Operation of the first factory was delayed for several years because of the French Revolution. The process was operated widely until it was progressively superseded by the Ammonia-soda process in 1872. But it was still in use in Bolton, UK, until 1938, and the last plant in Europe closed in 1992. See also Black ash. 

NaHCOs precipitate is filtered out of solution while NH4CI is obtained by crystallization followed by washing and drying. Ammonium chloride also is produced from spent calcium chloride liquor obtained in ammonia-soda process ... 

Calcium chloride is obtained as a by-product in the manufacture of sodium carbonate (soda ash) by ammonia-soda (Solvay) process. The process involves the reaction of sodium chloride with calcium carbonate and ammonia. Calcium chloride is currently produced in bulk amounts by evaporation of natural underground brines. In the laboratory, calcium chloride can be prepared by treating bmestone with hydrochloric acid followed by evaporation of solution to obtain crystals. The crystals are dehydrated to obtain anhydrous salt. Calcium oxide or hydroxide may be used instead of carbonate. 

Colorless cubic or monoclinic crystals refractive index 1.782 density 4.53 g/cm3 at 20°C decomposes at 470°C soluble in cold water very soluble in boiling water 127 g/100 mL at 100°C also soluble in caustic soda, caustic potash and ammonia solution, and moderately soluble in alcohol. 

W. P. Bloxam does not recommend the preparation of this salt by passing hydrogen sulphide into an alcoholic soln. of ammonia because a complex salt, (NH S.wNHiS, is obtained, and the crystals contain alcohol. R. Laming made an aq. soln. of ammonium hydrosulphide by heating ammonium carbonate or gas liquor with sodium sulphide P. Spence, by heating the tank waste from the Leblanc soda process or gas lime with ammonium salts in a stream of steam and J. J. Berzelius recommended subliming a mixture of ammonium chloride and potassium sulphide—not in excess. 

J. J. Watts and W. A. Richards patented the preparation of this salt by removing the proper quantity of carbon dioxide from sodium hydrocarbonate by adding sodium hydroxide, sodium carbonate, or the hydroxides of the alkaline earths, and crystallizing the soln. at about 35° C. Winkler obtained it from carbonated liquor of the ammonia-soda process and T. M. Chatard by the spontaneous evaporation of soln. of normal sodium carbonate which had been exposed to the air some time and thereby absorbed carbon dioxide. There is a fairly general agreement that a temp, below 35° is not favourable to the formation of trona and that the crystals develop better in sodium chloride soln. and excess of the normal carbonate also favours the formation of trona. J. J. Watts and W. A. Richards say that if an excess of the hydrocarbonate be used, it crystallizes out unchanged. T. M. Chatard studied the influence of the composition of the soln. on the formation of trona, and obtained the results indicated in Table LIV with soln. containing a mol. of the normal carbonate. H. N. McCoy and C. D. Test have studied the conditions under which the sesquiearbonate is formed, and their results are summarized in Fig. 73. 

A 1-1. three-necked flask is equipped with a mercury-sealed stirrer, an inlet tube, and a reflux condenser which is connected through a soda-lime tube to a gas-absorption trap.1 The apparatus is dried in an oven and assembled rapidly to exclude moisture it is advisable to set up the apparatus in a hood to vent ammonia which may escape by accident. The flask is cooled in a Dry Ice-trichloroethylene bath, and 200 ml. of anhydrous (refrigeration grade) ammonia is introduced through the inlet tube from an ammonia cylinder which is either inverted or equipped with a siphon tube. Just before the apparatus is assembled, 8.1 g. (0.35 gram atom) of sodium is cut, weighed, and kept under kerosene in a small beaker. The Dry Ice bath is removed, the inlet tube is replaced by a rubber stopper, and a crystal of hydrated ferric nitrate (about 0.2 g.) is added. A small (about 5-mm.) cube of the sodium is cut, blotted rapidly with filter paper, and added quickly to the liquid ammonia. The solution is stirred until the blue color disappears, after which the remainder of the sodium is added in narrow, thin strips about as rapidly as... 

Carbonates Ammonium carbonate, [CAS 506-87-6] (NH4)2C03, volatile, white solid, soluble, formed by reaction of NH4OH and CO2 by crystallization from dilute alcohol, loses NH3, C02. and H20 at ordinary temperatures, rapidly at 58 0 ammonium hydrogen carbonate, ammonium bicarbonate, ammonium add carbonate NH4HCO3, white solid, soluble, formed by reaction of NH4OH and excess CCL. This salt is the important reactant in the ammonia soda process for converting sodium chloride in solution into sodium hydrogen carbonate solid. 

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