Process for the manufacture of a double salt non-hygroscopic or slightly hygroscopic in partaut of the calcium nitrate

摘要

276,350. Azogeno Soc. Anon. per la Fabbricazione Dell'ammoniaca Sintetica e Prodotti Derivati Toniolo, C., and Tanzi, B. Aug. 19, 1926, [Convention date]. Manures.-A double salt which is non-hygroscopic or is less hygroscopic than calcium nitrate is prepared by mixing ammonium sulphate and anhydrous calcium nitrate in the presence of two molecules of water for one of nitrate. Twice this quantity of water may be present, but in this case the excess is finally expelled by heat. The water may be added to either salt or to the mixture as moist air, steam or liquid; or hydrated calcium nitrate Ca(NO3)24H2O prepared by cooling a 70 per cent solution of the nitrate may be used. Ammonium sulphate may be added to the dissolved salt. If the nitrate is basic, nitric acid is first added. The salts are preferably mixed in equimolecular proportions; excess nitrate or sulphate may, however, be added, but not less than 30 per cent of ammonium sulphite should be present. The ammonium sulphate may be replaced by mono- or bi-ammonium phosphate, and potassium salts, ammonium nitrate or urea added to obtain mixed fertilizers. The Specification, as open to inspection under Sect. 91 (3) (a) comprises also the use of excess ammonium sulphate, but less than two molecular equivalents to one of calcium nitrate. This subject-matter does not appear in the Specification as accepted.