8 BULLETIN 37, U. S. DEPARTMENT OE AGRICULTURE. 



tons sodium nitrate were exported. The total production of nitrates, 

 calculated to a basis of calcium nitrate, is equivalent to about 22,000 

 tons. During the year 1911, 2,302 tons calcium nitrate were imported 

 into the United States. 1 



CALCIUM CYANAMIDE. 



Calcium cyanamide is perhaps the most nitrogenous material manu- 

 factured for fertilizer purposes. It is prepared from calcium carbide 

 and free nitrogen, the latter being prepared from the atmosphere by 

 the removal of oxygen. The reaction between the two substances 

 may be represented by the following equation: 



CaC 2 + N 2 = CaCN 2 + C 



Calcium carbide Calcium cyanamide 



The product is a gray powder. In addition to nitrogen it contains 

 a high percentage of calcium and some finely divided carbon. In the 

 soil it reacts with water to produce urea and lime, the former being 

 acted upon further to form ammonia. 



Table IX. 



-Installations for manufacture of calcium cyanamide by the Frank and Caro 

 process. 



Name of company. 



Place of installation. 



Output per 

 annum. 



Nitrogen Fertilisers Co. (North-Western Cyanamide Co.) 



Do 



Soeieta Italiana de Prodotti Azotate 



Societa Italiana per il Carburo de Calcio 



Soeieta Piemontese per il Carburo de Calcio 



Soci&e Franchise pour les Produits Azotes 



Do 



Bayerisehe Stickstoff Werke 



Ost-Deutscher StickstofTcale und Chemische Werke 



A. G. Stickstoft'dunger 



Societa per l'Utilizzazione della Forze Idrauliche della Dal 

 mazia. 



Do.... 



Japanese Nitrogen Products Co 



American Cyanamide Co 



Do 



Odda, Norway 



Alby , Sweden 



Piano d'Orto, Italy 



Terni, Italy , 



San Marcel , Italy 



Martigny, Switzerland. . . 

 Notre Dame de Briancon 



Trostberg, Bavaria 



Bromberg, Prussia 



Knapsack, Germany 



Selenico, Dalmatia 



Dugirat, near Almissa 



Kinzei ; near Osaka 



Nashville, Tenn 



Niagara 



Tons. 



15,000 



15,000 

 4,000 



15,000 

 3,000 

 7.500 

 7.500 



15,000 

 2,500 



18,000 

 4,000 



80, 000 

 4,000 

 4,000 



12,000 



The composition of commercial calcium cyanamide is given in 

 Table X. 2 



Table X. — The composition of commercial calcium cyanamide. 



Constituent. 



Proportion. 



Constituent. 



Proportion. 





Per cent. 



45 

 4 



27 

 1 



14 





Per cent. 

 2 





Silica (SiO.0 



2 





4 







1 













1 Morton, "Utilization of Atmospheric Nitrogen," Bull. Dept. Commerce and Labor, Special Agent 

 Series No. 52. 



2 Pranke, J. Ind. Eng. Chem., 5, 159 (1913). 



