FIXED NITROGEN" RESEARCH LABORATORY. 499 



phosphate rock or Thomas slag, a very much greater cyanamide con- 

 tent may be used safely and effectively. 



If further work substantiates these indications, the results may be 

 of very considerable importance in finding an outlet for the product 

 of the cyanamide plant at Muscle Shoals, since the difference in cost 

 of manufacture, even for a part of the product, as between cyanamide 

 and ammonium salts may mean the difference between profit and loss. 



CYANIDES. 



In addition to the cyanamide and direct synthetic ammonia plants 

 near Muscle Shoals, the Government also, during the war, commenced 

 the construction at Saltville, Va., of a plant for the fixation of nitro- 

 gen as sodium cyanide (Biicher process). Considerable difficulties 

 were met with, and, although some cyanide was produced, the plant 

 did not reach commercial operation before the armistice, shortly after 

 which it was dismantled. When this process and plant were first 

 considered it was thought by some that it might be possible thereby 

 fo pass from free nitrogen through cyanide to ammonia at a lower 

 cost than through cyanamide, and even failing in this it would still 

 be a cheaper process for reaching the cyanides and hydrocyanic acid. 



By the time the construction of the Saltville plant was definitely 

 started, however, the problem had narrowed down to simply produc- 

 ing cyanides for the needs of the Chemical Warfare Service, but the 

 work at this plant by no means exhausted the experimental possi- 

 bilities for the use of the reactions involved, nor did it furnish us 

 with the fundamental knowledge of the exact mechanism of these 

 reactions. The alkali cyanide reactions have the advantage over those 

 of calcium cyanamide that they do not require electric-furnace tem- 

 peratures, nor so great a power consumption, but they are incomplete, 

 and the volatility of the substances introduces other complications. 

 The laboratory work on these cyanide reactions which was origi- 

 nally laid out has during the past year been nearly covered, and it 

 is hoped to complete this and publish the data secured during this 

 coming year. In the meantime, one commercial company has estab- 

 lished a plant in California and is manufacturing hydrocyanic acid, 

 largely for fumigation of fruit trees. The work at the Fixed Ni- 

 trogen Research Laboratory has not furnished us with any particu- 

 lar encouragement for obtaining fixed nitrogen at fertilizer prices 

 through any cyanide process operated primarily as such. There is, 

 however, still the chance that these reactions, when occurring inci- 

 dentally in other processes, particularly in the iron blast furnace, 

 may, if proper advantage can be taken of them, be made to furnish 

 crude cyanides as by-products at a low enough cost to permit of 

 making ammonia for fertilizer. 



It has been known for many years that in certain parts of the blast 

 furnace considerable amounts of cyanides are formed by the alkalies 

 and carbon in the charge taking up nitrogen from the blast, but in 

 the normal running of the furnace these are volatilized and swept 

 upward by the blast into zones of oxidation, where they are reoxidized 

 to carbonates, thus again liberating the nitrogen. The idea of draw- 

 ing off this material before it undergoes oxidation has long been sug- 

 gested and even patented, but still awaits thorough large-scale experi- 

 ^lentation and development. It happens to be a type of problem on 



