GB191112314A - A New or Improved Method of and Means for Binding and Utilising Atmospheric Nitrogen. - Google Patents

Abstract

12,314. Larsen, A. Sinding-. May 26, 1910, [Convention date]. Silicon chlorides and nitrides; silicon compounds; titanium nitrides. - In a process for fixing atmospheric nitrogen as silicon or titanium nitride, oxide materials, preferably such as contain silica or titanic acid, are heated in a suitable furnace with a reducing-agent and in the presence of a halogen or sulphur, or a body which splits off a halogen or sulphur, or a mixture or compound of these elements, and the halogen or sulphur compounds so obtained are treated directly or after the removal of byproducts with nitrogen at a higher temperature to form the nitrides. In an example, silicon nitrides of varying nitrogen contents are produced by heating quartz sand and coke in a blast furnace and introducing a mixture of chlorine and nitrogen slightly above the furnace bottom. Silicon tetrachloride is first formed and is afterwards converted into the trichloride, which at the high temperature is acted upon, the nitrogen present, forming silicon nitride . and reforming silicon tetrachloride. The siliconchlorine compounds in the escaping gases are condensed and returned to the furnace. It is convenient to maintain two zones in the furnace, one at a red heat in which the halogen compounds are formed, and another at a white heat in which the fixing of the nitrogen takes place. The process may be carried out in separate stages by leading chlorine, carbonyl chloride, or silicon tetrachloride into the furnace, separating the silicon-chlorine compounds formed, and treating these in a separate furnace in the presence of carbon monoxide, sulphur, &c. to take up the separated chlorine. To effect the addition of hydrogen to the nitride formed, the halogen or sulphur compounds used are mixed with halogen hydride or hydrogen sulphide. Carbon bisulphide or sulphur chloride are other suitable sulphur or halogen compounds.