Process for the continuous production of calcium-cyanamide

摘要

Calcium cyanamide is continuously produced by the reaction between elementary nitrogen and calcium carbide by injecting the finely divided carbide as an homogeneous suspension in a gaseous carrier, into a heated reaction chamber so that the carbide is maintained in suspension until the reaction is complete, whilst simultaneously injecting through nozzles separate from that for the suspension, oxygen and preheated nitrogen together with a preheated hydrocarbon gas, the combustion of which is sufficient to raise the temperature of the reaction chamber to at least 1200 DEG C, and finally separating the calcium cyanamide produced. The carrier gas may be nitrogen (preheated to 1000 to 1200 DEG C), air or a hydrocarbon gas. In the preferred embodiment a suspension of carbide in a hydrocarbon gas, such as coke oven gas, is injected into the end of a horizontal cylindrical reaction chamber. Simultaneously another jet of preheated hydrocarbon gas is introduced by separate nozzles, adjacent to which oxygen nozzles are provided, the amount of oxygen preferably being such that principally carbon monoxide and hydrogen result from the combustion. The nitrogen nozzles may be distributed about the entry of the carbide, gas and oxygen nozzles. The reaction temperature may be maintained by recycling hot residual gas and controlled by introducing coal gases or by providing movable cooling surfaces on which the reaction products are deposited. If a product free from elementary carbon is required, a quantity of oxygen sufficient to convert it to carbon monoxide may be introduced at a point remote from the main reaction zone.