Calciumcyanamid

VerwendenCalcium Cyanamide is used as a fertilizer, herbicide, insecticide, a steel-making additive and an ore processing material. It can also be used to make thiourea, guanidine and ferrocyanides. manufacture of calcium cyanide, melamine, dicyandiamide.

synthetischeCalcium cyanamide is prepared from calcium carbide. The carbide powder is heated at about 1,000°C in an electric furnace into which nitrogen is passed for several hours. The product is cooled to ambient temperatures and any unreacted carbide is leached out cautiously with water. CaC2 + N2 → CaCN2 + C (ΔHƒ°= –69.0 kcal/mol at 25°C)

Definitioncalcium cyanamide: A colourlesssolid, CaCN2, which sublimes at1300°C. It is prepared by heating calciumdicarbide at 800°C in a streamof nitrogen:CaC2(s) + N2(g) → CaCN2(s) + C(s)The reaction has been used as amethod of fixing nitrogen in countriesin which cheap electricity isavailable to make the calcium dicarbide(the cyanamide process). Calciumcyanamide can be used as afertilizer because it reacts with waterto give ammonia and calcium carbonate:CaCN2(s) + 3H2O(l) → CaCO3(s) +2NH3(g)It is also used in the production ofmelamine, urea, and certain cyanidesalts.