氰氨化钙 Calcium Cyanamide.docx

Calcium cyanamideCalcium cyanamideIUPAC nameCalcium cyanamideOther namesCyanamide calcium salt, Lime Nitrogen, UN 1403, NitrolimeIdentifiersCAS number156-62-7?YPubChem4685067ChemSpideYUNIIZLR270912W?YEC number205-861-8UN number1403RTECS numberGS6000000[Ca+2].N#CNInChI=1S/CH2N2.Ca/c2-1-3;/h2H2;/q;+2?YKey: STRTXDFFNXSZQB-UHFFFAOYSA-N?YInChI=1/CH2N2.Ca/c2-1-3;/h2H2;/q;+2Key: STRTXDFFNXSZQB-UHFFFAOYAAPropertiesMolecular formulaCaCN2Molar mass80.102 g/molAppearanceWhite solid (Often gray or black from impurities)OdorOdorlessDensity2.29 g/cm3Melting point1340 °C [1]Boiling point1150-1200 °C (sublim.)Solubility in waterReactsHazardsMSDSICSC 1639EU Index615-017-00-4EU classificationHarmful (Xn)Irritant (Xi)R-phrasesR22R37R41S-phrases(S2)S22S26S36/37/39NFPA 704Flash pointNon-flammableRelated compoundsRelated compoundsCyanamideCalcium carbide?YExcept where noted otherwise, data are given for materials in their standard state (at 25?°C, 100?kPa)Calcium cyanamide or CaCN2 is a calcium compound used as fertilizer, first synthesized in 1898 by Adolph Frank and Nikodem Caro (Frank-Caro process). It is formed when calcium carbide reacts with nitrogen. It is commercially known as Nitrolim.CaC2 + N2 → CaCN2 + CThe reaction takes place in large steel chambers. An electric carbon element heats the reactants to red heat. Nitrogen is pressurised at 2 atmospheres.It crystallizes in hexagonal crystal system with space groupR3m and lattice constantsa = 3.67, c = 14.85 (.10?1 nm).PreparationCalcium 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 (ΔH?°= –69.0 kcal/mol at 25°C)UsesThe main use of calcium cyanamide is in agriculture as a fertilizer. In contact with water it decomposes and liberates ammonia:CaCN2 + 3 H2O → 2 NH3 + CaCO3It was us