The chemical name of calcium carbide is calcium carbide, the molecular formula is CaC2, and the appearance is gray, brownish yellow, black or brown block solid. It is the basic raw material of organic synthetic chemical industry. Using calcium carbide as raw material, a series of organic compounds can be synthesized to provide raw materials for Industry, agriculture and medicine. The main component of industrial calcium carbide is calcium carbide, the rest is free calcium oxide, carbon, silicon, magnesium, iron, aluminum compounds and a small amount of phosphide and sulfide. The purity of industrial calcium carbide is about 70% - 80%, the impurity Cao accounts for about 24%, and carbon, silicon, iron, calcium phosphide and calcium sulfide account for about 6%. The appearance is gray, brown, purple or black solid with different calcium carbide content. Those with higher calcium carbide are purple. The industrial product has a density of 2.22g/cm3 (18 ℃) and a melting point of 2300 ℃. It can conduct electricity. The higher the purity, the easier it is to conduct electricity.
The chemical properties of calcium carbide are very active. It decomposes violently with water to produce acetylene gas and calcium hydroxide, and releases a lot of heat.
Its main uses are:
(1) Acetylene produced by the reaction of calcium carbide with water can synthesize many organic compounds, such as synthetic rubber, artificial resin, acetone, ketene, carbon black, etc; At the same time, acetylene oxygen flame is widely used in metal welding and cutting.
(2) When heating powdered calcium carbide and nitrogen, it reacts to produce calcium cyanamide, that is, lime nitrogen. The cyanide melt generated by the reaction of heated lime nitrogen and table salt is used in gold mining and non-ferrous metal industry.
(3) Calcium carbide itself can be used as desulfurizer in iron and steel industry.
(4) The generated gas is combustible in case of fire and can be illuminated.
