Calcium carbide, white crystal, inorganic compound, chemical formula is CaC?. It is the main component of calcium carbide. Industrial products are gray-black masses with purple or gray cross-sections.
Calcium carbide is an important basic chemical raw material used to generate acetylene gas, organic synthesis, oxyacetylene welding, etc.
Main application
Reaction principle:CaC2+2H2O==Ca(OH)2+C2H2↑
This is an exothermic reaction, ΔH = -120kJ/mol, so it is necessary to react with saturated brine to control the reaction rate.
CaC2 can conduct electricity, the higher the purity, the easier it is to conduct electricity
(1) Acetylene generated by the reaction of calcium carbide and water can synthesize many organic compounds such as synthetic rubber, synthetic 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 form calcium cyanamide, namely lime nitrogen:
CaC2 + N2 → CaCN2 + C , ΔH = -296kJ/mol
Lime nitrogen is an important raw material for preparing cyanamide. The melt produced by the reaction between heating lime nitrogen and table salt is used in gold mining and non-ferrous metal industries.
(3) Calcium carbide itself can be used as a desulfurizer in the steel industry.
(4) Production of polyvinyl chloride (PVC), the production of polyvinyl chloride by the calcium carbide method uses calcium carbide (calcium carbide CaC2), which produces acetylene (C2H2) in contact with water, and synthesizes acetylene and hydrogen chloride (HCl) to produce vinyl chloride monomer (CH2= CHCl), and then through the polymerization reaction to make vinyl chloride produce polyvinyl chloride-[CH2-CHCI] n-chemical reaction method.
(5) In the old days, miners went to the mine and put calcium carbide in an iron tank and used the generated acetylene (C2H2) to make calcium carbide lamps.
first-aid
Skin contact: Take off contaminated clothing immediately and rinse with plenty of running water for at least 15 minutes. Seek medical attention.
Eye contact: Lift the eyelid immediately and rinse thoroughly with plenty of running water or saline for at least 15 minutes. Seek medical attention.
Inhalation: Leave the scene to fresh air. Keep the airway open. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately. Seek medical attention.
Storage method
Store in a cool, dry, well-ventilated warehouse. Keep away from fire and heat sources. The relative humidity is kept below 75%. The packaging must be sealed and kept away from moisture. It should be stored separately from acids and alcohols, and avoid mixed storage. The storage area should be equipped with suitable materials to contain the leakage.
