Before we understand what sulfur hexafluoride is used for,let's first understand the basic properties of SF6 gas.SF6 gas has a history of 100 years.It was synthesized by two French chemists,Moissan and Lebeau,in 1900 and made commercially available in 1947.Sulfur hexafluoride is a volatile compound.It is yellowish-brown at room temperature and reddish brown in liquid and gas phases.It has strong alpha radioactivity.The melting temperature of 50.75℃.Boiling point 62.3℃.It does not sublimate at atmospheric pressure,but unlike uranium hexafluoride,it can change from liquid to gas.It's a strong oxidizing agent.Trace water vapor quickly hydrolyzes it to plutonioyl fluoride(PuO2F2).Pure SF6 gas is a colorless,odorless,basically non-toxic,non-combustible halogen compound.Its relative density is 6.16g/cm3(20℃,0.1MPa)in the gaseous phase and 1400g/cm3(20℃)in the liquid phase.The chemical properties of SF6 gas are very stable,do not burn in the air,do not support combustion,and water,alkali,ammonia,hydrochloric acid,sulfuric acid and so on do not react;At less than 150℃,SF6 gas is chemically inert,rarely melted in water,micromelted in alcohol.

　　What characteristics of sulfur hexafluoride are based on the various uses of sulfur hexafluoride gas?The reason why it is suitable for electric power equipment,its strong electronegativity,excellent arc extinguishing performance,high insulation strength,under atmospheric pressure for air 3 times.Under normal atmospheric pressure,the breakdown voltage value of sulfur hexafluoride is more than 2.5-3 times that of air,and the arc extinguishing capacity is more than 100 times that of air.The heat conduction performance is good and easy to compound,especially when SF6 dissociates due to discharge or arc effect.In addition,SF6 can be stored in small tanks because of the tendency to liquefy with high pressure at room temperature.

　　At present,sulfur hexafluoride gas is used in electrical engineering,semiconductor processing,magnesium purification process filling gas,sound insulation material preparation,leakage detection,torpedo silent propulsion and so on.Sulfur hexAFluORIDE IS widely USED IN such equipment as circuit breaker,high voltage transformer,gas closed combination capacitor,high voltage transmission line,transformer and so on for its good insulation performance and arc extinguishing performance.Electron grade high purity sulfur hexafluoride is an ideal electron etching agent,which is widely used in the field of microelectronics technology.As a refrigerant in the freezing industry,the refrigeration range can be between-45℃and 0℃.

　　The ELECTRICAL industry uses high purity sulfur hexAFluORide high dielectric strength and good arc extinguishing performance,used as high voltage switches,large capacity transformers,high voltage cables and gas insulation materials.It is used as reverse adsorbent in mining industry to replace oxygen in mine coal dust.Sulfur hexafluoride gas is also widely used in metal smelting(such as magnesium alloy melting furnace protective gas),aerospace,medical(X-ray machine,laser machine),meteorological(tracer analysis),chemical(***automobile tires,new fire extinguishers)and so on because of its chemical inert,non-toxic,non-combustible and non-corrosive.