Method of liquefying and condensing nitrogen trifluoride and a method of purifying nitrogen trifluoride

摘要

The present invention has as its technical theme to provide a liquefactive and condensable method that enables the reaction step of forming NF.sub.3 to be operated safely and continuously and purifying method that eliminates O.sub.2, N.sub.2, etc. in NF.sub.3.P PThe present invention is directed to a method wherein liquefaction and condensation of NF.sub.3 is carried out with an additive gas such as He, and Ne introduced in order to prevent H.sub.2 from mixing. The present invention is also directed to a purifying method wherein deeply cooled distillation of liquefied NF.sub.3 is carried out with one or more of He, He, and Ar introduced as a third component gas.PP According to the present invention, a safe long-term continuous operation has been made possible. Since O.sub.2, N.sub.2, etc. in NF.sub.3 can be eliminated efficiently, highly pure NF.sub.3 can be obtained.