Process for purifying nitrogen-fluoride

A process for continuously producing NF3 and a process for removing O2, N2, etc. from NF3 containing them are disclosed. This process comprises introducing an additional gas such as He, Ne, etc. in the liquefaction and concentration of NF3 for preventing contamination with a H2 gas. In addition, a process of introducing one or more of He, Ne and Ar as a third component in low temperature distillation of the resulting liquefied NF3 is also disclosed. This invention enables continuous operation safely for a long time and a highly pure NF3 can be obtained since O2, N2, etc. in NF3 can be effectively removed. ABSTRACT The present invention has as its technical theme to provide a liquefactive and condensable method that enables the reaction step of forming NF3 to be operated safely and continuously and purifying method that eliminates O2, N2, etc. in NF3. The present invention is directed to a method wherein liquefaction and condensation of NF3 is carried out with an additive gas such as He, and Ne introduced in order to prevent H2 from mixing. The present invention is also directed to a purifying method wherein deeply cooled distillation of liquefied NF3 is carried out with one or more of He, He, and Ar introduced as a third component gas. According to the present invention, a safe long-term countinuous operation has been made possible. Since O2, N2, etc. in NF3 can be eliminated efficiently, highly pure NF3 can be obtained. Procédé de production sûr et en continu de NF3 et procédé d'extraction d'O2, N2, etc. du NF3 les contenant. Ce procédé consiste à introduire un gaz supplémentaire tel que He, Ne, etc. pendant la liquéfaction et la concentration du NF3 de manière à prévenir la contamination avec de l'H2 à l'état gazeux. Est également décrit un procédé consistant à introduire un gaz parmi He, Ne et Ar en tant que troisième composant pendant la distillation à basse température du NF3 liquéfié résultant. Cette invention permet un fonctionnement continu et sûr pendant une longue durée et permet d'obtenir du NF3 très pur, étant donné que l'O2, le N2, etc. dans le NF3 sont extraits efficacement.