Purification of Fluorine by Distillation

Abstract

A vacuum-jacketed metal still for purifying half-pound quantities of commercial fluorine is described. Operating characteristics of a prototype still and of the present still are reported. The distillate is analyzed by an improved mercury-titration method, and a middle fraction of 99.9% or higher purity is collected. The impurities found in several cylinders of commercial fluorine by infrared and mass spectrographic analyses include N, 0, CO/sub 2/, NF/sub 3/, HF, CF/sub 4/, C/sub 2/H/sub 6/,C/sub 3/H/sub 8/,OF/sub 2/, Ar. (auth