Improvements in or relating to the purification of electrolytic fluorine

HF-contaminated electrolytic fluorine is contacted with sodium fluoride powder at between 0 DEG and 85 DEG C. and the absorbent containing absorbed HF is subsequently regenerated by heating, and the steps of removing HF contaminant in F2 by regenerated absorbent at the specified temperatures and regenerating are repeated. Regeneration may be at 200-400 DEG C. in situ, in a stream of inert gas, e.g. N2 or air. The NaF powder may be in shallow beds in trays disposed in a series of superimposed horizontal shelves, which may be heated for regeneration by a grid of electric cable below each layer of trays or by a cable buried in the bed. Residual HF may be removed by passing the F2 through a further tower packed with NaF pellets.