Cryolithe, naturelle et artificielle — Essai conventionnel pour l'évaluation de la teneur en fluorures libres

ISO/TR 4277:2009 describes a conventional test for the evaluation of the free fluorides content of natural, artificial and recovered cryolite.

This method is applicable to products having free fluorides content greater than 0,15 % (mass fraction) of AIF₃ or 0,4 % (mass fraction) of NaF.