ISO 4443:2022

Cryolite primarily used for the production of aluminium — Determination of elements — Wavelength-dispersive X-ray fluorescence spectrometric method using pressed powder tablets

Scope

This document specifies a wavelength-dispersive X-ray fluorescence spectrometric (XRF) method for the determination of cryolite (Na3AlF6) from the content of fluorine to the content of trace elements. The calibration reference materials are not specified in this method.
The method is applicable to cryolite, which is primarily used for the production of aluminium. Annex A provides conversion factors for converting elements to compounds. The validity and precision of test results for concentrations outside these ranges has not been determined.
The concentration range of fluorine (given as F) is from 510 g/kg to 560 g/kg. The concentration range of aluminium (given as Al) is from 120 g/kg to 150 g/kg. The concentration range of sodium (given as Na) is from 270 g/kg to 330 g/kg. The concentration range of silicon (given as SiO2) is from the lowest limit of detection (LLD) to 4,0 g/kg. The concentration range of iron (given as Fe2O3) is from LLD to 0,37 g/kg. The concentration range of sulfur (given as SO4) is from LLD to 5,0 g/kg. The concentration range of phosphorus (given as P2O5) is from LLD to 0,40 g/kg. The concentration range of calcium (given as CaO) is from LLD to 0,80 g/kg.