ISO International Standard

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.