90.93 Standard confirmed Jan 4, 2022
ISO
ISO/TC 226 Materials for the production of primary aluminium
International Standard
71.100.10 Materials for aluminium production
Published
Applicable to products having F contents of more than 0.003 % (m/m). Dissolution of a test portion by attack by sulphuric acid under pressure. Separation of the fluorine by distillation at a temperature of (150 1) °C by sulphuric acid. The distillation is carried out by the method described in ISO 1693. Formation of a blue coloured complex between fluorine and alizarin complexone/lanthanum chloride reagent at a pH between 4.5 and 4.6. Addition of acetone to increase the stability and sensitivity of the fluorine complex. Spectrophotometric measurement of the complex at a wavelength of about 620 nm. Has also been approved by the IUPAC.
PUBLISHED
ISO 2828:1973
90.93
Standard confirmed
Jan 4, 2022