95.99 Withdrawal of Standard Mar 3, 2010
ISO
ISO/TC 175 Fluorspar
International Standard
73.080 Non-metalliferous minerals
The principle of the method specified is to decompose a test portion by alkaline fusion with sodium carbonate and subsequent acidification with hydrochloric acid in the presence of boric acid to complex fluoride, selective reduction to the blue molybdosilicic acid complex, spectrometric measurement of the absorbance of the coloured complex at a wavelength corresponding to the absorption maximum of approximately 650 nm. Applies to products having silica contents, expressed as SiO2, in the range 0,2 % (m/m) to 30 % (m/m).
WITHDRAWN
ISO 9502:1989
WITHDRAWN
ISO 9502:1993
95.99
Withdrawal of Standard
Mar 3, 2010