Reference number
ISO 9502:1993
ISO 9502:1993
© ISO 2024
ISO 9502:1993
Metallurgical-grade fluorspar — Determination of silica content — Reduced-molybdosilicate spectrometric method
Edition 2
1993-03
1993-03
Withdrawn
Abstract
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).
Life cycle
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Previously
WithdrawnISO 9502:1989
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Now