Reference number
ISO 3200:1975
ISO 3200:1975
© ISO 2024
ISO 3200:1975
Sodium and potassium silicates for industrial use — Determination of sulphates content — Barium sulphate gravimetric method
Edition 1
1975-03
1975-03
Retirada
Resumen
Applicable to the analysis of products having contents either above 0.1 % (m/m) or above 0.25 % (m/m) according to whether the product is readily or sparingly soluble in water. The principle consists in dissolution of a test portion either directly or after alkaline fusion. Separation of the insoluble matter. Precipitation, while boiling, of the sulphate ions in an acid medium. Filtration, washing and calcination of the precipitate. Weighing of the barium sulphate after treatment with hydrofluoric acid in order to remove any silica which may be present. Has also been approved by the IUPAC.