Sodium and potassium silicates for industrial use — Determination of silica content — Gravimetric method by insolubilization

The information about the standard:

Designation standards: ISO 1690:1976
Publication date standards: 1.2.1976
The number of pages: 3
Approximate weight : 9 g (0.02 lbs)
Country: International technical standard
Category: Technical standards ISO

Annotation of standard text ISO 1690:1976 :

Description / Abstract: The procedure is based on evaporation to dryness of a test portion previously acidified with hydrochloric acid. Dissolution of the soluble salts, filtration and washing of the insoluble matter. Second evaporation of the filtrate and washings under the same conditions, further dissolution of the soluble salts, filtration and washing. Calcination and weighing of the two lots of insoluble matter simultaneously. Volatilization of silica by heating with hydrofluoric and sulphuric acids and weighing of the residue after calcination. The*difference in mass represents the silica present in the test portion.