Објављен
Three cases, defined by a preliminary test, are envisaged: silicates containing neither sulphides nor chlorates; silicates containing sulphides; silicates containing chlorates. The method based on boiling of an acidified test portion containing methyl orange and with a lead paper strip in the vapour. The presence of sulphides produces blackening of the paper and the presence of chlorates decolorizes the methyl orange. Volumetric*measurement of carbon dioxide evolved from silicates containing neither sulphides nor chlorates by reaction with a hydrochloric acid solution. The principle for the oxidation of sulphides and the reduction of chlorates are specified.
ОБЈАВЉЕН
ISO 1691:1976
90.93
Одлука о потврђивању стандарда
20. 10. 2023.
Natrijum-silikat i kalijum-silikat za industrijsku upotrebu — Određivanje sadržaja karbonata — Gasno-volumetrijska metoda
90.93 Одлука о потврђивању стандарда
Ispitivanje tehničkog natrijum-silikata i kalijum-silikata - Određivanje sadržaja karbonata (izraženog kao Na2CO3 ili K2CO3) - Gasno-volumetrijska metoda
95.99 Повучен