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ISO 1693:1976

Cryolite, natural and artificial — Determination of fluorine content — Modified Willard-Winter method

NORMA vydaná dňa 1.9.1976

Anglicky -
Elektronické PDF (54.20 EUR)
Anglicky -
Tlačené (54.20 EUR)


Francúzsky -
Elektronické PDF (54.20 EUR)
Francúzsky -
Tlačené (54.20 EUR)

Informácie o norme:

Označenie normy: ISO 1693:1976
Dátum vydania normy: 1.9.1976
Počet strán: 6
Približná hmotnosť: 18 g (0.04 libier)
Krajina: Medzinárodná technická norma
Kategória: Technické normy ISO

Anotácia textu normy ISO 1693:1976 :

Description / Abstract: Specifies the determination for natural and synthetic materials having a molar ratio sodium fluoride/aluminium trifluoride between 3 and 1,7 approximately. The principle consists in fusion of a test portion with sodium carbonate, separation of fluorine by distillation with sulphuric acid or perchloric acid. Titration with thorium nitrate solution in presence of sodium alizarinsulphonate/methylene blue as indicator. Alternatively, the thorium nitrate titration may be made using only sodium alizarinsulphonate, the end-point being*spectrophotometrically determined at 525 nm.