Криолит природный и искусственный. Определение содержания фтора. Модифицированный метод Вилларда-Винтера
Название (англ.):
Cryolite, natural and artificial; Determination of fluorine content; Modified Willard-Winter method
Описание (англ.):
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.
Дата введения:
01.09.76
Код КГС:
А19;Л19
Код ОКСТУ:
1711;1709;2109
Код ОКС(МКС):
71.060.50
Код ОКП:
1711;1709;2109
Нормативные ссылки:
BS 5050-1974, NEQ*NBN T 03-433-1983, EQV
Ключевые слова:
ALUMINIUM ORES CHEMICAL ANALYSIS CHEMICAL ANALYSIS AND TESTING CRYOLITE DETERMINATION OF CONTENT FLUORINE CHEMICAL ANALYSIS AND TESTIN