International Standard
ISO 4280:1977
Cryolite, natural and artificial, and aluminium fluoride for industrial use — Determination of sulphate content — Barium sulphate gravimetric method
Reference number
ISO 4280:1977
ISO 4280:1977
Edición 1
1977-11
1977-11
© ISO 2024
International Standard
p
ISO 4280:1977
10120
No disponible en español
Publicado
(Edición 1, 1977)
Esta norma se revisó y confirmó por última vez en 2020.
Por lo tanto, esta versión es la actual.
Resumen
Applicable to products having a content, expressed as sulphur trioxide, equal to or more than 0.1 % (m/m). Bases on alkaline fusion of a test portion with a mixture of sodium carbonate and boric acid. Extraction of the fused mass with perchloric acid solution and precipitation of the sulphate ions with barium chloride in an acidified medium. Filtration on a fine-texture, ashless filter paper (pore diameter approximately 0.4 to 1.0 m). Calcination after drying in an electric oven at (850 20) °C. Weighing of the residue.
Informaciones generales
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Estado: PublicadoFecha de publicación: 1977-11Etapa: Norma Internacional confirmada [90.93]
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Edición: 1Número de páginas: 3
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Comité Técnico :ISO/TC 226ICS :71.060.50
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