ISO 1691:1976
ISO 1691:1976

Status : Published (Under review)

This standard was last reviewed and confirmed in 2023. Therefore this version remains current.
Format Language
std 1 42 PDF
std 2 42 Paper
  • CHF42
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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.

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General information

  •  : Published
     : 1976-07
    : International Standard confirmed [90.93]
  •  : 1
     : 5
  • ISO/TC 47
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