The method specified is based on alkaline fusion of a test portion with a mixture of sodium carbonate and boric acid, dissolution of the melt in excess hydrochloric acid, reduction of the iron(III) with hydroxylammonium chloride, formation of the iron(II)-1,10-phenanthroline complex in a buffered medium (pH between 3 and 5), spectrometric measurement of the absorbance of the coloured complex at a wavelength of about 510 nm, corresponding to the absorption maximum. Applies to products having iron contents, expressed as Fe2O3, in the range 0,1 % (m/m) to 2,0 % (m/m).

General information

  • Status :  Withdrawn
    Publication date : 1993-03
  • Edition : 2
    Number of pages : 4
  • :
    ISO/TC 175
  • 73.080
    Non-metalliferous minerals

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