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).
Status: WithdrawnPublication date: 1993-03
Edition: 2Number of pages: 4
Technical Committee: ISO/TC 175 Fluorspar
- ICS :
- 73.080 Non-metalliferous minerals
ISO 9061:1993Stage: 95.99
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