Integrated scheme for micro-determination of iron oxidation states in silicates and refractory minerals

✍ Scribed by E. Kiss

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 777 KB
• Volume: 193
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)86137-1

✦ Synopsis

A micro-analytical scheme incorporating four methods is described for the determination of iron(I1) and iron(II1) in both hydrofluoric acid-soluble and refractory minerals. The acid-soluble minerals are analyzed for Fe0 by direct constant-current potentiometric titration with potassium dichromate, and a separate solution is titrated similarly after Zn/Hg reduction to give total iron. The micro-determination of Fe0 in chromite and other refractory minerals involves dissolution in a cerium(IV)/phosphoric acid mixture and constant-current potentiometric and indirect titration of excess of cerium(IV) (phosphatocerate) with iron(I1). Lithium tetraborate micro-fusion is required for measurement of total iron by atomic absorption spectrometry or spectrophotometry.

The average relative standard deviation ranged between 0.73 and 1.08%.