학술논문
The formation of iron(III) oxide hydroxides from iron(II) oxalate.
Document Type
Article
Author
Source
Australian Journal of Chemistry; 1976, Vol. 29 Issue: 10 p2149-2158, 10p
Subject
Language
ISSN
00049425; 14450038
Abstract
FeC2O4,2H2O(s) suspensions in sodium hydroxide solutions were oxidized by a fast air-bubble flow at room temperature until complete reaction had occurred. With amounts of NaOH in the range OH/Fe initial mole ratio ≤1.0, the reaction is FeC2O4, 2H2(s)+ OH-(aq)+ O2(g) → ⅔γFeOOH(s)+1/3Fe(C2O4)33-(aq)+13/6H2O With OH/Fe mole ratio ≥ 2.0 the reaction is FeC2O4, 2H2(s)+ 2OH-(aq)+ O2(g) → αFeOOH(s)+(C2O4)33-(aq)+ 5/2 H2O Mixtures of goethite (α-FeOOH) and lepidocrocite (γ-FeOOH) form at intermediate OH/Fe mole ratio. The oxidation process occurs in a solid-phase intermediate product. Comparisons with similar oxidations of iron(11)sulphate solutions showed that γ-FeOOH formation was favoured and α-FeOOH formation inhibited in the iron(11) oxalate oxidation. These differences are related to pH and dissolved iron concentrations.