Influence of Urotropin on the Precipitation of Iron Oxides from FeCl 3 Solutions

Šarić, Ankica and Musić, Svetozar and Nomura, Kiyoshi and Popović, Stanko (1998) Influence of Urotropin on the Precipitation of Iron Oxides from FeCl 3 Solutions. Croatica Chemica Acta, 71 (4). pp. 1019-1038. ISSN 0011-1643

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Abstract

Precipitations of iron oxides from FeCl3 solutions in the presenceof urotropin at 90 oC were monitored using the Fourier transforminfrared spectroscopy, Mössbauer spectroscopy, X-ray diffractionand transmission electron microscopy. Urotropin was used as agenerator of OH– ions. The precipitation processes depended on theconcentrations of FeCl3 and urotropin and the time of aging. After1 day of aging the precipitation systems up to pH ≈ 2, the β-FeOOHphase was precipitated, while in the region of 5 < pH < 6 the mixturesof β-FeOOH, α-Fe2O3 and α-FeOOH were precipitated, andat pH > 6 the mixtures of α-Fe2O3 and α-FeOOH were observed.The -FeOOH phase precipitated at 2.16 < pH < 5.55 dissolved after7 days, yielding soluble iron for the α-FeOOH growth on account ofα-Fe2O3. At pH ≈ 1.5 and less, β-FeOOH was present as a singlephase up to 7 days of aging the precipitation systems. The mechanismsof iron oxide precipitation in dependence on pH were discussed.The size and morphology of oxide particles were stronglyinfluenced by experimental conditions of the precipitation processas shown by transmission electron microscopy.

Item Type: Article
Date: 1998
Subjects: NATURAL SCIENCES > Physics
Divisions: Faculty of Science > Department of Physics
Publisher: Hrvatsko kemijsko društvo
Depositing User: Gordana Stubičan Ladešić
Date Deposited: 25 Apr 2014 09:01
Last Modified: 25 Apr 2014 11:26
URI: http://digre.pmf.unizg.hr/id/eprint/974

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