Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-24T17:14:12.944Z Has data issue: false hasContentIssue false
  • English
  • Français

Transformation of Akaganéite Into Goethite and Hematite in Alkaline Media

Published online by Cambridge University Press:  02 April 2024

R. M. Cornell  and
R. Giovanoli
R. M. Cornell
Affiliation:
ETHZ Zürich, Laboratory of Inorganic Chemistry, CH-8092 Zürich, Switzerland
R. Giovanoli
Affiliation:
University of Berne, Laboratory for Electron, Microscopy, Freiestrasse 3, CH-3000 Berne 9, Switzerland
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The conversion of akaganéite to goethite and/or hematite in alkaline media has been followed by X-ray powder diffraction and transmission electron microscopy (TEM). The rate of transformation fell and the amount of hematite in the product increased as the [OH−] decreased to < 1 M. Kinetic studies and TEM indicated that the transformation involved dissolution of akaganéite followed by reprecipitation of goethite and/or hematite. The rate-determining step was the dissolution of akaganéite.

Silicate species retarded the formation of goethite + hematite principally by inhibiting dissolution of akaganéite; to a lesser extent, they interfered with the nucleation of goethite. Silicate modified the morphology of goethite, but not hematite.

Comparison of the transformation behavior of akaganéite with that previously observed for ferrihydrite indicated that the composition of the reaction product depended strongly on the transformation conditions, i.e., pH and the presence of foreign species. The nature of the solid precursor was important insofar as its degree of crystallinity governed the dissolution kinetics and its surface properties influenced interaction with any foreign species in the system.

Keywords

AkaganéiteDissolutionGoethiteHematiteIron oxidesTransmission electron microscopyX-ray powder diffraction
Type
Research Article
Information
Clays and Clay Minerals , Volume 38 , Issue 5 , October 1990 , pp. 469 - 476
Copyright
Copyright © 1990, The Clay Minerals Society

References

Atkinson, R. J., Posner, A. M. and Quirk, J. P., 1977 Crystal nucleation and growth in hydrolyzing iron(III) chloride solutions Clays & Clay Minerals 25 49 – 56.CrossRefGoogle Scholar
Blesa, M. A., Mijalchik, M. and Villegas, M., 1986 Transformation of akaganéite into magnetite in aqueous hydrazine suspensions Reactivity of Solids 2 85 – 94.CrossRefGoogle Scholar
Brauer, G., 1954 Handbuch der Präparativen Anorganischen Chemie Stuttgart Ferdinand Enke 1020.Google Scholar
Brown, W. E. B. Dollimore, D., Galway, A. K., Bamford, C. H. and Tipper, C. H. F., 1980 Theory of solid state reaction kinetics Comprehensive Chemical Kinetics Amsterdam Elsevier 41 – 109.Google Scholar
Carlson, L. and Schwertmann, U., 1981 Natural ferrihy-drites in surface deposits from Finland and their association with silica Geochim. Cosmochim. Acta 45 421 – 429.CrossRefGoogle Scholar
Cornell, R. M. and Giovanoli, R., 1985 Effect of solution conditions on the proportion and morphology of goethite formed from ferrihydrite Clays & Clay Minerals 33 424 – 432.CrossRefGoogle Scholar
Cornell, R. M. and Giovanoli, R., 1987 The influence of silicate species on the morphology of goethite (a-FeOOH) grown from ferrihydrite (5Fe2O3-9H2O) J. Chem. Soc. Chem. Commun. 413 – 414.CrossRefGoogle Scholar
Cornell, R. M. and Giovanoli, R., 1988 Acid dissolution of akaganéite and lepidocrocite: The effect on crystal morphology Clays & Clay Minerals 36 385 – 390.CrossRefGoogle Scholar
Cornell, R. M., Giovanoli, R. and Schindler, P. W., 1987 Effect of silicate species on the transformation of ferrihydrite into goethite and hematite in alkaline media Clays & Clay Minerals 35 21 – 28.CrossRefGoogle Scholar
Cornell, R. M., Giovanoli, R. and Schneider, W., 1989 Review of the hydrolysis of iron(III) and the crystallization of amorphous iron(III) hydroxide hydrate J. Chem. Tech. Biotechnol. 46 115 – 134.CrossRefGoogle Scholar
Feitknecht, W. and Michaelis, W., 1962 Über die Hydrolyse von Eisen(III)-Perchlorat-Lösungen Helv. Chim. Acta 45 212 – 224.CrossRefGoogle Scholar
Hamada, S. and Matijevic, E., 1982 Formation of mono-dispersed colloidal cubic hematite particles in ethanol + water solutions J. Chem. Soc. Farad. Trans. I. 78 2147 – 2156.CrossRefGoogle Scholar
Hixon, A. W. and Crowell, J. H., 1931 Dependence of reaction velocity upon surface agitation Ind. Eng. Chem. 23 923 – 981.CrossRefGoogle Scholar
Lewis, D. G. and Farmer, V. C., 1986 Infrared adsorption of surface OH groups and lattice vibrations in lepidocrocite and boehmite Clay Miner. 21 93 – 100.CrossRefGoogle Scholar
Patterson, E. and Tait, J. M., 1977 Nitrogen adsorption on synthetic akaganéite and its structural implications Clay Miner. 12 345 – 350.CrossRefGoogle Scholar
Santschi, P. H. and Schindler, P. W., 1974 Complex formation in the ternary systems Ca2+-H4SiO4-H2O and Mg2+-H4SiO4-H2O J. Chem. Soc. Dalton 181 – 184.CrossRefGoogle Scholar
Schwertmann, U. and Fischer, W. R., 1966 Zur Bildung von a-FeOOH and a-Fe2O3 aus amorphem Ei-sen(III)hydroxid: Z Anorg. Allg. Chem. 346 137 – 142.CrossRefGoogle Scholar
Schwertmann, U. and Murad, E., 1983 The effect of pH on the formation of goethite and hematite from ferrihydrite Clays & Clay Minerals 31 277 – 284.CrossRefGoogle Scholar
Schwertmann, U. and Taylor, R. M., 1972 The transformation of lepidocrocite to goethite Clays & Clay Minerals 20 151 – 158.CrossRefGoogle Scholar
Schwertmann, U. and Taylor, R. M., 1972 The influence of silicate on the transformation of lepidocrocite to goethite Clays & Clay Minerals 20 159 – 164.CrossRefGoogle Scholar
Vogel, A. I., 1961 A Textbook of Quantitative Inorganic Analysis 3rd London Longmans 809.Google Scholar
Winter, G., 1979 Anorganische Pigmente: Disperse Festkörper mit technische verwertbaren optische und magnetische Eigenschaften Fortschr. Miner. 57 172 – 202.Google Scholar