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Acid Dissolution of Hematites of Different Morphologies

Published online by Cambridge University Press:  09 July 2018

R. M. Cornell  and
R. Giovanoli
R. M. Cornell
Affiliation:
University of Berne, Laboratory for Electron Microscopy, Freiestrasse 3, 3000 Berne 9, Switzerland
R. Giovanoli
Affiliation:
University of Berne, Laboratory for Electron Microscopy, Freiestrasse 3, 3000 Berne 9, Switzerland
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Abstract

Dissolution in HCl of hematite particles with different morphologies led to sigmoidal dissolution vs. time curves. The rate of dissolution was directly proportional to the sample surface area and independent of crystal morphology. Hematites produced by heating goethite at 600 or 800~ dissolved more rapidly per unit area than did hematites grown from solution. TEM showed that some platy crystals developed central holes after prolonged acid attack; the hole formation was attributed to enhanced dissolution at screw dislocations present on the (001) faces of the crystals. Except where particularly susceptible regions involving strained areas or dislocations were present, there appeared to be no preferential acid attack at any particular crystal face. The original morphology was usually maintained during the reaction.

Type
Research Article
Information
Clay Minerals , Volume 28 , Issue 2 , June 1993 , pp. 223 - 232
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1993

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References

Barron, V., Herruzo, M. & Torrent, J. (1988) Phosphate adsorption by aluminous hematites of different shapes. Soil Sci. Soc. Am. J. 52, 647–51.CrossRefGoogle Scholar
Brown, W.E.B., Dollimore, D. & Galway, A.K. (1980) Chapter 3, Heterogeneous Reactions Pp. 41-109 in: Comprehensive Chemical Kinetics (C.H. Bamford & C.F.H. Tipper, editors). Elsevier, Amsterdam.Google Scholar
Cornell, R.M. (1985) Effect of simple sugars on the alkaline transformation of ferrihydrite into goethite and hematite. Clays Clay Miner. 33, 219–227.Google Scholar
Cornell, R.M. & Giovanoli, R. (1985) Effect of solution conditions on the proportion and morphology of goethite formed from ferrihydrite. Clay Clay Miner. 33, 424–432.Google Scholar
Cornell, R.M. & Giovanoli, R. (1988) Acid dissolution of akaganeite and lepidocrocite: The effect on crystal morphology. Clays Clay Miner. 36, 385–390.Google Scholar
Cornell, R.M. & Schindler, P.W. (1987) Photochemical dissolution of goethite in acid/oxalate solution. Clays Clay Miner. 35, 347–352.Google Scholar
Cornell, R.M., Posner, A.M. & Quirk, J.P. (1974) Crystal morphology and the dissolution of goethite. J. Inorg. Nucl. Chem. 36, 1937–1946.Google Scholar
Cornell, R.M., Posner, A.M. & Quirk, J.P. (1975) The complete dissolution of goethite. J. Appl. Chem. Biotechnol. 25, 701–706.Google Scholar
Cornell, R.M., Posner, A.M. Quirk, J.P. (1976) Kinetics and mechanisms of the acid dissolution of goethite. J. Inorg. Nucl. Chem. 38, 563–567.Google Scholar
LaKind, J.S. & Stone, A.T. (1989) Reductive dissolution of goethite by phenolic reductants. Geochim. Cosmochim. Acta 59, 961–971.Google Scholar
Rendon, J.L. & Serna, C.J. (1981) IR spectra of powder hematite; effects of particle size and shape. Clay Miner. 16, 375–384.CrossRefGoogle Scholar
Schwertmann, U. (1984) The influence of aluminium on iron oxides: IX. Dissolution of Al-goethites in 6 m HC1. Clay Miner. 19, 9–19.Google Scholar
Schwertmann, U. (1991) Solubility and dissolution of iron oxides. Plant Soil, 130, 1–25.Schwertmann, U. & Cornell, R.M. (1991) Hematite. Pp. 101-110 in: Iron Oxides in the Laboratory. VCH, Weinheim.Google Scholar
Sidhu, P.S., Gilkes, R.J., Cornell, R.M., Posner, A.M. & Quirk, J.P. (1981) Dissolution of iron oxides and oxyhydroxides in hydrochloric and perchloric acids. Clays Clay Miner. 29, 269–276.CrossRefGoogle Scholar
Sunagawa, I. (1962a) Mechanism of growth of hematite. Am. Miner. 47, 1139–1155.Google Scholar
Sunagawa, I. (1962b) Mechanism of natural etching of hematite crystals. Am. Miner. 47,1332–1345.Google Scholar
Torrent, J., Schwertmann, U. & Barron, V. (1987) The reductive dissolution of synthetic goethite and haematite in dithionite. Clay Miner. 22, 329–337.CrossRefGoogle Scholar