Hostname: page-component-5c6d5d7d68-sv6ng Total loading time: 0 Render date: 2024-08-08T16:21:20.251Z Has data issue: false hasContentIssue false

Synthesis and Properties of Poorly Crystalline Hydrated Aluminous Goethites

Published online by Cambridge University Press:  01 July 2024

Martin Venn Fey*
Affiliation:
Department of Soil and Crop Sciences, Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas 77843
Joe Boris Dixon
Affiliation:
Department of Soil and Crop Sciences, Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas 77843
*
1Present address: Department of Soil Science and Agrometerology, University of Natal, P.O. Box 375, Pietermaritzburg 3200, Republic of South Africa.

Abstract

Al-substituted goethites were prepared by rapid oxidation of mixed FeCl2-AlCl3 solutions at pH 6.8 in the presence of CO2 at 25°C. A combination of Al substitution and adsorption of CO2 reduced crystal size (except for an increase at small additions of Al) and produced unusual thin, porous particles. Product goethites had surface areas up to 283 m2/g and unit-cell expansions induced by hydration. Substitution of Al for Fe reduced the 111 spacing and increased infrared OH-bending vibrational frequencies. Al substitution split the goethite dehydroxylation endotherm during differential thermal analysis into a doublet and increased the temperature of all reactions. Both cold and hot alkali solutions dissolved Al from the goethite structure.

After drying the product in vacuo at 110°C. X-ray powder diffraction data indicated minimal deviation from Vegard's law for the goethite-diaspore solid solution up to about 30 mole % Al substitution. Goethite prepared in the presence of 40 mole % Al had a 111 spacing of 2.403 Å corresponding to 36 mole % structural Al if Vegard's law was obeyed. Rapid oxidation of mixed FeCl2-AlCl3 solutions appears to be conducive to a higher degree of Al substitution in goethite than alkaline aging of hydroxy-Fe(III)-Al coprecipitates.

Резюме

Резюме

Аl-замещенные гетиты были приготовлены путем быстрого окисления смешанных растворов FeCl2-AlCl3 при рН = 6,8 в присутствии СO2 при температуре 25°С. Сочетание замещения А1 и адсорбции СO2 уменьшало разиер кристаллов (исключая их увеличение при малых добавках Аl) и производило необычно тонкие, пористые частицы. Полученные гетиты имели площади поверхности до 283 M2/г и расширение элементарных ячеек, вызванное гидрацией. Замещение алюминия ферритом уменьшило 111 параметр решётки и увеличило инфракрасные ОН-изгибающие колебательные частоты. Замещение Аl расщепило эндотермальные кривые дегидроксилации гетита во время дифференциального термического анализа в дуплет и увеличило температуру всех реакций. Оба, холодный и горячий щелочные растворы вытесняли Аl из структуры гетита. После высушения продукта в вакууме при 110°С, данные по рентгеновской порошковой дифракции показали минимальное отклонение от закона Вегарда для твёрдых растворов гетита-диаспора до около 30 молярных % замещения А1. Гетит, приготовленный в присутствии 40 молярных % Аl, имел 111 расстояние, равное 2,403 Å, что соответствует 36 молярных % структурного А1, если применить закон Вегарда. Быстрое окисление смешанных растворов FeCl2-AlCl3 может скорее привести к замещению А1 в гетите, чем щелочное старение совместных осадков гидрокси-Fe(III)-Al. [Е.С.]

Resümee

Resümee

Al-substituierte Goethite wurden durch schnelle Oxidation von FeCl2-AlCl3-Lösungsgemischen bei pH 6,8 und bei der Anwesenheit von CO2 bei 25°C hergestellt. Eine Kombination von Al-Substitution und CO2-Adsorption reduzierte die Kristallgröße (ausgenommen einer Vergrößerung der Kristalle bei geringer Al-Zugabe) und erzeugte ungewöhnlich dünne, poröse Partikel. Die erzeugten Goethite hatten eine Oberfläche bis zu 283 m2/g und zeigten Vergrößerungen der Einheitszelle aufgrund von Hydratation. Die Substitution von Al für Fe reduzierte den 111-Abstand und vergrößerte die OH-Deformations-schwingungsfrequenzen im Infrarot. Bei der Differentialthermoanalyse wurde die Dehydroxylierungs-Endotherme des Goethit dutch Al-Substitution in ein Dublett aufgespalten und erhöhte die Temperatur aller Reaktionen. Sowohl kalte als auch heiße Alkali-Lösungen lösten Aluminium aus der Goethitstruktur.

Röntgenpulverdiffraktometer-Daten zeigten nach dem Trocknen des Produktes im Vakuum bei 110°C eine minimale Abweichung von Vegard'schen Gesetz für Goethit-Diaspor-Mischkristalle bis zu 30 Mol.−% Al-Substitution. Goethit, der in der Anwesenheit von 40 Mol.−% Al hergestellt wurde, hatte einen 111-Abstand von 2,403 Å, was bei Gültigkeit des Vegard'schen Gesetzes 36 Mol.−% Al in der Struktur entspräche. Die schnelle Oxidation von FeCl2-AlCl3-Lösungsgemischen scheint für eine höhergradige Al-Substitution im Goethit förderlicher zu sein als die Alterung dutch alkalische Lösungen von Hydroxy-Fe(III)-A1-Mischfällungen. [U.W.]

Résumé

Résumé

Des goethites substituées à l'Al ont été préparées par oxidation rapide de solutions mélangées FeCl2-AlCl3 à un pH de 6,8 en présence de CO2 à 25°C. Une combinaison de substitution à Al et d'adsorbtion de CO2 a réduit la taille du cristal (sauf pour un agrandissement lors de l'addition de petites quantités d'Al) et a produit des particules rares, minces, et poreuses. Les goethites produites avaient des aires de surface jusqu’ à 283 m2/g et des expansions de maille induites par hydration. La substitution d'Al à Fe a réduit l'espacement (111) et a accru les fréquences vibrationelles pliant OH de l'infrarouge. La substitution d'Al a divisé I'endotherme de déshydroxylation de la goethite pendant l'analyse thermique différentielle en un doublet e t a accru la température de toutes les réactions. Des solutions chaudes et froides alkalines ont dissolu l'Al de la structure de la goethite.

Après avoir seché le produit in vacuo à 110°C, des données de diffraction poudrée aux rayons-X ont indiqué une déviation minimale de la loi de Vegard pour la solution solide goethite-diaspore jusqu’à près de 30 mole % de substitution d'Al. La goethite préparée en présence de 40 mole % d'Al avait un espacement (111) de 2,403 Å correspondant à 36 mole % d'Al structural si la loi Vegard était suivie. L'oxidation rapide de solutions mélangées FeCl2-AlCl3 semble être plus favorable à un plus haut degré de substitution d'Al dans la goethite que le vieillisement alkalin de coprécipités hydroxy-Fe(III)-Al. [D.J.]

Type
Research Article
Copyright
Copyright © 1981, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Atkinson, R. J. Posner, A. M. and Quirk, J. P., (1977) Crystal nucleation and growth in hydrolysing iron(III) chloride solutions Clays & Clay Minerals 25 4956.CrossRefGoogle Scholar
Beneslavsky, S. J., (1957) Neue aluminiumhaltige Minerale in Bauxiten Dokl. Akad. Nauk S.S.S.R. 133 11301132.Google Scholar
Bronevoi, V. A. and Furmakova, L. N., (1975) Formation conditions for aluminogoethites in bauxites Zap. Vses. Mineral. Obshchest. 104 461466.Google Scholar
Caillère, S. and Pobeguin, T., (1966) Problèmes de structures posés par la présence du fer dans les diaspores C.R. Acad. Sci. Paris Ser. D 263 13491351.Google Scholar
Cornell, R. M. Posner, A. M. and Quirk, J. P., (1974) Crystal morphology and the dissolution of goethite J. Inorg. Nucl. Chem. 36 19371946.CrossRefGoogle Scholar
Correns, C. W. and von Engelhardt, W., (1941) Röntgenographische Untersuchungen über den Mineralbestand sedimentärer Eisenerze Nachr. Akad. Wiss. Gottingen, Math. Phys. Kl. 213 131137.Google Scholar
Correns, C. W. and Thiel, R., (1963) Zum System α-FeOOH–α-AlOOH Naturwissenschaften 50 16.CrossRefGoogle Scholar
de Villiers, J. M. and van Rooyen, T. G., (1967) Solid-solution formation of lepidocrocite-boehmite and its occurrence in soil Clay Miner. 1 229235.CrossRefGoogle Scholar
Farmer, V. C. and Farmer, V. C., (1974) The anhydrous oxide minerals The Infrared Spectra of Minerals London Mineralogical Society 183204.CrossRefGoogle Scholar
Fey, M. V. and le Roux, J., (1977) Properties and quantitative estimation of poorly crystalline components in sesquioxidic soil clays Clay & Clay Minerals 25 285294.CrossRefGoogle Scholar
Fitzpatrick, R. W. le Roux, J. and Schwertmann, U., (1978) Amorphous and crystalline titanium and iron-titanium oxides in synthetic preparations at near ambient conditions and in soil clays Clays & Clay Minerals 26 189201.CrossRefGoogle Scholar
Galbraith, S. T. Baird, T. and Fryer, J. R., (1979) Structural changes in β-FeOOH caused by radiation damage Acta Crystallogr. A35 197200.CrossRefGoogle Scholar
Golden, D.C., Bigham, J. M., and Weed, S.B. (1977) Surface charge and phosphate adsorption on Al-substituted goethite: Agron. Ahstr. 1977, p. 188.Google Scholar
Greenland, D. J. and Oades, J. M., (1968) Iron hydroxides and clay surfaces Trans. 9th Int. Congr. Soil Sci. (Adelaide) New York Elsevier 657668.Google Scholar
Hingston, F. J. Atkinson, R. J. Posner, A. M. and Quirk, J. P., (1968) Specific adsorption of anions on goethite Trans. 9th Int. Congr. Soil Sci. (Adelaide) New York Elsevier 669678.Google Scholar
Janot, C. and Gibert, H., (1970) Les constituants du fer dans certaines bauxites naturelles étudiées par effet Mössbauer Bull. Soc. Fr. Mineral. Crystallogr. 93 213233.Google Scholar
Jónás, K. and Solymár, K., (1970) Preparation, X-ray, derivatographic and infrared study of aluminum-substituted goethites Acta Chim. (Budapest) 66 383394.Google Scholar
Kelly, W. C., (1956) Application of differential thermal analysis to the identification of natural hydrous ferric oxides Amer. Mineral. 41 353355.Google Scholar
Klug, H. P. and Alexander, L. E., (1974) X-ray Diffraction Procedures for Polycrystalline and Amorphous Materials 2 New York Wiley.Google Scholar
Kohyama, N. Fukushima, K. and Fukami, A., (1978) Observation of the hydrated form of tubular halloysite by an electron microscope equipped with an environmental cell Clays & Clay Minerals 26 2540.CrossRefGoogle Scholar
MacKenzie, R. C. and MacKenzie, R. C., (1957) The oxides of iron aluminum and manganese The Differential Thermal Investigation of Clays London Mineralogical Society 229328.Google Scholar
Murphy, P. J. (1973) Formation and characterization of hydrolyzed ferric chloride solutions. Ph.D. thesis. Univ. Western Australia, Nedlands, Western Australia.Google Scholar
Nahon, D. Janot, C. Karpoff, A. Paquet, H. and Tardy, Y., (1977) Mineralogy, petrography, and structures of iron crusts (ferricretes) developed on sandstones in the western part of Senegal Geoderma 19 263277.CrossRefGoogle Scholar
Norrish, K. and Taylor, R. M., (1961) The isomorphous replacement of iron by aluminum in soil goethites J. Soil Sci. 12 294306.CrossRefGoogle Scholar
Papée, D., Tertian, R., and Biais, R. (1958) Recherches sur le constitution des gels et hydrates crystalisés d’alumine: Bull. Soc. Chim. Fr., 13011310.Google Scholar
Parfitt, R. L. Farmer, V. C. and Russell, J. D., (1977a) Adsorption on hydrous oxides. I. Oxalate and benzoate on goethite J. Soil Sci. 28 2939.CrossRefGoogle Scholar
Parfitt, R. L. Frazer, A. R. Russell, J. D. and Farmer, V. C., (1977b) Adsorption on hydrous oxides. II. Oxalate, benzoate and phosphate on gibbsite J. Soil Sci. 28 4047.CrossRefGoogle Scholar
Rooksby, H. P. and Brown, G., (1961) Oxides and hydroxides of aluminum and iron The X-ray Identification and Crystal Structures of Clay Minerals London Mineralogical Society 354392.Google Scholar
Russell, J. D. Paterson, E. Frazer, A. R. and Farmer, V. C., (1975) Adsorption of carbon dioxide on goethite (α-FEOOH) surfaces and its implications for anion adsorption J. Chem. Soc. Faraday Trans. I. 72 10821087.Google Scholar
Ryskin, Y. I. and Farmer, V. C., (1974) The vibrations of protons in minerals: hydroxyl, water and ammonium The Infrared Spectra of Minerals London Mineralogical Society 137181.CrossRefGoogle Scholar
Schwartzmann, E. and Sparr, H., (1969) Die Wasserstoffbrückenbindung in Hydroxiden mit Diasporstructur Z. Naturforsch. 24b 811.CrossRefGoogle Scholar
Schwertmann, U., (1959) Über die Synthese difinierter Eisenoxyde unter verschiedenen Bedingungen Z. Anorg. Allg. Chem. 298 337348.CrossRefGoogle Scholar
Schwertmann, U., (1964) Differenzierung der Eisenoxide des Bodens durch Extraction mit Ammoniumoxalat-Lösung Z. Pflanzenernaehr, Dueng., Bodenk. 105 194202.CrossRefGoogle Scholar
Schwertmann, U. and Fitzpatrick, R. W., (1977) Occurrence of lepidocrocite and its association with goethite in Natal soils Soil Sci. Soc. Amer. J. 41 10131018.CrossRefGoogle Scholar
Schwertmann, U. Taylor, R. M., Dixon, J. B. and Weed, S. B., (1977) Iron oxides Minerals in Soil Environments Madison, Wisconsin Soil Sci. Soc. Amer. 145180.Google Scholar
Searle, P. L. and Daly, B. K., (1977) The determination of aluminum, iron manganese and silicon in acid oxalate soil extracts by flame emission and atomic absorption spectrometry Geoderma 19 110.CrossRefGoogle Scholar
Serna, C. J. White, J. L. and Hem, S. L., (1977) Anion-aluminum hydroxide gel interactions Soil Sci. Soc. Amer. J. 41 10091013.CrossRefGoogle Scholar
Solymár, K. and Jónás, K., (1971) Aluminum inclusions in the goethite lattice and their importance for the Hungarian Bauxites Banyasz. Kohasz. Lapok. 104 226235.Google Scholar
Taylor, R. M. and Schwertmann, U., (1978) The influence of aluminum on iron oxides. Part I. The influence of Al on Fe oxide formation from the Fe(II) system Clays & Clay Minerals 26 373383.CrossRefGoogle Scholar
Thiel, R., (1963) Zum system α-FeOOH–α-AlOOH Z. Anorg. Allg. Chem. 326 7078.CrossRefGoogle Scholar
Towe, K. M. and Rützler, K., (1968) Lepidocrocite iron mineralization in keratose sponge granules Science 162 268269.CrossRefGoogle ScholarPubMed
van Oosterhout, G. W., (1960) Morphology of synthetic submicroscopic crystals of α- and γ-FeOOH and of γ-Fe2O3 prepared from FeOOH Acta Crystallogr. 13 932935.CrossRefGoogle Scholar
Watson, J. H. L. Cardell, R. R. and Heller, W., (1962) The internal structure of colloidal crystals of β-FeOOH and remarks on their assemblies in Schiller layers J. Phys. Chem. 66 17571763.CrossRefGoogle Scholar
Weed, S. B., Golden, D. C., and Bigham, J. M. (1976) Properties of aluminum substituted goethite: Agron. Abstr. 1976, p. 133.Google Scholar
Weiser, H. B. and Milligan, W. O., (1940) Electron diffraction study of hydrous oxides J. Phys. Chem. 44 10811094.CrossRefGoogle Scholar