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The Nature of TiO2 in Kaolinite

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Clays and Clay Minerals

Abstract

SEM, TEM, and electron probe studies indicate that the anatase in Georgia kaolins, and probably anatase in general, consists of subspherical particles (TiO2 pellets) 0.05–0.1 µm dia. Some pure anatase aggregates may be pseudomorphic after ilmenite and have a tabular shape, but much of the anatase is formed from Ti that occurs as scattered ions in the octahedral sheets of biotite. When removed from the biotite this material forms TiO2 pellets. These pellets can occur as: single pellets; irregular aggregates; layered aggregates; spherical aggregates; mixed aggregates (with kaolinite); coated aggregates (with kaolinite). Physical energy can be used to break TiO2—kaolinite aggregates, separate single TiO2 pellets from kaolinite plates and remove kaolinite coatings from TiO2 aggregates.

Al and Si are present in all TiO2 aggregates and the Si—Al ratio is lower in the aggregates than in the kaolinite. An amorphous Si—Al compound may be present and act as a cement.

The anatase apparently is formed from Ti that is released from the parent mineral as Ti (OH)4. The Ti (OH)4 precipitates to form an amorphous hydrous oxide gel which dehydrates to form a granular aggregate of small anatase crystals.

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References

  • DeKimpe, C., Gastuche, M. C. and Brindley, G. W. (1961) Ionic coordination in alumino-silicis gels in relation to clay mineral formation: Am. Min. 46, 1370–1381.

    Google Scholar 

  • Dolcater, D. L., Syers, J. K. and Jackson, M. L. (1970) Titanium as free oxide and substituted forms in kaolinites and other clay minerals: Clays & Clay Minerals 18, 71–79.

    Article  Google Scholar 

  • James, R. O. and Healy, T. W. (1972) Adsorption of hydrolyzable metal ions at the oxide water interface—III. A thermodynamic model of adsorption: J. Colloid Interface Sci. 40, 65–81.

    Article  Google Scholar 

  • Jepson, W. B. and Rowse, J. B. (1975) The composition of kaolinite—an electron microscope microprobe study: Clays & Clay Minerals 23, 310–317.

    Article  Google Scholar 

  • Sayin, M. and Jackson, M. L. (1976) Anatase and rutile determination in kaolinite deposits: Clays & Clay Minerals 24, 437–444.

    Google Scholar 

  • Sherman, G. D. (1952) The titanium content of Hawaiian soils and its significance: Proc. Soil Sci. Am. 16, 15–18.

    Article  Google Scholar 

  • Weaver, C. E. (1968) Electron microprobe study of kaolin: Clays & Clay Minerals 16, 187–189.

    Article  Google Scholar 

  • Weaver, C. E. and Wampler, J. M. (1972) The illite–phosphate association: Geochimica et Cosmochemica Acta 36, 1–13.

    Article  Google Scholar 

  • Weiser, H. B. and Milligan, W. O. (1939) The constitution of colloidal systems of the hydrous oxides: Chem. Rev. 25, 1–30.

    Article  Google Scholar 

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Authors and Affiliations

  1. Georgia Institute of Technology, School of Geophysical Sciences, Atlanta, GA, 30332, U.S.A.

    Charles E. Weaver

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  1. Charles E. Weaver
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Weaver, C.E. The Nature of TiO2 in Kaolinite. Clays Clay Miner. 24, 215–218 (1976). https://doi.org/10.1346/CCMN.1976.0240501

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  • DOI: https://doi.org/10.1346/CCMN.1976.0240501

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