Dissolution Kinetics of TiO2 in HF-HC1 Solutions

Authors

  • ERIC BRIGHT,

    1. Department of Ceramic Engineering, The Ohio State University, Columbus, Ohio 43210–1178
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    • Member, the American Ceramic Society.

    • Now with Spectran, Inc., Sturbridge, MA.

  • DENNIS W. READEY

    1. Department of Ceramic Engineering, The Ohio State University, Columbus, Ohio 43210–1178
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    • Member, the American Ceramic Society.


  • Presented at the 84th Annual Meeting of the American Ceramic Society, Cincinnati, OH, May 3, 1982 (Joint Session Paper No. 4-JV–82).

  • Supported by the National Science Foundation under Grant No. DMR-8112557 and by an Argonne National Laboratory Nuclear Waste Fellowship.

Abstract

The dissolution kinetics of TiO2 powders in HF-HCl solutions was studied as a function of time, temperature, and acid concentration. The rate of dissolution was linear with time, directly proportional to [HF], independent of [HCl], and exhibited an exponential temperature dependence with an activation energy of 74.9 kj/mol. The results are explained in terms of a surface reaction mechanism involving an activated complex at a cation surface site formed by the substitution of an HF molecule into the coordination sphere of the titanium ion.

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