Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-05T04:24:23.144Z Has data issue: false hasContentIssue false

Aqueous Dissolution of Perovskite (CaTiO3): Effects of Surface Damage and [Ca2+] in the Leachant

Published online by Cambridge University Press:  03 March 2011

Zhaoming Zhang*
Affiliation:
Australian Nuclear Science & Technology Organisation, Lucas Heights, NSW 2234, Australia
Mark G. Blackford
Affiliation:
Australian Nuclear Science & Technology Organisation, Lucas Heights, NSW 2234, Australia
Gregory R. Lumpkin
Affiliation:
Australian Nuclear Science & Technology Organisation, Lucas Heights, NSW 2234, Australia; and Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, United Kingdom
Katherine L. Smith
Affiliation:
Australian Nuclear Science & Technology Organisation, Lucas Heights, NSW 2234, Australia
Eric R. Vance
Affiliation:
Australian Nuclear Science & Technology Organisation, Lucas Heights, NSW 2234, Australia
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

We have characterized thermally annealed perovskite (CaTiO3) surfaces, both before and after aqueous dissolution testing, using scanning electron microscopy, cross-sectional transmission electron microscopy, x-ray photoelectron spectroscopy, and atomic force microscopy. It was shown that mechanical damage caused by polishing was essentially removed at the CaTiO3 surface by subsequent annealing; such annealed samples were used to study the intrinsic dissolution behavior of perovskite in deionized water at RT, 90 °C, and 150 °C. Our results indicate that, although mechanical damage caused higher Ca release initially, it did not affect the long-term Ca dissolution rate. However, the removal of surface damage by annealing did lead to the subsequent spatial ordering of the alteration product, which was identified as anatase (TiO2) by both x-ray and electron diffraction, on CaTiO3 surfaces after dissolution testing at150 °C. The effect of Ca2+ in the leachant on the dissolution reaction of perovskite at 150 °C was also investigated, and the results suggest that under repository conditions, the release of Ca from perovskite is likely to be significantly slower if Ca2+ is present in ground water.

Type
Articles
Copyright
Copyright © Materials Research Society 2005

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

REFERENCES

1Ringwood, A.E.: Safe Disposal of High Level Nuclear Reactor Waste: A New Strategy (Australian National University Press, Canberra, Australia, 1978).Google Scholar
2Ringwood, A.E., Kesson, S.E., Reeve, K.D., Levins, D.M. and Ramm, E.J. Synroc, in Radioactive Waste Forms for the Future, edited by Lutze, W. and Ewing, R.C. (Elsevier, Amsterdam, Netherlands, 1988), p. 233.Google Scholar
3Fielding, P.E. and White, T.J.: Crystal chemical incorporation of high level waste species in aluminotitanate-based ceramics: Valence, location, radiation damage, and hydrothermal durability. J. Mater. Res. 2, 387 (1987).Google Scholar
4Smith, K.L., Hart, K.P., Lumpkin, G.R., McGlinn, P., Lam, P. and Blackford, M.G. A description of the kinetics and mechanisms which control the release of HLW elements from synroc, in Scientific Basis for Nuclear Waste Management XIV, edited by Abrajano, T.A. Jr. and Johnson, L.H. (Mater. Res. Soc. Symp. Proc. 212, Pittsburgh, PA, 1991), p. 167.Google Scholar
5Lumpkin, G.R., Smith, K.L. and Blackford, M.G.: Electron microscope study of synroc before and after exposure to aqueous solutions. J. Mater. Res. 6, 2218 (1991).CrossRefGoogle Scholar
6Smith, K.L., Lumpkin, G.R., Blackford, M.G., Day, R.A. and Hart, K.P.: The durability of synroc. J. Nucl. Mater. 190, 287 (1992).CrossRefGoogle Scholar
7Lumpkin, G.R., Smith, K.L. and Blackford, M.G. Development of secondary phases on synroc leached at 150°C, in Scientific Basis for Nuclear Waste Management XVIII, Part 2, edited by Murakami, T. and Ewing, R.C. (Mater. Res. Soc. Symp. Proc. 353, Pittsburgh, PA, 1995), p. 855.Google Scholar
8Smith, K.L., Colella, M., Thorogood, G.J., Blackford, M.G., Lumpkin, G.R., Hart, K.P., Prince, K., Loi, E. and Jostsons, A. Dissolution of synroc in deionized water at 150°C, in Scientific Basis for Nuclear Waste Management XX, edited by Gray, W.J. and Triay, I.R. (Mater. Res. Soc. Symp. Proc. 465, Pittsburgh, PA, 1997), p. 349.Google Scholar
9Jostsons, A., Smith, K.L., Blackford, M.G., Hart, K.P., Lumpkin, G.R., McGlinn, P., Myhra, S., Netting, A., Pham, D.K., Smart, R.St.C. and Turner, P.S.: Description of Synroc Durability: Kinetics and Mechanisms of Reaction, NERDDP Report No. 1319 (Australian National Energy Research Development and Demonstration Program, ANSTO, Sydney, Australia, 1990).Google Scholar
10Cooper, J.A., Cousens, D.R., Hanna, J.A., Lewis, R.A., Myhra, S., Segall, R.L., Smart, R.St.C., Turner, P.S. and White, T.J.: Intergranular films and pore surfaces in synroc C: Structure, composition and dissolution characteristics. J. Am. Ceram. Soc. 69, 347 (1986).Google Scholar
11Myhra, S., Bishop, H.E., Riviere, J.C. and Stephenson, M.: Hydrothermal dissolution of perovskite (CaTiO3). J. Mater. Sci. 22, 3217 (1987).CrossRefGoogle Scholar
12Myhra, S., Smart, R.St.C. and Turner, P.S.: The surfaces of titanate minerals, ceramics and silicate glasses: Surface analytical and electron microscope studies. Scanning Microsc. 2, 715 (1988).Google Scholar
13Turner, P.S., Jones, C.F., Myhra, S., Neall, F.B., Pham, D.K. and Smart, R.St.C. Dissolution mechanisms of oxides and titanate ceramics—electron microscope and surface analytical studies, in Surfaces and Interfaces of Ceramic Materials, edited by Dufour, L.-C., Monty, C., and Petot-Ervas, G. (Kluwer Academic Publishers, Dordrecht, Netherlands, 1989), p. 663.CrossRefGoogle Scholar
14Pham, D.K., Neall, F.B., Myhra, S., Smart, R.St.C. and Turner, P.S. Dissolution mechanisms of CaTiO3—solution analysis, surface analysis and electron microscope studies—implications for synroc, in Scientific Basis for Nuclear Waste Management XII, edited by Lutze, W. and Ewing, R.C. (Mater. Res. Soc. Symp. Proc. 127, Pittsburgh, PA, 1989), p. 231.Google Scholar
15Kastrissios, T., Stephenson, M., Turner, P.S. and White, T.J.: Hydrothermal dissolution of perovskite: Implications for synroc formulation. J. Am. Ceram. Soc. 70, C-144 (1987).CrossRefGoogle Scholar
16McGlinn, P.J., Hart, K.P., Loi, E.H. and Vance, E.R. pH dependence of the aqueous dissolution rates of perovskite and zirconolite at 90°C, in Scientific Basis for Nuclear Waste Management XVIII, Part 2, edited by Murakami, T. and Ewing, R.C. (Mater. Res. Soc. Symp. Proc. 353, Pittsburgh, PA, 1995), p. 847.Google Scholar
17Myhra, S., Savage, D., Atkinson, A. and Riviere, J.C.: Surface modification of some titanate minerals subjected to hydrothermal chemical attack. Am. Mineral. 69, 902 (1984).Google Scholar
18Myhra, S., Pham, D.K., Smart, R.St.C. and Turner, P.S. Surface reactions and dissolution of ceramics and high temperature superconductors, in Science of Ceramic Interfaces, edited by Nowotny, J. (Elsevier, Amsterdam, Netherlands, 1991), p. 569.Google Scholar
19Mitchell, D.R.G., Attard, D.J. and Carter, M.L.: Cross-sectional transmission electron microscopy of metallographic damage in hollandite nuclear wasteforms. Mater. Charact. 48, 359 (2002).Google Scholar
20van der Heide, P.A.W.: Surface core level shifts in photo-electron spectra from the Ca, Sr and Ba titanates. Surf. Sci. 490, L619 (2001).CrossRefGoogle Scholar
21Liou, J-K., Lin, M-H. and Lu, H-Y.: Crystallographic facetting in sintered barium titanate. J. Am. Ceram. Soc. 85, 2931 (2002).Google Scholar
22Mitchell, R.H.: Perovskites—Modern and Ancient (Almaz Press, Thunder Bay, Ontario, Canada, 2002).Google Scholar
23Hu, M., Wenk, H-R. and Sinitsyna, D.: Microstructures in natural perovskites. Am. Mineral. 77, 359 (1992).Google Scholar
24Sano, T., Saylor, D.M. and Rohrer, G.S.: Surface energy anisotropy of SrTiO3 at 1400°C in air. J. Am. Ceram. Soc. 86, 1933 (2003).Google Scholar
25Inoue, Y. and Yasumori, I.: Catalysis by alkaline earth metal oxides. III. X-ray photoelectron spectroscopic study of catalytically active MgO, CaO, and BaO surfaces. Bull. Chem. Soc. Jpn. 54, 1505 (1981).Google Scholar
26Banfield, J.F. and Veblen, D.R.: Conversion of perovskite to anatase and TiO2 (B): A TEM study and the use of fundamental building blocks for understanding relationships among the TiO2 minerals. Am. Mineral. 77, 545 (1992).Google Scholar
27Ban, S. and Maruno, S.: Hydrothermal–electrochemical deposition of hydroxyapatite. J. Biomed. Mater. Res. 42, 387 (1998).3.0.CO;2-F>CrossRefGoogle ScholarPubMed
28Strachan, D.: Pacific Northwest National Laboratory. Private communication, 2005.Google Scholar
29Wolery, T.J.: EQ3/6, a Software Package for Geochemical Modeling of Aqueous Systems: Package Overview and Installation Guide, UCRL-MA-110662 PT 1 (Lawrence Livermore National Laboratory, Livermore, CA, 1992).Google Scholar
30Knauss, K.G., Dibley, M.J., Bourcier, W.L. and Shaw, H.F.: Ti(IV) hydrolysis constants derived from rutile solubility measurements made from 100 to 300°C. Appl. Geochem. 16, 1115 (2001).CrossRefGoogle Scholar
31Clynne, M.A., Potter, R.W. II: Solubility of some alkali and alkaline earth chlorides in water at moderate temperatures. J. Chem. Eng. Data 24, 338 (1979).CrossRefGoogle Scholar
32Fyfe, W.S., Price, N.J. and Thompson, A.B.: Fluids in the Earth’s Crust (Elsevier, Amsterdam, Netherlands, 1978), p. 30.Google Scholar
33Vance, E.R., Karioris, F.G., Cartz, L. and Wong, M.S. Radiation effects on sphene and sphene-based glass-ceramics, in Advances in Ceramics, Vol. 8, edited by Wicks, G.G. and Ross, W.A. (American Ceramic Society, Westerville, OH, 1984), p. 62.Google Scholar