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A 27Al MAS nmr study of Synroc crystallization from alkoxide precursors

Published online by Cambridge University Press:  03 March 2011

J.S. Hartman
Affiliation:
Department of Chemistry, Brock University, St. Catharines, Ontario L2S 3A1, Canada
E.R. Vance
Affiliation:
Australian Nuclear Science and Technology Organization, Menai, New South Wales 2234, Australia
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Abstract

27Al MAS nmr spectra from alkoxide-derived Al2O3-BaO-CaO-TiO2-ZrO2 Synroc precursors were studied after isochronal annealing in air for 1 h at temperatures between 200 and 1300 °C. At temperatures below 1000 °C, some tetrahedral and a trace of 5-coordinated Al were observed together with a majority of octahedral Al. The amount of nonoctahedral Al reached a maximum at 400–700 °C, beyond which it diminished and disappeared; essentially, complete conversion to octahedral Al took place on full crystallization at 1200–1300 °C, with the Al being contained in barium hollandite and minor α-alumina. The hollandite nmr signal was absent in Synroc which was hot-pressed at 1200 °C/20 MPa, presumably because of coincorporation of paramagnetic Ti3+ in the hollandite phase, but a signal from α-alumina was observed. Samples containing simulated waste fission products gave results similar to their waste-free counterparts when calcined at 750 °C in 3.5% H2/N2 and when hot-pressed.

Type
Articles
Copyright
Copyright © Materials Research Society 1994

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References

REFERENCES

1Ringwood, A. E., Kesson, S. E., Hibbertson, W. D., Ware, N. G., and Major, A., Nature 278, 219 (1978).Google Scholar
2Ringwood, A. E., Kesson, S. E., Reeve, K. D., Levins, D. M., and Ramm, E. J., in Radioactive Waste Forms for the Future, edited by Lutze, W. and Ewing, R. C. (Elsevier, New York and London, 1988), pp. 233234.Google Scholar
3Vance, E. R., Davis, R. L., and Hawkins, K. D., unpublished work.Google Scholar
4Vance, E. R., Cassidy, D. J., Smith, K. L., and Woolfrey, J. L., in Nuclear Waste Management III, edited by Wicks, G. G. and Ross, W. A. (The American Ceramic Society, Westerville, OH, 1990), pp. 7181.Google Scholar
5Kisel, N. G., Limar, T. F., and Cherednichenko, I. F., Inorg. Mater. 8, 1782 (1985).Google Scholar
6Savenko, V. G. and Sakharov, V. V., Russ. J. Inorg. Chem. 24, 770 (1970).Google Scholar
7Fyfe, C. A., Solid State NMR for Chemists (C.F.C. Press, Guelph, Ontario, Canada, 1983).Google Scholar
8Engelhardt, G. and Michel, D., High-Resolution Solid-State NMR of Silicates and Zeolites (John Wiley & Sons, Chichester, 1987), Chaps. IV and V, especially pp. 134145.Google Scholar
9Kirkpatrick, R. J., in Spectroscopic Methods in Mineralogy and Geology, edited by Hawthorne, F. C., Rev. Mineral. 18, 341 (1988).Google Scholar
10Kirkpatrick, R. J. and Phillips, B. L., Appl. Magn. Reson. 4, 213 (1993).Google Scholar
11Smith, M. E., Appl. Magn. Reson. 4, 1 (1993).CrossRefGoogle Scholar
12Alemany, L. B., Appl. Magn. Reson. 4, 179 (1993).CrossRefGoogle Scholar
13Alemany, L. B., Massiot, D., Sherriff, B. L., Smith, M. E., and Taulelle, F., Chem. Phys. Lett. 177, 301 (1991).CrossRefGoogle Scholar
14Ray, G. J. and Samoson, A., Zeolites 13, 410 (1993).Google Scholar
15Prabakar, S., Rao, K. J., and Rao, C. N. R., J. Mater. Res. 6, 2701 (1991).Google Scholar
16Stebbins, J. F., Farnan, I., and Klabunde, U., J. Am. Ceram. Soc. 72, 2198 (1989).Google Scholar
17Smith, K. L., Hart, K. P., Lumpkin, G. R., McGlinn, P., Bartlett, J., Lam, P., and Blackford, M. G., 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
18Lumpkin, G. R., Smith, K. L., and Blackford, M. G., J. Mater. Res. 6, 2218 (1991).CrossRefGoogle Scholar
19Grimmer, A-R., Von Lampe, F., Magi, M., and Lippmaa, E., Z. Chem. 23, 343 (1983); Sherriff, B. L. and Hartman, J. S., Can. Mineral. 23, 205 (1985).Google Scholar
20Blackford, M. G., Smith, K. L., and Hart, K. P., in Scientific Basis for Nuclear Waste Management XV, edited by Sombret, C. G. (Mater. Res. Soc. Symp. Proc. 257, Pittsburgh, PA, 1992), p. 243.Google Scholar
21Wu, Y., Sun, B. Q., and Pines, A., J. Magn. Reson. 89, 297 (1990); Xu, Z. and Sherriff, B. L., Appl. Magn. Reson. 4, 203 (1993).Google Scholar
22Hartman, J. S., Koffyberg, F. P., and Ripmeester, J. A., J. Magn.Reson. 91, 400 (1991).Google Scholar
23Bastow, T. J., Smith, M. E., and Stuart, S. N., Chem. Phys. Lett, 191, 125 (1991).Google Scholar
24Bastow, T. J., Moodie, A. F., Smith, M. E., and Whitfield, H. J., J. Mater. Chem. 3, 697 (1993), and references therein.CrossRefGoogle Scholar
25Smith, K. L., Lumpkin, G. R., Blackford, M. G., Day, R. A., and Hart, K. P., J. Nucl. Mater. 190, 287 (1992).Google Scholar