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Cesium Extraction from Cs0.8Ba0.4Ti8O16 Hollandite Nuclear Waste Form Ceramics in Nitric Acid Solutions

Published online by Cambridge University Press:  01 June 2005

Vittorio Luca ,
David Cassidy ,
Elizabeth Drabarek ,
Keith Murray  and
Boujemaa Moubaraki
Vittorio Luca*
Affiliation:
Australian Nuclear Science and Technology Organization, NSW 2234, Australia
David Cassidy
Affiliation:
Australian Nuclear Science and Technology Organization, NSW 2234, Australia
Elizabeth Drabarek
Affiliation:
Australian Nuclear Science and Technology Organization, NSW 2234, Australia
Keith Murray
Affiliation:
School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
Boujemaa Moubaraki
Affiliation:
School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
*
a) Address all correspondence to this author. e-mail: vluca@cnea.gov.ar
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Abstract

The leaching of Cs from well-characterized Cs-bearing hollandite powders with ideal formula Cs0.8Ba0.4Ti8O16 was studied at 200 °C under static oxidizing conditions achieved using dilute nitric acid solutions. A variety of techniques were used to elucidate the leaching mechanism including x-ray powder diffraction, magnetic susceptibility, x-ray absorption near edge structure, and electron microscopy. Under the conditions of the study, Cs is leached from Cs-hollandite according to a deceleratory rate law with contracting geometries. The principal reaction products are rutile and brookite. The leaching mechanism involves the formation of a quasi-continuous, and hence relatively impermeable, secondary titanium oxide phase (rutile and/or brookite) on the surfaces of the hollandite crystallites. The driving force for the leaching reaction appears to be the oxidation of Ti3+ in the structure by the oxidizing acid, which then promotes extraction of Cs and Ba from the hollandite tunnels followed by tunnel destabilization and transformation to rutile and brookite.

Keywords

CeramicCorrosionIntercalation
Type
Articles
Information
Journal of Materials Research , Volume 20 , Issue 6 , June 2005 , pp. 1436 - 1446
Copyright
Copyright © Materials Research Society 2005

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References

REFERENCES

1Ringwood, A.E., Kesson, S.E., Reeve, K.D., Levins, D.M. and Ramm, E.J.: Radioactive Waste Forms for the Future, edited by Lutze, W. and Ewing, R.C. (North-Holland, New York, 1988), p. 233.Google Scholar
2Donald, I.W., Brenchley, M.E., Greedharee, R.S., and Metcalfe, B.L.: In Proceedings of International Congress on Glass (1998), pp. 511–516.Google Scholar
3Bunker, B.C.: Molecular mechanisms for corrosion of silica and silicate glasses. J. Non-Cryst. Solids 179, 300 (1994).Google Scholar
4Carter, M.L., Vance, E.R., Mitchell, D.R.G., Hanna, J.V., Zhang, Z. and Loi, E.: Fabrication, characterization, and leach testing of hollandite, (Ba,Cs)(Al,Ti)2Ti6O16. J. Mater. Res. 17, 2578 (2002).Google Scholar
5Blesa, M.A., Morando, P.J. and Regazzoni, A.E.: Chemical Dissolution of Metal Oxides (CRC Press, Boca Raton, FL, 1993).Google Scholar
6Pham, D.K., Myhra, S. and Turner, P.S.: The surface reactivity of hollandite in aqueous solution. J. Mater. Res. 9, 3174 (1994).Google Scholar
7Cheary, R.W.: Cesium substitution in the titanate hollandites BaxCsy(Tiy +2x 3+Ti8−2x −y 4+)O16 from 5 to 400 K. Acta Crystallogr. Sect. B: Struct. Sci. B47, 325 (1991).Google Scholar
8Giovanoli, R. and Balmer, B.: A new synthesis of hollandite. A possibility for immobilization of nuclear waste. Chimia (Aarau). 35, 53 (1981).Google Scholar
9Ferradini, C. and Jay-Gerin, J.P.: Radiolysis of water and aqueous solutions—History and present state of the science. Can. J. Chem.—Rev. Can. De Chimie 77, 1542 (1999).Google Scholar
10Tang, J.S. and Radulescu, G.: Radiolytic production of nitric acid outside a 21-PWR waste package, in Radiation Protection & Shielding Division of the American Nuclear Society Biennial RPSD Topical Meeting, Proceedings, (2002), p. 818.Google Scholar
11Barkatt, A., Barkatt, A. and Sousanpour, W.: Gamma radiolysis of aqueous media and its effects on the leaching processes of nuclear waste disposal materials. Nucl. Technol. 60, 218 (1983).Google Scholar
12Shoesmith, D.W.: Fuel corrosion processes under waste disposal conditions. J. Nucl. Mater. 282, 1 (2000).Google Scholar
13Hartman, J.S., Vance, E.R., Power, W.P. and Hanna, J.V.: A 133Cs magic angle spinning nuclear magnetic resonance study of cesium environments in barium hollandites and synroc. J. Mater. Res. 13, 22 (1998).CrossRefGoogle Scholar
14Howard, C.J. and Hunter, B.A.: A Computer Program for Rietveld Analysis of X-Ray and Neutron Powder Diffraction Patterns (Lucas Heights Research Laboratories, NSW, Australia, 1998), p. 1.Google Scholar
15Ressler, T.: WinXAS: a program for x-ray absorption spectroscopy data analysis under MS-Windows. J. Synchrotron Radiat. 5, 118 (1998).Google Scholar
16Knauss, 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).Google Scholar
17Yamabi, S. and Imai, H.: Crystal phase control for titanium dioxide films by direct deposition in aqueous solutions. Chem. Mater. 14, 609 (2002).CrossRefGoogle Scholar
18Bursill, L.A.: Structural relationships between b-gallia, rutile, hollandite, psilomelane, ramsdellite and gallium titanate type structures. Acta Crystallogr. B B35, 530 (1979).Google Scholar
19Machin, D.J. and Murry, K.S.: The magnetic properties of some vanadium (IV) complexes. J. Chem. Soc. 1330 (1967).Google Scholar