Study of the chemical durability of a hollandite mineral leached in both static and dynamic conditions

Abstract

Hollandite is a ceramic used for the confinement of cesium. In this study, we synthesized a hollandite of chemical formula: K_0.28Ba_0.76Ti_7.10Cu_0.9O₁₆, where K simulates cesium. This new formulation of a copper-containing hollandite was synthesized by a double calcination; the first one at 950°C during 18 h, and the second one at 1000°C during 6 h. The mineral was identified by X-ray diffraction. Various leaching tests are employed in order to assess the chemical durability of this mineral. The static test MCC1 gave elemental leaching rates of: 7.097 10^-5 g cm^-2 d^-1 for Cu, 5.592 10^-7 g cm^-2 d^-1 for Ti and 4.630 10^-6 g cm^-2 d^-1 for Ba, after 42 days. This corresponds to dissolved elements percentages of: 5.7% Cu, 0.0007% Ti and 0.2% Ba. The equivalent amount of dissolved K is 0.0029%. A static test in the presence of a clay barrier, gave the best leaching rates (at 42^nd day, NR<3.704 10^-7 g cm^-2 d^-1 of Cu, and <1.11 10^-9 g cm^-2 d^-1 of Ti and <3.67 10^-9 g cm^-2 d^-1 of Ba). This corresponds to 0.030% of Cu, 10^-6 % of Ti and 0.002 % of Ba, and about 0.002% of K. In MCC5 dynamic test, the leaching rates of Cu, Ti and Ba reached 2 10^-6, 1,468 10^-7, and 1.084 10^-5 g cm^-2 d^-1, respectively, corresponding to 0.028% Cu, 0.0003% Ti, and 0.082% Ba, after seven days. The estimated K leaching rate is 3.613 10^-6 g cm^-2 d^-1, ie 0.082% K dissolved in the leachate. There is no passivation layer formation. The MCC5 test is considered as a dissolution test.

Keywords

• Hollandite,Cesium,Leaching,MCC1,MCC5

References

1. Reference1 A.E. Ringwood, V.M. Oversby, S.E. Kesson, W. Sinclair, N. Ware, W. Hibberson, and A. Major, “immobilization of high-level nuclear reactor wastes in Synroc: a current appraisal”, Nuclear and Chemical Waste Management, vol. 2, pp.287-305, Oct. 1981.
2. Reference2 Aubin-Chevaldonnet, “Synthèse, caractérisation et étude du comportement sous irradiation électronique de matrices de type hollandite destinées au confinement du césium radioactif”, thesis, Lab. Chimie Appliquée Etat Solid., Université Pierre et Marie Curie − PARIS VI, Paris, Nov. 2004.
3. Reference3 A. Byström, and A. M. Byström, “The crystal structure of hollandite, the related manganese oxide minerals and α-MnO2”, Acta Cryst., vol. 3, pp. 146-154, Mar.1950.
4. Reference4 R.W. Cheary, “An analysis of the structural characteristics of hollandite compounds”, Acta Cryst., vol. B42, pp. 229-236, June. 1986.
5. Reference5 D.S. Filimonov, Z.-K. Liu, and C.A. Randall, “Synthesis and thermal stability of a new barium polytitanate compound, Ba1.054Ti0.946O2.946”, Mater. Res. Bull, vol. 37, pp. 467-473, March. 2002.
6. Reference6 J.E. Post, R.B. Von Dreele, and P. R. Buseck, “Symmetry and cation displacements in hollandites: structure refinements of hollandite, cryptomelane and priderite”, Acta Crys, vol. B38, pp. 1056-1065, April 1982.
7. Reference7 J. Vicat, E. Fanchon, P. Strobel, and D.T. Qui, “The structure of K1.33Mn8O16 and cation ordering in hollandite-type structures”, Acta Cryst, vol. B42, pp. 162-167, Apr. 1986.
8. Reference8 J. Zhang, and C.W. Burnham, “Hollandite-type phases: Geometric consideration of unit-cell size and symmetry”, Am. Mineral, vol. 79, pp. 168-174, Jan.-Feb. 1994.

9. Reference9 F. Angeli, P. McGlinn, and P. Frugier, “Chemical durability of hollandite ceramic for conditioning cesium”, J. Nucl. Mater, vol 380, pp. 59–69, Oct. 2008.
10. Reference10 V. Aubin-Chevaldonnet, D. Caurant, A. Dannoux, D. Gourier, T. Charpentier, L. Mazerolles, and T. Advocat, “Preparation and characterization of (Ba,Cs)(M,Ti)8O16 (M = Al3+, Fe3+, Ga3+, Cr3+, Sc3+, Mg2+) hollandite ceramics developed for radioactive cesium immobilization”, J. Nucl. Mater, vol 366, pp. 137-160, June 2007.
11. Reference11 A.Y. Leinekugel-le-Cocq, P. Deniard, S. Jobic, R. Cerny, F. Bart, and H. Emerich, “Synthesis and characterization of hollandite-type material intended for the specific containment of radioactive cesium”, J. Solid State Chem, vol 179, pp. 3196-3208, Oct. 2006.
12. Reference12 V. Aubin-Chevaldonnet, P. Deniard, M. Evain, A.Y. Leinekugelle-Cocq-Errien, S. Jobic, D. Caurant, V. Petricek, and T. Advocat, “Incommensurate modulations in a hollandite phase Ba-x(Al,Fe)2xTi8-2xO16 intended for the storage of radioactive wastes: a (3+1) dimension structure determination”, Z. Kristallogr, vol 222, pp. 383-390, Jul. 2007.
13. Reference13 M.L. Carter, E.R. Vance, D.R.G. Mitchell, J.V. Hanna, Z. Zhang, and E. Loi, “Fabrication, characterization, and leach testing of hollandite, (Ba,Cs)(Al,Ti)2Ti6O16”, J. Mater. Res, vol. 17, pp. 2578-2589, Oct. 2002.
14. Reference14 E. Bart, G. Leturcq, and H. Rabiller, Iron-substituted Barium Hollandite Ceramics for Cesium Immobilization, Environnemental Issues and Waste Management Technologies in the Ceramic and Nuclear Industries IX, Part I: Ceramics for Waste or Nuclear Applications, vol. 155, pp. 11-20, April 2012.
15. Reference15 M.L. Carter, E.R. Vance, G.R. Lumpkin, and G.R. Loi, “Aqueous dissolution of Rb-bearing hollandite and Synroc-C at 90 °C”, Mater. Res. Soc. Sym. Proc, vol. 663, pp. 381-388, Aug. 2000.
16. Reference16 H. Rabiller, F. Bart, F.Miserque, G. Leturcq, D. Rigaud, Leaching behavior of hollandite ceramics for cesium immobilization, ATALANTE, Nimes, Juin 2004.
17. Reference17 S.E. Kesson, and T. J. White, “Radius ratio tolerance factors and the stability of hollandites”,J. Solid State Chem, vol. 63, pp. 122-125, Jun 1986.
18. Reference18 Philips X’Pert High Score Package, Diffraction Data CD-ROM, International Center for Diffraction Data, Newtown Square, PA, 2004.
19. Reference19 D.M. Strachan, “Glass dissolution: Testing and modelling for long-term behavior”, Journal of Nuclear Materials, vol.298, pp. 69-77, Sep 2001.
20. Reference20 JCPDS, PCPDFwin. Diffraction Data CD-ROM. International Center for Diffraction Data, Newtown Square, PA, 2004.
21. Reference21 C. Fillet, and Nicolas Dacheux, Matrices céramiques pour conditionnements spécifiques, Dossier Techniques de l’Ingénieur bn3770, Ed. Techniques de l’Ingénieur, Paris, France, 2011.
22. Reference22 G. Leturcq, P. Mcglinn, C. Barbé, M.G. Blackford, and K.S. Finnie, “Aqueous alteration of nearly pure Nd-doped zirconolite (Ca0.8Nd0.2ZrTi1.8Al0.2O7), a passivating layer control”, Applied geochemistry, vol. 20, pp. 899-906, May 2005.
23. Reference23 G. Leturcq, T. Advocat, K. Hart, G. Berger, J. Lacombe, and A. Bonnetier, “Solubility study of Ti,Zr-based ceramics designed to immobilize long-lived radionuclides”, American Mineralogist, vol. 86, pp. 871–880, July 2001.
24. Reference24 D. Bregiroux, “Synthèse par voie solide et frittage de céramiques à structure monazite”, thesis, faculté des sciences et techniques, Université de Limoges, France, Novembre 2005
25. Reference25 N. Kamel, H. Ait amar, and S. Telmoune, “Study of the dissolution of three synthetic minerals: zirconolite, y-britholite and mono-silicate fluorapatite”, Annales de chimie et science des matériaux,vol. 32, pp: 547-559, March 2007.
26. Reference26 Shabalin В., Titov Y., Zlobenko B., Bugera S., Ferric titanous hollandite analogues — Matrices for immobilization of Cs-containing radioactive waste: Synthesis and properties, Mineralogy, vol. 35, pp. 12-18, Nov. 2014.
27. Reference27 T. Suzuki-Muresan , J. Vandenborre, A. Abdelouas, B. Grambow, and S. Utsunomiya, “Studies of (Cs,Ba)-hollandite dissolution under gamma irradiation at 95 °C and at pH 2.5, 4.4 and 8.6”, Journal of Nuclear Materials, Vol. 419, pp. 281–290, Dec 2011.
28. Reference28 A.G. Solomah, P.G. Richardson, and A.K. McIlwain, “Phase identification, microstructural characterization, phase microanalyses and leaching performance evaluation of SYNROC-FA crystalline ceramic waste form”, Journal of Nuclear Materials, Vol. 148, pp. 157-165, Apr 1987.
29. Reference29 S.P. Kumar, and B. Gopal, “Synthesis and leachability study of a new cesium immobilized langbeinite phosphate: KCsFeZrP3O12”, Journal of Alloys and Compounds, Vol. 615, pp. 419-423, Dec 2014.
30. Reference30 Z. Klika, Z. Weiss, M. Mellini, and M. Drabek, “Water leaching of cesium from selected cesium mineral analogues”, Applied Geochemistry, Vol. 21, pp. 405–418, March 2006.