Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-24T17:34:09.045Z Has data issue: false hasContentIssue false

Dissolution of a Complex Borosilicate Glass at 60°C: The Influence of pH and Proton Adsorption on the Congruence of Short-Term Leaching

Published online by Cambridge University Press:  10 February 2011

P. K. Abraitis
Affiliation:
Dept. of Earth Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL
D. J. Vaughan
Affiliation:
Dept. of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL
F. R. Livens
Affiliation:
BNFL, Research & Technology, Waste Technology Group, Sellafield, Cumbria CA20 1PG
J. Monteith
Affiliation:
BNFL, Environmental Assessments, Consultancy Services, R202, Rutherford House, Risley, Warrington, Cheshire WA6 3AS
D. P. Trivedi
Affiliation:
BNFL, Environmental Assessments, Consultancy Services, R202, Rutherford House, Risley, Warrington, Cheshire WA6 3AS
J. S. Small
Affiliation:
BNFL, Environmental Assessments, Consultancy Services, R202, Rutherford House, Risley, Warrington, Cheshire WA6 3AS
Get access

Abstract

The short-term dissolution behaviour of a complex borosilicate glass has been investigated by controlled pH leaching, surface titration and leach rate temperature dependence experiments. The results indicate that the rates, congruence and mechanisms of dissolution vary significantly with pH. At low pH, dissolution occurs via a proton-promoted mechanism which results in enhanced release of B and many network modifying elements (relative to Si). At 60°C in high pH media, dissolution is essentially congruent. Here, dissolution is surface reaction controlled and occurs via a hydroxyl-promoted network dissolution process. Selective leaching is favoured at low and near-neutral pH. Congruent dissolution occurs in solutions of pH greater than that at the point of zero net proton charge.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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

[1] Brady, P. V., Physics and Chemistry of Mineral Surfaces, Ist ed. (CRC Press, New York, 1996), p. 249256.Google Scholar
[2] Knauss, K., Boucier, W. L., McKeegan, K. D., Merzbacher, C. I., Nguyen, S. N., Ryerson, F. J., Smith, D. K., and Weed, H. C., Mat. Res. Soc. Symp. Proc. 176, p. 371381 (1990).Google Scholar
[3] Guy, C. and Schott, J., Chemical Geology 78 p. 181204 (1989).Google Scholar
[4] Bunker, B.C., Journal of Non-Crystalline Solids 179 p. 300308 (1994).Google Scholar
[5] Bunker, B. C., Arnold, G. W., Beaucamp, E. K. and Day, D. E., Journal of Non-Crystalline Solids 58 p. 295322 (1983).Google Scholar
[6] Wogelius, R. A. and Walther, J. V., Geochim. Cosmochim. Acta, 55 p. 943954 (1991).Google Scholar
[7] Carroll-Webb, S. A. and Walther, J. V., Geochim. Cosmochim. Acta, 52 p. 26092623 (1988).Google Scholar
[8] Carroll, S. A., Bourcier, W. L. and Phillips, B. L., Mat. Res. Soc. Symp. Proc. 333, p. 533540 (1994).Google Scholar
[9] Berger, G., Claparols, C., Guy, C. and Daux, V., Geochim. Cosmochim. Acta, 58 p. 48754886 (1994).Google Scholar
[10] Casey, W. H. and Bunker, B. in Mineral-Water Interface Geochemistry, ed. Hochella, M. F. Jr. and White, A. F., Reviews in Mineralogy 23, p. 397426 (1990).Google Scholar
[11] Perrin, D. D. and Dempsey, B. Buffers for pH and Metal Ion Control, (Chapman and Hall, London), p. 4454 (1974).Google Scholar
[12] Gin, S., Godon, N., Mestre, J. P., Vernaz, E. Y. and Beaufort, D., Applied Geochemistry, 9 p. 255269 (1994)Google Scholar
[13] Lasaga, A. C. in Kinetics of Geochemical Processes, ed. Lasaga, A. C. and Kirkpatrick, R. J., Reviews in Mineralogy 8, p. 3035 (1981).Google Scholar