Contents

1. Corrosion of Inorganic Non-Metallic Materialspart 3 Corrosion of glassAles Helebrant, Antonin JirickaDepartment of Glass and Ceramics ICT Prague, Czech Republicwww.usk.cz Corrosion of Materials Course

2. Contents • Introduction, glass structure, main industrial glasses • Partial processes of glass corrosion • Development of kinetic models • Rana & Douglas • Hlaváč & Matěj • Boksay & Doremus • Strachan • DGC ICT model • Examples • Experimental testing of glass durability • Thermodynamic approach (Plodinec, Conradt, Aagard & Helgeson) • Conclusions and outlook Corrosion of Materials Course

3. Introduction – main industrial glasses • Silica glass: • SiO2 • Water glass: • 70 SiO2 – 30 Na2O (wt.%) • Flat glass, bottles: • 72 SiO2 – 12 CaO – 14 Na2O • Crystal glass: • 60 SiO2 – 26 PbO – 14 K2O (PbO between 24-36) • 3.3 glass (Pyrex, Simax): • 80 SiO2 – 15 B2O3 – 5 Na2O • Glass fibres: • 53 SiO2 – 15 Al2O3 – 16 CaO – 4 MgO – 10 B2O3 Corrosion of Materials Course

4. Introduction – glass structure [Gedeon, Macháček] Corrosion of Materials Course

5. Introduction glass sol. t=0 sol. glass t>0 Hench, L.L.: in Physical Chemistry of Glass Surfaces, Proc. XI Intl. Cong. Glass (ed. Götz J.), ČVTS Prague 1977, Vol I. pp. 343-369 Corrosion of Materials Course

6. Partial processes Corrosion of Materials Course

7. Kinetic models sol. glass sol. glass sol. glass sol. glass Rana & Douglas Rana M.A., Douglas R.W.: Phys. Chem. Glasses 2, 179 (1961) Corrosion of Materials Course

8. Kinetic models sol. glass Hlaváč & Matěj a DA Hlaváč J., Matěj J.: Ceramics-Silikáty7, 261 (1963) Corrosion of Materials Course

9. Kinetic models sol. glass Boksay & Doremus a DA Hl-M. Doremus, R.H.: Chemical durability of glass. In: Tomozawa, M;, Doremus, R.H. (eds.): Treatise on Materials Science and Technology 17, Academic Press 1979, pp. 41-67 Corrosion of Materials Course

10. Kinetic models Strachan Initial dissolution rate R0 Congruent dissolution Strachan D.M.: in Wicks G.G., Ross W.A. (eds.) Advances in Ceramics, Vol. 8, Amer. Ceram. Soc., Columbus, Ohio 1984, p.12 Corrosion of Materials Course

11. Kinetic models DGC ICT sol. glass Precip.layer Helebrant A., Matoušek J.: Glastech. Ber. Glass Sci. Technol 68C1, 207 (1995) Corrosion of Materials Course

12. Durability testing Stainless pot jar PE Teflon vessel Leaching Pt wire solution Stainless holder Glass grains sample Deionised water 1) 2) 3) • Static (cs, k+) • Dynamic (k+,k-, D/h) • VHT (precipitates) Corrosion of Materials Course

13. Examples • GlassComposition (in mol%) • SK1 - 15% Na2O, 10%CaO, 75% SiO2 • SK2 - 15% Na2O, 10%MgO, 75% SiO2 • Preparation • Pt/Rh crucible 1450°C – 1 hour • grinding – melting – 1 hour • cooling 500°C • fraction 0.3-0.5 mm Corrosion of Materials Course

14. Examples PE vessel Leaching solution Glass grains • Corrosion experiments • Polyethylene vessels • 80°C • S/V= 298.1 m-1 • up to 22 days • Solution analysis • AAS (Atomic AbsorptionSpectroscopy) • Surface analysis • SNMS (Secondary Neutral Mass Spectrometry) Corrosion of Materials Course

15. Examples Glass SK1 Corrosion of Materials Course

16. Examples Glass SK2 Corrosion of Materials Course

17. Examples Precipitation: CaO*3SiO2 MgO*2.8SiO2 Corrosion of Materials Course

18. Thermodynamic approach Plodinec et al. ln QSi Metasilicates Oxides DGhydr Plodinec M.J. Jantzen C.M., Wicks G.G.: in Wicks G.G., Ross W.A. (eds.) Advances in Ceramics, Vol. 8, Amer. Ceram. Soc., Columbus, Ohio 1984, p.491 Corrosion of Materials Course

19. Thermodynamic approach Conradt Phase diagram Silicates, oxides… DG + correction to glassy state H+, OH- on surface pH Conradt R.: J. Nucl. Mater. 298, 19 (2001) Corrosion of Materials Course

20. Thermodynamic approach Aagard & Helgeson Semiempirical pH influence Arrhenius temperature dependence Saturation effect K=? Aagaard, P., Helgeson, H. C.: American Journal of Science, 282, 237 (1982) Corrosion of Materials Course

21. TD approach - examples SK1 0.10 Corrosion of Materials Course

22. TD approach - examples SK2 Corrosion of Materials Course

23. TD approach - examples congruent congruent precipitation precipitation Time [days] Time [days] SK2 SK1 Corrosion of Materials Course

24. TD approach – examples SK1 supersaturation corrosion after 14 days undersaturation Glass [mol/kg] PHREEQC:http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc Corrosion of Materials Course

25. TD approach – examples SK2 supersaturation corrosion after 14 days undersaturation Glass [mol/kg] PHREEQC:http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc Corrosion of Materials Course

26. TD approach - examples Surface of SK1 after 2 days in deionised water, 80°C, S/V = 298,1 m-1, bar=100 mm Surface of SK1 after 13 days in VHT, 200°C, S/V = 298,1 m-1, bar=10 mm Corrosion of Materials Course

27. TD approach - examples Surface of SK2 after 2 days in deionised water, 80°C, S/V = 298,1 m-1, bar=50 mm (left) 5 mm (right) Corrosion of Materials Course

28. Conclusions & Outlook Conradt – influence of solution pH, glass composition Aagard & Helgeson – influence of T, solution composition, back precipitation (geochemical code) Kinetic model – influence of S,V,F, interdiffusion Back precipitation kinetics? Corrosion of Materials Course

29. Thank you Corrosion of Materials Course