Slide1 l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 29

Contents PowerPoint PPT Presentation


  • 209 Views
  • Uploaded on
  • Presentation posted in: General

Corrosion of Inorganic Non-Metallic Materials part 3 Corrosion of glass Ale s Helebrant , Antonin Jiricka Department of Glass and Ceramics I CT Prague , Czech Republic www.usk.cz. Contents. Introduction, glass structure, main industrial glasses Partial processes of glass corrosion

Download Presentation

Contents

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Slide1 l.jpg

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


Contents l.jpg

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


Introduction main industrial glasses l.jpg

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


Slide4 l.jpg

Introduction – glass structure

[Gedeon, Macháček]

Corrosion of Materials Course


Slide5 l.jpg

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


Slide6 l.jpg

Partial processes

Corrosion of Materials Course


Slide7 l.jpg

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


Slide8 l.jpg

Kinetic models

sol.

glass

Hlaváč & Matěj

a

DA

Hlaváč J., Matěj J.: Ceramics-Silikáty7, 261 (1963)

Corrosion of Materials Course


Slide9 l.jpg

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


Slide10 l.jpg

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


Slide11 l.jpg

Kinetic models

DGC ICT

sol.

glass

Precip.layer

Helebrant A., Matoušek J.: Glastech. Ber. Glass Sci. Technol 68C1, 207 (1995)

Corrosion of Materials Course


Slide12 l.jpg

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


Slide13 l.jpg

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


Slide14 l.jpg

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


Slide15 l.jpg

Examples

Glass SK1

Corrosion of Materials Course


Slide16 l.jpg

Examples

Glass SK2

Corrosion of Materials Course


Slide17 l.jpg

Examples

Precipitation:

CaO*3SiO2

MgO*2.8SiO2

Corrosion of Materials Course


Slide18 l.jpg

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


Slide19 l.jpg

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


Slide20 l.jpg

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


Slide21 l.jpg

TD approach - examples

SK1

0.10

Corrosion of Materials Course


Slide22 l.jpg

TD approach - examples

SK2

Corrosion of Materials Course


Slide23 l.jpg

TD approach - examples

congruent

congruent

precipitation

precipitation

Time [days]

Time [days]

SK2

SK1

Corrosion of Materials Course


Slide24 l.jpg

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


Slide25 l.jpg

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


Slide26 l.jpg

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


Slide27 l.jpg

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


Slide28 l.jpg

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


Slide29 l.jpg

Thank you

Corrosion of Materials Course


  • Login