Transcript The influence of Mg2+ and Ca2+ ions on the glass corrosion

Corrosion of Inorganic Non-Metallic
Materials
part 3 Corrosion of glass
Ales Helebrant, Antonin Jiricka
Department of Glass and Ceramics
ICT Prague, Czech Republic
www.usk.cz
Corrosion of Materials Course
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
• 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
Introduction – glass structure
[Gedeon, Macháček]
Corrosion of Materials Course
Introduction
sol.
glass
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
Partial processes
Corrosion of Materials Course
Kinetic models
Rana & Douglas
Qi  u  wt
Qi  u  s t
sol.
sol.
glass
sol.
glass
glass
k  k
sol. h
glass
k
s  2c A0  c Asur 
DA

s  2cs  cl 0 
D

Rana M.A., Douglas R.W.: Phys. Chem. Glasses 2, 179 (1961)
Corrosion of Materials Course
w  k cS  cl 0 
D
h
Kinetic models
Hlaváč & Matěj
a
sol.
glass
a
DA
at
w
 const
 xSi
QA  c A 0at 
QSi  atxSi 
1
lcA 0
2


1 
1
t
D
ln
 al 
2  A

2a
1  al


DA
l
1 DA 

QAt   c A0 at 
2 a 

Hlaváč J., Matěj J.: Ceramics-Silikáty 7, 261 (1963)
Corrosion of Materials Course
Kinetic models
Boksay & Doremus
sol.
glass
a
a
DA
at
w
 const
 xSi
QSi  atxSi 
c A
  c A 
c

 DA
  a A
t
y 
dy 
dy

D 

 

QA  c A0 at  A  erf
  ierfc
a 
2
2 

a 2t
where  
DA
Hl-M.
 D 
QA  c A0 at  A 
a

 D 
QA  c A0 at  A 
 2a 
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
Kinetic models
Strachan
Initial dissolution rate R0
Congruent dissolution


  R0 S F  
1
c
 t 
1  exp  
1 c s  F R0 S 
  c sV V  
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
Kinetic models
DGC ICT
sol.
t
 adt
D
k
dQSi
 1 k   h c s  c 
dt
k D
h
k D
h cs  c
k   D xSi
h
D
k
dc S
F
 1 k   h c s  c   c
dt V
V
k D
h
ak
glass

0
QSi 
B
1  exp( Kt )  wt
K

B,K,W  f k  , k ,D / h,cs ,F,V,S



QNa  x
Precip.layer

z
0
Na
z    xNa dy  x
t
0
Na
0
 adt
0
xNa
xNa 
xNa
 

D

a


A
t
y 
y 
y


QMe  QSi
xMe
xSi
prec

 xSi x Me

prec
1  k x
Me xSi

Helebrant A., Matoušek J.: Glastech. Ber. Glass Sci. Technol 68C1, 207 (1995)
Corrosion of Materials Course




Durability testing
1)
2)
1
1. Corrosion solution
2. Polyethylene tubing
3. Peristaltic pump
4. Thermostat
5. Water bath
6. Porous membrane
7. Cell
8. Specimen
9. Collecting bottle
4
PE
vessel
6
Leaching
solution
7
2
3
8
6
Glass
grains
3)
Stainless
pot
5
jar
1) Static (cs, k+)
Teflon
sample
9
Pt wire
2) Dynamic (k+, k-, D/h)
Stainless holder
3) VHT (precipitates)
Deionised water
Corrosion of Materials Course
Examples
• Glass Composition (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
Examples
• Corrosion experiments
–
–
–
–
Polyethylene vessels
80°C
S/V= 298.1 m-1
up to 22 days
• Solution analysis
– AAS (Atomic Absorption
PE
vessel
Leaching
solution
Glass
grains
Spectroscopy)
• Surface analysis
– SNMS (Secondary Neutral Mass
Spectrometry)
Corrosion of Materials Course
Examples
0.8
Q(i) [g.m -2]
0.7
Q(Si)
0.6
Q(Na)
0.5
Q(Ca)
0.4
Si model
0.3
Na congr. model
0.2
Ca congr. model
0.1
Na B-D model
0
0
5
10
15
20
25
time [days]
Glass SK1
Corrosion of Materials Course
Ca precip
Examples
Q(i) [g.m -2]
3
Q(Si)
2.5
Q(Na)
2
Q(Mg)
Si model
1.5
Na congr. model
1
Mg congr. model
Na B-D model
0.5
Mg precip
0
0
5
10
15
20
25
time [days]
Glass SK2
Corrosion of Materials Course
Examples
SK1
interdiffusion coefficient D [m2.s -1]
initial dissolution rate a0 [m.s -1]
-1
final dissolution rate an [m.s ]
SK2
5.1x10-19
6.5x10-11
8.3x10-19
1.6x10-10
1.9x10-12
2.0x10-12
0.3
0.35
k - [1]
Precipitation:
CaO*3SiO2
MgO*2.8SiO2
Corrosion of Materials Course
Thermodynamic approach
Plodinec et al.
lnQSi   Ghydr
ln QSi
Metasilicates
Oxides
Ghydr
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
Thermodynamic approach
Conradt
Phase diagram
Silicates, oxides…
G + correction to glassy state
H+, OH- on surface
pH
Conradt R.: J. Nucl. Mater. 298, 19 (2001)
Corrosion of Materials Course
Thermodynamic approach
Aagard & Helgeson
dQSi
 k0 aH  e
dt
 Ea
RT
  Q 
1  K 
  
Semiempirical pH influence
Arrhenius temperature dependence
Saturation effect
K=?
n
Q  aSimaMe
...
Aagaard, P., Helgeson, H. C.: American Journal of Science, 282, 237 (1982)
Corrosion of Materials Course
TD approach - examples
SK1
NR(Glas) [g/m2/d]
0.60
0.50
0.40
y = -49.948x + 0.4625
2
R = 0.8291
K = 0.009
0.30
0.20
0.10
0.00
0.E+00 2.E-03 4.E-03 6.E-03 8.E-03 1.E-02
a (SiO2)
0.7505
2+ 0.07
0.10
• a (Ca )
Corrosion of Materials Course
TD approach - examples
SK2
2
NR (Glas) [g/m /d]
1
y = -165.97x + 0.8857
R2 = 0.8004
K = 0.005
0.8
0.6
0.4
0.2
0
0.E+00
2.E-03
a (SiO2)
0.7581
4.E-03
2+ 0.10
• a (Mg )
Corrosion of Materials Course
6.E-03
TD approach - examples
350
1200
Si
Na
Ca
250
Kongruentes
Si congruent
Auflösen
Na
Mg
Kongruentes
congruent
Auflösen
c (i) [mg/l]
c (i) [mg/l]
300
200
precipitation
Abscheidung
150
100
800
precipitation
Abscheidung
400
50
0
0
0
5
10
15
Zeit [days]
[Tage]
Time
20
25
0
10
Zeit [Tage]
Time
[days]
SK2
SK1
Corrosion of Materials Course
20
TD approach – examples SK1
30.00
20.00
Übersättigung
supersaturation
Korrosionafter
Test
corrosion
nach
14 Tagen
14
days
10.00
0.00
-20.00
-30.00
-40.00
Chalcedony
Dicalcium silicate
Gyrolite
Na2SiO3
Natrosilite
Okenite CaSi2O4(OH)2:H2O
SiO2(am)
Tobermorite-11A
Xonotlite
Untersättigung
SI
-10.00
-50.00
-60.00
-70.00
0.000001
0.00001
0.0001
0.001
0.01
[mol/kg]
GlassGlas
[mol/kg]
PHREEQC:http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc
Corrosion of Materials Course
0.1
1
TD approach – examples SK2
80
60
40
SI
20
Anthophyllite
Chalcedony
Enstatite
Na2SiO3
Natrosilite
SiO2(am)
Brucite
Chrysotile
Forsterite
Na4SiO4
Sepiolite
Talc
Übersättigung
supersaturation
0
-20
-40
-60
-80
0.000001
corrosion
Korrosionafter
Test
14 Tagen
14nach
days
Untersättigung
0.00001
0.0001
0.001
0.01
Glas
[mol/kg]
Glass
[mol/kg]
PHREEQC:http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc
Corrosion of Materials Course
0.1
1
TD approach - examples
Surface of SK1 after 2 days in
Surface of SK1 after 13 days in
deionised water, 80°C,
VHT, 200°C,
S/V = 298,1 m-1, bar=100 mm
S/V = 298,1 m-1, bar=10 mm
Corrosion of Materials Course
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
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
Thank you
Corrosion of Materials Course