Transcript Slide 1

Impact of Glass Composition on the Production of Borosilicate HGMs
Fabienne C. Raszewski, Erich K. Hansen, David K. Peeler and Ray F. Schumacher
Savannah River National Laboratory, Aiken, SC 29808
This work was sponsored by Washington Savannah River Company (WSRC) for the United States Department of Energy under Contract No. DE-AC09-96SR18500.
The Savannah River National Laboratory is operated for the U.S. Department of Energy by Washington Savannah River Company.
Hollow Glass Microspheres (HGMs)
Glass Selection
LDRD Glasses
• HGMs are produced by a flame
forming (FF) process using an
experimental apparatus designed at
SRNL
R2O (R=alkali metals)
Alkali-Borosilicate
Immiscibility Region
• Baseline composition is derived from the
Na2O-B2O3-SiO2 system
• Two components were modified
• Sized glass frit containing a blowing
agent is passed through a flame at
elevated temperatures (~1300°C)
Zero Glasses
• Eliminate minor components (one at a time)
from the baseline composition
Solid beads, defects, etc.
SiO2
Log (viscosity in Pa·s)
50
40
+6 SiO2
2.0
+3 SiO2
1.0
-6 SiO2
30
20
-3 SiO2
Base
3.0
57
62
SiO2 Content (wt% )
80
80
70
70
40
2.0
Base
B/R -0.5
0.0
20.5
21.5
B2O3 Content (wt% )
22.5
Density
20
20
10
10
0
23.5
0
0 wt%
3
ZnO
0 wt%
4
P2O5
0 wt%
5
F
6
0.8
0.7
B/R +0.5
Density (g/cc)
Density (g/cc)
-3 SiO2
-6 SiO2
0 wt%
2
CaO
Density
0.7
+3 SiO2
0.4
Base
1
No data for “0 wt% CaO” – yield
was too low
+6 SiO2
0.5
40
30
0.8
0.6
50
Viscosity of the glass is provided for reference.
0.8
0.7
60
30
0
19.5
67
90
50
B/R +0.5
0
90
60
1.0
Viscosity of the glass is provided for reference.
Density (g/cc)
4.0
10
0.0
52
HGMs Yield
5.0
100
Yield (%)
Viscosity
100
Yield (%)
6.0
70
3.0
• Fluorine
Yield
80
60
• ZnO
Yield
90
4.0
• P2O5
Zero Glasses
Yield (%)
Log (viscosity in Pa·s)
5.0
• CaO
LDRD Glasses
100
Viscosity
HGMs Yield
B/R -0.5
• Constant SiO2 content
HGMs (g)
HGM Yield (%) 
100
HGMs (g)  Other FF Products (g)
6.0
+3 wt% SiO2
-6 wt% SiO2
• B2O3/R2O molar ratio
• Yield is determined by:
B 2O 3
+6 wt% SiO2
B
• Constant B2O3/R2O molar ratio
• Average diameters are within the
range of 45 – 75 μm
Immiscibility
-3 wt% SiO2
• SiO2 content (wt%)
• HGMs are quenched with water and
collected
HGM Forming
Region
B/R +0.5
0.6
0.5
0.4
Base
Base
0.6
0.5
0.4
B/R -0.5
0.3
0.3
50
55
60
65
70
19
20
SiO2 Content (wt% )
21
22
B2O3 Content (wt% )
• Baseline composition has the highest yield
• Yield is maximized in the region of ~60 – 62 wt% SiO2 and ~21.5 – 22 wt% B2O3
• Density increases linearly with increasing SiO2 and B2O3 content
• Density of baseline composition is low – no explanation at the present time
23
24
0.3
0
Base
1
0 wt%
2
ZnO
0 wt%
3
P2O5
0 wt%
4
F
5
• Elimination of ZnO, P2O5 or F from baseline
composition has no influence on yield
• Yield is considerably reduced when CaO is
removed from the baseline composition
• Density is relative unaffected by the removal of
ZnO, P2O5 or F from the baseline composition