Brown fused alumina is made from high quality bauxite by
fusing in an electric arc furnace at high temperature. It has good toughness and high hardness. It is suitable for manufacturing of vitrified and
resin bonded tools, and for lapping,polishin, and sand blasting and sand cleaning.
It
can be also used to make superior refractory products.¡¡ |
 |
Chemical
& Physical Properties
Crystal Form
|
Alpha alumina trigonal system
|
Chemical nature
|
Amphoteric
|
Reaction with acids
|
Subject to mild attack by aqua and/or
hydrofluoric acid
|
Reaction with Alkalies
|
Very slight with strong hot solution
only
|
Oxidation-reduction effects
|
None
|
True Density(g/cm3)
|
3.97
|
Hardness
|
Knoop(kg/cm2)
|
2000-2200
|
Moh¡¯s
|
9.0
|
Color
|
Dark Brown
|
Color after firing
|
Light blue
|
Melting point
|
2000¡ãC
|
Max Usable temperature
|
1900¡ãC
|
Specific heat¡¡(cal/g.¡ãC)
|
0.26(20-29¡ãC)
|
Coefficient of thermal conductivity
£¨cal/cm2.sec.¡ãC)
|
Room temperature
|
900¡ãC
|
0.047
|
0.013
|
Electrical resistivity (Wcm)
|
30¡ãC
|
300¡ãC
|
900oC |
1600¡ãC |
1016
|
1013
|
105
|
104
|
Coefficient of liner expansion (x10-6)
|
7-9(0-1600¡ãC)
|
Chemical Composition (% by weight)
Grit
Item |
10
¨C 90 |
100
¨C 180 |
220
- 220 |
230-400 |
500-1200 |
Al2O3 |
94.5
- 97.0 |
93.5
min |
92.5
min |
91.0
min |
89.0
min |
TiO2 |
1.5
- 3.8 |
1.5
- 3.8 |
1.5
- 3.8 |
4.0
max |
4.0
max |
Magnetic Matters Contents (% by weight)
Grit No.
|
Magnetic
Matters Content
|
16#-30
|
<0.0380 |
36#-60#
|
<0.0280
|
70-120#
|
<0.0230
|
150#-220#
|
<0.0170
|
Available Sizes
F12,F14,F16,F18,F20,F22,F24,F36,F40,F46,F54,F60,F70,F80,F90,F100,F120,F150,F180,F220,
F230£¬F240,F280,F320,F360,F400,F500,F600,F800,F1000,F1200
|
P24,P30,P36,P40,P50,P60,P70,P80,P90,P100,P120,P150,P180,P220,P240,P280,P320,P360,
P400,P500,P600,P800,P100,P1200
|
JIS240,JIS280,JIS320,JIS360,JIS400,JIS500,JIS600,JIS800,JIS1000,JIS1200,JIS1500,JIS2000,
JIS2500,JIS3000
|
Other sizes can be also available on request.
|
Application
Vitrified
tools |
Lapping |
Resinoid
tools |
Blasting |
Polishing |
Scrubing |
Tumbling |
Deburring |
Self-tumbling |
Non-slip |
Lapping
compound |
Wire
saw |
Brown Fused Alumina Refractories (% by weight)
Group
Sizes of BFA
|
Mixed
Sizes of BFA
|
Sizes
(mm)
|
Chemical Content
|
Sizes
(mm)
|
Chemical Content
|
8-5
5-3
3-1
1-0
|
Al2O3>94.50
SiO2<1.2
Fe2O3<0.2
TiO2<3.8
CaO<0.5
MgO<0.4
|
25-0
10-0
5-0
3-0
|
Al2O3>94.50
SiO2<1.2
Fe2O3<0.2
TiO2<3.8
|
Packing
25 kgs or 50 kgs packed into
three layers bags, or can be packed on request. |
