Wollastonite powder for ceramics
1. used as an asbestos fibre substitute
2.used as a general filler
Wollastonite powder for ceramics is calcium silicate
(CaSiO3) which forms as
aggregates of needle-shaped crystals. Crystals with high aspect
ratio (long needle shapes) are used as an asbestos fibre
substitute, and for reinforcing in thermoplastics and thermoset
polymers. Wollastonite with a low aspect ratio is used as a general
filler, and in some ceramic bodies where its low coefficient of
thermal expansion reduces shrinkage, cracking, and crazing.
The physical properties and chemical components :
PHYSICAL PROPERTY |
CHEMICAL COMPONENT |
||
Coefficient of expansionmm/mm/ |
6.0×106 |
SiO2 |
50%min |
Refractive index |
1.63 |
CaO |
46%min |
Melting point |
1450 |
Fe2O3 |
0.3%max |
hardness |
4.55.0 |
AL2O3 |
0.46%max |
Specific Gravity |
2.91 |
MgO |
0.60%max |
Whiteness |
8892 |
MnO |
0.02%max |
PH(10% slurry) |
9.8 |
TiO2 |
0.02%max |
Aspect Ratio |