Brown Fused Alumina

Listing ID #2978728

Chemical & physical properties
crystal form alpha alumina trigonal system
chemical nature amphoteric
reaction with acids subject to mild attack by aqua andor hydrofluoric acid
reaction with alkalis very slight with strong hot solution only
oxidation-reduction effects none
true density(gcm3) 3.97
hardness knoop(kgcm2) 2000-2200
moh̢۪s 9.0
color dark brown
color after firing light blue
melting point 2000 °c
max. Usable temperature 1900 °c
specific heat (calg °c) 0.26 (20-29 °c)
coefficient of thermal conductivity
(calcm2.sec.°c) room temperature 900 °c
0.047 0.013
electrical resistivity (wcm) 30 °c 300 °c 900 °c 1600 °c
1016 1013 105 104
coefficient of liner expansion (x10-6) 7-9(0-1600°c)
chemical composition (% by weight)
grit item 10 – 90 100 – 180 220-220 230 – 400 500 -1200
al2o3 94.5 – 97.0 9305 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