| abstract |
A fused abrasive grain, useful for inclusion in coated abrasives and bonded abrasives, consists essentially of alumina; titanium oxide containing from about 0.42 to about 0.84% titanium, by weight of the abrasive grain, present as a reduced titanium oxide having an average oxidation state lower than in Ti 2 O 3 ; from about 0.05 to about 0.3% by weight carbon; from about 0.02 to about 0.1% by weight Na 2 O; and from 0 to about 0.1% by weight total of calcium and silicon oxides. The grain before roasting has a gain on ignition of from about 0.4 to about 0.7% by weight, and is produced in an electric furnace by fusing high-purity titania, alumina containing Na 2 O as the only significant oxide impurity, and carbon, followed by crushing and roasting the fused grain. |