The electrothermal fusion of bauxite at 2100°C yields an impure and brown electrofused
alumina product called brown fused alumina, sometimes simply brown corundum. Brown
fused alumina exhibits coarse grains, and the major impurity in brown fused alumina is
titania or titanium dioxide (TiO2) coming from the bauxite ore. Therefore, commercially,
two grades of brown fused aluminas can be distinguished according to their titania content:
the friable grade, with 1.5 wt.% TiO2, and the standard grade, with 3 wt.% TiO2
, which exhibits a greater toughness than the friable grade.
