The titanium-rich slags produced by ilmenite smelting are unusual in several respects, including their low viscosity, high electrical conductivity, propensity to solidify predominantly as one phase (pseudobrookite), and reactivity (with oxidizers) in the liquid and solidified form. The low viscosity is related to the unexpectedly "basic" behavior of Ti 4ϩ ; the high conductivity is likely through an electron transfer mechanism involving the Ti 4ϩ -Ti 3ϩ pair; the oxidation behavior is caused by the presence of a significant amount of Ti 3ϩ . Possible reasons for the nearly single-phase structure of the solidified slag are considered, and it is concluded that the most likely cause is the presence of a eutectic groove close to the M 3 O 5 (pseudobrookite) composition. This conclusion was tested by examining the compositions and microstructure of slag samples from a pilot smelter. The results show that the slags do contain a small amount of rutile, in line with predictions.

No abstract