Because the environmental problems are occurred by greenhouse gases such as CO2, the industries
have tried to increase electric motor efficiency to reduce CO2 emissions. A core material of electric
motor is high-silicon electrical steel. The ferrosilicon (FeSi) alloy, a raw material for the production of
electrical steel, affects the electric properties of silicon steel. The main impurities such as Ca, Al and
Ti make inclusions or precipitates that causes core loss. The slag treatment has been widely used
to remove impurity elements. Thermodynamic principles for the refining of several impurities,
specifically Ca and Al, have been investigated, whereas thermodynamic behaviour of Ti has not
been fully understood yet. Therefore, in the present study, the titanium distribution ratio (𝐿􀯍􀯜) between
ferrosilicon and CaO-SiO2-Al2O3 slag system at 1773 K was investigated.
The results show that 𝐿􀯍􀯜 is influenced by both the basicity and stability of titanium ion in the slag.
Specifically, 𝐿􀯍􀯜 exhibits a minimum value at about C/S=0.7 indicating a shift in the titanate structure
unit from [TiO5]-square pyramid to [TiO4]-tetrahedron because of lack of Ca2+ ions in a C/S<0.8>
region, contributing to an increase in titanate capacity and 𝐿􀯍􀯜.