*3.2. Influence of Basicity on the Titanium Distribution Ratio*

The relation between *L*Ti,cal or *L*Ti,mea and binary basicity ((%CaO)/(%SiO2)), complex basicity ((%CaO) + 1.4(%MgO))/((%SiO2) + (%Al2O3)), or optical basicity Λ (Λ = *xi*·λ*i*, where *xi* is the mole fraction of a component, and λ*<sup>i</sup>* is the optical basicity of a component in slag) obtained by using Pauling electronegativity [33] are depicted in Figures 3–5 (where *R* is the linear correlation coefficient), respectively. It is evident that (1) the relationship between log *L*Ti,cal by the IMCT model or

log *L*Ti,mea and optical basicity had a better dependence than that with the binary or complex basicity of CaO–SiO2–Al2O3–MgO–FeO–MnO–TiO2 slags and (2) raising the basicity can give rise to a distinctly increasing titanium distribution ratio. Linear fit results indicated that the optical basicity could better reflect the structure of the slags, and it is suggested to reflect the correlation between the titanium distribution ratio and basicity of the slags. The reasons for the different linear fits of these models is attributed to the different definitions of basicity. As for optical basicity, all the components in the slag are taken into account, which can reflect the whole features of the slag, while for binary basicity or complex basicity, the de-titanium contributions of other components were ignored.

**Figure 3.** Correlation between binary basicity and titanium distribution ratio: (**a**) calculated by IMCT; (**b**) industrial measurements.

**Figure 4.** Correlation between complex basicity and titanium distribution ratio: (**a**) calculated by IMCT; (**b**) industrial measurements.

**Figure 5.** Correlation between optical basicity and titanium distribution ratio: (**a**) calculated by IMCT; (**b**) industrial measurements.
