Distributions of Mg²⁺, Ni²⁺, Co²⁺, Zn²⁺, Mn²⁺(Me²⁺) and Fe²⁺ ions between ilmenite and 2-N aqueous chloride solution were experimentally determined in the temperature range from 500 to 800°C under 1 kb. The experimental results were analyzed thermodynamically taking into consideration the aqueous speciation.
     Distribution coefficient (K_DN=(X_MeTiO3/X_FeTiO2)/(m_MeCl2⁰aq/m_FeCl2⁰aq)) vs. ionic radius (PC-IR) diagrams are drawn for the experimental results. Log K_DN vs. ionic radius curves are parabolic with a maximum between Co²⁺ and Fe²⁺. However, Ni²⁺ and Zn²⁺ deviate from such a tendency. The anomaly of Zn²⁺ and Ni²⁺ may be attributable to their strong preferency of the tetrahedral sites of the aqueous chloro-complexes and the octahedral sites of the ilmenite structure, respectively. The K_DN value for Ni²⁺ decreases with increasing temperature, whereas those for Mg²⁺, Zn²⁺ and Mn²⁺ increase. The optimum ionic radius for ilmenite seems to decrease slightly with increasing temperature.