Distribution Behavior of Nickel, Cobalt, and Copper between Al<sub>2</sub>O<sub>3</sub>–Li<sub>2</sub>O–CaO Slag or Al<sub>2</sub>O<sub>3</sub>–Li<sub>2</sub>O–SiO<sub>2&lt

The distribution of Ni, Co, and Cu between the Al2O3–Li2O–CaO slag or the Al2O3–Li2O–SiO2 slag and the Ni–Co–Cu alloy at 1623 K was investigated. In the oxygen partial pressure (pO2) range of 10−14 to 10−12, the distribution ratio, LX, of component X (X: Co, Ni, or Cu) between the Al2O3–Li2O–CaO slag and the molten Ni–Co–Cu alloy was LNi < LCu < LCo. The valences of Ni and Co in the Al2O3–Li2O–CaO slag system are mainly divalent, and that of Cu is mainly monovalent, as determined from the log pO2 dependence of log LX in the pO2 range of 10−14 to 10−12. The pO2 of the Al2O3–Li2O–CaO system is three to five orders of magnitude lower than that of the Al2O3–Li2O–SiO2 system and the previously reported slag system without Li2O, even though the distribution ratios (LNi, LCo, and LCu) are similar. The activity coefficients of Ni, Co, and Cu in the Al2O3–Li2O–CaO system are all lower than those in the Al2O3–Li2O–SiO2 system and the previously reported slag system without Li2O. In particular, [γCoO] is approximately two orders of magnitude lower.