Electronic/Ionic Properties of Fe_xO–SiO₂–CaO–Al₂O₃ Slags at Various Oxygen Potentials and Temperatures

Abstract

As a fundamental study on properties of the Fe_xO-bearing slags, the total electrical conductivity and electronic/ionic properties of Fe_xO–SiO₂–CaO–Al₂O₃ slags were measured at different oxygen potentials (controlled by CO–CO₂ mixture gas) and temperatures by using four-electrode method. From experiments results, it can be seen that the total conductivity changes little as increasing the ratio of CO to CO₂ (decreasing the oxygen potential), while the electronic and ionic conductivities of all slags decreases and increases monotonously, respectively. The temperature dependences of the total electrical conductivity, electronic, and ionic conductivities follow the Arrhenius law. It was also found that with increasing CaO/Al₂O₃ ratio, the total electrical conductivity and ionic conductivity firstly decrease and then increase, while electronic conductivity firstly almost keeps constant but then increases from CaO/Al₂O₃=1. The minimum values of the total electrical conductivity and ionic conductivity occurs near CaO/Al₂O₃ = 1, which is mainly resulted from the charge compensation effect of Al³⁺ ions.