Electrical and electronic conductivity of CaO-SiO2-FeO x slags at various oxygen potentials: Part I. Experimental results

Abstract

The oxygen potential dependences of total electrical and partial electronic/ionic conductivities for 'FeO'-CaO-SiO 2 slags have been studied both experimentally and theoretically in the present work. In the first part of this two-part article, the experimental results are presented for slags with 30 wt pct 'FeO' and CaO/SiO 2 wt ratios of 0.5, 1.0, and 2.0. For each slag composition, measurements of total electrical conductivity and electronic transference were made over a range of oxygen potentials and temperatures. The results were used to calculate the partial conductivities. A maximum was achieved in total and electronic conductances as a function of equilibrium CO 2 /CO. The CO 2 /CO corresponding to the maximum was shifted to lower values with increasing slag basicity (CaO/SiO 2 ratio). The other effect of basicity was increasing total and partial conductivities, with a magnitude that depends on oxygen potential and temperature. The activation energies for ionic and electronic conductances were in similar ranges and decreased with the basicity.

The Dynamic Interfacial Oxygen Potential Between Iron-Carbon Droplets and Oxidizing Slag

“…This observation is not consistent with the temperature effect on electronic conductivity observed by Barati and Coley. [26] Employing the Melts database in Factsage 6.4 TM , the activation energy of viscous flow for several cases in Figure 5 was estimated to have a magnitude of 100 kJ/mol. This estimation indicates that the temperature might have a larger effect on mass transfer coefficient than implied by Figure 5.…”

Effect of Applied Voltage on Electroreduction with Controlled Oxygen Flow of Molten Slag Containing FeO at 1723 K

“…48,58,59) It is inferred that slag penetration into the zirconia membrane and the phase transformation with an increase of the monoclinic phase amount can induce an increase of electronic conductivity of the zirconia membrane. Thus the external current (I ex ) is actually the sum of the pure oxygen ionic current ( I O 2−) and the internal electronic current (I e ) passing directly through the MSZ membrane as shown in Fig.…”

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

“…The experimental apparatus and the measuring procedure are made following the work of Barati and Coley. 14) This method requires the four-high-temperature-resistant, inert conducting rods, which serve as electrodes, to immerse into the slag. The experimental arrangement is drawn schematically in Fig.…”

“…[1][2][3][4][5][6][7][8][9][10] Indeed, many researches have been conducted on investigating the electrical conductivity of molten slags. For instance, the electrical conductivities of Fe x O-CaO-SiO 2 , [11][12][13][14] Fe x O-CaO-MgO-SiO 2 , 15) Fe x O-CaO-SiO 2 -Al 2 O 3 , 16) Ni x O-CaO-SiO 2 , 17) and Ni x OCaO-MgO-SiO 2 17) slags had been measured and reported in published literatures. Because the electrical conductivity includes two parts, ionic conductance and electronic conductance, the estimation for both of them will be difficult.…”