Diffusion in Iron Oxide Melts

Abstract

The interdiffusivity of iron and oxygen in iron oxide melts has been measured by the capillary method in a temperature range from 1430 to 1550°C and for a composition range from r (=Fe³⁺/ΣFe)=0.12 to 0.42. At 1550°C, the interdifrusivity is 4×10^-4-5×10^-5cm²/sec, which is very high as compared with the diffusivity of silicate slags. Activation energies for diffusion are 10.7±0.6 and 16.6±0.2 kcal/mol at r=0.12 and 0.33, respectively. The diffusivity decreases with increase of r.
At higher Fe³⁺ content (r>-0.25), this decrease of diffusivity becomes to a larger extent. The observed results are interpreted with relation to the constitution of the melts and other properties such as electrical conductivity and viscosity.