Determination of the chemical diffusion of oxygen in liquid iron oxide at 1615 °c |
| |
Authors: | Y Sayadyaghoubi S Sun S Jahanshahi |
| |
Affiliation: | (1) BHP Research-Melbourne Laboratories, Mulgrave, Australia;(2) CSIRO Division of Minerals, G.K. Williams Cooperative Research Center for Extractive Metallurgy, Clayton, Australia |
| |
Abstract: | The chemical diffusion of oxygen in liquid iron oxide has been studied by the oxidation of a melt in a long capillary at 1615
°C. When pure oxygen was used as the oxidizing agent, the surface composition of the slag was found to be in close agreement
with the expected gas-slag equilibrium, suggesting that diffusion is the controlling step. This was not the case when air,
5 pct oxygen in argon or pure CO2 was used to oxidize the slag. The deviation of the surface composition from the expected equilibrium was in accordance with
a mechanism of mixed control by both the gas-slag reaction and diffusion in the bulk. The average value of the chemical diffusivity
of oxygen (or iron) in liquid iron oxide with Fe2+/Fe
T
between 0.25 and 0.77 was established to be 3(±1) × 10-7 m2/s. This value is one to two orders of magnitude higher than those from earlier studies. There seems to be a reasonable correlation
between the chemical and the ionic self-diffusivities through the Darken equation. A quantitative analysis in this respect
and on the role of electron hole migration depends on the availability of data on the ionic conductivity and the tracer diffusivities.
Formerly Postgraduate Student |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|