Permeabilities of Oxygen through Molten CaO-SiO₂-Al₂O₃ System with Fe₂O₃ or CaF2

Abstract

The permeabilities of oxygen through the molten Fe₂O₃-CaO-SiO₂-Al₂O₃and CaF₂-CaO-SiO₂-Al₂O₃systems were measured by means of an experimental procedure which was developed by the authors. Those trough the Fe₂O₃-CaO-SiO₂-Al₂0₃and CaF₂-CaO-SiO₂-Al₂O₃melts were found to be in the range of 1×10^-8to 1×10^-6and 5×10^-12to 5×10^-8moles O₂/cm·s, respectively. The permeability was raised by a factor of 10 to the 10th power when 0.2 wt% of Fe₂O₃was added to 40 wt%CaO-40 wt%SiO2-20 wt% Al₂O₃melt. The permeabilities through the molten slags with Fe₂O₃are proportional to the 1/4th power of oxygen partial pressure in the atmosphere. The permeabilities through the molten slags without Fe₂O₃are directly proportional to the oxygen partial pressure in the atmosphere. They increase when CaF₂is added to the Fe₂O₃-CaO-SiO₂-Al₂O₃melt.