Discussion on Construction of Electrode of Oxygen Probe for Molten Slag

Abstract

In order to obtain a guide for determination of oxygen potential in molten slag, the discussion is made on the reason why EMF is induced from oxygen concentration cell of which electrode immersed in molten slag does not contact at the surface of the solid electrolyte. The following conclusions are obtained :
1) The EMF is determined only by oxygen chemical potential in the slag when solid electrolyte doesn't dissolve into the molten slag. On the other hand, The EMF is determined by oxygen chemical potential and diffusion potential induced by the dissolved materials when solid electrolyte is dissolved into the molten slag.
2) In the case of the oxygen concentration cell of which electrode immersed in the molten slag doesn't contact at solid electrolyte surface, the minimum distance between the solid electrolyte surface and the electrode under the present experimental condition was 2 mm in order to prevent influence of diffusion potential.
3) Oxygen probe for molten steel with molybdenum electrode should not be used in molten slag, except the slag being rapidly flowing.