The Continuous Measurement of Hydrogen Activities in Molten Copper using Proton-Conductive Solid Electrolyte.

Abstract

To measure hydrogen activity in a molten copper, a galvanic cell-type hydrogen sensor had developed. The special feature of this sensor was to be used in the in site measurement of hydrogen activity in molten copper. The sensor consists of a hydrogen concentration cell utilizing a perovskite-type oxide, CaZr0.9In0.1O3-δ, as a solid electrolyte. The electromotive force of the cell was found to be generated by difference of not only hydrogen but also oxygen activities between electrodes in high temperature region more than about 1, 200 K. In this paper, the hydrogen activities in molten copper held in the atmosphere with controlled hydrogen and oxygen activities were measured and the values were compared with the theoretical ones calculated by a method developed by the present authors. The performance of this hydrogen sensor was checked with monitoring the hydrogen activity changes on some treatment to the melt in air and on solidification of the melt in hydrogen atmosphere.