Determination of Hydrogen Content and Dehydrogenation in Molten Aluminum by Concentration Cell Method

Abstract

The CaZr0.9In0.1O3-α proton conductor was prepared by solid reaction method with high purity and small particle size. Two types hydrogen sensors and pump based on the proton conductor were fabricated for monitoring the hydrogen content and dehydrogenation in molten aluminum at 760 . The °C electromotive force (EMF) and time of hydrogen sensor with the inverted-U electrolyte tube followed a smooth curve in which the EMF tended to be stable after about 13 min whose sensing performance was superior to that with the upright-U electrolyte tube. The sensor EMF increased with the pressure or flow rate of referent gas according to Nernst equation. The equilibrium time of EMF increased and the transferring resistance between the Pt electrode and proton conductor’s transfer resistance decreased with the flow rate of reference gas. Therefore, inverted-U type tube and flow rate value of reference gas were very important to acquire the sensitive and accurate hydrogen content values in molten aluminum. In addition, hydrogen pump based on concentration cell had feasibility and actual using value for the dehydrogenation of molten aluminum.