ジルコニア固体電解質電池法によるFe_xO-B₂O₃系溶融スラグのFe_xOの活量測定

抄録

The Values of emf of the galvanic cell (+) Mo |Mo (s), MoO₂(s)| ZrO₂(+MgO)| Fe^xO (in slag), Fe |Ag| Fe (-) involving zirconia solid elektrolyte have been measured at 1467K-1641K in order to obtain the activity of Fe_xO in Fe_xO-B₂O₃ system molten slag and the standard free energy of formation of Fe_xO.
Activity of B₂O₃ were also determined by virtue of Gibbs-Duhem integration (α-function integration).
The standard free energy of formation of Fe_xO. was determined as the following equation:
ΔG° (Fe_xO) /kJ·mol^-1=-264.3+0.06486T
Activity of Fe_xO deviates from negative to positive on the N_FexO=0.55 at 1473 K and N_Fe^xO=0.64 at 1573K from Raoult's law, and show constant value, 0.20, independent of temperature over the two liquids phase range below N_FexO=0.48. Activity of B₂O₃ show constant value, 0.65, over the same two liquids phase range and decrease beyond N_FexO concentration, 0.48.