Electrochemical studies of lanthanum and lanthanum–zinc alloys in fused LiCl–KCl eutectic

Abstract

The electromotive force of cells of the type La(s)/LiCl–KCl (eutectic) + LaCl3/(La + Zn, saturated liquid alloy) has been measured over the temperature range 450–600 °C. Thermodynamic functions for the limiting lanthanum–zinc solid intermetallic compound existing in this range are: ΔGf0, −58.8 kcal/mole, ΔSf0, −53 cal/deg mole, and ΔHf0, −97 kcal/mole at 450 °C. The standard potential (mole fraction scale) of the La(III)/La(0) electrode is −2.883 V with respect to the Pt(II)/Pt reference electrode at 450 °C. The significance of these measurements for the electrochemical separation of lanthanum and uranium is discussed.