Electrochemical Studies on Zirconium and Hafnium in Molten LiCl-KCl Eutectic

Abstract

Electrode potential and polarographic studies have been made on solutions of zirconium and hafnium ions in molten normalLiCl‐normalKCl eutectic at 450°–550°C. Anodic dissolution of Zr at 450°C yielded Zr(IV), but at 550°C, chiefly Zr(II). Only Hf (IV) was observed over this range. Apparent standard electrode potentials were (mole fraction scale, Pt(II)/Pt(0) reference) normalZr)(II/normalZr)(0;−1.77normalv at 550°C normalZr)(IV/normalZr)(0;−1.86normalv at 450°C normalHf)(IV/normalHf)(0;−1.88normalv at 450°C;−1.92normalv at 550°C

Electroanalytical Chemistry in Molten Salts—A Review of Recent Developments

“…The results of coulometric studies are similar to those reported by Baboian et af. ; (75) namely, up to 400°C zirconium was oxidized to Zr 4 +, whereas at 510°C and higher temperatures only Zr2+ was formed. Eon et af.…”

“…(75) potentiometrically and voltammetrically. They showed that ZrH was the stable species produced in the melt by anodic dissolution of zirconium at lower temperatures.…”

Evaluation of methods for decladding LWR fuel for a pyroprocessing-based reprocessing plant

“…39 Electrolytic dissolution of Zircaloy in anhydrous molten 52 salts4° is also probably feasible; such a process has been proposed by ANL for LWR decladding (see Electrotransport). Aqueous electrolytic processes in nitric acid media disintegrate Zircaloy cladding and also dissolve the U0 2 .…”

Electrochemistry of zinc, cadmium, and mercury ions in fused AlCl3–NaCl–KCl eutectic

“…Although the method of measuring transition times used throughout this work (26) gave the ratios cited, other measurement techniques gave values closer to 3 for the mercury system. Two similar cases in which mixtures of oxidation states have been produced by electrochemical anodization of metals in fused salts are niobium in fused LiCI-KC1 (27), in which the ratio between Nb(1V) and Nb(II1) concentrations was approximately equal to 3, and zirconium in the same solvent, in which the proportion of Zr(I1) and Zr(1V) obtained is temperature dependent (28).…”