Electrochemical studies of uranium and thorium in molten LiF--NaF--KF at 500$sup 0$C

Journal Article · Tue Jan 01 00:00:00 EST 1974 · J. Electrochem. Soc., v. 121, no. 1, pp. 86-90

OSTI ID:4370151

Clayton, F R; Mamantov, G; Manning, D L

Electrochemical studies of U(IV) in molten Lif--NaF-KF (46.5-process at a platinum electrode. The first step is complicated by disproportionation of U(III) to regenerate U(IV); the second step involves formation of uranium metal. Standard electrode potentials with respect to a unit mole fraction Ni(II)/Ni electrode are estimated for the U(IV)/U(III) and U(III)/U couples as --1.41 and -- 1.81V, respectively. These values must be considered tentative because of complications in the electrode process. The voltammetric oxidation of U(IV) at platinum and pyrolytic graphite electrodes in LiF--NaF--KF occurs at ~+ 1.3V vs. a Ni(II) (saturated)/Ni reference electrode. The results point to the disproportionation of electrochemically generated U(V). In voltammetric studies of Th(IV) in molten LiF--NaF--KF at 500 deg C, a reduction wave is obtained at nickel and tungsten electrodes, with a peak potential of --2.02 V (vs. a Ni(II) (saturated)/Ni reference electrode). Analysis indicated that Th(IV) is reversibly reduced to the metal with alloy formation between the deposited thorium and the nickel. A standard electrode potential for the Th(IV)/Th couple in this melt is calculated to be -2.13V vs. a unit mole fraction Ni(II)/Ni electrode. (auth)

• Research Organization: Univ. of Tennessee, Knoxville
• NSA Number: NSA-29-012629
• OSTI ID: 4370151
• Journal Information: J. Electrochem. Soc., v. 121, no. 1, pp. 86-90, Other Information: Orig. Receipt Date: 30-JUN-74
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

N40420* -Chemistry-Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
*THORIUM- ELECTROCHEMISTRY
*URANIUM- ELECTROCHEMISTRY
CATIONS
HIGH TEMPERATURE
LITHIUM FLUORIDES
MOLTEN SALTS
OXIDATION
POTASSIUM FLUORIDES
POTENTIOMETRY
REDUCTION
SODIUM FLUORIDES
THORIUM COMPOUNDS
URANIUM COMPOUNDS
VOLTAMETRY