Leonid F. Yamshchikov

Thermodynamic properties of gadolinium in Ga–Sn and Ga–Zn eutectic based alloys

Thermodynamic properties of gadolinium in Ga–Sn and Ga–Zn eutectic based alloys were studied. Temperature dependences of gadolinium activity in the studied alloys were determined at 573–1073 K employing the EMF method. Solubility of gadolinium in the Ga–Sn and Ga–Zn alloys was measured at 462–1073 K using IMCs sedimentation method. Activity coefficients as well as partial and excess thermodynamic functions of gadolinium in the studied alloys were calculated on the basis of the obtained experimental data.

Thermodynamic properties of rare earth elements in La–RE–Ga–In alloys (RE = Nd, Y)

Thermodynamic properties of La, Nd, and Y were studied in pseudo-quaternary systems La–Nd–(Ga–In)eut and La–Y–(Ga–In)eut. Temperature dependences of lanthanum, neodymium, and yttrium activity in the alloys were determined at 300–800 °C employing the e.m.f. method. Partial thermodynamic functions of lanthanum in the alloys studied were calculated on the basis of the experimental data.

Solubility and excessive thermodynamic characteristics of Pr and Nd in the Ga–Sn eutectic alloy

The praseodymium and neodymium solubilities in the gallium–tin eutectic melt were measured for the first time in a temperature range of 423–1073 K using a high-temperature sampling technique. The data on the activity and solubility are used to calculate the activity coefficients, the excessive thermodynamic characteristics of α-praseodymium and α-neodymium in the Ga–Sn eutectic melts, and the separation factor for the Pr/Nd pair on gallium–tin electrodes in chloride melts.

Uranium and neodymium partitioning in alkali chloride melts using low-melting gallium-based alloys

Abstract Partitioning of uranium and neodymium was studied in a ‘molten chloride salt - liquid Ga-X (X = In or Sn) alloy’ system. Chloride melts were based on the low-melting ternary LiCl-KCl-CsCl eutectic. Nd/U separation factors were calculated from the thermodynamic data as well as determined experimentally. Separation of uranium and neodymium was studied using reductive extraction with neodymium acting as a reducing agent. Efficient partitioning of lanthanides (Nd) and actinides (U), simulating fission products and fissile materials in irradiated nuclear fuels, was achieved in a single stage process. The experimentally observed Nd/U separation factor valued up to 106, depending on the conditions.

Thermodynamic properties of metallic Ga-In alloys saturated with lanthanum

The activity of lanthanum is determined in a Ga-In eutectic alloy and alloys with indium in the temperature range 573–1073 K using the electromotive force (emf) method.

Thermodynamic properties of alloys of praseodymium with the gallium-indium eutectic melt

Equilibrium potentials of Pr-In alloys containing 8.7–12.1 mol % Pr and alloys of Pr with In-Ga eutectic saturated by praseodymium up to 6.71 mol % Pr are measured by the emf method between 573–1073 K in the (Li-K-Cs)Cleut based salt melt. Metallic praseodymium is used as the reference electrode when studying the Pr-In system, and the two-phase praseodymium-indium alloy L + PrIn3 with the known thermodynamic properties having no phase transitions in the studied temperature range is used as the reference electrode when studying the Pr-In-Ga system. Partial thermodynamic properties and activity of praseodymium in alloys with indium and the Ga-In eutectic mixture are calculated.

Study of uranium solubility in gallium-indium eutectic alloy by emf method

Activity, activity coefficients and solubility of uranium in Ga-In eutectic alloy as well as activity of uranium in U-Ga and U-In alloys were determined between 573 and 1073 K using electromotive force (emf) method.

Thermodynamics of Nuclear Waste Reprocessing: Separation of Lanthanides Using Liquid Metals and Alloys

Thermodynamics of separation of praseodymium and neodymium employing liquid low-melting metals and alloys is considered. Pr/Nd separation factors on liquid Ga, In, Bi, and Ga-In eutectic were calculated from the thermodynamic data. The obtained results are compared with the literature data on experimentally determined separation factors on “traditional” liquid metals: Bi, Zn, and Cd. It is shown that one-stage selective extraction of praseodymium or neodymium from the mixture using any of the mentioned metals is not possible. In the separation process of lanthanides from minor actinides using a chloride molten salt–liquid metal system, cerium group lanthanide fission products will be accumulated in the salt phase.