Internal Cation Mobilities in Molten (K, Dy_1/3)Cl

Abstract

Internal cation mobility ratios in the molten system KCl-DyCl 3 have been measured at 1093 K by Klemm's countercurrent electromigration method. From these, and data available on the conductivities and molar volumes of the mixtures, the internal mobilities b of both cations have been calculated. With increasing concentration of Dy, b K decreases. The decrease of b K is attributed to the tranquilization effect by Dy 3+ ions which strongly interact with Cl~ ions. With increasing concentration of K + , b Dy decreases; this may be attributed to the stronger association of Dy 3+ with CP ions due to the enhanced charge asymmetry of the two cations neighboring to the CP ions. It could not been clarified whether a species such as [DyCl 6 ] 3_ is also an electrically-conducting species in the K + rich range.

Internal cation mobility in molten CsCl–NdCl3 system at 1073K

“…1 with corresponding literature data for MCl-NdCl 3 systems (M: Li [7], Na [8] and K [5]). It is easy to notice, that ε increases with the increase of atomic number of alkali metal cation (its ionic radius) and y Nd , and reveals a maximum somewhere near equivalent fraction of NdCl 3 equal to 0.5 (it is equivalent to formula M 3 NdCl 6 or stoichiometry of NdCl 6 3− complex anion). It is reasonable to consider a very characteristic form of curve for the cesium system illustrates cumulated result of the diameter of cesium ion, its small polarization force and hence high stability of NdCl 6 3− complex anion (cesium ions are more mobile than other alkali metal ones in this relative scale in the NdCl 3 -deficient part of the system, and it quickly changes in the NdCl 3 -rich part; at the same time relative mobilities in other systems change moderately).…”

“…Arrangement of the migration quartz cell and details of experiments based on electrolysis of salt melts of required composition have been presented in papers reporting measurements of internal mobility of cations in MCl-LnCl 3 systems (M: Li, Na, K; Ln: La, Nd, Dy) [4][5][6][7][8]. The cell was modified by replacing reduction of gaseous chlorine to chloride ions on graphite electrode with electrodeposition of neodymium.…”

“…The observed significant concentration of multivalent cations in the anodic part of the migration cell inspired further, more basic investigations aimed at determining possible correlations between internal mobilities of cations in nonsymmetrical binary molten salt systems of the form MCl-LnCl 3 (M: alkali metal; Ln: rare earth metal) and composition of the melt, temperature and ionic radii of cations. So far, the group of five systems MCl-LnCl 3 (KCl-LnCl 3 (Ln: La [4], Nd [5], Dy [6])) and MCl-NdCl 3 (M: Li [7], Na [8]) was investigated. It was suggested on the basis of results for three KCl-LnCl 3 systems [9] that internal mobility of lanthanide cations is in a simple, one-parameter relation with the mobility of Ln 3+ in pure molten LnCl 3 (b 0 Ln ) and equivalent fraction of LnCl 3 in molten alkali metal chloride (y Ln ) (see Eq.…”

Molecular Dynamics Study on the Adsorption Selectivity for Negative Elements in Aluminosilicates

“…For this purpose we have developed py rochemical processes [1] such as countercurrent elec tromigration [2] and electrowinning [3-71, as was proposed by the Argonne National Laboratory [8], In addition, we have estimated the enrichment degree and investigated the electrochemical behavior of Cs in molten alkali ternary chloride [9 -11] and fluoride [11] systems by both experiment and Molecular Dy namics (MD) simulation. These results lead to the conclusion that it is rather difficult to enrich and re cover Cs in these systems, although we demonstrated that one can recover La3+ [12], Nd3+ [13], and Dy3+ [14,15]. There are other candidates for processes to function as inorganic ion exchangers [16][17][18].…”

A Molecular Dynamics Simulation of the Transport Properties of Molten (La1/3, K)Cl

“…La 3+ [5], Dy 3+ [6], and Nd 3+ [7] in a chloride bath. We have also estimated the limitation of the enrichment degree in alkali chloride and fluoride ternary [8,9] and quaternary [10] melts by molecular dynamics (MD) simulation.…”