Eutectic KCl Research Articles

Electroanalytical Study of the Reduction of K 2WCl6 in Molten LiCl ‐ KCl Eutectic

The mechanism of the reduction of in molten eutectic was studied using cyclic voltammetry, chronopotentiometry, and controlled potential coulometry over a temperature range of 400 to 500°C and a concentration of 0.0005 to 0.005 mol/liter. A single irreversible wave attributed to the reduction of W(IV) to W(III) was observed. The experimental results further indicated the process to be diffusion controlled with and α ranging from 0.85 to 0.95. W(III) is soluble at 500°C and insoluble, but still electroactive, below 460°C.

Distribution of plutonium, americium, and several rare earth fission product elements between liquid cadmium and LiClKCl eutectic

Separation factors were measured that describe the partition between molten cadmium and molten LiClKCl eutectic of plutonium, americium, praseodymium, neodymium, cerium, lanthanum, gadolinium, dysprosium, and yttrium. The temperature range was 753–788 K, and the range of concentrations was that allowed by the sensitivity of the chemical analysis methods. Mean separation factors were derived for Am-Pu, Nd-Am, Nd-Pu, Nd-Pr, Gd-La, Dy-La, La-Ce, La-Nd, Y-La, and Y-Nd. Where previously published data were available, agreement was good. For convenience, the following series of separation factors relative to plutonium was derived by combining the measured separation factors: Pu, 1.00 (basis); Am, 1.54; Pr, 22.9; Nd, 23.4; Ce, 26; La, 70; Gd, 77; Dy, 270; Y, 3000. These data are used in calculating the distribution of the actinide and rare earth elements in the pyrochemical reprocessing of spent fuel from the Integral Fast Reactor.

Electrochemical Study of the Properties of Indium in the Fused LiCl ‐ KCl Eutectic

Solutions of In ions in molten eutectic at 450°C have been studied using voltammetry and chronopotentiometry. The indium oxidation states +1 and +3 have been shown to exist in solutions as well as in mixtures. Convolutional voltammetry and chronopotentiometry at a tungsten electrode in solutions were used as evidence that In(III) ion reduction occurred via two reversible steps. The first step, In(III)/In(I), involved two soluble species, with . The second step, In(I)/In(0), involved indium metal of constant activity, with. The reference electrolyte contained 0.75 mole per kg of eutectic mixture.

Solution growth of Bi-Sr-Ca-Cu-O compounds using alkali chlorides

Single crystal growth of Bi-Ca-Cu-O compounds using high-temperature solution methods has been studied. Bi-Sr-Ca-Cu-O thin plates were grown from KCl or KCl-NaCl eutectics maintained at 920 to 960°C. Single crystals were obtained by cleaving parallel to the plane of these plates. The electrical properties of the as-grown crystals strongly depended on the starting compositions. Crystals with T c of about 80 K were prepared using the composition BiSrCaCu 2O y .

Some Redox Reactions on Semiconducting Tin Oxide Electrodes in Molten LiCl ‐ KCl Eutectic at 450°C

The electrode reactions of Eu(III)/Eu(II), Cr(III)/Cr(II), Cu(II)/Cu(I), Fe(III)/Fe(II), and Pt(IV)/Pt(II) redox couples have been studied using cyclic voltammetry at n‐type semiconducting electrodes in molten eutectic at 450°C. The highly doped oxide electrode is a stable indicator electrode usable at anodic potentials up to chlorine evolution. The redox couples examined are reversible at the tin oxide electrode, indicating no effect of electron depletion on the electron transfer kinetics. Electron tunneling through the space charge barrier takes place more easily in the high temperature melt system. For the oxidation of Cu(I) and Pt(II), which do not show diffusion controlled current peaks, an adsorption effect due to anionic bridge formation on the oxide covered with adsorbed chloride has been suggested.

Effect of Moisture on the Chromium (III)‐Chromium (II) Electrode Reaction in Molten LiCl ‐ KCl Eutectic

The hydrolysis of chromium (III) in molten eutectic has been studied by varying the ratio of to vapor pressure in equilibrium with the melt using cyclic voltammetry at a glassy carbon indicator electrode. The initial process is a reversible hydrolysis to form an electroactive species, believed to be , followed by slower polymerization reactions culminating in the irreversible formation of an insoluble phase. Raising the temperature from 450° to 500°C causes the initial reversible hydrolysis to be less pronounced, and to increase the rate of the subsequent irreversible processes.

A Zinc Chlorine Molten Salt Cell

not Available.

Electrochemical Reduction of Cr(III) in Molten LiCl ‐ KCl Eutectic

The reduction of chromium (III) was studied in eutectic at 500°C by means of cyclic voltammetry. It has been shown to proceed via a two‐step process to the metal. The intermediate Cr(II) species reacts with the solvent anions to form an insoluble compound, . The pseudo first‐order rate constant for the chemical step is , while the heterogeneous rate constant for the charge transfer is . The diffusion coefficient of Cr+3 was determined to be at 500°C. No adsorption of any species present in solution was found to occur on the vitreous carbon working electrode.

Monolayer Formation in the Reduction of Nickel and Silver Ions from the LiCl ‐ KCl Eutectic

The deposition of nickel and silver on platinum from the eutectic at 400°C has been studied using the chronopotentiometric, cyclic voltammetric, and potential step techniques. An observed predeposition of nickel on platinum was observed to take place at 0.5V anodic to the equilibrium potential between nickel in bulk and the solution of its ions. The predeposition process was studied by an a‐c impedance method and delineated as the formation of an adsorbed monolayer. A similar but less well‐defined predeposition step was observed with silver at 0.1V anodic to the reversible potential. Notwithstanding the predeposition phenomena, diffusion coefficients for both metal ions were determined by each of the voltammetric techniques and found to be in reasonable agreement with each other and with previously reported values.

The Near-infrared Absorption Spectra of Lanthanide Chlorides Dissolved in Molten LiCl–NaCl–KCl Eutectic

Abstract Using a high temperature cell for molten salts, a spectrophotometric investigation in the near-infrated region form 0.8 to 2.6 μ and at temperatures from 400 to 800°C has been carried out with fourteen lanthanide chlorides dissolved in a LiCl–Nacl–KCl mixture of eutectic composition (49.0-17.3-33.7 mol%, m.p. 333°C. Praseodymium, neodymium, samarium, dysprosium, holmium, erbium, thulium and ytterbium have characteristic absorption bands in this region. Most of the near-infrated absorption bands of lanthanide chlorocomplexes have been compared to similar spectra obtained in molten nitrate media. However the several absorption bands have been found to be different in molten nitrate and chloride eutectics. Thus, the absorption bands of europium and terbium have been observed in nitrate, wheras their bands have not been found in chloride, and the absporption bands of praseodymium, samarium and holuium beyond the 1.4 μ range have been found to be located at different wavelengths. these solvent, for the ligand field affects the 4f-electronic energy levels of the above elements. The absorption peaks of lanthanide ions decrease as the teperature increases, partly due to the change in the concetration of the ions associated with the volume change. However, all the characteristic absorption bands of lanthanide in the near-infrared region have stable molar absorptivities at a constant temperature. These absorption bands can be used for the investigation of chemical constitution and electronic structure, for anlysis and for other purposes.

Electrical Conductance of the LiCl–KCl Eutectic Melt Containing Halides and Alkali Titanium Fluorides as Solutes

The electrical conductances over the temperature range 350 to 400 of the LiCl-KCl eutectic melt and solutions of NaCl, LiF, NaF, KF, Li/sub 2/TiF/sub 6/, Na/sub 2/TiF/sub 6/, and K/sub 2/TiF/sub 6/ in this melt are reported for the region of dilute concentrations of the solutes. A reduced total specific conductance is found on the addition of fluorides to the chloride eutectic. The decrease in totai conductance on the addition of the alkali titaaium fiuorides to the chloride melt is interpreted in light of the previous cryoscopic results as due to a primary dissociation with the formation of alkali fluoride and TiF/sub 4/ , the latter most probably existing as (TiF/sub 4/ Cl/sub 2/)/sup -2/ or some similar complex ion. (auth)

Cryoscopy of the LiCl–KCl Eutectic Melt Containing Alkali Halides and Alkali Titanium Fluorides as Solutes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCryoscopy of the LiCl–KCl Eutectic Melt Containing Alkali Halides and Alkali Titanium Fluorides as SolutesG. J. Janz, C. Solomons, H. J. Gardner, J. Goodkin, and C. T. BrownCite this: J. Phys. Chem. 1958, 62, 7, 823–826Publication Date (Print):July 1, 1958Publication History Published online1 May 2002Published inissue 1 July 1958https://doi.org/10.1021/j150565a013RIGHTS & PERMISSIONSArticle Views59Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (497 KB) Get e-Alerts

Heat of Fusion, Entropy of Fusion and Cryoscopic Constant of the LiCl–KCl Eutectic Mixture

Heat of Fusion, Entropy of Fusion and Cryoscopic Constant of the LiCl–KCl Eutectic Mixture