In order to better assess advantages of the ionic liquids with ethyl group at the position N-3 of the imidazolium cation, 1,3-diethylimidazolium bromide, 1-butyl-3-ethylimidazolium bromide, 1-hexyl-3-ethylimidazolium bromide and 1-octyl-3-ethylimidazolium bromide ionic liquids are synthesized and fully characterized by NMR, IR, and thermogravimetric measurements. All mentioned ionic liquids are obtained applying both, classical synthetic path, and also microwave assisted reaction approach respecting the main principles of green chemistry – energy consumption as well as reaction time reduction. Physicochemical properties of pure ionic liquids and nature of the interactions in aqueous solutions have been investigated measuring density, electrical conductivity, and viscosity over the whole composition range at different temperatures at atmospheric pressure. The effect of the alkyl chain length in on thermodynamic and transport properties is examined applying experimental techniques and molecular dynamic simulations. A possible application of these ionic liquids as novel electrolytes in different technological areas, corrosion inhibitors or new extractants is also examined.

A carbochlorination process of the modified titanium-bearing blast furnace slag in molten salts was proposed. Mixtures consisting of the slag and petrocoke were chlorinated using chlorine-nitrogen gases. Thermodynamic analysis of the reaction system showed that the main oxide components follow a thermodynamic chlorination ability order of CaO> MnO> FeO> MgO> TiO2> Al2O3> SiO2 at 976-1300 K. Effects of the composition of initial molten salts, reaction temperature, chlorine partial pressure and carbon content on the chlorination extent were examined. The proportion of potassium chloride and sodium chloride in a wide range of 1:1 to 1:5 had an insignificant effect on the chlorination extent. The chlorination extent increased by raising the temperature, chlorine partial pressure and carbon content, respectively. A high chlorination extent of 92.6% was attained with the carbon content of 12% and chlorine partial pressure of 60 kPa after 90 min of reaction at 800¡æ, which was verified in mineral phases by XRD. Variations of the concentration of main chlorides in the molten salts and their viscosity and surface tension with their use cycles were discussed.

Carbon hollow nanospheres and a few atomic layer nanosheets were prepared from organic polymer-NaN3 and Me2CO3-reductant mixtures using solid state combustion method. The structural properties and surface chemistry were characterized by nitrogen sorption at 77 K, transmission electron microscopy and Raman spectroscopy. The results showed that the obtained carbon possessed unique porous structure: mesopores with the size of 2 to 50 nm and macropores at 50~200 nm. Both of the shape and porous structure could be controlled by adjusting the initial mixture composition and the combustion temperature. The electrochemical performance was investigated by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy in 1-6M KOH. Analysis revealed that the combustion process could greatly enhance the capacitance and high meso/macro-porosity ensured high rate performance. Due to the highest meso/macro-porosity and high content of heteroatoms, such as O2 ( also N2) the combustion-derived carbon samples showed superior electrochemical performance: specific capacitance of 250F g-1 and capacitance retention of 70-75%.

Molten inorganic fluorides are materials with high potentialities in nuclear engineering field: Generation IV molten salt reactors, pyrochemical reprocessing, blanket material for the fusion reactor, separation technique of fluorination, etc. In fuel salt reprocessing different possible processes have been proposed for soluble fission products removals such as reductive extraction in liquid metal, electrowinning, low-pressure distillation or precipitation of oxides.
The distillation pyrochemical process is used to recover renewable salts from the salt wastes without salt loss and minimize the radioactive wastes. Based on the difference of vapor pressures between carrier salt and rare earth fluoride, distillation is convenient for such removal. In the present work, the feed material, consisting of alkali fluorides containing various rare earth species, are treated by low-pressure distillation which requires temperature from 700¡aC to 1000¡aC and pressure from 1Pa to 1000Pa. The experimental results are presented including inactive studies for pure alkali and FLiNaK eutectic salt distillation, feed material composition influence. The demonstration of distillation rates of several ten grams per hour for eutectic FLiNaK and rare earth mixtures were available by lab-scale thermo-gravimetric distillation system. Tests with the mixture give decontamination factor of rare earth higher than 1000. The recovery yield of salt is higher than 95 % for eutectic mixtures using a closed chamber distillation system. Low-pressure distillation development is still in progress as a large variety of technical challenges have to be solved. Future works will focus on the qualification of molten salt distillation for the whole composition domain of spent salts from MSR.

Direct reduction of TiO2 and ZrO2 by Mg has a potential to be the next-generation method of producing low-cost Ti and Zr metal powders. Many technological steps (especially the chlorination of oxides) do not have to be used when metal oxides are used as a raw material, and Mg is used as a reductant. The main challenge for producing Ti and Zr metals from corresponding oxides is relatively large concentration of oxygen that remain in the final metal powders. According to the literature reports more than 2.0 wt. % oxygen was always found in Ti(Zr) powders fabricated from the oxide precursors. The purpose of this work is to develop an alternative reduction process of oxide materials in order to synthesize Ti and Zr metals with low oxygen content. For this purpose, the reduction process was conducted under the combustion mode in an argon atmosphere. Moreover, different inorganic salts, such as CaCl2, MgCl2, Ca(OH)2 and KClO4 were added to the reaction mixture for affecting the morphology and chemical purity of Ti and Zr powders. It was found that some of these salts can effectively reduce the concentration of oxygen bellow 1.5 wt. %. The mechanism of oxygen reduction is discussed in regard to combustion chemistry and the nature of inorganic salt used in the experiments.

The boundaries of phase regions and 3D models of T-x-y diagrams of systems LiF-PuF3-RbF and EF-PuF3-RbF are simulated assembled using the schemes of mono- and invariant equilibria, which are compiled from the data of invariant reactions occurring in binary and ternary systems. The projection of all elements of phase diagrams into the Gibbs triangle divides it on two-, one- and zero-dimensional concentration fields. Models of T-x-y diagrams permit to consider all possible crystallization schemes in these systems and to define each microstructural element taking into account its origin. The characteristics of processes proceeding in the concentration fields can be analyzed with the help of diagrams of vertical mass balances, which show the increase or decrease of phases portions for each phase region. They also permit to compare the processes taking place in the different concentration fields and qualitatively show the cases in which some concentration fields differ by the schemes of phase reactions, but have the same microconstituents. Forecast of microconstituents for the concentration fields of varying dimension allows to plan and reduce the further experimental research.
This work has been performed under the program of fundamental research SB RAS (project 0336-2014-0003) and was partially supported by the Russian Foundation for Basic Research (projects 14-08-00453, 15-43-04304).

At the present time, molten salt mixtures containing cadmium dichloride are widely used as reaction media for synthesizing nuclear materials as well as for obtaining semiconducting thin films.
In the present work, the electrical conductivity of 14 compositions of (3LiCl-2KCl) - CdCl2 mixtures was measured with increments of ~ 10 mol.% CdCl2 using capillary quartz cells with platinum electrodes. The concentration range of 0–10% has been studied in more detail because it is presumably the most important for practical purposes. In order to determine the onset of the crystallization temperature, the lower temperature of the measurements was set at 5–10 degrees below the liquidus temperature for all compositions. This allowed the liquidus line of the system to be plotted based on conductivity data. The upper temperature was 880-900 K. Molar conductivity and activation energy calculations were carried out. These showed that the molar conductivity of molten CdCl2 (106.6 S·cm2/mol) is greater than the conductivity of LiCl-KCl (84.74 S·cm2/mol at 600 0C) and that the activation energy gradually decreases from 13.8 kJ/mol (LiCl-KCl) to 10.2 kJ/mol (CdCl2), with a blurred broad maximum around 60 mol.% CdCl2 (600 0C).
The results were interpreted in terms of coexistence and mutual influence of the complexes formed by the Li+ and Cd2+ cations.
This work was supported by the Ministry of Education and Science of the Russian Federation, project No. 14.607.21.0084 (RFMEFI60714X0084).

In quartz capillary type cells of two different designs the electrical conductivity of molten CdCl2 was measured across a wide temperature range (∆T = 628 K), from 846 K to as high as 1474 K (when the vapor pressure reached 1.5 MPa), which is by 273 K higher than the temperature previously achieved.
In the temperature range of 846-1474 K the electrical conductivity of molten CdCl2 increases from 1.886 to 2.891 S/cm. At the same time, the conductivity growth rate gradually slows down and the conductivity activation energy decreases from ~ 8.9 to ~ 3.3 kJ/mol. It is evident that at higher temperatures a maximum conductivity will be reached, after which the electrical conductivity begins to decrease. In our opinion, about 100 degrees remain to reach the conductivity maximum.
By combining our and Grantham’s data, we evaluated the effect of the metallic cadmium additions on the electrical conductivity of molten CdCl2. Surprisingly, we obtained an alternating result. The addition of 10.1 at% Cd to molten CdCl2 changes its conductivity as follows: -3.1% (873 K), -1.1% (973 K), ~ 0% (1083 K), + 0.7% (1173 K), + 1.7% (1273 K), + 3.7% (1373 K) and + 9.1% (1473 K).
Some conclusions regarding the structural changes in the CdCl2 and CdCl2 - Cd melts with temperature were drawn.
This work was supported by the Ministry of Education and Science of the Russian Federation, project No. 14.607.21.0084 (RFMEFI60714X0084).
Keywords: Molten CdCl2, CdCl2 - Cd solutions, electrical conductivity.

The electrolytic extraction and refining of zirconium and hafnium processes need data on the electrical conductivity of ZrCl4 and HfCl4 solutions in molten alkali chlorides. In general, these systems are characterized by a high saturated vapor pressure. However, there are two concentration "windows" (the high temperature window, 0-30 mol % MCl4, and the low temperature one, 55-70 mol % MCl4) applicable for technical purposes because the vapor pressure of these melts is below the atmospheric one.
In this work the electrical conductivity of ZrCl4 solutions in molten LiCl, NaCl, KCl, CsCl and NaCl-KCl (1:1) and HfCl4 solutions in molten KCl were measured for the first time. The measurements were carried out using quartz U-shaped capillary type cells with Pt- or W-electrodes at the concentrations of 0-30 mol % MCl4 and temperatures 600-850 0C.
It was found that conductivity of the ionic melts ranges from 0.6 to 6 S/cm, increases with increasing the temperature, decreases with increasing MCl4 concentration and reduces from Li+ to Cs+, depending on the salt-solvent cation size.
High volatile molecular ZrCl4 and HfCl4 are held in molten alkali chlorides environment as a part of strong complex anions ZrCl62- and HfCl62-.
The established regularities in the electrical conductivity changes are discussed.
This work was supported by the Ministry of Education and Science of the Russian Federation, project No. 14.607.21.0084 (RFMEFI60714X0084).
Keywords: Electrical conductivity, melts, alkali metal chloride, ZrCl4 and HfCl4 solutions.

The aim of the present study is electrodeposition of high-purity silicon onto graphite substrate as adherent coating and investigation of deposit morphology depending on the conditions of electrodeposition. Methods: cyclic voltammetry, potentio- and galvanostatic electrolysis, X-ray phase analysis, optical and scanning electron microscopy. For continuous silicon coating obtaining, K2SiF6 concentration was maintained within 8-14 mol% range at a constant potential. Electrodeposition was carried out at potential -0,75±0,05 V versus Pt or Ag reference electrode. Current strength varied within 10-100 mA/cm2 range. During the deposition, uniform continuous silica deposits were obtained. Silicon coatings containing grains of wedge shape up to 1 mm thick were obtained with the duration of electrolysis 5-6 hours. Electrodeposited silicon was easily separatable from the graphite base. The cross-section of deposits indicates nodular or dendritic growth up to a few millimeters on the surface of the main adherent layer of silicon. The grain size was about 250 nm. Larger grains (up to 750 nm in diameter) were formed with the electrolysis duration more than 5-6 hours. X-ray phase analysis shows only the polycrystalline silicon presence in the deposit. In addition, the electronic microprobe studies and analysis of X-rays scattering energy have revealed no impurities. However, levels of Li, Cr, Ni, Fe, Cu, Ag, Mn, Pb, and Al impurities up to 0.02% were detected by emission spectral analysis. The most common impurities are Cu, Fe, Ni, and Ag, but the overall level of their concentrations cannot impact significantly the performance of solar cells. Deposits purity degree was in general over 99.99%. Four-probe measurement method showed differences in specific resistivity at different places of electrodeposited silicon. At room temperature, experimental resistance values for silicon electrodeposited from this system was always greater than 1 ohm•cm.<br />Keywords: silicon, coating, electrodeposition, fluoride melt.

Electrochemical technology is an important procedure for processing spent nuclear fuel due to its potential advantages: compactness, compatibility with diverse fuel types, and ability to produce low purity products which benefit to non-proliferation. In this work, the electrochemical behaviors of Ans and Lns in LiF-NaF-KF (FLiNaK£¬46.5-11.5-42.0 mol%) were investigated, based on which the electrodeposition experiments were conducted.
The experimental results indicated that U4+ was reduced to metallic uranium through two steps: U4+ was first reduced to U3+ at -1.42 V (vs Ni2+/Ni) followed by U3+ reduction to U0 at -1.82 V (vs Ni2+/Ni); In contrast, reduction of Th4+ to Th0 was a simple four-electron transfer mechanism occurring at -1.80 V (vs Ni2+/Ni). The electrolysis experiments were performed in FLiNaK-UF4 and FLiNaK-ThF4 eutectic salts. Metallic uranium and UO2 were the major products on Ni cathode when FLiNaK-UF4 was electrolyzed, which contain more than 30wt% uranium; the electrolysis of FLiNaK-ThF4 revealed the formation of metallic thorium on Pt electrode in spite of the relatively low yield and separation efficiency. The experimental results show the feasibility for the recovery of U and Th from fluoride molten salt using the electrochemical method.
The electrochemical behaviors of several Lns were also studied. The results show that the reduction of Y3+, Gd3+, and Nd3+ in FLiNaK exhibits three electrons transfer from Ln3+ to Ln0, but in the case of Sm3+ and Eu3+, only one electron transfer process was observed, which indicates that the reduction from Sm3+¡uSm2+ and Eu3¡uEu2+ occurs.

In this work are presented the results of high-temperature electrochemical synthesis of intermetallic compounds of holmium and of metals of the iron group powders. The principal possibility of synthesis of holmium and nickel (cobalt, iron) intermetallic compounds electrochemically from chloride melt is showed.
Objective: Development of the electrochemical method of producing nanopowders of intermetallic compounds of holmium and Nickel (Cobalt, Iron) in halide melts.
High-temperature electrochemical synthesis of intermetallides of holmium and Nickel was carried out in a galvanostatic mode in the melt KCl-NaCl-HoCl3-NiCl2.
Identification and study of the obtained samples were carried out by the following methods:
• X-ray elemental analysis elemental analyzer SPECTROSCAN MACS-GV (Spa «device»);
• X-ray method– x-ray diffractometer DRON-6 (SPE «Burevestnik»), x-ray diffractometer D2 Phazer;
• Diffraction analysis – laser diffraction analyzer FritschAnalysette-22 (Nanotech);
• Scanning electron microscopy – scanning electron microscope VEGA3 LMH(TESCAN) with energodispersive x-ray microanalyzer (OXFORD).
Our investigation showed the main potentiality of holmium and nickel (cobalt, iron) intermetallic compounds synthesis by electrolysis of halide melts;
The X-Ray phase analysis and laser diffraction particle size analysis of the synthesized powders showed the presence of different stable phases of the alloys with cobalt and holmium: IiÑi5, IiÑi3, Ii2Ñi17 ;Ohe results of X-ray phase analysis indicated the presence of intermetallic compounds stable phases of holmium with iron: HoFe2 and HoFe5.Ii2Ñi17 .

The electrochemistry of UF4 in LiCl-KCl eutectic on tungsten electrode was studied at 723K. Both cyclic and square wave voltammetry showed that U4+ was reduced to U0 via two steps. Firstly, U4+ underwent a reversible and diffusion controlled reduction to form U3+ followed by a subsequent three-electron reduction to metallic uranium on tungsten electrode around -1.6V(vs Ag/AgCl, 5mol%), the latter of which is quasi reversible due to the negative shift of the reduction potential as the sweep rate increases. Cyclic voltammetry and chronopotentiometry were employed to determine the diffusion coefficients both U3+ and U4+ in the presence of F- ions in LiCl-KCl eutectic, which indicates the influence of F- on the diffusion process of uranium cations in comparison to the previously published data obtained in chloride molten salts. Based on the above experimental results, separation of uranium fluoride from LiCl-KCl molten salt was carried out using pulse current electrolysis, which revealed that up to 98% uranium could be removed from molten salt. Our experimental investigation demonstrates the possibility of direct separation of UF4 from LiCl-KCl molten salt by using electrochemical methods.

Titanium (Ti) is attractive for using as protective coatings due to its excellent corrosion resistance. Ionic liquids (ILs) have been used to electrodeposit Ti for a long time, but only trace Ti has been obtained until now. Here Ti was electrodeposited in the 1-isobutyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([BisoMPyrr]NTf2) IL containing 0.2M TiCl4 onto the Ag substrate. X-ray Diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were utilized for characterization of the electrodeposits. It was found that only TiCl3 and TiO2 were detected. Electrochemical behavior of Ti(IV)was studied by cyclic voltammetry (CV), showing the reduction of Ti(IV) in [BisoMPyrr]NTf2 was a little complex. To understand the reduction process, ultraviolet-visible (UV-Vis) spectroscopy was used for identification of the Ti species in the electrolyte, and only Ti(IV) was detected before the electrolyte was used. However, there is no Ti(IV) any longer in the solution after electrodeposition and the absorption peak of other Ti species is not obtained. From the above analysis, it could be seen that it was very difficult to directly reduce Ti(IV) completely to the metal in this IL and the detected TiO2 should be from the oxidation of trace Ti deposit.
Acknowledgment: The authors gratefully acknowledge the financial support from the National Basic Research Program of China (2013CB632606), General Program Youth of National Natural Science Foundation of China (51404230), and Director Fund Product of Research Center for Eco-Environmental science of Shenyang Normal University (EERC-P-201503)

Eutectic melt composition and temperature in the subsystem LiF-NaF-NaNdF4(R2) were found by the isopleths of ternary system Li,Na,Nd||F investigation. Eutectic melt solidifies according to the phase reaction scheme LE->LiF+NaF+R2. Methods of differential thermal and X-ray analysis, as well as the high-temperature x-ray diffractometry, were used. Eutectic melt has been appeared during the salt mixture heating at 580 C and consists of 33 mole % NaF, 53 mole % LiF and 14 mole % NdF3. It resembles the “heterogeneous” liquid and includes the mixtures of microgroupings with the different cationic ratios, where fluoride anions do not form a homogeneous matrix. Analysis of the eutectic melt structure is based on the models derived from data of high-temperature x-ray diffractometry. Modeling of melt structure was solved by the reverse Monte Carlo method. Coordination number ZNd(F)>6 depends on temperature, demonstrating in favor of polyhedron’s spatial inhomogeneity. It is difficult to establish the form of this coordinating polyhedron in the melt because the structural parameters are defined clearly enough. Coordination number ZF(F)~7-8. Neodymium cations do not form locally ordered centres with the attached thereto fluoride polyhedrons containing the atoms of sodium or lithium inside. Within the crystal NdF3 six F-F links have the distances 2,46-2,66 A, and other six F-F links have the distances 3,61-3,89 A. In the crystal NaNdF4 5 RF-F distances are equal 2,82 A and 2 RF-F distances are equal 3,71 A. This work has been performed under the program of fundamental research SB RAS (project 0336-2014-0003) and was partially supported by the Russian Foundation for Basic Research (projects 14-08-00453, 15-43-04304).

Molten salt frozen-wall is a means for protecting the metallic walls from corrosion by a layer of frozen salt during the pyroprocessing of spent fuel, especially in the process of Fluoride Volatility. The frozen-wall is formed and maintained by controlling the radial temperature gradient, the internal heat source and outer wall cooling are two key factors. In our home-built experimental equipment£¬the research on the formation and controlling of molten salt frozen-wall was carried out by adopting Nitrate Molten Salt (m.p. 142¡æ) and Fluoride Molten Salt(m.p. 454¡æ).The outer wall of test tank was cooled by heat transfer oil or compressed air. The formed frozen-wall is a uniform layer, attaching to the metallic surface tightly. The thickness could be changed from several millimeters to centimeters and it could be figured out by the measured radial gradient temperature. The frozen-wall could reach to static equilibrium by controlling the heat transfer rate. During the period of static equilibrium, the temperature gradient and the thickness of frozen-wall were constant. We also simulated the real application scenarios to test the operation parameters and get some good results. On the other hand, solidification and sustainability characteristics of frozen-wall are analyzed based on the obtained numerical analysis model. Analytical solutions for finding the interface locations at various time steps are obtained and validated by experiments. All the research results will promote the applications of molten salt frozen-wall technology during the pyroprocessing of spent fuel.

The purpose of this work was the synthesis of heat resistant chromium disilicide nanocrystalline powders, single crystals, and coatings.<br />CrSi2 as the nanocrystalline powder was synthesized by co-reducing of anhydrous CrCl3 and Na2SiF6 with Na.<br />Single crystals were obtained by solution growth method with molten Sn-Zn (in weight ratio 1:10) as a flux. Cr and Si powder 99.9% purity in an atomic ratio 1:2 were added to Sn-Zn melt in weight ratio 1:10.<br />CrSi2 coatings were obtained by currentless deposition of Si onto pure chromium substrate in the molten KCl-NaCl-NaF-Na2SiF6-Si system.<br />TGA and DSC results show that the highest oxidation resistance in the air has nanocrystalline CrSi2 powders (800 ºC). Single crystals and coatings were resistant up to 700 ºC. A slight increase of samples weight (from 4,6% to 6,8%) was found. Subsequently, the protective oxide layer of SiO2 was formed on samples surface. Obtained values of temperature resistance for nanocrystalline powders, single crystals, and coatings were different. It can be related to size and morphology of synthesized samples, and also with the method of product obtaining. Due to high oxidation resistance, obtained samples could be used as heat resistant details and coating for devices working at elevated temperatures.<br />Keywords: chromium disilicide, X-ray diffraction, differential thermogravimetric analysis, oxidation resistance.

Ionosilicas, defined as silica based materials containing covalently anchored ionic groups [1], recently emerged as a new family of functional materials. Ionosilicas combine high porosity, regular architecture on the mesoscopic level with an unmatched chemical versatility, induced by the high variability and the high number of incorporated ionic species. Due to their mixed ionic-mineral nature, ionosilicas are situated at the interface of ionic liquids and silica hybrid materials.
The first part of this talk will focus on the synthesis of structured ionosilica mesophases. Ionosilicas are obtained under very mild reaction conditions via template directed hydrolysis-polycondensation reactions starting from trialkoxysilylated ionic precursors [2,3]. The formation of structured ionosilica mesophases can only be achieved from suitable surfactant-precursor ion pairs. This approach is particularly appealing as both precursor and surfactant can be modulated, thus allowing a control over chemical constitution and architecture of the formed materials.
Ionosilicas can be considered as heterogenized and porous ionic liquid phases. They exhibit tunable interfacial properties in terms of hydrophilicity and water affinity [4]. Ionosilicas represent a real alternative for applications in catalysis and separation. This feature will be illustrated by the unique properties in ion exchange. Ionosilicas efficiently trap anionic metal complexes [5], halides [6] and drugs [7] and therefore have great potential for applications in fields as different as medicine, water treatment or the nuclear fuel management.
In summary, ionosilicas represent a very particular class of functional silica based materials displaying unique chemical and physico-chemical properties, together with remarkable surface properties. For this reason, ionosilicas have an outstanding position in the area of silica based materials and are more than simple silica supported ionic liquids.

This paper presents results of investigations of liquidus temperature and solidus temperature of LaF3-LiF molten salts in various compositions which were determined by dynamic thermal analysis. According to the data of liquidus temperature, the structural ions of LaF3-LiF molten salts were studied by the cryoscopic method and the results were compared with previous similar research on the LiF-NdF3 system. The comparisons showed that the phase diagram of LiF-LaF3 (LaF3=0-40% mole) was reliable. LaF4- was identified as the most possible La-F ion in LaF3-LiF molten salts in which LaF3 mole fraction was less than 15%. As mentioned above, in REF3-LiF (RE=La, Nd) molten salts, the anions were F- and REF4-, and Li+ was the only cation.

Ferrotitanium alloy is prepared by either melting of metallic iron and titanium with predetermined ratio or thermite process from ilmenite ore with Al powder as a reducing agent. The former could produce higher purity ferrotitanium than the latter since part of aluminum is contaminated as a titanium aluminide during the combustion reaction. However, the thermite process occupies significant portion of ferrotitanium production because ilmenite is able to be directly utilized without complicate chemical treatment. In this study electroreduction process was used to produce ferrotitanium in LiCl-Li2O electrolyte which is relatively low temperature molten salt. In this electrochemical reduction process at low temperature of 625 ◦C, ilmenite minerals at the cathode reduced to ferrotitanium alloy through several steps. The reduction step involved the exfoliation of ilmenite powder into flake, simultaneous iron oxide reduction and formation of ferrotitanium alloy with titanium oxide reduction. The reduction ratio of ilmenite to ferrotitanium alloy found to be more than 99% and closed recycle of Li2O was confirmed by the observation of its concentration monitoring in the electrolyte. The reduction mechanism was verified by using electrochemical analysis, such as SEM, EDX and XRD.

All LnX3-MX binary systems (M = Li, Na, K, Rb, Cs; Ln = lanthanide; X = halide) are characterized by negative enthalpies of mixing. The molar mixing enthalpy exhibits a minimum shifted towards the alkali halide-rich composition and located in the vicinity of x(LnX3) ≈ 0.3-0.4. The alkali metal ionic radius influences both the mixing enthalpy magnitude as well as its minimum location. The smaller the alkali metal ionic radius, the smaller the mixing enthalpy absolute value and the minimum more shifted towards the alkali bromide-rich composition. The comparison of different LnX3-MX binary systems (Ln = lanthanide, X = Cl, Br, I) showed that mixing enthalpy also depends on lanthanide and halide ionic radii. Its absolute value increases reversely with lanthanide and halide ionic radii. In all the LnX3-MX binary systems, a negative value of interaction parameter λ is observed, λ representing the energetic asymmetry of the melts under investigation. Its absolute value increases significantly with the ionic radius of alkali metal cation. All systems exhibit more negative values of the interaction parameter in the alkali halide-rich compositions. The nature of the relationship between the interaction parameter and composition depends on the alkali metal cation. In the systems containing lithium and sodium halides, this dependence is practically linear. Starting from potassium halide, a broad minimum occurs at a lanthanide halide molar fraction x(LnX3) of about 0.2-0.3. This minimum can be undoubtedly ascribed to the formation of LnX63- octahedral complexes in the related systems.

Pickling treatment step is performed to remove impurities and oxide film on the cladding surface in a nuclear fuel manufacturing process. Waste acid solution occurring in this process has been discarded by doing neutralization treatment, and a large amount of Zirconium are dissolved in this solution. Precipitation compound of spent acid solution occurred in the process can be recycled by recovering as pure Zirconium and Zirconium alloys such as Cu-Zr using molten salt electro-winning method. Molten salt electro-winning process is a eco-friendly process, compared with the conventional rare metals aqueous metallurgical technology, because of utilizing an oxidation-reduction potential of the metal. Through this process, the Zirconium present in the pickling solution can be recovered as high purity metals 99% or more and reused for the manufacturing the cladding tube. It is also possible to use it as the form of Master alloys in general industry. Thus, it is expected to significantly reduce the manufacturing cost of the metal and the alloy by increasing the existing Zirconium scrap recycling rate. So, it has a technical importance to predict the electrodeposition behavior of Zirconium using the molten salt electro-winning technology for scale up. In this study, therefore, the composition of the Cu-Zr alloy depending on the position of the electrode was anticipated and calculated by using COMSOL Multiphysics simulation code.

Solvionic S.A. is a SME specialized in the synthesis, production and supplying of ionic liquids. Since its creation in 2003, a significant part of our activities is devoted to the research and development of new materials and processes based on their use.
Our presentation will be devoted to the description of our products (ionic liquids and polymerizable ionic liquids), their properties, the way they are produced as well as their potential applications.
Some examples of new materials based on ionic liquids as a component itself or as a template or solvent support will be given. Their potential applications will be given through the description of R&D projects. We will show how the use of ionic liquids can lead to new products in several fields such as electrochemical energy storage, surface treatments, advanced materials, etc.

The Pebble-Bed Fluoride-Salt Cooled High Temperature Reactor (PB-FHR) is an advanced nuclear reactor concept design that combines high temperature and low pressure fluoride salt coolants with solid fuel elements containing encapsulated TRISO fuel particles. Compared to current commercial nuclear power plants operating with coolant temperature under ~ 400 °C or below, which ends up running steam turbines with cycle efficiency below ~34%, coolant temperature in FHR is in the range of 600 °C – 700 °C with high power conversion efficiency and power peaking capability by using an open-Brayton cycle can be achieved. This design takes advantage of the inherent and passive safety features enabled by heat transfer and chemical properties of fluoride salt and robust particle fuel. Working with fluoride salt has big challenges, such as, fluoride salts exhibit high melting point ~450 °C, salt redox potential shows significant effects on coolant performance (corrosion, neutronic/thermal properties, etc.), interaction between salt and graphite fuel particle tends to affect fuel pebble integrity and potentially change salt redox potential. This article presents the research work pertaining to fluoride salt behavior with application to FHR design in University of Wisconsin-Madison, including a salt freezing experiment to investigate the solidification phenomena of fluoride salts, salt chemistry and electro-chemistry experiment to study applicability of current electrochemistry techniques to high temperature molten fluoride salts, and an experiment to study salt intrusion into graphite under various conditions (pressure, temperature, graphite surface finish). In the end, discussion about how the current research in UW-Madison will contribute to fluoride salt study for FHR design is presented.

We have developed an innovative technology for extraction of non-ferrous, rare and precious metals from complex, hard mineral, man-made and recycled materials. Technology is based on the combined use of electrochemical reactions in the amount for one reactor producing the leaching agent, and the reaction metal extraction into solution. The source of sulfur leaching agents in the alkaline solution used sulfur graphite composite electrode. Experimental data on the parameters of metal leaching, from complex raw materials, on the characteristics of solutions (pH, electrical conductivity) was obtained. As was evidenced how these parameters change using sulfur-graphite electrode as an anode and as a cathode. Leaching was performed at the different initial concentration of alkali in solution. The changes in the parameters (pH, conductivity of solutions, etc.) in the leaching of various materials, using sulfur-graphite electrode, was investigated. Application of sulfur-graphite electrode as a cathode and an anode led to the same results of sodium metal formation into solution, results that in this case may be increased by selective extraction of metals in solution.

The lanthanide halides and their mixtures with alkali metal halides play a very important role in many modern technologies. They are extensively used in optical and scintillation devices [1] and are attractive components for doses in high-intensity discharge lamps and new highly efficient light sources with energy saving features, lasers, etc.[2]. The wide band gap materials like fluorides and other halides co-doped by lanthanide ions provide valuable insight into many aspects of luminescence centers and have wide applications [3]. <br />Such wide applications of these compounds requires knowledge of their structural, physicochemical, and, in particular, their thermodynamic properties. In connection with our research program on lanthanide halides and their systems with alkali metal halides [4], we have investigated the binary system of neodymium(III) bromide with potassium bromide. <br />The only literature information on this system was the phase diagram reported, as a graphic, by Blachnik and Jaeger-Kasper [5]. The phase equilibrium in the NdBr3-KBr binary system was established in the present work by differential scanning calorimetry (SETARAM LABSYS evo TG/DSC 1600). <br />This system includes the K3NdBr6, K2NdBr5 and KNd2Br7 compounds and three eutectics located at the NdBr3 molar fractions x = 0.192 (T = 849 K), x = 0.532 (T = 754 K) and x = 0.689 (T = 802 K), respectively. K3NdBr6 undergoes a solid-solid phase transition at 680 K and melts congruently at 918 K. K2NdBr5 melts incongruently at 822 K with the formation of solid K3NdBr6 and finally KNd2Br7 melts congruently at 814 K. <br />The electrical conductivity of NdBr3-KBr liquid mixtures was measured over the whole composition range and a wide temperature range. <br />References:<br />[1] V.B. Motalov, M.F. Butman, L.S. Kudin, K.W. Kramer, L. Rycerz, M. Gaune-Escard, J. Mol. Liq. 142 (2008) 78-82.<br />[2] T. Markus, U. Nieman, K. Hilpert, J. Phys. Chem. Solids 66 (2005) 372-375.[3] J. Cybinska, J. Legendziewicz, G. Boulon, A. Bensalah, G. Meyer, Opt. Mater. 28 (2006) 41-52.<br />[4] I. Chojnacka, L. Rycerz, M. Berkani, M. Gaune-Escard, Journal of Alloys and Compounds 582 (2014) 505-510. <br />[5] R. Blachnik and A. Jaeger-Kasper, Z. Anorg. Allg. Chem., 461 (1980) 74-86.

Under cooling from the critical temperature Tcr to T0 = Tm/2 (Tm - melting point) actual processes of solidification are slowed down by about 20 orders of magnitude. The characteristic time &#61556; (e.g., structure relaxation time according to Maxwell), increases from about the oscillation period of the atom (~10-13 s) to a year and extends beyond the measuring capability. Viscosity increases from about 10-4 Pa·s to 1016 Pa·s, the diffusion coefficient decreases from 10-7 to 10-27 m2/s, etc.
At the classical motion of atoms (molecules), all our molecular dynamics simulations gave liquid-like values of &#61556;&#61484;&#61472;&#61544;&#61484;&#61472;D even if the temperature was low enough, T << Tm [1, 2]. The rate of processes from Tcr to T0 slows down not 20, but approximately 2 orders of magnitude only, as in the gases. The motion of particle remains a drift and activationless (EA < RT), no any tendency to solidification is observed. The results of the other authors are similar.
The real stiffness of the structure and solidification are obtained only if the quantum “freezing” of atomic freedom degrees is taken into account in the computer model. In the crystals, not less than 10% of the atoms are “frozen” ones. They are at zero energy level, i.e. have zero energy. If they are considered to be fixed, the model yields the real solidification and the real stiffness of the lattice.
Literature
1. Pavlov V., Potapov A. Hardness of a crystal lattice as a consequence of quantum “freezing” of atomic degrees of freedom. Z. Naturforsch. (2008) 63A, S.329-338.
2. Pavlov V.V. On the crisis of the kinetic theory of liquids and solidification. Ekaterinburg, USMU, 1997, 394 p. // Website: Pavlovvalery.ru

Because of severe experimental hindrances, the knowledge on molten fluoride salts chemistry has long remained limited to few experimental approaches. Molten fluorides mixtures can be strongly organized at unusually long distances due to the predominance of coulombic interactions and described by the formation of an intermediate range ordering. The description of free fluorine content evolution is also of primary importance for a better understanding of their properties. NMR spectroscopy is one of the techniques able to provide such information. Nevertheless, these systems cumulate high temperatures (from 500 K to 1800 K), corrosive properties towards most of the materials and sensitivity to moisture and oxygen making the NMR experiment a real challenge. We have already shown that thanks to the specific design of the sample container and of the heating system it was possible to obtain NMR spectra in the melt and to follow the evolution of the local structure with temperature and composition up to 1500°C. The signal position, or the isotropic chemical shift, is the weighted averaged chemical shift of the different components in the melt. Knowing the chemical shift of the individual species, it is possible to define their proportions depending on the composition, except when the number of individual species becomes too high compare with the equilibrium equations. We are now able to calculate directly the chemical shifts corresponding to the system, thanks to the coupling between molecular dynamic calculations and theoretical approach of the NMR chemical shifts DFT calculations.
This new step towards a better description of the speciation in such molten salts will provide a new capability to determine the physical and chemical properties of molten fluorides.

Promising classes of nanostructured carbon-based materials varied from spherical empty and endohedral fullerenes encapsulating metal atoms to carbon nanotubes and aggregated graphene sheets have attracted a large scientific and technological interest because of unique chemical, mechanical and electrical properties and high perspectives of applications in high-tech devices.
The first works of electrochemical production of carbon materials from molten salts were carried out in the 1960s in the Institute of General and Inorganic Chemistry [1, 2], but structural and morphological properties of obtained products were not studied because of absent of high resolution electron microscopy devices.
This work is devoted to study of structural and morphological properties of electrolytic carbon produced by electrolysis of salt melts (NaCl-KCl (1:1), NaCl-KCl-CsCl (0.3:0.245:0.455), saturated by CO2 gas under excessive pressure up to 1,5 MPa in temperature range 500-800oC on metal cathodes. The experimental details of the electrolytic synthesis are published in [3]. The produced powders were characterized by XRD analysis, TEM, SEM and Raman spectroscopy. It was found that products contain carbon nanosized particles of different forms and structures: blocks formed by small amorphous carbon particles, carbon nanotube-like objects (CNTLO) of curved form and nanofibres. Small crystalline particles of metallic and salt phases, those are situated on the surface, inside and on the ends of the tubes, have been found in carbon deposits. The origin of the impurities may be the result of the interaction of cathode (Pt) and reactor (stainless steel) material with the carbon phase that is formed and of poor powder cleaning. Correlation between product structure and yield against the electrolysis conditions and regimes were established.

The structure, thermophysical and electrochemical properties of copper ionic liquid analogous compared with choline chloride (ChCl)-urea is reported. The structure of the ionic liquid analogous is preliminarily investigated by Fourier transform infrared spectroscopy. The physical properties of the ionic liquid such as density, speed of sound refractive index, electrical conductivity, molar conductivity were measured as the function of temperature and composition. We used the following compositions: ChCl-Urea (1:2)M, ChCl-Urea-CuCl (1:2:0.05)M , ChCl-Urea-CuCl (1:2:0.1)M and ChCl-Urea-CuCl2 (1:2:0.1)M . Using the measured data of density, speed of sound, and refractive index, the following thermodynamical parameters such as isentropic or adiabatic compressibility coefficient and molar refractivity have been computed with the standard relations. Calculated values of the acoustic impedance adiabatic compressibility, space filling factor , specific refraction and relaxation strength at various temperatures were calculated for the studied ionic liquids. Also were determined the coefficients of thermal expansion, molecular volume, standard entropy and lattice energy at different temperatures. Fitting parameters, correlation coefficient R2 obtained for density, the speed of sound and refractive index along with the absolute average percentage deviation AAD % are reported for all studied LIs. Calculated values of refractive index for the studied ionic liquids, using the relation between refractive index and density, were also correlated from several empirical equations. The electrical conductivity and correlations for its temperature dependence were established and discussed in terms of Arrhenius theory. The electrochemical potential window of ChCl-urea and the electrochemical behaviour of ChCl-urea-CuCl/CuCl2 were also determined by cyclic voltammetry.
Keywords: thermodynamics of ionic liquids (ionic liquids, FTIR, density, speed of sound, refractive index, conductivity, correlation)

The aim of the present work is the realization of high-temperature electrochemical synthesis of VI-B group metals silicides by electrolysis of halide-oxide melts.<br />Methods: cyclic voltammetry, potentio- and galvanostatic electrolysis, X-ray phase analysis.<br />Preliminary experiments on electrolysis of chromium (molybdenum, tungsten) and silicon containing melts make it possible to generalize findings into the following sequence of steps for electrosynthesis of silicides of molybdenum and tungsten: I—deposition of more electropositive metals (molybdenum or tungsten); II—deposition of the second component-silicon-on the surface of Mo or W deposited earlier; III—silicon reaction diffusion into the depth of metal-salt “pear” with formation of silicides phases of different compositions up to higher silicides. <br />Unlike high-temperature electrochemical synthesis of silicides of molybdenum and tungsten, during this synthesis, one of the components are not deposited in elementary form but rather in oxide form, and the other act as a reducing agent of the mentioned oxide to form binary compounds.<br />Thus, during electrolysis of chromium (molybdenum, tungsten) and silicon containing melts, high temperature electrochemical synthesis of powders of silicides of chromium, molybdenum, and tungsten was implemented.<br />Keywords: Chromium, molybdenum, tungsten, silicides, synthesis, dispersed powders, ionic melts.

In the present work results of electrochemical synthesis of tungsten silicide in halide-oxide melts are given. Optimum conditions of carrying out electrosynthesis of WSi2 are found: structure of melts, electrolysis regime and electrolysis temperature. The principal possibility of synthesis of tungsten silicide by electrolysis halide oxide melts was found.

One of the perspective ways to develop the traditional Hall-Heroult technology is to introduce new, inert electrode materials. Titanium diboride has been considered to be the most perspective cathode material for the last decades, due to its following properties:
i. good electric conductivity,
ii. perfect wettability by aluminum under cryolite,
iii. protection sodium expansion to graphite,
iv. high corrosion resistance toward liquid aluminum and cryolite melt, etc.
The objective of this work was to study and to develop a method for electrochemical synthesis of titanium diboride protective coherent coating from cryolite-alumina melts contain boron and titanium oxides.
The chemical and electrochemical behavior of titanium and boron oxides in cryolite -alumina melts were studied by cyclic voltammetry in air and argon atmosphere at 1273 K. Titanium diboride coherent coatings were deposited by electrochemical synthesis from the molten salts system Na3AlF6-Al4B2O9-CaTiO3 onto graphite.

Graphene-based nanomaterials (NM) such as graphene and carbon nanotubes (CNT’s), both single-walled (SWCNT’s) and multi-walled (MWCNT’s) are evoking a new industrial revolution due to the requirement for denser and stronger materials with higher surface areas, which makes them useful for electronics, optoelectronics, chemical sensors and energy storage devices. These materials are based upon carbon, which has the ability to form to form complex molecular structures and/or stable allotropes of varying size and shape, thus providing them with unique electrical, thermal, optical and mechanical properties. Graphene-based NMs can be produced using a variety of methods including chemical vapour deposition (CVD), arc discharge, exfoliation and laser ablation and more recently molten salt electrolysis, however their global market is estimated to be reasonably small, with graphene at ~US$50 million (in 2016) and CNT’s at ~US$350 million (in 2014), in comparison to other sectors, such as cement, at ~US$237 billion (in 2011). This has been linked to their high costs, for example graphene is currently sold at ~$200 kg-1, SWCNT’s at ~$200 g-1 and MWCNT’s at ~$100 g-1 (in 2016) at reasonably high purities. However the steady rise in publications and patents for such materials supports the realization that if costs are lowered, the market share can increase. Therefore the objective of this article is to predict the future costs of these materials using economic models and investigate the strategic interaction between major manufacturers in the current market to help with their decision-making processes.

It is well-known that the global average surface temperature of the earth has risen by ~0.8'C during the 20th century. This can be attributed to an increase in quantities of greenhouse gases (GHG's) in the atmosphere, arising from anthropogenic sources and changing land use. This temperature rise has been linked to major catastrophes, such as hurricanes, heat waves, floods, droughts, evaporation of lakes, rising sea levels and melting of ice glaciers. One of the main contributors to GHG emissions are energy-intensive industries (EIIs), such as the cement process. This process emits between 0.65-0.92 kg tonne-1 of carbon dioxide (CO2) of cement, and accounts for 5% of global CO2 emissions annually. This is mainly due to the high temperatures required to achieve its process conditions (~1500°C), emitting CO2 directly (from limestone decomposition) or indirectly (through electricity usage). One method of reducing such emissions could be molten salt synthesis (MSS), which involves dissolving reactants in a molten salt and reacting in solution. MSS has proven to be an alternative route to many compounds; therefore in our project we investigated the synthesis of the cementitious compounds; calcium metasilicate (Ca2SiO4) and sodium metasilicate (Na2SiO3) in sodium chloride (NaCl). Our results suggested a-Ca2SiO4 and a-Na2SiO3 could be produced at 830°C, however other compounds such as Ca3SiO5 required higher temperatures (>1100°C). The dissolution of the reactants; silicon dioxide (SiO2), calcium carbonate (CaCO3) and sodium carbonate (Na2CO3) in molten NaCl were also investigated at 830°C and our results suggested that Na2CO3 and CaCO3 decomposed to CO2, calcium oxide (CaO) and sodium oxide (Na2O), and SiO2 only dissolved with a limited solubility. This suggests that molten salts could be suitable media to reducing CO2 emissions from such processes and hence improve the overall energy requirement. These MSS reactions were also depicted on predominance diagrams, to illustrate how these compounds could be produced using electrolytic methods.

The aim of the present study is theoretical backgroundation of the possibility of high-temperature electrochemical synthesis (HTES) and metallothermic synthesis of chromium silicides for the practical implementation of these processes.<br />Methods: thermodynamical calculations, cyclic voltammetry, potentio- and galvanostatic electrolysis, X-ray phase analysis.<br />At a temperature of electrolysis 1000 K, silicon containing compounds can be arranged in the order of descending equilibrium isolation potential of silicon as follows:<br />SiF4 >Na2SiO3 >Li2SiO3 >Mg2SiO4 >Na2Si2O5 >Li2Si2O5 >MgSiO3 >SiO2 <br />From the decomposition voltage values, it follows that the most energetically profitable process is the direct silicon deposition process. However, it will depend on the kinetic characteristics of the process, which reaction will take place.<br />Deposition potentials for chromium (-0.7-1.0 V) and for silicon (-1,6-1,9 V) differ substantially. Therefore, the electrochemical synthesis of chromium silicide is possible only in kinetic mode.<br />HTES of chromium silicides was realized from the molten KCl-Na3AlF6-K2CrO4-SiO2 mixture. Volt-ampere dependencies show reduction waves for oxyfluoride complexes of Cr and Si at potentials -0.7 ÷ -0.9 and -1.6 ÷ -1.9 V, respectively, which is congruent with thermodynamical calculations results. Depending on the electrolyte composition and parameters of electrolysis, phases of Cr2O3, higher silicide CrSi2, and silicide Cr3Si mixed with aluminum compounds were obtained.<br />To optimize the yield of chromium silicides, HTES was performed in the KCl-KF-K2SiF6-K2CrO4 system. At the current-voltage dependencies for this system, waves were also found for the reduction of oxyfluoride complexes of Cr and Si at the significantly different potentials. Depending on the electrolyte composition and parameters of electrolysis, both individual Cr2O3, Cr3Si, and CrSi2 phases and mixtures of these phases with low silicon content were obtained.<br />Experimental data on the phase composition of the electrolysis products show that the process of silicothermic reduction of Cr2O3 depends on several factors including the crucial role played by the temperature and duration of the process.<br />Thermodynamic background of metallothermic reduction of halogen containing compounds of chromium and silicon allowed to classify the process conditions by metals-reducers and silicides of different composition. It was confirmed experimentally that obtaining of CrSi2 nanopowders is possible using the method of metallothermic reduction of chromium chloride and sodium fluorosilicate by metals-reducers (Na, K, Mg, Ca).<br />Keywords: chromium silicides, thermodynamics, metallothermic synthesis, electrochemical synthesis.

Critically evaluated experimental data are essential to carry out innovative chemical process design, or to improve material and energy efficiencies of existing chemical processes. Developed under the auspices of IUPAC (Project 2003-020-2-100), ILThermo (http://ilthermo.boulder.nist.gov/) is a data archive of experimental thermophysical properties (including 120 thermodynamic, transport and thermochemical properties) of ionic liquids and mixtures that contain them. Version 1.0 was announced at COIL-1 [1]. Detailed capabilities were described [2]. Recently, Version 2.0 [3] was released by NIST’s Thermodynamics Research Center. ILThermo is a web-based open-access database that provides data and metadata from published experimental studies of ionic liquids, including numerical values of thermophysical properties, chemical structures, measurement methods, sample purity, critically evaluated standard uncertainties of property values, as well as other significant measurement details. Version 2.0 is keyed on the chemical structure of each chemical species that is curated, which brings inherent advantages to users of the database. Best practices are described for search and retrieval of thermophysical properties and phase behavior data from ILThermo for use in sustainable processing applications.
References
[1] J. W. Magee, J. A. Widegren, M. Frenkel, Q. Dong, C. Muzny, R. D. Chirico and V. V. Diky "Comprehensive Data Retrieval System for Ionic Liquids," 1st International Congress on Ionic Liquids, Salzburg, Austria, June 19-22, 2005.
[2] Q. Dong, C. D. Muzny, A. Kazakov, V. Diky, J. W. Magee, J. A. Widegren, R. D. Chirico, K. N. Marsh, and M. Frenkel, J. Chem. Eng. Data, 2007, 52, 1151-1159.
[3] A. Kazakov, J.W. Magee, R.D. Chirico, V. Diky, C.D. Muzny, K. Kroenlein and M. Frenkel "NIST Standard Reference Database 147: NIST Ionic Liquids Database - (ILThermo)", Version 2.0, National Institute of Standards and Technology, Gaithersburg MD, 20899, http://ilthermo.boulder.nist.gov .

The work of M. Faraday played a crucial role in the development of ideas about the nature of the chemical bond and the practical application of electrochemical processes, and others. In the XX century, has gained a huge experimental material, which confirms the correctness of M. Faraday's views on the impact of electric current on the chemical reactions. The key points following basic thesis work of M. Faraday:
1. The identity of the energy manifestations of the interaction of material objects.
2. The discrete nature of electric current.
The position of the discrete nature of the electrical current enables the use of a combination of electrical conditions for organizing unusual chemical reactions. Regulation on the identity of the energy manifestations of the interaction of material objects provides a basis for the revision of scientific statements about the mechanism of heat transfer between material objects.

The wettability of molten carbonate fuel cell materials by molten carbonate mixtures under MCFC operating conditions was studied by means of the sessile drop method using an optical instrumental system. Observations were made of the melting and spreading of a solid carbonate pellet upon controlled temperature increase, under either a reducing atmosphere (80%H2/20%CO2 humidified at 45oC) or pure CO2. The mass of the carbonate pellet was found to have an effect on the development of the contact angle on dense and smooth Ni foil (purity 99.5%) under a reducing atmosphere. The contact angle showed a significant decrease (suggesting increased wettability) when the mass of the carbonate decreased below a certain weight. This appeared to be correlated with the generation of gas bubbles at the interface which decreased the effective contact of solid Ni surface with the liquid carbonate. It was observed that large bubbles were generated under reducing atmosphere, which disappeared quickly when the gas atmosphere was changed to the pure CO2 atmosphere. On the contrary, small bubbles were generated but disappeared quickly and spontaneously during the melting and wetting of the carbonate on a solid smooth Ni surface under pure CO2 atmosphere, while large bubbles reappeared at the interface of the solid Ni surface and liquid carbonate after switching to the reducing gas. We infer from this that the water gas shift equilibrium CO2+H2=CO+H2O (1)
is established very rapidly at the scale of individual droplets or films of molten carbonate on nickel, and leads to gas bubble formation due to the very different levels of solubility of H2, CO, and CO2 in molten carbonate. To determine the effect of porosity of the anode on the wetting by molten carbonate, spreading and absorption of carbonate by potential Ni-Al alloy anode substrate with porosity of 25-35% was tested using carbonate pellets of various mass.

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