Molten salts are an important reaction medium in the reprocessing of spent oxide nuclear fuel. In the conventional process, the oxide mix in the spent fuel is first reduced chemically in a melt of LiCl to the corresponding metals. The metal mix formed is then separated in a eutectic melt of LiCl/KCl by electro-deposition. The FFC-Cambridge Process is a relatively new metallurgical oxide reduction method that would enable the electrochemical oxide-to-metal conversion of the spent oxide fuel in one step in a melt of CaCl2. This article summarises the fundamental aspects of the process and highlights its potential benefits for the reprocessing of spent nuclear fuel.
Keywords: FFC-Cambridge Process, Spent oxide nuclear fuel, Reprocessing

This presentation concerns with the use of CO2 - lasers (10.6 µm) as heating source in order to prepare a variety of materials and study their structural properties using Raman spectroscopy.
a) Container-less levitation techniques and CO2-laser heating were used to prepare series of difficult-to-make glasses alkaline earth silicate glasses along the compositional join (1-x) MO-xSiO2 with M=Mg, Ca and x ranging between 0.60 and 0.27; thus reaching compositions beyond the orthosilicate limit (X=0.33). Polarized and depolarized Raman spectra measured at ambient conditions for all these glasses show systematic and smooth band intensity changes with composition indicating the presence of a variety of silicate species. Beyond the x=0.33 limit, the glass structures are characterized by isolated negatively charged 'tetrahedral' SiO44- and O2- anions with M2+ (M =Mg, Ca) as counter cations, held together by pure Coulombic (ionic) interactions
b) Aerodynamic levitation and CO2 - laser melting have been used to synthesize glasses, the yttrium aluminum garnets (YAG) and aluminosilicates of the type zY2O3-yAl2O3-xSiO2. Micro-Raman spectra were used to identify the two polyamorphic LDA (low density) and HDA (high density) phases in these systems. The stability of the LDA phase against crystallization appears to be lower than that of the HDA phase.
c) Self-support melting with CO2-laser techniques were used to obtain in situ quantitative Raman spectra of vitreous and molten silica from 77K to 2200K. The relative intensities of the two 'defect peaks' D1 and D2 associated with the corresponding four- and three-membered ring structures were measured and found to be invariant to temperature. The data show that the vitreous/liquid structure and the ring populations associated with a fictive temperature in the quenching experiments do not reflect by any means the 'equilibrium' structure at that temperature.
d) A novel method for the fast, single-step epitaxial growth of large-area homogeneous graphene film on the surface of SiC(0001) using an infrared CO2 - laser as the heating source is described. Uniform, low-strain graphene film is demonstrated by scanning electron microscopy, X-ray photoelectron spectroscopy, secondary ion-mass spectroscopy, and micro-Raman spectroscopy.

In this study, a new environmentally-friendly salt electrolyte was applied for the extraction of copper from Cu2S (white metal- containing approximately 78 wt.% Cu), supplied from KBI Black Sea Copper Works Inc. The effects of process parameters, namely current density and time on the cathodic current efficiency and copper yield were systematically investigated. The molten salt electrolysis was performed at a constant temperature of 1200 °C in a borax electrolyte at current densities ranging from 100 to 800 mA/cm2 for periods of 15 to 60 minutes. The highest cathodic current efficiency (Iii) calculated according to Faraday's Law was found as 40.8% at 600 mA/cm2 for 15 minutes. It was seen that the increase in process time does not have any significant influence on the value of current efficiency (Iii). However, the yield of copper was raised to 79.58% after longer process time; for instance, 38 g Cu was recovered from 60 g Cu2S at 400 mA/cm2 in 1 hour. The cell potential values were increased with increasing current density and measured as 5.6 V at 800 mA/cm2. The specific energy consumption was reached up to 5.8 kWh/kg at 600 mA/cm2. The analyses revealed that the extracted copper had 97.3 wt. % of purity with minor amounts of lead, zinc, iron. The mechanism of copper extraction from Cu2S was suggested with possible reactions. The scanning electron microscopy and energy dispersive spectrometry (SEM-EDS) inspections confirmed the condensed sulphur and zinc oxide formations on the cold part of the system, i.e. graphite crucible and anode.

The density of room temperature ionic liquids (RTILs) at ambient pressure but over a temperature range can be estimated sufficiently accurately from the ionic volumes of the constituent ions with just two universal parameters. The ionic volumes of inorganic ions are well established, and those of alkyl-substituted imidazolium, pyridinium, pyrrolidinium, quaternary ammonium and phosphonium cations and sulfate anions are linear with the number of carbon atoms in the chains. The molar volumes of liquid RTILs are larger than Avogadro's number times the sum of the ionic volumes of cations and anions because of the expansion of the crystalline solids on melting and the creation of ion-sized cavities.

The aim of this work was deposition of thin films of the refractory metal carbides such as NbC, TaC, Cr7C3 on carbon steels and carbon fibers with further study their properties.
For deposition coatings of the refractory metal carbides, a currentless transfer in molten salts at temperatures 1073-1123 K was used with the time of the process from 6 up to 24 hours.
The corrosion rates of the refractory metal carbides in concentrated acids HCl, HNO3, H2SO4 and H3PO4 were evaluated by the loss of the sample weight. Coatings significantly reduce the corrosion rate of the steel substrates in concentrated acids.
The wear resistance tests of refractory metals carbides coatings on steel were carried out by using apparatus SMTS-2 at the limit load of 5 MPa in the medium of transformer oil at a slip rate of 1.2 m/s. The counter body was a sample of hardened St. 45. The tests were performed at a route section of 2000 m. The wear resistance was evaluated by the sample mass loss with the accuracy of 0.1 mg. The mass loss of a sample from hardened St.45 was 35.2 mg cm-2 and that of a coated with a chromium carbide-4.7 mg cm-2, niobium carbide-2.9 mg cm-2 and tantalum carbide-2.2 mg cm-2.
Deposition of NbC coatings on parts of oil pumps increased their lifetime in several times. Coatings of Cr7C3 or TaC on the knifes for cutting rubber, made of St. 3, improve their wear resistance and increase a tool life in 2.1 times.
Coatings of NbC or TaC on carbon fibers make better a fibers mechanical resistance and they are compatible with fibers up to 1473 K in an aggressive atmosphere.

Pyrochemical technology using high-temperature molten salts and molten metal media presents a potential interest for an overall separation and transmutation strategy for long-lived radionuclides. Within the frame of the two French acts on radioactive waste management, a pyrochemical R&D program was launched at the CEA Marcoule in the late 90's. The developed so called DOS (Direct Oxide Solubilisation) process, based on a two- step liquid-liquid (molten salt/liquid metal) extraction, aims to demonstrate the feasibility of a group separation of actinides with sufficient decontamination from fission products.
The first step consists of a selective reductive extraction of actinides coming from direct dissolution of oxide fuel in the molten fluoride salt, into liquid aluminium metal. The second step is the actinides back-extraction, which consists of a liquid/liquid oxidative stripping of the An from aluminium matrix into molten chloride media. The DOS process has been successfully demonstrated for treatment of oxide type fuels within the last years: the core of the process has been already assessed and the studies have shown high selectivity and a quantitative recovery of actinides.
Within the framework of the SACSESS European research program, the present work focuses on a potential application of the DOS process for the reprocessing of MgO based CERCER transmutation targets. The behaviour of Mg was investigated regarding the solubility of MgO in the fluoride salt and then regarding Mg reductive extraction in metallic Al. The impact of Mg on the efficiency of An reductive extraction was also studied using U3O8 simulating the behaviour of MA oxides. Eventually, the validity of the DOS process was demonstrated on a Pu0.5Am0.5O2-x-MgO FUTURIX CERCER pellet synthesized at the ATALANTE facility within the framework of Eurotrans program. Substantial amount of Nd2O3 was added during the demonstration experiment in order to simulate fission products behaviour. Quantitative recovery of purified Pu and Am was achieved in a single batch experiment.

On sample of smelting slag, containing 0,71% of copper (76,71% sulphide copper and 23,29% oxide copper), it was investigated possibility of agitation leaching with sulphuric acid with and without of oxidants presence. Since the content of oxide copper is relatively small in the relation to content of sulphidic copper, process of agitation leaching is provided in presence of following oxidants, iron (III) sulphate Fe2 (SO4) • H2O and iron (III) chloride FeCl3 • 6H2O. It was also tested the influence of the oxidants concentration on the leaching degree of total copper. By using iron (III) sulphate leaching degree of total copper has increased from 23,3% to 30,5%, while the application of iron (III) chloride FeCl3 • 6H2O increased level of total copper leaching to 44,7%.

In order to reduce the high temperature aluminum electrolysis process it is proposed to apply so-called low-melting electrolytes. It is considered that KF-AlF3-based solutions are promising electrolytes in this process. In this work, the electrical conductivity of low-melting electrolytes (nKF/nAlF3=1.3-1.7) with Al2O3 (4 mas.%), NaF (2-6 mas.%) and LiF (2-6 mas.%) additives was investigated using BN tube type cell. The melts were measured by continuously varying cell constant (CVCC) method. AC - techniques with a sine wave signal with 10mV amplitude in the high frequency range (5-100 kHz) were applied. Electrical conductivity of aqueous solution of KCl, molten KCl and Na3AlF6 was measured to check the measuring method. The results prove that the method is reliable and accurate. The conductivity of investigated electrolytes was found to vary linearly with temperature. The activation energy of conductance was calculated based on Arrhenius equation. The electrical conductivity is decreased with Al2O3 and increased with NaF and LiF additions.

The reliable data on the physical and chemical properties of low-melting salt compositions containing ZrCl4 and alkali metal chlorides having a subatmospheric saturated vapor pressure are required for the development of novel technologies and for the improvement of the current manufacturing processes.
In this work, the electrical conductivity of the molten mixtures of ZrCl4 with NaCl, KCl and CsCl with high tetrachloride concentration (54-75 mol %) at 210-460 0C was measured as a function of temperature and molten salt composition.
The electrical conductivity of melts was found to decrease with increasing ZrCl4 concentration and with the salt solvent changing in passing along the row NaCl > NaCl-KCl (1 : 1 molar) > NaCl-KCl (8 : 29 molar) > KCl > CsCl, when the large and less mobile cations of K+ and Cs+ are substituted by the Na+ cations and when the complex chloride anions of tetravalent zirconium (mainly Zr2Cl9-), which are formed due to interaction of the components in the molten mixtures, become stronger.
This research was partially supported by the Russian Ministry of Education and Science through Targeted Federal Program (project number: 14.607.21.0084).
Keywords: Electrical conductivity, low-temperature melts, ZrCl4, NaCl, KCl, CsCl.

Pyroelectrochemistry is one of the most prospective approach for reprocessing spent nitride nuclear fuel (nitride SNF). It includes the anode dissolution of the SNF pellets in the (LiCl-KCl)eut melt with subsequent electrochemical separation of U, Pu, Np, Am from other constituents. In the present work, the experimental results and theoretical evaluation of electrical conductivity and some other properties (density, viscosity, liquidus line) for the LiCl-KCl molten eutectic containing chlorides of uranium, plutonium and fission products (Cs, Nd, Ce, Ba, La, Pr, Sm, Am, Sr and others) are presented. These data are required for the creation of general model for electrolyzer operation and for the development of complied technological equipment. The compositions of simulated nuclear fuel consisted of 3-6 components. Properties of which are similar to properties of real SNF were proposed. This research was partially supported by the Russian Ministry of Education and Science through Targeted Federal Program (project number: 14.607.21.0084). Keywords: SNF reprocessing, pyroelectrochemistry, molten chlorides, electrical conductivity, density evaluation.

Neodymium is a lanthanide and belongs to the rare earth elements. Its implementation in current devices such as computers or LCD-screens and its utilization in green technologies such as electric cars and wind turbines increase every year. In these technologies the neodymium is incorporated in permanent magnet (Nd2Fe14B).
Neodymium, as fission product in nuclear reactors, can be recovered from fission products by pyrochemical process. This process represents an alternative to the hydrometallurgical process (PUREX) in order to separate actinides and lanthanides.
Neodymium, contained in Nd2Fe14B-Magnets, can be recycled using hydrometallurgical and/or pyrometallugical processes, which have some disadvantages such as a high energy demand or/and huge amounts of chemicals. An alternative method could be a selective reduction of the neodymium contained in the magnets. In order to recover the neodymium as pure metal using molten salts, the thermochemical and electrochemical properties of neodymium have to be well known. The solubility, diffusion coefficients redox potential and the interaction between neodymium and molten salts are important characteristics to obtain a successful extraction. In this paper, the electrochemical behavior of neodymium in mixed molten salts investigated by classical transient electrochemical techniques will be presented and discussed.

Lithium hydride (LiH) is an attractive material for some industrial applications (electrical energy production, hydrogen storage, metallic hydride formation in molten salts) due to its highly reducing character and its low molecular weight. However, lithium hydride is very sensitive to oxygen and moisture, which complicates its use in industrial processes and should be handled under protected atmosphere. In this work, the electrochemical properties of lithium hydride (LiH) in the LiCl-KCl molten eutectic were investigated at 425 °C using classical transient electrochemical techniques. The H2/H- redox system (n=1) was found reversible even if the produced hydrogen at the electrode escapes and does allow to reduce it partially only. The diffusion coefficient of hydride anions was found to be close to 2-3.10-5 cmA².s-1, whereas the apparent standard potential was determined to be close to 1.825 V vs. Ag/AgCl at 425 °C.

The results of studies of electrochemical extraction of zirconium from its dioxide by the FFC Cambridge Process are presented in this report. In contrast to the known technical solution, it was proposed a carry out electrochemical reduction on liquid gallium cathode. As the electrolyte, the system CaO-CaCl2-MCl, where M = Li, Na was used. In the temperature range 873-1023 K, the recovery of zirconium is at least 75% and is higher than the lowest acid strength melt-electrolyte. Effective recovery zirconium dioxide occurs when the current density is not lower than 0,2 A/cm2.The product of recovery is finely zirconium powder with particle size 0,01-0,03 mm and specific surface area of 20,84 m2/g. The content of impurities of gallium and oxygen in obtained zirconium were not found.

The necessity of hard and corrosion-resistant surfaces on engineering components becomes progressively more vital to provide longer service life with better performance. Transition metal borides, an important subgroup of advanced ceramics, are the perfect candidate for various applications due to their extraordinary properties; i.e., high melting points and extreme hardness along with good wear resistance and fair corrosion resistance as well as excellent thermal and electrical properties. <br />Boriding, a thermal boron diffusion process, is one of the common surface modification technique to form metal borides MeB, MeB2, etc. (Me= metal) on the surface of metallic workpieces. Among several boriding processes, pack and paste boriding are found conventional applications due to their simplicity. However, these processes have many disadvantages, such as expensive powder usage, long process durations and solid waste generations. All these negative sides of currently used boriding techniques make boriding economically and environmentally very costly and hence hinder its widespread application. As an alternative, in this study, a new boriding method called CRTD-Bor (Cathodic Reduction and Thermal Diffusion based boriding) was applied to different metals and their alloys, namely Inconel 600, titanium, Ti6Al4V, TiNi and steels (AISI 1018 low alloyed, 440 martensitic stainless steel, and AISI 4140 alloy steel). The main benefit of this novel boriding technique is its ability to provide the high growth rate of boride layers in a short time. Besides, the environmental issues as experienced in the conventional boriding processes are also eliminated with the usage of a uniquely formulated electrolyte composition. Cross-sectional examinations along with thin film X-ray diffraction analyses confirmed the homogenously thick boride layer formations on different substrates. The grown boride layers improved the surface hardness of the alloys at least eight times; i.e., 2000HV, 3500HV, 1600 HV to 1900HV on Inconel, titanium, steels, respectively.

Volumetric and transport properties of binary liquid mixtures of 1-butyl-1-methylpyrrolydinium bis(trifluoromethylsulfonyl)imide, [bmpyrr][NTf2], with I³-butyrolactone (GBL) were measured at temperatures from (293.15 to 323.15) K and at atmospheric pressure over the whole composition range. Excess molar volumes have been calculated from the experimental densities and fitted with the Redlich-Kister polynomial equation. These values are positive over the whole range of ionic liquid mole fraction and at all temperatures. In the range between 0.55 and 0.60 [bmpyrr][NTf2] mole fraction, an ideal behavior of the ionic liquid mixture with molecular solvent was observed for the first time. Other volumetric properties, such as isobaric thermal expansion coefficients, partial molar volumes and partial molar volumes at infinite dilution have been also calculated, in order to obtain information about interactions between GBL and selected ionic liquid. Positive values of these properties for both components also indicate weaker interactions between GBL and IL compared to the pure components. From the viscosity results, the Angell strength parameter was calculated and found to be 3.24 indicating that [bmpyrr][NTf2] is a "fragile" liquid. From the obtained results of the volumetric and transport properties, the formation of the [bmpyrr]+ micellar structures was also discussed.

In the present day, electrolytic process for aluminium production uses a fluoride electrolyte, in which alumina is dissolved. Having a carbon anode and a liquid aluminium cathode, CO2 is being evolved at the anode and aluminium is deposited at the cathode, according to the reaction:
½ Al2O3 + ¾ C = Al + ¾ CO2 which is operated at 960 °C.
Per each ton of aluminium produced, about 1.5 tons of CO2 are being emitted. Due to sulphurous impurities in the anode, the gas also contains SO2, COS, CS2, H2S.
By replacing the carbon anode by an inert, oxygen-evolving anode, the cell reaction will be:
½ Al2O3 = Al + ¾ O2
The exit gas will only be oxygen, together with some fluoride fumes.
To replace the carbon anode, inert anodes made of electronically conducting ceramics, cermets or metals (metal with oxide layer) can be used. All oxide materials have a finite solubility in the fluoride electrolyte, so that the anode will slowly dissolve, leading to contamination of the aluminium produced. To mitigate this problem, the electrolyte composition should be changed in order to lower the electrolyte temperature to about 800 °C. Various approaches on how to achieve that will be outlined.
Inert anode research is being conducted by major aluminium companies in USA, Russia and China and by research institutes and universities. Several cell designs have been proposed and tested. However, a major problem remains; metal contamination, and we are still searching for a final solution to this problem.

The aim of the present work is the study of the second coordination sphere influence on the standard rate constants of charge transfer (ks) for the Nb(V)/Nb(IV) redox couple in chloride melts and the investigation of the working electrode nature on kinetics of the redox reaction.
Cyclic voltammetry was employed, using a VoltaLab-40 potentiostat with complementarily packaged software VoltaMaster 4, version 6. The potential scan rate varied between 5x10-2 and 2.0 V s-1.
The electrochemical redox process:
Nb(V) + e- = Nb(IV) (1)
in KCl-NbCl5 and CsCl-NbCl5 melts at 0.75 V s-1 up to 2.0 V s-1 was determined as quasi-reversible. For the NaCl-KCl (equimolar mixture)-NbCl5 melt even at a sweep rate 2.0 V s-1, the process (1) was reversible and the determination of ks could not be done.
The theory of determining the standard rate constants of charge transfer for the quasi-reversible redox processes, which are not complicated by the formation of insoluble product, was developed by Nicholson. The standard rate constants for the Nb(V)/Nb(IV) redox couple were calculated on the basis of cyclic voltammetry data.
The ks obtained in KCl-NbCl5 melt were higher than ks determined in CsCl-NbCl5 molten system. So, in alkali chloride melts, it was defined that ks (CsCl) < ks (KCl) < ks (NaCl-KCl. It was found that ks increased with increasing temperature and values of ks obtained at platinum electrode were higher than those at a glassy carbon electrode. The values of the standard rate constants testify that the redox process (1) proceeds quasi-reversibly.

Molten salt method that is frequently used for preparation of different materials or pure compound at high temperatures, suffers with one unfavourable but principal complication. When particular phases are mixed and melted, some reaction usually takes place and consequent cooling provides product of these chemical or physical processes. The reaction product, however, usually contains impurities that arise either from i) starting components or ii) competitive reactions. Both major and minor phases are either known and fully structurally characterized, or their stoichiometry is believed to be known based on only XRD. The following complications may arise: i) phase characterized by only XRD may happen to be shown as incorrect ii) the unknown phase is present and its composition could be estimated based on isostructural properties, iii) the amount of the phase is below detection limit of XRD and remains unrevealed.
X-ray photoelectron spectroscopy could reveal the presence of low concentration phases, as unreacted reactants or product of competitive reactions because the detection limit of this spectroscopy is much lower. Moreover, some important information about the structural properties can be retrieved from surface of studied samples.
X-ray photoelectron spectroscopy was applied for identification of differently bonded fluorine atoms in series of compounds NaF, K2TaF7, K3TaF8, K2ZrF6, Na7Zr6F31 and K3ZrF7. Three different types of fluorine atoms were described qualitatively and quantitatively. Uncoordinated fluorine atoms (F-) provide signals at lowest binding energies, followed by signals from terminally coordinated fluorine atoms (M-F) and then bridging fluorine atoms (M-F-M) at highest energy. Based on XPS signals assigned to fluorine atoms in compounds with correctly determined structure it was suggested that fluorine atoms in K3ZrF7 have partially bridging character.
In the second example, the series of the phases KTaF6, K2TaF7, K3TaF8 vs KNbF6, K2NbF7 and K3NbF8, correlation of XPS data was performed.

Growing application of niobium and its alloys in electronics, chemical technology, aerospace and nuclear industry leads to increasing world demands for high-purity metallic niobium. Electrolytic refining in molten chlorides is one of the most prospective methods of high-purity niobium production. Prolonged contact of niobium-containing melts with metallic niobium can be employed for stabilizing necessary niobium species in the electrolytic baths. A complex of independent physical and chemical methods of analysis was used to study the mechanism of niobium interaction with niobium chloro-species in fused salts.
In the current study, we found that upon contacting metallic niobium with a melt containing higher oxidation state niobium ions, the average oxidation state of niobium in the salt phase, mass of the metal and potential difference between niobium and an indicator electrodes decreases. After a certain period of time, these parameters tend to achieve certain constant values. This moment corresponds to the stationary state of the system. Analysis of the experimental data showed that the mixture of niobium (III) and (IV) ions is the final product of interaction of niobium-containing chloride melts with niobium metal and therefore, a mixture of niobium ions in two oxidation states is present in equilibrium with the metal. The average oxidation state of niobium in the obtained melts (after contacting with Nb metal) increases by increasing the niobium concentration. This observation correlates with the results of cathodic current efficiency measurements during niobium electrorefining. Thermodynamic calculations were performed using niobium red-ox and equilibrium electrode potentials in NaCl-KCl based melts at 700 0C. The results confirmed that equilibrium oxidation state of niobium in the fused chloride can increase by increasing the total concentration of niobium in the melt.

The science of chemistry includes a study of properties, composition, and structure of matter, the changes in structure and composition which matter undergoes, and the accompanying energy changes. Learning to use to the full the chemical reaction products is a present-day problem of chemistry. The melting point of the equimolar mixture NaOH-KOH is 170 C; at this temperature, water is in the form of steam. On addition of silica to the NaOH-KOH melt, one mole of water is formed, whose steam energy can be used as kinetic one. It follows that this reaction can be used instead of the petrol combustion process in internal-combustion engine. The space containing alkalis is heated through electricity to temperature above the melting point of alkalis (>200 C); then an oxide mixture is thrown in, the pressure rises, and the pistons move; then the next portion of oxides is thrown in, and the process repeats. This reaction can also be used for water production. Another product, sodium or potassium silicate, is a raw material for glass industry. When up to 10% silicate is formed in the system, the NaOH-KOH melt begins to crystallize through silicate formation; it is necessary either to raise the melt temperature or to remove silicate from the melt. Addition of boric acid to the NaOH-KOH melt leads to the formation of two moles of water, hence the steam pressure is higher than in the case with silica. This reaction is endothermal, therefore heat supply is needed. The saturation of the melt by borax takes place at a concentration of over 50%. But as boric acid is lighter than the melt, it floats on the melts surface and retards the reaction. Therefore, it is worth-while to add a boric acid - silica mixture to the melt; the density of this mixture must be higher than that of the melt. Also gamma-Al2O3 mixed with boric acid may be used instead of silica; since gamma-Al2O3 also contains water, this will lead to an increase in vapor pressure. To obtain kinetic energy, the use of chemical reactions which are not combustion reaction and the complete utilization of the products of these reactions are possible. One of these reactions is interaction of oxides with molten alkalis. This reaction is ecofriendly and economically advantageous.

Ionic liquids (ILs) are gaining wide recognition as novel solvents in chemistry that remain in liquid state in a wide range of temperature. It is well known that ILs are "designed" solvents because of their tunable physical and chemical properties (the first and the second generation of ILs). Recently, the third generation of ILs with targeted biological properties containing biologically active components, extends the sphere of their use in pharmacy and medicine as the potential drugs, and also for regulation of plant growth and protection from unwanted diseases.
In this work, binary mixtures of synthesized 1-butyl-3-methylimidazolium salicylate, [bmim][Sal], and water were studied. Due to the lack of information about the physical-chemical properties of salicylate ILs, interactions of cation with salicylate and interactions of both cation and salicylate with water molecules, a detailed investigation of thermodynamic and transport properties of this mixture was performed. The results and conclusions were conducted applying both experimental (volumetric and transport properties) and computational approach (molecular dynamics). The obtained data provided significant information about structure making properties of salicylate based ionic liquid and interactions of [bmim][Sal] and water.

Li-ion batteries are used as the power source for nomad electronics due to their high energy density. To increase their safety and stability, the development of electrolytes based on ionic liquids (ILs) instead of flammable, organic carbonates gained a lot of attention. With graphite (Cgr) electrode, addition of organic carbonates (e.g. vinylene carbonate, VC) is essential to improve their performance due to the creation of interfacial compatibility between the Cgr and IL. Simulations of [Li+] doped ILs showed the transport of the [Li+], coordinated by four [NTf2-] is realized through [NTf2-] exchange in the first coordination shell. But the carbonate additive can destroy these ion pairs. Consequently, in IL//VC media, could VC contribute both in SEI formation and in the coordination [Li+]?
In this work, in C1C6ImNTf2//VC(5% vol.)//LiNTf2 (1mol.L-1), we determine through {1H-7Li}, {1H-19F} (HOESY), pulsed field gradient spin-echo (PGSE) NMR experiments and simulation study, the coordination shell of [Li+], and its interface with graphite electrode through surface techniques: XPS, SEM-FIB, impedance. Then, it was tested in safe and low-cost full cell based on Cgr//LiFePO4 (LFP) at 60A°C.
Results demonstrates: i) the vicinity of [Li+] and VC in solution, ii) on Cgr surface, the presence of IL layers (<5nm), LiF peak from anion and from the relative ratio of Ncation/Nanion a higher degradation of cation.
Keywords: ionic liquid, vinylene carbonate Li-ion batteries, interface, NMR, XPS

The possibility of copper protection against corrosion using newly synthesized 1-butyl-3-ethylimidazolium bromide ionic liquid as potential inhibitor in acidic 0.1 M sodium sulphate solution (pH=3) was investigated by weight loss, dc polarization and electrochemical impedance spectroscopy (EIS) methods. All applied methods confirmed that tested compound has good inhibitory properties against corrosion of copper in acidic environment at the given conditions. It was found that [beim]Br acts as a mixed inhibitor, whereby its effectiveness depends on the applied concentration. The results also indicate that the [beim]Br ions are adsorbed on the surface quickly and spontaneously forming stable film which was able to protect the copper against corrosion in acidic media. On the basis of the parameters obtained by the polarization measurements, the mechanism of copper dissolution was discussed in the absence and in the presence of inhibitor. EIS results showed that the effect of the investigated ionic liquid in copper protection manifests through an increase of the total resistance and a decrease of the double layer capacitance compared with the blank solution.

Materials selection is a very important problem for the nuclear power systems of the new generation. In recent years, the interest in the study of salt melts as promising working media including the fuel compositions, coolants as well as the fluids for high-temperature processing of spent fuel, natural and man-made materials containing rare earth and radioactive metals has substantially increased. For these reasons, the reliable experimental data on the thermal conductivity, like other thermophysical properties, are necessary for the development of new nuclear power systems. The thermal conductivity of molten salts, especially fluorides and chlorides, is the most difficult property to measure experimentally due to their corrosiveness at high temperatures. That is why we would have to look for theoretical and semi-empirical methods for evaluating thermal conductivity of molten salts. In this work, we analyze different approaches to forecasting the thermal conductivity of molten salts by the example of fluoride and chloride melts. In particular, the correlation between available experimental values of the thermophysical properties of fluorides melts and the apparent ionic potential of salt medium μc = I£ Ni *zi *ri-1 where Ni, zi, and ri are mole fraction of i-component of fluoride mixture, nominal charge, and radius of i-cation, respectively, is discussed. The correlation assigned describes adequately the thermal conductivity of binary and ternary fluoride melts and can be used for evaluating that of similar unexplored systems.
Keywords: thermal conductivity, molten salts, halides, nuclear power engineering
This research was partially supported by the Russian Ministry of Education and Science through Targeted Federal Program (project number: 14.607.21.0084).

The corrosion of some metallic inert anodes during electrolysis of cryolite – alumina melts was studied.
By SEM analyses, the structure and composition of the reaction layer were measured, as well as the distribution of some elements (O, Fe, Ni, Al, F, etc) in this layer.
The oxygen content into the reaction layer increases from the metal core to the outside part of the layer, but the content of the metals into the reaction layer decreases. This shows that the discharge of the oxygen takes place near the interface: reaction layer/electrolyte and the diffusion of the metals is hindered.
Due to this, the corrosion of some metallic inert anodes is low and the impurity level in the aluminium cathodes is also low.
A composition of an alloy very resistent to the oxidation was found, which could be used as inert anodes for aluminium electrolysis.

The carbon cathode used for aluminium electrolysis may appear very dense and impenetrable. However, after 4 years of service, it contains 35 wt % salts. This, in spite of that the porosity at the start is about 20 %. The reactions start with penetration of metallic sodium followed by molten Na3AlF6 and NaF. The penetration and reactions are studied by laboratory experiments as well as by core samples of used industrial cathodes. Products that form and partly disappear are NaCN, AlN, NaAlO2, Na2O.11Al2O3, AlC4 and Na5Al3F14. The behavior is explained by a thermodynamic model.

Potential modeling studies on ionic liquids using local structure analysis have an important role in understanding the liquid structure. The ultimate target of these studies is to find a good potential for Molecular Dynamics (MD) simulations that can be transferable between different systems. MD simulation studies, which employ two-body interionic polarizable potentials obtained by experimental data fitting, give successful structural and spectral results with real systems. However, in certain cases where two-body interactions are inadequate to fully describe the system properties; ab initio or density functional theory (DFT) calculations might be very helpful in the local structure analysis part of the potential modeling studies.
In the present study, structure of the (ZnCl2)n clusters, where n=1-9, were investigated using DFT methodology. The distorted tetrahedral coordination of group-2B metal atom by halogens was also under pursuit for a better understanding of the liquid structure. The convergent of the Cl-Cl/Zn-Cl bond lengths towards the magic value 1.63 were investigated within the calculations. Chemical reactivity indices such as global and local hardness and softness and fukui functions were employed to predict the larger cluster properties.

Solvionic S.A. is an 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.

Ionic liquids (ILs) have been described as molten salts with a melting point below 100 °C, consisting of large asymmetric organic cations and organic or inorganic anions. In addition to the favorable physical and chemical properties of ionic liquids, their negligible vapor pressure, non-flammability, biodegradability and recyclability, make them interesting for a wide range of applications as potentially green solvents associated with little waste, risk and hazard problems. Since the ionic liquids are essentially ionic conductors, their utilization as novel electrolytes for electrochemical devices, such as lithium-ion batteries, has also been the subject of intense studies. Exchange of common organic solvents by ILs can enhance the safety of lithium-ion batteries. The high viscosity of ILs, which is limiting factor for their practical application, can be overcome by mixing ILs with appropriate molecular solvents.
Ionic liquids with dicyanamide anion (DCA) were investigated due to their properties such as low melting point and low viscosity, efficient mass transport and a higher electrical conductivity. Because of the coordinating ability of the DCA anion, metal salts are often better soluble in dicyanamide based ionic liquids. Also, they are less moisture sensitive and have wide electrochemical window which makes them the good candidates for electrochemical devices.
Molecular liquids such as I³-butyrolactone (GBL) have a high boiling point, low melting point and low vapor pressure. The GBL is also a non-corrosive liquid suitable for electrochemical cells operating over a wide temperature range for a long time. Thus, GBL can be used as a solvent at improving volumetric and transport properties of ILs and has been already usually applied in the new generation of lithium-ion batteries and electrochemical devices. In addition, since its polarity GBL possesses excellent salvation properties of lithium ions and the increasing conductivity.
In this work, density, viscosity and electrical conductivity of 1-Butyl-1-methylpyrrolidiunium dicyanamide [BMPYR][DCA] and 1-Butyl-3-methylimidazolium dicyanamide [BMIM][DCA] binary mixtures with GBL were examined in the temperature range from (273.15 to 323.15) K and at atmospheric pressure. The results are compared with those obtained in our previous studies of the systems with bis(trifluoromethylsulfonylimide) (NTf2) based ionic liquids containing the same cations. After that, lithium salt was added at the appropriate IL-GBL mixtures and physicochemical properties, electrochemical and thermal properties were investigated. The systems with DCA show high electrochemical and thermal stability and higher values of electrical conductivity and lower viscosities compared with NTf2 based ionic liquids.

The rapid development of the global economy and intense use of electric and electronic equipment lead to the increase of the waste quantity (WEEE). Due to their high toxicity, these materials have become one of the major environmental risks. The necessity for the treatment of WEEE results from the large quantities generated and the content of valuable metals (as Cu, Sn, Zn, Pb et all.). Globally, the recovery of WEEE contained metals is a subject which has generated numerous studies, leading to the development of some technologies based on combining the classical pyro- and hydrometallurgical methods, specific for obtaining metals. Since copper and tin are important metals for industries, the development of Cu, Sn recycling processes is an important issue. The aim of this paper is to recover Cu and Sn by using from the multicomponent alloy obtained by pyro-metalurgic technology from WEEE. We aim to develop a novel ecological technology for the recovery of metals from WEEE by leaching and electrodeposition using ionic liquids based on choline chloride (ChCl). In order to obtain the leaching state, we used mixtures of ChCl-X (X=Urea, Malonic acid and CuCl2i&#65533;2H2O). Metallic copper and tin were then electrowon from the ionic liquids in the electrowinning stage. It was found that the peak potentials for Cu and Sn ions reduction are very similar using either Pt or glassy carbon as counter electrode. The electrochemical study allowed determining the mechanism for Cu2+ and Sn2+ reduction in ChCl-A ionic liquids, which appears to be a two steps mechanism for copper probably involving copper chloride complex and a one step mechanism for tin. Finally, the obtained metallic deposits on the Cu anode were the subject of determination of XRD, SEM and XPS in order to be sure of the deposits structure. <br />Key words: metals recovery from WEEE, ionic liquids

The world is facing increasing needs of technologies for removal of pollutants in industrial flue gases emitted to the atmosphere in order to avoid environmental hazards as acid rain and smog with severe consequences for the nature, human health and man-made constructions. In addition, the issue of climate changes due to the large amount of carbon dioxide also emitted industrially to and accumulated in the atmosphere is now more than ever recognized as a global concern which needs a global solution. The large industries -with a need for pollution control- that will be addressed in this presentation, include power, cement, glass manufacture and waste incineration plants as well as sea transport units.
We are carrying out research dedicated to solve these problems not only by traditional catalytic routes where we, from a molecular understanding of the catalyst performance, try to improve the composition and catalyst life-time. But the problems may also be attacked by new materials, like supported ionic liquid phase (SILP) gas absorbers, where the pollutants may be selectively absorbed, desorbed and finally converted to useful mineral acids of commercial grade, really a green waste-to-value approach that we pursue instead of the traditional cleaning processes that use chemicals to form new waste. Our recent results for selective reversible absorption of SO2, NO and CO2 by SILP materials will be highlighted.

The aim of this work is the development of computer models of phase diagrams (PD) for the ternary systems contained on the boundaries of LiF-NaF-KF-PuF3 system. The data about the structure of binary systems and the topological structure of primary crystallization surfaces is a basis for reproducing of full geometric structure of PD, including the phase regions with melt as well as the solid phase regions. By using the diagrams of vertical mass balance (which permit to analyze the quantitative content of phases in the whole temperature range for the given composition) we produced the investigation of two, one and zero-dimensional concentration fields for each studied system, compiled the lists of intersecting surfaces and phase regions and formed the schemas of phase reactions and sets of microconstituents elements. As a result, the concentration fields with the same or unique sets of microconstituent elements are identified.<br />The schemas of mono- and invariant transformations and the data about the structure of ternary systems PD are the base for producing the prototype of PD for quaternary system LiF-NaF-KF-PuF3, which can be a theoretical basis for its experimental study.<br />The obtained models of PD bounding LiF-NaF-KF-PuF3 system can be used for the prediction of the properties of fuel composition for molten-salt reactor.<br />The work was partially supported by the Russian Foundation for Basic Research (projects 14-08-00453 and 14-08-31468).

Close to the critical temperature, Тcr liquids have a viscosity of about 10-4 Pa·sec that corresponds to strain relaxation and the Maxwell structure time I„ = I•/G of the order of period of atom vibration I„ = I„0 ~ 10-13 sec; here G is the shear modulus. The fastest processes of diffusion, ionic electrical conductivity, etc. have approximately the same specific time near Tcr.
The opposite limit of the slowest processes, affordable for measuring, in the condensed substance can be achieved close to temperature Т0 ~ Tm/2, where Tm is the melting point. Here, the typical time for processes exceeds a year, that is why the measurements are very difficult and the experimental data are rare. The viscosity here reaches 1016 Pa·sec that is by the 20 orders of magnitude higher than that near the critical temperature (10-4 Pa·sec). The distinctive time for diffusion and other processes increases by the 20 orders of magnitude as well. This corresponds to the increase of the processes activation energy from zero to 46 RT because exp(46) = 1020.
If the liquid does not crystallize but vitrifies, then, within the considered temperature range, it passes such stages as "as water", "sun oil", "as dense honey", "pit asphalt", "deformable solid", "brittle solid".
A stage of consolidation is not taken into account in the traditional computer atomic model. Those processes, which in real situation last over a year, in model during computer experiment proceed for less than one nanosecond (10-9 s). Solidification, similar to the real one, was considered in the model on the assumption of that the quantum "freezing" atoms at the zero energetic level is motionless. The activation energy EA at cooling increases proportionally to the fraction of "freezing" atoms; and the solidification stages, specified above, from "as water" to "brittle solid" are present in the model. The melting point and hardness index accurately correlate with the "quantum degree" of the atomic system, in the simplest case - with the average atomic weight.
Keywords: consolidation, quantum "freezing" of atoms, activation energy, deceleration of atomic processes.

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 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 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.

Transformation of lignocellulosic material into potentially valuable resources is compromised by its complicated structure. Consequently, there is a clear need to develop new economical and feasible conversion/fractionation techniques that render value-added products. Herein, wood lignin and hemicelluloses were extracted from birch chips (B. pendula) using an alkanol amine (monoethanol amine, MEA) and an organic superbase (1,8-diazabicyclo-[5.4.0]-undec-7-ene, DBU) derived Switchable Ionic Liquid (SIL) triggered by SO2 (Scheme 1). The dissolved lignin and hemicelluloses were recovered from the spent SIL using a two-step recovery protocol using different organic solvents, targeting one compound at a time.
The dissolved materials from the SIL treatment of wood were selectively recovered by a step-wise method using an anti-solvent to induce precipitation. The treatment was carried out at 160°C for 2 hours in absence of any agitation. The SIL was recycled after concentration and evaporation of the added molecular solvents. All fractions were analyzed by gas chromatography (GC), Fourier transform infrared spectroscopy (FT-IR), 13C nuclear magnetic resonance spectroscopy (NMR) and Gel permeation chromatography (GPC). Selective extraction was demonstrated to obtain almost pure fractions cellulose, hemicellulose and lignin. The use of this simple two-step solvent extraction can be applied to recover dissolved fractions from the SIL.
Further studies from our group will focus on improving the recovery of the dissolved lignin and hemicelluloses as well as to quantify and further refine these materials to bio-chemicals and fuels.

Calcium aluminosilicates CaO Al2O3 SiO2 (CAS) with compositions (CaO SiO2)x(Al2O3)1-x for x < 0.5 and (Al2O3)x(SiO2)1-x for x < 0.5 are studied using density functional theory molecular dynamics modelling. Simulated structure factors are found to have an excellent agreement with experiment. Local atomic structures from simulations reveal the role of calcium cations as a network modifier and aluminium cations as a non-tetrahedral network former. Distributions of tetrahedral order show that an increasing concentration of the network former Al increases entropy, while an increasing concentration of the network modifier Ca decreases entropy. The two-body correlation entropy S2 is found to not correlate with reference excess entropy values obtained from thermochemical databases, while the inclusion of a three-body orientational correlation such as tetrahedral order, O-M-O or M-O-M bond angle show a clear linear correlation between computed entropy and reference excess entropy. The possible relationship between atomic structures and excess entropy is discussed.

The cell for measuring an electrical conductivity of molten salts at temperatures as high as 1500 K and vapor pressures of salts up to several tons of atmospheres was designed. The electrical conductivity of the molten ZnCl2, BeCl2, PbCl2 and CdCl2 was measured at temperatures as high as 1421, 823, 1320 and 1474 K, respectively, which is by 280, 62, 307 and 273 K higher than the temperature values previously achieved. The rate of conductivity rise for the melts decreases with temperature.
The technique for the density data elongate extrapolation, which considers the non-linear decrease in density at high temperatures (near and beyond boiling point), was proposed; molar conductivities were calculated for the same temperatures for the first time. Some correlations between the physical-chemical properties of these salts are suggested. The totality of our and literature data allows one to draw out some conclusions regarding structural changes in the melts, being studied, with temperature.
This research was partially supported by the Russian Ministry of Education and Science through Targeted Federal Program (project number: 14.607.21.0084).

Molten Salt Reactor is one of the future reactor concepts considered in the Generation IV technology. The main characteristic of such reactor that differs from the other concepts is the physical nature of the fuel which is liquid. The fuel must fulfill several requirements in terms of its physical properties and neutronics and the most promising candidates seem to be molten fluoride salts, including the alkali fluoride matrix with dissolved actinide fluorides. Since the fuel is a multi-component system, for practical reasons it is very important to have a thermodynamic database that describes many of relevant physico-chemical properties for all possible compositions thus making it possible to optimize the fuel selection. At JRC-ITU, a thermodynamic database that describes most relevant systems of the molten salt reactor fuel has been developed in the past decade including both modelling of phase equilibria and experimental work. Especially the latter one has been a challenging task as it required a full development of a technique that made it possible to handle actinide containing fluoride salts at high temperatures during the measurements. In this paper, we will highlight the techniques used and we will show the latest results obtained using calorimetric and mass spectrometric facilities. It will be shown how these data are successively used to model the phase diagrams of studies systems and how the resulting database is applied to optimize the fuel composition with respect to its criteria, mainly the melting temperature. We will also show how useful the database is in predicting the properties of a fuel salt containing fission products which are accumulated during the reactor operation.

The ionic melts based on the Bi2O3-P2O5-SiO2 system are of interest for the glasses production as the materials with the unique combination of properties that may be used as photo resists, optical storage devices, holographic systems, optical waveguides, fiber-optic amplifiers and oscillators. The goal of this study is to obtain information on thermodynamic properties and vaporization processes of Bi2O3-P2O5-SiO2 melts at the temperature range 1400-1600 K that will be necessary for producing glasses with the properties required. Knudsen effusion mass spectrometric method was used to found the content of vapor, partial pressures of vapor species, activities of components and Gibbs energies in the melts under consideration. Vaporization of Bi2O3-P2O5-SiO2 melts was done from the molybdenum effusion cells covered by iridium. The negative deviations from the ideal behavior were observed in the melts studied. The generalized lattice theory was used for modeling thermodynamic properties of Bi2O3-P2O5-SiO2 melts and for the calculation of the relative numbers of chemical bonds formed in these melts when the second coordination spheres of atoms were taken into consideration. The financial support of the current study according to the project N 13-03-00718 by the Russian Fund for Basic Research is gratefully acknowledged.

Alkaline melts are widely used in various industries. Due to the high corrosivity of these melts, the question remains on the behaviour of metal oxides in such systems. This paper presents the results of the thermodynamic analysis of previously obtained data on the solubility of a number of metal oxides in molten alkali metal hydroxides.
It was shown the use of the regular solution model to describe systems molten alkali metal hydroxide-solid oxide.

Due to the growing industrial needs, the list of critical metals is ever growing, and so far includes Be, Co, Mn, Ni, and most of the Lanthanides. These metals are recovered by hydro- and pyrometallurgical methods, generating significant amounts of waste and lacking in performance. This work is focused on evaluating a clean molten-salts based electrochemical method of recovering valuable metals. In order to achieve high electroreduction efficiency, as well as high metal extraction rate, a novel mixed-salt system is proposed. Sodium borate salts are used to dissolve metals from waste feedstock. The valuable metal cations are transferred to the sodium chloride melt, where the electrolysis is conducted. Metals included in this analysis are Co, Cu, Mn and Ni. To evaluate the basic electrochemical and thermodynamical behaviour of the system, potentiodynamic electrochemical measurement methods were used. Cyclic voltammetry measurement data was analysed to find the best potentials for specific metals reduction and separation. Scanning electron microscopy with X-ray microanalysis was used to further analyse the reduced metal as the reaction product. As a result, the feasibility and efficiency of the electrochemical recovery of valuable metals from specific molten salts was evaluated.

The investigation of volume properties of molten salts is important from both views; practical view as well as the theoretical one. Density is one of the most important thermodynamic properties of liquids. The knowledge of density of molten salts is needed for concentration calculations at investigation of kinetics of processes running in the electrolytes. Density of electrolyte determines whether the metal after the electrodeposition will be collected at the bottom of electrolytic bath or will be on the electrolyte level. From the density data volume properties can be calculated and volumetric studies are of considerable value in investigation of the structure of liquids. Volume properties and molar volumes, excess molar volumes and partial molar volumes of different fluoride melts especially of tantalum, niobium, zirconium and aluminium are compared in this work. Based on excess partial molar volumes of compounds (so called parameter of compressibility), we have discussed the volume contraction/expansion.

The interfaces between solids and ionic liquids (ILs) play a central role in a variety of processes (stabilization of nano-suspensions, surface reactions, extraction) and devices (supercapacitors, captors, active electronic devices). This is why a lot of effort is currently devoted to the understanding of the local arrangement of the ILs near solid surfaces. However, most of this work is carried out through complicated computer simulations or onerous characterization techniques such as near-field microscopy or x-ray diffusion.<br />In this work, a more pragmatic approach is adopted, based on more conventional and accessible techniques such as wetting angle and electrochemical impedance spectrometry measurements. These techniques have been used to:<br />* Measure the capacitance of the electrical double layer on various electrodes<br />* Evaluate the kinetics of penetration of ILs into porous materials.<br />This knowledge has been used to successfully metallize a 3 micrometer thick layer of microporous Si with Cu, by penetration of a solution of mesitylcopper (CuMes) in 1-alkyl-3-methylimidazolium bistrifluoromethylsulphonylimide (C1C4ImNTf2), followed by in-situ decomposition of CuMes. The latter is shown to result from a reaction of CuMes with surface hydrides within the pores. As a result, the internal surface of the pores was covered with dense and small Cu islands (about 10 nm in diameter). The resulting composite material (porous Si + Cu) could be used to fabricate highly integrated and efficient columns for gas separation.

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