[en] A blended composite of LiLaPO₄-coated Li[Ni_0.5Co_0.2Mn_0.3]O₂ and AlF₃-coated Li[Ni_0.5Co_0.2Mn_0.3]O₂ was tested as the cathode of lithium secondary batteries. The rate capability, cyclic performance, and thermal stability of the blended electrode were characterized and compared with pristine, AlF₃-coated, and LiLaPO₄-coated electrodes. The blended sample showed good cyclic performance and thermal stability, which implies that blending these two cathode coatings were effective in obtaining their advantages and lessening their weaknesses.

[en] This article is devoted to economic aspects of aluminium production. Therefore, the perspectives of development of aluminium production, the base components of aluminium cost and economic security of enterprise are considered in this chapter.

[en] Different concentrations of ErF/sub 3/ and HoF/sub 3/ ranging from 0.1 to 1.5 wt. % have been doped to an AlF/sub 3/-based glass with composition (mol %) 3.2 AlF/sub 3/ - 10.6 BaF/sub 2/ - 20.2 CaF/sub 2/ - 8.3YF/sub 3/ - 3.5 MgF/sub 3/ - 3.8 NaF - 13.2 SrF/sub 2/ - 10.2 ZrF/sub 4/. The values of Avrami exponent, n, and activation energy, E, for the base glass as well as the doped glasses have been calculated by analysing differential scanning calorimetric data according the the amended Ozawa-Chen and Augis and Benett equations. In the light of these results we observe that the introduction of suitable amount of rare-earth ions improved the thermal stability of the base glass. (author)

[en] Aluminum fluoride phases are established catalysts in many classes of fluorocarbon transformations, particularly important at this time because they are key to the production of CFC alternatives. Much of what has been known about the various phases of AlF₃, however, is open-quotes folkloreclose quotes and many of the reported phases appear to be spurious. Of the two well-characterized phases, the open-framework beta-AlF₃ has been found to be much more active than the condensed form, alpha-AlF₃. In an effort to find new, more reliable synthetic routes to beta-AlF₃, the pyrolysis of a variety of organic-[AlF₄] salts was attempted. This technique not only produced the beta-form but also a variety of new forms now designated as eta, theta, and kappa. Since these new phases were produced only in a microcrystalline state, it was not possible to characterize their structures by conventional single-crystal diffraction techniques. As a result, ab initio structural studies using synchrotron powder data were used to characterize these phases. All of the new phases consist of corner-shared AlF₆ octahedra and all contain channels. The paper details the synthesis of these new phases, the value of powder diffraction as a structural tool, and the structural relationships among the various AlF₃ phases

[en] ${}^{18}$F-fluorination using aluminum-fluoride ([${}^{18}$F]AlF) chelate technique has been reported to give a low-to-moderate radiochemical yield, between 5 and 20%. Therefore, the work described here outlines the optimum ${}^{18}$F-fluorination condition for the formation of [${}^{18}$F]AlF${}^{2+}$ and [${}^{18}$F]AlF-NOTA-NHS complex with the radiochemical yield (RCY) and purity (RCP) of more than 90% as a prerequisite step before proceeding with the radiopharmaceutical preparation using the [${}^{18}$F]AlF-bifunctional chelator technique. As well as being simple, the suggested method is practical and relevant for beginners interested in ${}^{18}$F-fluorination with [${}^{18}$F]AlF-chelate complex technique or also for a researcher who aims to proceed on an extensive scale.

[en] This article is devoted to technology of obtaining of cryolite and aluminium fluoride from alumina- and fluoride containing wastes of aluminium production. Thus, the investigations on elaboration of technology of obtaining of cryolite and aluminium fluoride from alumina- and fluoride containing wastes of aluminium production by means of sulfuric acid decomposition method are carried out. The optimal parameters of technological processes are found. The physicochemical analysis of fluoride containing wastes is conducted. The flowsheet of obtaining of cryolite, aluminium fluoride and alumina from alumina- and fluoride containing wastes is presented.

[en] This patent describes a process for producing metal fluorides for low optical loss glass applications selected from the group. It comprises: aluminum trifluoride, hafnium tetrafluoride and zirconium tetrafluoride. The steps comprise: incompletely reacting reactants of a fluorinating agent selected from the group consisting of F₂, NF₃, N₂F₂, N₂F₄, ClF₃, BrF₃, IF₅ and SF₄ and a metal selected from the group consisting of aluminum, hafnium and zirconium, or the corresponding metal's compound to produce a reaction product comprising the metal fluoride and at least an amount of the residual metal or its compound effective to react with any metal fluoride impurities in the reactants, and separating the metal fluoride from the reaction product by heating the reaction product to selectively vaporize the metal fluoride for separate recovery from the reaction product and to react the residual metal or its compound with the metal fluoride impurities

[en] The new class of 2D MXene material exfoliated from transition metal carbides receives increasing research interest due to its extraordinary properties and high potential in energy and environmental applications. However, the exfoliation of Ti₃C₂T_x, a widely studied MXene, from its precursor Ti₃AlC₂ by chemical etching in HF solution remains to be optimized. This study investigated the optimum exfoliation condition through systematic evaluating potential effects of reaction parameters, including the weight ratio of Ti₃AlC₂ in HF solution, etching time, reaction temperature, repeating etching, and sonication, on the yield, purity, and structure of produced Ti₃C₂T_x. Results show that a high weight percentage (5 wt%) of Ti₃AlC₂ etching at 50 °C for 36 h produced highly exfoliated MXene material. Etching at lower weight percentages (0.6–2.5 wt%) of Ti₃AlC₂ resulted in observable byproduct (AlF₃). Degradation of MXene layers with AlF₃ enrichment was observed under prolonged etching or higher temperatures. Room temperature etching failed to exfoliate Ti₃AlC₂ and the repeated etching denatured the MXene material. Introduction of controlled sonication during the etching produced highly exfoliated MXene with minimum etching time, which can be a promising alternative for high quality MXene production. (paper)

[en] The paper presents the results of studies on optimal parameters for the flux obtaining from industrial wastes. The optimal composition of the batch has been defined, including: waste - 80%, fluorite concentrate - 10% and aluminum fluoride - 10%. Melting point - 710 deg C, has coating and refining properties in relation to primary aluminum. The results of pilot industrial tests indicate that the main physical and chemical characteristics and environmental indicators of flux from industrial wastes comply with standard indicators. The cost of obtained flux is significantly lower than the cost of previously used fluxes. (author)

[en] The phase transformations have been studied when roasting a charge of zircon and aluminium fluoride. The transformations in zircon-fluoride mixtures were studied by methods of physical and chemical analyses. To explain the effects observed, the changes in the phase composition of mixtures under heating have been investigated. For this purpose the heat treated samples have been studied by X-ray phase and crystal-optical analyses. Basing on the phase transformation studies of an equimolar charge of zircon-aluminium fluoride mixture during roasting, it is possible to draw a conclusion that zircon interacts with AlF₃ while forming corundum and baddeleyite at 800-850 deg C. Within the same temperature range topaz Al₂F₂SiO₄ is formed which disintegrates into corundum, mullite and silicon tetrafluoride at 1000-1050 deg C. At 1100-1250 deg C the solid products of interaction are presented mainly by baddeleyite, corundum and a residual zircon