[en] The invention relates to a method for eliminating fluoride-containing contaminating substances from nitric acid. The method consists in adding aluminium ions to the acid so as to form a non-distilling complex fluoride, and distilling the nitric acid once purified. This can be applied to the reprocessing of nuclear fuels and to uranium refining

[en] This study reports on the synthesis of carbon nanofibers via chemical vapor deposition using Co and Cu as catalysts. In order to investigate the suitability of their catalytic activity for the growth of nanofibers, we prepared catalysts for the synthesis of carbon nanofibers with Cobalt nitrate and Copper nitrate, and found the optimum concentration of each respective catalyst. Then we made them react with Aluminum nitrate and Ammonium Molybdate to form precipitates. The precipitates were dried at a temperature of 110 .deg. C in order to be prepared into catalyst powder. The catalyst was sparsely and thinly spread on a quartz tube boat to grow carbon nanofibers via thermal chemical vapor deposition. The characteristics of the synthesized carbon nanofibers were analyzed through SEM, EDS, XRD, Raman, XPS, and TG/DTA, and the specific surface area was measured via BET. Consequently, the characteristics of the synthesized carbon nanofibers were greatly influenced by the concentration ratio of metal catalysts. In particular, uniform carbon nanofibers of 27 nm in diameter grew when the concentration ratio of Co and Cu was 6:4 at 700 .deg. C of calcination temperature; carbon nanofibers synthesized under such conditions showed the best crystallizability, compared to carbon nanofibers synthesized with metal catalysts under different concentration ratios, and revealed 1.26 high amorphicity as well as 292 m²g^-1 high specific surface area

[en] Two Al-MOFs, i.e., MIL-53 (Al) and (NH 2)-MIL-53 (Al) have been synthesized using aluminium nitrate as metal ligands and 1,4 benzene dicarboxylic acid, amino 1,4 benzene dicarboxylic acid as organic linkers in aqueous medium at room temperature, respectively. Both Al-MOFs have been confirmed through different microscopy and spectroscopy tools. Afterwards, the optical properties of Al-MOFs have been confirmed in polar and non-polar solvents using photoluminescence spectroscopy. Finally, both Al-MOFs have been explored for optical nitrobenzene (NB) sensing. Interestingly, we have found excellent optical ability of NH₂-MIL-53 (Al) over MIL-53 (Al) due to structural π-π* transitions. The photo-induced electron transfer mechanism has been found during the MOF-analyte interaction. Importantly, we confirmed that NH₂-MIL-53 (Al) is an excellent sensing material for NB with a 0.28 ppb limit of detection over MIL-53 (Al). (author)

[en] For the simplification of technology process, substitution syntheticammonia on cheap natural compounds and also for decreasing heat costs atobtaining of Al₂O₃ from nitrate salts by authors offered the method ofobtaining of Al(OH)₃ by aluminium nitrate processing by carbonate ofalkaline earth metals

[en] This paper deals with application of Taguchi methodology for the preparation of an important ceramic (mullite) material by hydrolysis method at low temperature. The study aims at production of the greatest yield quantity from the reaction between aluminum nitrate nona-hydrate and silicon ethoxide to obtain mullite precursor (3Al_2O_3 .2SiO_2 ). Three factors were considered to estimate their effects on the quantity of the product yield. These factors are the reactants concentration (factor A), reacting medium temperature (factor B) and ph (factor C). Three levels for each factor were considered (A:1, 2 and 3 wt.% mullite solids), (B: 50, 60 and 70 °C) and (ph: 4, 6 and 8). Three way analysis of variance (ANOVA) and signal to noise ratio (S/N) based on a higher value is a better formula, with an orthogonal array L9 for the design of experiments (DOE) were considered. (S/N) HB, explains that the conditions that maximize the production are; concentration of 3%, reaction temperature 70 °C and ph 6. ANOVA shows that both concentration and ph are significant factors for all confidence levels 90, 95 and 99% while temperature is significant only at 90 and 95% confidence levels

[en] The acid decomposition of aluminosilicate ores may justify the study of systems: Al(NO₃)₃-H₂O; Al(NO₃)₃-HNO₃-H₂O; Al(NO₃)₃-Na(K)NO₃-HNO₃-H₂O. In the Al(NO₃)₃-H₂O system, crystallisation regions of Al(NO₃)₃-n (n = 9, 8, 6) have been found. In the Al(NO₃)₃-HNO₃-H₂O system, the crystallisation region of the compound Al(NO₃)₃-nH₂O (n = 6, 8, 9) was found. In the system Al(NO₃)₃-Na(K)NO₃-HNO₃-H₂O no crystallisation regions of the above salts were found. This subsection does not cover all phase diagrams, but the diagrams presented show the validity of acid decomposition of aluminosilicate ores.

[en] Acetohydroxamic acid (AHA) is a hydrophilic organic complexing agent with excellent masking or stripping effects on the tetravalent actinides in the extraction operations. Therefore, AHA is a promising reagent for the spent nuclear fuel reprocessing. In the reprosessing of spent uranium-aluminum fuel with a high U-235 enrichment which is used in research reactor, the dissolver solution contains a high concentration of Al(NO₃)₃, several orders of magnitude higher than that of minor actinides such as plutonium, and dilute tri-n-butyl phosphate(TBP)/n-dodecane is adopted as the extractant. In this research, complexation of Pu(IV) with AHA under the condition of U-Al fuel reprocessing is investigated. Results show that Al(NO₃)₃ insignificantly affects the mentioned complexation reaction. Further, the possibility of uranium purification against Pu(VI) is also investigated by using AHA in the presence of a high concentration of Al(NO₃)₃ by simulating some experiments on the separation process. (author)

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No abstract available

[en] The relative effectiveness of perforated, nozzle, and burred plates from a capacity and extraction standpoint were studied in a pulsed liquid-liquid extraction system. The experiments were conducted in a 3.8 x 10^-2 m diameter column using a mixture of aluminum nitrate, nitric acid, and uranyl nitrate as the aqueous phase, and tributyl phosphate dissolved in AMSCO 125-90 W as the organic phase. The uranium was extracted from the aqueous phase to the organic phase. A standard cartridge was made for each type of plate and consisted of an assembly of plates spaced 5.08 x 10^-2 m apart. Each plate had 3.2 x 10^-3 m holes spaced on 6.1 x 10^-3-m centers, and contained 23% free area. 16 references, 4 figures, 1 table