Speciation of Niobium in Chloride Melts: An Electronic Absorption Spectroscopic Study / Polovov I.B., Brevnova N.P., Volkovich V.A., Chernyshov M.V., Vasin B.D., Rebrin O.I. // Molten Salts Chemistry and Technology. - 2014. - V. , l. . - P. 243-255.

ISSN:
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Type:
Book Chapter
Abstract:
The results of spectroscopic studies of niobium metal anodic dissolution, dissolution of niobium pentachloride and reaction of various niobium oxides (NbO, NbO2, Nb2O5) with HCl in LiCl-KCl and NaCl-CsCl eutectics and NaCl-KCl equimolar melts at 450-750°C are presented. Niobium(III) species, NbCl63-, is the major product of niobium anodic dissolution in chloride melts. Addition of NbCl5 to the chloride melts predominantly leads to the formation of niobium(V) species, NbCl6-. Upon increasing niobium(V) concentration they tend to decompose to Nb(IV) species and Cl2. NbO3+ ions are the final products of all studied niobium oxides chlorination. Reaction of NbO and NbO2 with hydrogen chloride proceeds via the intermediate oxygen-containing niobium(IV) complexes. In a separate series of experiments the speciation of niobium was studied using exchange reactions between niobium metal and bismuth, silver or nickel ions in NaCl-KCl melt. Six-coordinated NbCl62- ions are the major products of such reactions. The preliminary results of spectroelectrochemical studies of niobium-containing chloride melts are also presented. © 2014 John Wiley & Sons, Ltd.
Author keywords:
Chloride melts; Chlorination; Electronic absorption spectra; Exchange reactions; Niobium; Niobium chlorides; Niobium oxides; Spectroelectrochemistry; Spectroscopy
Index keywords:
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DOI:
10.1002/9781118448847.ch4d
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Affiliations Department of Rare Metals and Nanomaterials, Ural Federal University, Russian Federation
Author Keywords Chloride melts; Chlorination; Electronic absorption spectra; Exchange reactions; Niobium; Niobium chlorides; Niobium oxides; Spectroelectrochemistry; Spectroscopy
References Polyakov, E.G., Niobium in molten salts: speciation an electrochemical behaviour (review, in Russian)) (1998) Zh. Prikl. Khim. (Russ. J. Appl. Chem.), 71 (2), pp. 181-193; Maslov, S.V., Vasin, B.D., Spectroscopic investigation of niobium-containing (Na-Cs)Cleut-based melts (in Russian) (1993) Rasplavy (Melts), 3, pp. 66-70; Bachtler, M., Rockenberger, J., Freyland, W., Electronic absorption spectra of reduction products of pentavalent niobium and tantalum in different alkali chloride and oxichloride melts (1994) J. Phys. Chem., 98 (3), pp. 742-747; Barner, J.H., Bierrum, N.J., Smith, G.P., Chlorocomplexes in molten salts. VII. Potentiometric, spectrophotometric and Raman spectroscopic study of the system KCl-AlCl3-NbCl5at 300 C (1978) Acta Chim. Scand., 32 A (3), pp. 837-845; Voyiatzis, G.A., Pavlatou, E.A., Papatheodorou, G.N., Reduction products of pentavalent niobium and tantalum in fused chloride solvents (1993) International Symposium on Molten Salt Chemistry and Technology, 93-99, pp. 252-264. , eds M.-L. Saboungi, H. Kojima, J. Duruz and D. Shores), The Electrochemical Society, Inc., Honolulu; Schellkes, E., Hong, X., Holtz, M., High temperature 93Nb NMR and raman spectroscopic investigation of the structure and dynamics of solid and liquid NbCl5- alkali chloride solutions (2003) Phys. Chem. Chem. Phys., 5 (24), pp. 5536-5543; Maslov, S.V., Volkovich, V.A., Vasin, B.D., Dissolution of niobium metal in molten eutectic mixture of sodium and cesium chlorides (in Russian) (1994) Rasplavy (Melts), 4, pp. 37-40; Rosenkilde, C., Voyiatzis, G., Jensen, V.R., Raman spectroscopic and ab initio quantum chemical investigations of molecules and complex ins in the molten system CsCl-NbCl5-NbOCl3 (1995) Inorg. Chem., 34 (17), pp. 4360-4369; Vasin, B.D., Maslov, S.V., Volkovich, Application of oxidimetry for determining speciation of transition metals in molten chlorides (2005) Proceedings of the 7th International Symposium on Molten salts Chemistry and Technology, 1, pp. 337-340. , Toulouse, France, 2005; Volkovich, V.A., May, I., Charnock, J.M., Lewin, B., Reactions and speciation of technetium and rhenium in chloride melts: a spectroscopy study (2002) Phys. Chem. Chem. Phys., 4 (23), pp. 5753-5760; Polovov, I.B., Volkovich, V.A., Charnock, J.M., In situ spectroscopy and spectroelectrochemistry of uranium in high-temperature alkali chloride molten salts (2008) Inorg. Chem., 47 (17), pp. 7474-7482; Gibalo, I.M., (1967) Analytical Chemistry of Niobium and Tantalum (in Russian), , Nauka, Moscow; Lorthioir, G., Saile, A., Basile, F., Continuous refining of niobium in molten salts (1991) Fr. Mater. Sci. Forum, 73-75, pp. 449-455; Araurault, L., Bouteillon, J., Poignet, J.C., Chemical stability of solutions of niobium (V) in NaCl-KCl at 750°C (1995) J. Electrochem. Soc., 142 (1), pp. 16-19; Rosenkilde, C., Ostvold, T., Chemistry of niobium chlorides in the CsCl-NaCl eutectic melt. 2. Voltammetric studies of niobium chlorides and oxochlorides in the CsCl-NaCl eutectic melt (1995) Acta Chim. Scand., 49 (2), pp. 85-95; Stohr, U., Freyland, W., Electrochemical impedance investigations of redox mechanisms of refractory metal compounds in molten salts. I. Niobium chloride and oxychloride in CsCl-NaCl eutectic melt (1999) Electrochim. Acta, 44 (13), pp. 2199-2207; (2007) HSC Chemistry, , Version 6.12; Smirnov, M.V., (1973) Electrode Potentials in Molten Chlorides (in Russian), , Nauka, Moscow; Chernyshov, M.V., Polovov, I.B., Volkovich, V.A., Electronic absorption spectra of vanadium species in halide melts (2010) ECS Trans, 33 (7), pp. 287-296
Correspondence Address Polovov, I.B.; Department of Rare Metals and Nanomaterials, Ural Federal UniversityRussian Federation
Publisher Wiley Blackwell
ISBN 9781118448847; 9781118448731
Language of Original Document English
Abbreviated Source Title Molten Salts Chem. and Technol.
Source Scopus