ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Reactions of Vanadium Oxide with Cryolite

M. Chrenková, A. Silný, and F. Šimko

Institute of Inorganic Chemistry, Slovak Academy of Sciences, SK-845 36 Bratislava

E-mail: uachchre@savba.sk

Received: 19 December 2003

Abstract: Reactions between cryolite and vanadium oxide were examined in laboratory experiments using the cryoscopic method and measuring the mass losses during heating and melting. The reaction products were identified by X-ray diffraction analysis and IR spectroscopy. The measurements were supplemented also by the thermodynamic calculation of the reaction Gibbs energies.
From the results of the uroscopic measurements as well as on the basis of the calculated reaction Gibbs energies it may be assumed that the introduced vanadium oxide reacts in the electrolyte with cryolite under formation of volatile VF₅, which escapes from the melt. Besides reactions with cryolite, vanadium compounds present in the electrolyte are also reduced electrochemically, which lowers the current efficiency of the process. In the presence of metallic aluminium, chemical reduction of vanadium compounds in the electrolyte is possible ms well.

Full paper in Portable Document Format: 592a85.pdf

Chemical Papers 59 (2) 85–88 (2005)