Advances in Molten Salts

ISBN Print: 1-56700-142-4

Niobium and Tantalum Interaction with Chloride Carbonate Melts

Résumé

Niobium and tantalum interaction with chloride- carbonate melt NaCl-KCl-K2C03 (5 wt %) was investigated in the temperature range 973-1123 K. It was indicated that niobium and tantalum in the chloride- carbonate melt convert to oxide electrodes, whose potentials are determined by the ratio of the metal activity in the oxide phase and the activity of oxygen ions in the melt. The products of interaction of niobium are NbO and NaNb03, the NaNbO3 fraction increasing with temperature. In contrast to niobium, tantalum interaction with the melt, even at the temperature 1123 K, according to the XRD, does not lead to the formation of a significant amount of tantalates on its surface, and the principal phase is TaO. The rates of niobium and tantalum corrosion were determined depending on the temperature and exposure time.