INFLUENCE OF OXYGEN-CONTAINING IMPURITIES ON THE ELECTROCHEMICAL-BEHAVIOR OF NIOBIUM IN CSCL-KCL-NACL-NBCL5 MELTS

Linear-sweep voltammetry was used to study the changes in the mechanis m of niobium reduction which occur in the chloride melt when quartz, m olybdenum glass, or niobium pentoxide were added to the melt or when t he melt was allowed to come in contact with air oxygen. These operatio ns produce additional waves in the voltammograms and lower the niobium concentration in the melt, since the oxides and oxyhalides formed hav e a low solubility. It was shown that oxide materials when used in cel ls designed for studies of the electrochemical behavior of niobium in chloride melts lead to distorted current-voltage curves and an incorre ct interpretation of the results obtained.