CHROMATOGRAPHIC-SEPARATION OF NIOBIUM AND TANTALUM IN A HYDROFLUORIC-ACID HYDROCHLORIC-ACID SYSTEM WITH MACROPOROUS POLYACRYLATE RESIN BEADS

The separation of niobium and tantalum was examined by using macroporo us polyacrylate polymer beads (Amberlite XAD-7) as an adsorbent in hyd rofluoric acid-hydrochloric acid mixtures. The adsorption of niobium a nd tantalum was measured as a function of each acidic concentration; i t was found that niobium showed a lesser adsorption than did tantalum, and that both metals could be released by weakly acidic solutions. Co lumn chromatography was carried out using the resin as a stationary ph ase and acidic solutions of appropriate concentrations as a mobile pha se. The niobium and tantalum were successfully separated from each oth er, and application to a multielemental sample containing both metals was also demonstrated. By using this chromatographic system, trace tan talum was effectively removed from the niobium matrix.