The fabrication of niobium powder by sodiothermic reduction process

Niobium powder was fabricated by sodiothermic reduction process using K(2)NbF(7) as a raw materials, KCl and KF as the diluents and sodium as a reducing agent. The apparatus for the experiment was designed and built specifically for the present study. Varying properties of niobium powder depending on reaction temperature and excess of reducing agent were analyzed. The niobium particle size increased significantly as reduction temperature increased from 993 to 1093 K. The particle size was fairly uniform at given reaction temperature, varying from 0.2 mu m to 50 nm depending on the reaction temperature. The yield of niobium powder increased from 58% to 83% with a increase in reaction temperature. The average particle size of niobium powder was improved from 70 nm to 0.2 Pm with increase in the amount of sodium excess. In addition, the yield of niobium powder was 82% in the 5% sodium excess. (C) 2009 Elsevier Ltd. All rights reserved.