Metallurgical Engineering

Metallurgical Engineering

The Effect of the Amount of CaCl2 flux on the Calciothermic Reduction of Tantalum Oxide Process

Document Type : Research Paper

Authors
Iran University of Science and Technology
Abstract
Tantalum is a refractory metal which has often been considered for high temperature applications because of its high melting point (2996◦C). In the present study, the tantalum powder characteristics produced by calciothermic reduction of Ta2O5 under argon atmosphere at different amounts of flux was studied. A fixed value of Calcium was used for the reduction of Tantalum oxide which amounted to two times of the stoichiometric ratio while various amounts of CaCl2 flux of 1, 1.5, 2, 2.5 and 3 times of the stoichiometric amount was utilized. XRD analysis on the product showed that the obtained powder contains tantalum and calcium tantalate phases. ICP technique was used to determine the calcium content of the reduced samples. The minimum value of remained Calcium in the product was obtained when the CaCl2 flux amounted to 2.5 times of stoichiometry, which was 23614 ppm. The morphology of the products was studied by scanning electron microscopy. Based on the SEM results, the morphology of the tantalum powder was coral-like which the size of the particles decreases by increasing the amount of CaCl2 flux
Keywords

Volume 18, Issue 60
Winter 2016
Pages 3-10

  • Receive Date 10 March 2015
  • Revise Date 08 January 2016
  • Accept Date 02 February 2016