PREPARATION OF TANTALUM CARBIDE FROM AN ORGANOMETALLIC PRECURSOR

• Main Authors: C. P. SOUZA, C. FAVOTTO, P. SATRE, A. L' HONORÉ, M. ROUBIN
• Format: Article
• Language: English
• Published: Brazilian Society of Chemical Engineering 1999-03-01
• Series: Brazilian Journal of Chemical Engineering
• Subjects: organometallic; tantalum carbide; precursor
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66321999000100001

In this work we have synthesized an organometallic oxalic precursor from tantalum oxide. This oxide was solubilized by heating with potassium hydrogen sulfate. In order to precipitate Ta2O5.nH2O, the fused mass obtained was dissolved in a sulfuric acid solution and neutralized with ammonia. The hydrated tantalum oxide precipitated was dissolved in an equimolar solution of oxalic acid/ammonium oxalate. The synthesis and the characterization of the tantalum oxalic precursor are described. Pyrolysis of the complex in a mixture of hydrogen and methane at atmospheric pressure was studied. The gas-solid reaction made it possible to obtain tantalum carbide, TaC, in the powder form at 1000oC. The natural sintering of TaC powder in an inert atmosphere at 1400°C during 10 hours, under inert atmosphere made it possible to densify the carbide to 96% of the theoretical value.