SYNTHESIS AND CHARACTERIZATION OF THE NIOBIO MIXED CARBIDE AND NANO-RUCTURED TURN NB (1-X) TA (X) C FROM THE COLUMBIT BASED MINERAL (FE, MN) (NB, TA) 206

摘要

synthesis and characterization of the nanostructured niobium and tantalum mixed carbide [nb (1-x) ta (x)] c from the columbite base mineral [(fe, mn) (nb, ta) 2o6]. This patent relates to the synthesis of niobium carbide and nanostructured tantalum from the base mineral columbite through gas-solid reactions at low temperatures. Initially, this starting mineral was treated for 10 hours. therefore, the synthesis of the precursor, a more reactive reagent, the hydrated ammonium tris (oxalate) oxyniobium tantalate complex [(nh4) 3 (nb (1-x) tax) o (c2o4) 3.nh2o], and this oxalate precursor showed high reactivity due to the shape, particle size (less than 2 µm) and porosity. The synthesis reaction takes place between the precursor and a gas mixture of h2 / ch4. [nb (1-x) ta (x)] c was produced from a new methodology at lower temperatures and time (between 930 ° c and 980 ° c, and 1.5 hours and 2.5 hours) than those used in the conventional method. The synthesized product was characterized and the obtained results showed that the synthesis technique used allows the production of the compound with the following composition [nb0,57ta0-43] c, being the contents of niobium and tantalum dependent on the quantity in the base mineral.