Preparation of high purity vanadium nitride by magnesiothermic reduction of V2O3 followed by nitriding in N2
(State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China)
Abstract: High purity vanadium nitride (VN) powders were prepared via a two-step process using vanadium trioxide (V2O3) as the raw material. The V2O3 was firstly reduced at 873 K in Ar atmosphere via magnesiothermic reduction reaction to get the mixture of V and MgO, and then the products were further nitrided at 1473 K in N2 atmosphere. Finally, the as-prepared samples were acid-leached to obtain pure VN powders. X-ray diffractometry and field-emission scanning electron microscopy were used to analyze the phase transition and morphological evolution of the samples. The results reveal that the overall morphology of the obtained VN powder retains the morphology of the initial V2O3 powders. After removing MgO by acidic leaching, the porous VN particles can be obtained, with the oxygen content of 0.178 wt.%. Compared with the traditional methods, high purity VN powders with a small amount of oxygen and no carbon can be obtained.
Key words: magnesiothermic reduction reaction; nitridation reaction; vanadium nitride powder; preparation