Preparation of high quality ferrovanadium nitride by carbothermal reduction nitridation process

Abstract

High quality ferrovanadium nitride was prepared successfully by carbothermal reduction nitridation process by using V 2 O 5 and Fe as the raw materials. The effects of reaction temperature and C/O molar ratio (content of O is defined as the oxygen in V 2 O 5) on the quality of ferrovanadium nitride were investigated in detail. It was demonstrated that C/O molar ratio had a great influence on the residue carbon, as well as the nitrogen content in the final products. It was found that the nitrogen content of the final product achieved 11.52% when the C/O molar ratio was 90% of the stoichiometric value. However, the nitrogen contents of the final products decreased with the further increase of C/O molar ratio. For the temperature higher than 1773 K, Fe became liquid phase and surrounded the solid V(C, N, O) particles tightly. The formation of liquid Fe was beneficial for the further removal of oxygen atoms left in the V(C, N, O) lattice, since it provided a liquid tunnel for carbon diffusion which greatly enhanced the reaction kinetics. From the results of X-ray diffraction (XRD) and thermodynamic calculations, phase evolution sequence of V 2 O 5 can be obtained as: V 2 O 5 →VO 2 →V 2 O 3 →V(C, N, O). Moreover, the kinetic process from V 2 O 3 to VN was studied and the results shown that the reaction rate can be described by Jander diffusion model with the extracted activation energy of 188.173 kJ/mol.

Preparation of Vanadium Oxides from a Vanadium (IV) Strip Liquor Extracted from Vanadium-Bearing Shale Using an Eco-Friendly Method

“…As such, it can significantly improve the performance of steel [7]. The low-valence vanadium oxides (VO 2 and V 2 O 3 ) are suitable for the manufacture of high vanadium-containing ferrovanadium and vanadium nitride [8,9]. In addition, VO 2 has a metal-semiconductor phase change property, which makes it suitable for use in photoelectric and magnetic thermally-sensitive materials, for a variety of applications, including smart window layers, memory layers, thermal sensors, and electrical and infrared light switching devices [10][11][12].…”

A novel method of preparing vanadium-based precursors and their enhancement mechanism in vanadium nitride preparation

“…The first stage is from room temperature to 710 °C, which is caused by the pre-reduction of V 2 O 5 . 41 The second stage is from 710–1188 °C, which is the carbonization process of low-price vanadium oxide after pre-reduction to generate vanadium carbide. The third stage 1188–1281 °C is caused by the formation of vanadium nitride from vanadium carbide nitride.…”

Synthesis of high‐quality vanadium nitride particles by one‐step vacuum carbothermal reduction–nitridation method: Theoretical and experimental study

“…However, the reaction temperature is usually higher than 1673 K, resulting in higher energy consumption and higher production costs. Yu et al 18 proposed the preparation of VN via a one-step method of carbothermal reduction and nitridation of V 2 O 3 at 1673 K. Wu et al 35,36 obtained high-quality ferrovanadium nitride (VN and elemental iron) by roasting a mixture of V 2 O 5 , graphite, and Fe 2 O 3 under an N 2 atmosphere (V 2 O 5 + Fe 2 O 3 + 8C + N 2 = 2VN + 2Fe +8CO) in the temperature range of 1673−1873 K, where the formation of VN is a result of the typical one-step CRN method. Similarly, Zhou et al 37 obtained high-quality ferrovanadium nitride using the raw materials Fe 3 O 4 , V 2 O 5 , and graphite via a one-step CRN method at 1773−1823 K; the reaction temperature was mainly determined by the formation of VN from a thermodynamic analysis.…”

“…Yu et al 18 . proposed the preparation of VN via a one‐step method of carbothermal reduction and nitridation of V 2 O 3 at 1673 K. Wu et al 35,36 . obtained high‐quality ferrovanadium nitride (VN and elemental iron) by roasting a mixture of V 2 O 5 , graphite, and Fe 2 O 3 under an N 2 atmosphere (V 2 O 5 + Fe 2 O 3 + 8C + N 2 = 2VN + 2Fe +8CO) in the temperature range of 1673−1873 K, where the formation of VN is a result of the typical one‐step CRN method.…”