Preparation of Vanadium Nitride Using a Thermally Processed Precursor with Coating Structure

Abstract

Abstract:A new effective method is proposed to prepare vanadium nitride (VN) via carbothermal reduction-nitridation (CRN) of the precursor, obtained by adding carbon black (C) to the stripping solution during the vanadium recovery from black shale. VN was successfully prepared at a low temperature of 1150 • C for only 1 h with a C/V 2 O 5 mass ratio of 0.30 in N 2 atmosphere, but a temperature of 1300-1500 • C is required for several hours in the traditional CRN method. The low synthesis temperature and short period for the preparation of VN was due to the vanadium-coated carbon structure of the precursor, which enlarged the contact area between reactants significantly and provided more homogeneous chemical composition. In addition, the simultaneous direct reduction and indirect reduction of the interphase caused by the coating structure obviously accelerated the reaction. The phase evolution of the precursor was as follows: (NH 4 The precursor converted to V 6 O 13 and VO 2 completely after being calcined at 550 • C, indicating that the pre-reduction of V 2 O 5 in the traditional CRN method can be omitted. This method combined the synthesis of VN with the vanadium extraction creatively, having the advantages of simple reaction conditions, low cost and short processing time.

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

“…Although the formation of vanadium nitride can be promoted by preparing precursor. 29,30 However, in this study, a precursor with uniform particle size and porous surface morphology was used to prepare vanadium nitride, a fact we consider an essential difference. Therefore, we had to investigate this precursor.…”

“…When the particle size is too small, vanadium and C do not form a package structure, the contact area decreased. When the particle size of is too large, the particle envelope formed with C as the nucleation point is too thick, 29 that C in the middle of the structure cannot be fully released to participate in the response, affecting the progress of the reaction. Therefore, the decreased and uniformity of precursor particle size is the mainly reason to promote the increase of N content.…”

“…Compared with the conventional carbon thermal reduction technique, the reaction temperature can be reduced and the reaction time can be shortened. 29 In addition, Huang used microwave efficient heating to promote the preparation of vanadium nitride, and the N content of the VN was 12-16 wt%. 30 However, studies on the precursor properties are not common.…”

Reduction and Nitridation of Iron/Vanadium Oxides by Ammonia Gas: Mechanism and Preparation of FeV45N Alloy

“…Although nitrogen is capable of being introduced into the melt by blowing N-bearing gases, the final composition of the melt is generally corrected by adding N-bearing alloys. Up to now, various alloys, including vanadium nitride (VN), vanadium carbonitride (V(C, N)) and ferrovanadium nitride (FeVN), have been proposed for the combined introduction of vanadium and nitrogen into the molten steel [5][6][7][8][9]. Vanadium carbonitride has been researched for many years; however, its practical use is inhibited by its low briquette density (≈3 g/cm 3…”

Mechanism of Novel K2SO4/KCl Composite Roasting Additive for Strengthening Vanadium Extraction from Vanadium–Titanium Magnetite Concentrate

“…Vanadium is an important rare metal that plays important roles in the steel, aviation, chemical, battery, medicine, and other industries due to its superior characteristics [1][2][3][4][5]. China's vanadium resources mainly exist in two forms: vanadium-containing shale and vanadium-titanium magnetite [6].…”