Preparation of Direct Reduced Iron and Titanium Nitride from Panzhihua Titanomagnetite Concentrate Through Carbothermic Reduction-Magnetic Separation

Abstract

Abstract:A novel process for preparing direct reduction iron (DRI) and titanium nitride (TiN) from Panzhihua titanomagnetite concentrate is proposed. This process involves pelletizing, direct reduction roasting and magnetic separation. The effects of reduction temperature, coal dosage and reduction time on the phase transformation of composite pellets were investigated by X-ray diffraction. Results show that TiN formation proceeds less easily than metallic iron formation. Increasing the reduction temperature, reduction time and coal dosage can promote the transformation of titanium to TiN. Titanium was almost completely transformed into TiN under the conditions of 1300 • C reduction temperature, 26 wt % coal dosage and 90 min reduction time. The scanning electron microscopy (SEM) analysis showed that near-spherical metallic iron particles with diameters from dozens of microns to about 300 µm were formed in the reduced pellets, whereas the TiN particles generally measured less than 10 µm. The energy dispersive spectroscopy (EDS) results revealed that the TiN phase contains a certain amount of vanadium and carbon, and traces of other impurities. The reduced composite pellets under the optimum conditions were processed by grinding and subsequent magnetic separation. As a result, a DRI with 92.88 wt % Fe, 1.00 wt % Ti, and 0.13 wt % V was obtained, and the recoveries of Fe, Ti, and V were 92.85 wt %, 9.00 wt %, and 19.40 wt %, respectively. 91.00 wt % Ti and 80.60 wt % V were concentrated in the rough TiN concentrate.

Effect of Sodium Borate on the Preparation of TiN from Titanomagnetite Concentrates by Carbothermic Reduction–Magnetic Separation and Acid Leaching Process

“…A XCGS-50 Davis tube (Nanchang Li Yuan Mining and Metallurgy Equipment Co., Ltd., Nanchang, China) with a magnetic induction intensity of 0.04T was used to separate the slurry. The methods of roasting, grinding, and magnetic separation were based on previous studies [15,21].…”

“…The carbothermic reduction and nitridation reactions of titanomagnetite and ilmenite could be divided into two stages. The first stage was the reduction of titanomagnetite and ilmenite to Fe and M3O5, and the second stage was the reduction and nitridation of M3O5 to TiN/Ti(C,N) [15,[25][26][27][28][29][30]. The possible reactions were described as Equations (2-9).…”

“…In our previous study, a new process was proposed to prepare TiN and direct reduced iron (DRI) from TMCs [15]. In this process, the TMCs were first reduced by anthracite to metallic Fe and TiN, and then magnetically separated to produce DRI and impure TiN.…”

Evolution of Viscosity and Structure Property of Vanadium Slag during Iron‐Extracting Reduction Process

“…Specifically, in the first step, vanadium in the slag was enriched by selective carbothermic or silicothermic reduction of FeO x , and this prereduced slag was finally reduced by aluminothermic reduction. [ 9–12 ] When carbon was selected as a reductant, the endothermic reduction reaction required a large amount of energy to maintain the reduction process at high temperatures, [ 13–15 ] and the emission of CO facilitated the formation of foaming slag, inhibiting the separation of the hot metal and the slag. [ 16 ] On the contrary, when silicon metal was used as a reductant, the exothermic reduction reaction maintained the slag bath temperature and contributed to the settlement and separation of the hot metal from the slag; [ 17 ] however, the cost was high.…”

Carbothermic Reduction of Ore-Coal Composite Pellets in a Tall Pellets Bed

“…There are some studies regarding the reduction of ore-coal composite pellets [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Kasai et al carried out some reduction experiments in a combustion bed packed with the composite pellets.…”