scholarly journals Investigations of MgO on Sintering Performance and Metallurgical Property of High-Chromium Vanadium-Titanium Magnetite

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 324 ◽  
Author(s):  
Liheng Zhang ◽  
Songtao Yang ◽  
Weidong Tang ◽  
Xiangxin Xue
Keyword(s):  
X Ray Diffraction ◽  
Metallurgical Property ◽  
Degradation Index ◽  
High Chromium ◽  
Comprehensive Index ◽  
Uniform State ◽  
Melting Properties ◽  
Vanadium Titanium ◽  
Reduction Index ◽  
Titanium Magnetite

High-chromium vanadium-titanium magnetite (HCVTM) in the Hongge region has been used as an essential mineral resource in ironmaking. The effects of MgO on sintering performance and metallurgical properties were investigated by sintering pot tests, X-ray diffraction (XRD), and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). HCVTM sinters with varying MgO contents (2.7–3.5%), which was achieved by adding dolomite, were tested for yield, strength, reduction degradation index (RDI), reduction index (RI), and softening-melting properties. The productivity and the comprehensive index were evaluated. The results show that yield and productivity increased, while the vertical sintering speed and the tumbler index (TI) initially increased then decreased with the increase of MgO content. The mineral structure of HCVTM sinter changed from a non-uniform state to a uniform state with increased MgO content. Most of the Mg2+ entered the magnetite lattice, while a small amount entered the perovskite and the calcium silicate. The increase of MgO content improved RDI and softening-melting properties while reducing RI. The best recommended amount of MgO was 3.3% from the comprehensive index.

scholarly journals Effect of Basicity on Sintering Behavior and Metallurgical Properties of High-Chromium Vanadium-Titanium Magnetite

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 569
Author(s):  
Liheng Zhang ◽  
Zixian Gao ◽  
Songtao Yang ◽  
Weidong Tang ◽  
Xiangxin Xue
Keyword(s):  
Sintering Behavior ◽  
High Chromium ◽  
Softening Behavior ◽  
Comprehensive Index ◽  
Opposite Trend ◽  
Melting Properties ◽  
Vanadium Titanium ◽  
Disintegration Index ◽  
Index Value ◽  
Titanium Magnetite

Basicity has an important effect on the behavior of high-chromium vanadium-titanium magnetite (HCVTM) sinter. The effect of basicity on sintering, reduction, and softening-melting properties was investigated in an experiment-scale sinter pot. The results showed that with the basicity increasing from 1.7 to 2.5, the vertical sinter speed, the productivity, the particle size, the reduction disintegration index (RDI), and the reducibility index (RI) increased. The yield increased first and then decreased, while the tumble index (TI) had the opposite trend. The perovskite content increased first and then stabilized, and the silico-ferrite of calcium and aluminum (SFCA) increased from the basicity of 2.3. The HCVTM sinter had a better tendency of the softening behavior with the basicity increase. In addition, the melt droplet comprehensive index S increased, which indicated that the increase in basicity negatively affected the droplet performance. As the basicity increased, the comprehensive index value increased. Considering the adverse effect of basicity on softening-melting properties, the best recommended value is 2.3.

Phases Transition and Consolidation Mechanism of High Chromium Vanadium-Titanium Magnetite Pellet by Oxidation Process

2016 ◽  
Vol 35 (7) ◽  
pp. 729-738
Author(s):  
Jue Tang ◽  
Man-sheng Chu ◽  
Cong Feng ◽  
Feng Li ◽  
Zheng-gen Liu
Keyword(s):  
Phase Transition ◽  
Oxidation Process ◽  
Consolidation Process ◽  
High Chromium ◽  
Oxidized Pellet ◽  
Three Stages ◽  
Roasting Temperature ◽  
Vanadium Titanium ◽  
Roasting Time ◽  
Titanium Magnetite

AbstractBased on the fundamental characteristics of high chromium vanadium-titanium magnetite (HCVTM), the effects of roasting temperature and roasting time on the phase transition and oxidation consolidation during the oxidation were investigated systematically. It was shown that the oxidation of HCVTM pellet was not a simple process but complex. With increasing roasting temperature and time, the compressive strength of oxidized pellet was improved. The phase transition during oxidation was hypothesized to proceed as follows: (1) Fe3O4 → Fe2O3; (2) Fe2.75Ti0.25O4 → Fe9TiO15 + FeTiO3 → Fe9TiO15 + Fe2Ti3O9; (3) Fe2VO4 → V2O3 → (Cr0.15V0.85)2O3; (4) FeCr2O4 → Cr2O3 → Cr1.3Fe0.7O3 + (Cr0.15V0.85)2O3. The oxidation consolidation process was divided into three stages: (1)oxidation below 1,173 K; (2) recrystallization consolidation at 1,173 – 1,373 K; (3) particle refining recrystallization-consolidation by the participation of liquid phase at 1,373 – 1,573 K. To obtain the HCVTM oxidized pellet with good quality, the rational roasting parameters included a roasting temperature of 1,573 K and a roasting time of 20 min.

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

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 426
Author(s):  
Renmin Li ◽  
Tao Liu ◽  
Yimin Zhang ◽  
Jing Huang
Keyword(s):  
Sulfuric Acid Concentration ◽  
X Ray Diffraction ◽  
Volume Percentage ◽  
Solid Ratio ◽  
Vanadium Extraction ◽  
Magnetite Concentrate ◽  
Main Decomposition ◽  
Vanadium Titanium ◽  
Hematite Fe2o3 ◽  
Titanium Magnetite

In this paper, a novel K2SO4/KCl composite roasting additive was used to extract vanadium from vanadium–titanium magnetite concentrate. Further, the mechanism of K2SO4/KCl for extracting vanadium was studied. The results indicate that the vanadium leaching efficiency reached 82.04%, an increase of 7.43% compared to that of single K2SO4 and 10.05% compared to single KCl under the following conditions: a total dosage of K2SO4/KCl of 7 wt % with a mass ratio of 6/4, a roasting temperature of 950 °C, a roasting time of 1 h, a leaching temperature of 95 °C, a sulfuric acid concentration of 10% (v/v: volume percentage), and a leaching time of 1.5 h with a liquid-to-solid ratio of 3 mL/g. Moreover, crystal chemistry analyses indicated that the essence of the vanadium extraction with roasting was the conversion of cubic crystal systemic vanadium-bearing magnetite (FeO(Fe,V)2O3) to trigonal crystal systemic hematite (α-Fe2O3), and as most Fe(V)–O bonds were broken with the reconstructed conversion, the dissociation of V(III) occurred. Furthermore, the main decomposition products of K2SO4/KCl were K2O, SO2, and Cl2. X-ray diffraction (XRD) and related SEM-EDS analyses indicated that there were mainly three aspects in the mechanism of K2SO4/KCl for extracting vanadium. Firstly, activated K2O could combine with vanadium to generate soluble KVO3 rather insoluble Ca(VO3)2; secondly, SO2 could react with CaO to form CaSO4 to prevent the generation of acid-consuming Ca(VO3)2, which was beneficial to the dissolution of vanadium-bearing sphene (Ca(Ti,V)SiO4O); thirdly, Cl2 could destroy the structure of hematite (Fe2O3) to reduce its wrapping extent to KVO3.

Experimental Study of Softening and Melting Properties on Indonesia Vanadium-Titanium Sinters

2011 ◽  
Vol 284-286 ◽  
pp. 1039-1043 ◽  
Author(s):  
Qiang Jian Gao ◽  
Guo Wei ◽  
Lin Mu ◽  
Gang Du ◽  
Feng Man Shen
Keyword(s):  
Blast Furnace ◽  
Molten Slag ◽  
Softening Temperature ◽  
Melting Zone ◽  
Raw Material ◽  
Blast Furnace Process ◽  
Furnace Process ◽  
Melting Properties ◽  
Vanadium Titanium ◽  
Titanium Magnetite

As a raw material, Indonesia vanadium-titanium sinters are being applied to the blast furnace process for iron making in the typical iron and steel plant. In order to keep the health running of blast furnace process, in this work we have investigated the softening and melting properties of Indonesia vanadium-titanium sinters. We found that the content of vanadium-titanium magnetite in sinter is correlated with the softening and melting ranges for those sinters considered here. With the increasing of the vanadium-titanium magnetite in sinter, the starting softening temperature increases gradually and the final softening temperature increases as well, thereby the softening range becomes narrow. Both starting and final melting temperatures begin to ascent, and the variation of melting range is not obvious. In addition, we also found that the coke is wetted by the molten slag and iron. From the viewpoint of blast furnace process, the softening and melting zone has to move downward. In this zone of blast furnace the contact area of solid-liquid phase will get larger because of the close contract among the molten slag, iron and coke. On one hand, this kind of behavior can definitely speed up the reduction of iron oxide. On the other hand, it simultaneously worse the ventilation properties and affect the normal running of air flow, because a lot of iron and slag can not be got smoothly into the hearth through coke layer.

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