Reduction Kinetics of Hongge Vanadium Titanomagnetite-Oxidized Pellet with Simulated Shaft Furnace Gases

Abstract

The reduction kinetics of Hongge vanadium titanomagnetite (HVTM)‐oxidized pellet with simulated gas compositions of dry pulverized coal gasification (DPCG), water‐coal slurry gasification (WCSG), Midrex, and HYL‐III is investigated in the current study. The experiments are carried out at temperatures ranging from 900 to 1050 °C, simulating the reduction zone in gas‐based shaft furnace direct reduction processes. The reduction degree is the highest when reduced with the gas composition of HYL‐III while the lowest when reduced with DPCG. The reduction degree, as well as the reaction rate constant and effective diffusion coefficient, is found to decrease in the order of HYL‐III > Midrex > WCSG > DPCG. The reduction process is controlled by interfacial chemical reaction at initial stage and by both interfacial chemical reaction and internal diffusion at later stage. The scanning electron microscope (SEM) coupled with energy‐dispersive spectroscopy (EDS) and X‐ray diffraction (XRD) are used to estimate the reduction mechanism of HVTM‐oxidized pellet with different gas compositions. This study aims to obtain scientific direction for reactor design and operational parameter determination of gas‐based shaft furnace, as well as provide both theoretical and technical basis for the comprehensive utilization of HVTM.

Effect of Al2O3 on the Viscosity and Crystallization Behavior of CaO-SiO2-MgO-Al2O3-TiO2-Cr2O3 Slag

“…Unfortunately, it is difficult to commercially recover titanium from BF slag due to its low content (20-25% TiO 2 ) and dispersion in the slag. [11][12][13][14][15] In addition to the BF process, the gasbased reduction process can be used to obtain highquality product with low environmental pollution and CO 2 emission compared to those of the coalbased direct reduction in which coal is used as the reducing agent. These advantages endow gas-based direct reduction with strong competitiveness and development potential.…”

Slag-metal Separation and Reduction Behaviors of Vanadium-bearing Titanomagnetite Metallized Pellets

“…Tang et al 15) studied the slag-metal separation behavior of highchromium vanadium-bearing titanomagnetite metallized pellet obtained from gas-based direct reduction. 16) With the optimized parameters (melting temperature: 1 625°C, melting time: 40-50 min, additive CaF 2 : 2% and basicity: 1.1), the recovery ratios of Fe, V and Cr could reach around 99%, 97% and 92%, respectively.…”

Influence of B₂O₃ on the Oxidation and Induration Process of Hongge Vanadium Titanomagnetite Pellets

“…To efficiently utilize HVTM, a novel and clean smelting process has been proposed by our laboratory that greatly increased the recovery rates of valuable elements. 21,22) In this process, HVTM is pelletized, oxidized, and indurated, and then reduced in a shaft furnace and subjected to melting separation to comprehensively recover iron, titanium, vanadium, and chromium. The production of oxidized pellets is an essential step in this process.…”