Isothermal reduction kinetics and mineral phase of chromium-bearing vanadium–titanium sinter reduced with CO gas at 873–1273 K  

作　　者：Song-tao Yang Mi Zhou Tao Jiang Xiang-xin Xue 

机构地区：[1]School of Metallurgy,Northeastern University,Shenyang 110819,China [2]School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,China [3]Key Laboratory of Liaoning Province for Recycling Science of Metallurgical Resources,Shenyang 110819,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2018年第2期145-152,共8页矿物冶金与材料学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51604065 and 51674084);the Fundamental Funds for the Central Universities(Nos.150203003 and 150202001);the Natural Science Foundation of Liaoning Province(20170540316);the China Postdoctoral Science Foundation(2017M611246);the NEU Postdoctoral Science Foundation(No.20160304)

摘　　要：Reduction of chromium-bearing vanadium–titanium sinter（CVTS） was studied under simulated conditions of a blast furnace, and thermodynamics and kinetics were theoretically analyzed. Reduction kinetics of CVTS at different temperatures was evaluated using a shrinking unreacted core model. The microstructure, mineral phase, and variation of the sinter during reduction were observed by X-ray diffraction, scanning electron microscopy, and metallographic microscopy. Results indicate that porosity of CVTS increased with temperature. Meanwhile, the reduction degree of the sinter improved with the reduction rate. Reduction of the sinter was controlled by a chemical reaction at the initial stage and inner diffusion at the final stage. Activation energies measured 29.22–99.69 k J/mol. Phase transformations in CVTS reduction are as follows： Fe_2O_3→Fe_3O_4→FeO→Fe; Fe_2TiO_5→Fe_2TiO_4→FeTiO_3; FeO·V_2O_3→V_2O_3; FeO·Cr_2O_3→Cr_2O_3.Reduction of chromium-bearing vanadium–titanium sinter（CVTS） was studied under simulated conditions of a blast furnace, and thermodynamics and kinetics were theoretically analyzed. Reduction kinetics of CVTS at different temperatures was evaluated using a shrinking unreacted core model. The microstructure, mineral phase, and variation of the sinter during reduction were observed by X-ray diffraction, scanning electron microscopy, and metallographic microscopy. Results indicate that porosity of CVTS increased with temperature. Meanwhile, the reduction degree of the sinter improved with the reduction rate. Reduction of the sinter was controlled by a chemical reaction at the initial stage and inner diffusion at the final stage. Activation energies measured 29.22–99.69 k J/mol. Phase transformations in CVTS reduction are as follows： Fe_2O_3→Fe_3O_4→FeO→Fe; Fe_2TiO_5→Fe_2TiO_4→FeTiO_3; FeO·V_2O_3→V_2O_3; FeO·Cr_2O_3→Cr_2O_3.

关 键 词：sinter kinetics reduction mineral phase 

分 类 号：TF046.4[冶金工程—冶金物理化学]