Behaviors of vanadium and chromium in coal-based direct reduction of high-chromium vanadium-bearing titanomagnetite concentrates followed by magnetic separation

作     者：赵龙胜 王丽娜 陈德胜 赵宏欣 刘亚辉 齐涛 Long-sheng ZHAO;Li-na WANG;De-sheng CHEN;Hong-xin ZHAO;Ya-hui LIU;Tao QI

作者机构：中国科学院大学北京100049 中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室北京100190 中国科学院过程工程研究所绿色过程与工程院重点实验室北京100190 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2015年第25卷第4期

页      面：1325-1333页

核心收录：

学科分类：080602[工学-钢铁冶金] 081902[工学-矿物加工工程] 0819[工学-矿业工程] 08[工学] 0806[工学-冶金工程] 

基　　金：Projects(2013CB632601,2013CB632604)supported by the National Basic Research Program of China Project(51125018)supported by the National Science Foundation for Distinguished Young Scholars of China Project(KGZD-EW-201-2)supported by the Key Research Program of the Chinese Academy of Sciences Projects(51374191,21106167,51104139)supported by the National Natural Science Foundation of China 

主　　题：high-chromium vanadium-bearing titanomagnetite concentrates coal-based direct reduction magnetic separation reduction behavior vanadium chromium 

摘      要：The reduction behaviors of FeO·V2O3 and FeO·Cr2O3 during coal-based direct reduction have a decisive impact on the efficient utilization of high-chromium vanadium-bearing titanomagnetite concentrates. The effects of molar ratio of C to Fe n(C)/n(Fe) and temperature on the behaviors of vanadium and chromium during direct reduction and magnetic separation were investigated. The reduced samples were characterized by X-ray diffraction(XRD), scanning election microscopy(SEM) and energy dispersive spectrometry(EDS) techniques. Experimental results indicate that the recoveries of vanadium and chromium rapidly increase from 10.0% and 9.6% to 45.3% and 74.3%, respectively, as the n(C)/n(Fe) increases from 0.8 to 1.4. At n(C)/n(Fe) of 0.8, the recoveries of vanadium and chromium are always lower than 10.0% in the whole temperature range of 1100-1250 °C. However, at n(C)/n(Fe) of 1.2, the recoveries of vanadium and chromium considerably increase from 17.8% and 33.8% to 42.4% and 76.0%, respectively, as the temperature increases from 1100 °C to 1250 °C. At n(C)/n(Fe) lower than 0.8, most of the FeO·V2O3 and FeO·Cr2O3 are not reduced to carbides because of the lack of carbonaceous reductants, and the temperature has little effect on the reduction behaviors of FeO·V2O3 and FeO·Cr2O3, resulting in very low recoveries of vanadium and chromium during magnetic separation. However, at higher n(C)/n(Fe), the reduction rates of FeO·V2O3 and FeO·Cr2O3 increase significatly because of the excess amount of carbonaceous reductants. Moreover, higher temperatures largely induce the reduction of FeO·V2O3 and FeO·Cr2O3 to carbides. The newly formed carbides are then dissolved in the γ(FCC) phase, and recovered accompanied with the metallic iron during magnetic separation.