微波场中铌、铁选择性还原行为研究  

Selective Reduction of Niobium and Iron in Microwave Field

作　　者：郭嘉诚 金永丽[1] 赵增武[1] Guo Jiacheng;Jin Yongli;Zhao Zengwu(Key Laboratory of Integrated Exploitation of Bayan-Obo Multi-Metal Resources,Collaborative Innovation Center of Integrated Exploitation of Bayan-Obo Multi-Metal Resources,National and Local Joint Engineering Research Center of Integrated Exploitation of Bayan Obo Associated Mineral Waste Resources,School of Materials and Metallurgy,Inner Mongolia University of Science&Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,白云鄂博矿多金属资源综合利用重点实验室,白云鄂博共伴生矿资源高效综合利用省部共建协同创新中心,白云鄂博共伴生矿废弃物资源综合利用国家地方联合工程研究中心,内蒙古包头014010

出　　处：《稀有金属》2024年第1期68-78,共11页Chinese Journal of Rare Metals

基　　金：国家重点研发计划项目(2020YFC1909102);国家自然科学基金项目(51464039,52064044);内蒙古自然科学基金项目(2019MS05010)资助。

摘　　要：为了综合利用白云鄂博尾矿中的铌、铁资源,将微波冶金技术与直接还原技术耦合,进行白云鄂博尾矿低温碳热还原试验,研究微波场中铌和铁的选择性还原行为,优化工艺参数。结果表明:微波能够降低白云鄂博尾矿碳热还原的温度,加快金属化速度,并且随着温度的升高、保温时间的延长、升温速率的加快,铁的金属化率增加。铌矿物的还原行为与矿物中含铁量和嵌布关系有关。在富含CaO和CaF_(2)的区域,铌酸铁发生FeNb_(2)O_(6)→Nb_(2)O_(5)→CaNb_(2)O_(6)→Ca_(2)Nb_(2)O_(6)F的矿相转变;铌酸钙发生CaNb_(2)O_(6)→Ca_(2)Nb_(2)O_(7)→Ca_(2)Nb_(2)O_(6)F的矿相转变。当矿物中全铁含量(T_(Fe))=10.60%,温度小于1100℃时,铌矿物中的铌不能被C还原,主要以Ca_(2)Nb_(2)O_(6)F的形式分布在渣相中;当T_(Fe)=29.20%,铌矿物中的铌在1000℃时开始被C还原成NbO_(2)和NbC,并与Fe,FeS紧密粘连。微波场中铌、铁选择性还原的条件是还原温度900℃,保温时间40 min,升温速率30℃·min^(-1)时,铁的金属化率达到93.07%,铌矿物中的铌未被还原,实现了铌、铁的选择性还原。The reserves of niobium resources in Bayan Obo are abundant,but the niobium minerals in it have the characteristics of"multiple species,low grade,fine particle size and complex embedded relationships",as a result,in the traditional beneficiation process based on"iron and rare earth",niobium resources are scattered in all levels of beneficiation processes,and finally accumulated in tailings dams,with zero utilization rate.China is rich in non-coking coal resources,and the direct reduction technology does not depend on coke,eliminating the need for cooking equipment,and can also obtain high-grade iron concentrates.It is in line with Chinese resource utilization direction,and it is an effective method to deal with complex co-existing ores.However,the high reduction temperature required by the direct reduction technology limits the selective reduction of valuable elements in the ore.Carbon can effectively absorb microwaves.In the process of carbothermic direct reduction,microwaves are selected for heating,which can take advantage of the characteristics of bulk heating and selective heating of microwave heating to achieve rapid temperature rise.The coupling of microwave metallurgy technology and direct reduction technology can reduce the reaction temperature of direct reduction,speed up the reaction speed,and enhance the reduction ability.Based on this,this work proposed a new technology of"superconducting niobium separationmicrowave iron removal-electrolytic niobium extraction"to deal with Bayan Obo tailings resources.Through the"permanent magnetelectromagnetic-superconducting"cascade magnetic separation technology and step-by-step flotation technology,the niobium was enriched in the form of niobium-rich ore.Under the action of external field strengthening,the selective reduction of niobium-rich ore was carried out to remove iron to further realize the enrichment of niobium in niobium-rich ore.Finally,the selective reduction characteristics of electrochemical metallurgy were used to extract niobium in the form of fer

关 键 词：微波 选择性还原 铌酸铁 铌酸钙 含铁量 

分 类 号：TF19[冶金工程—冶金物理化学]