工程科学学报，第41卷，第6期：741-747,2019年6月 Chinese Journal of Engineering,Vol.41,No.6:741-747,June 2019 DOI:10.13374/j.issn2095-9389.2019.06.005:http://journals.ustb.edu.cn 从选铜尾矿中选择性还原回收铁 邵爽，邢鹏，张文娟，马保中四，王成彦，陈永强，王玲 北京科技大学治金与生态工程学院，北京100083 ☒通信作者，E-mail:bzhma@126.com 摘要提出采用煤较低温度下选择性还原选铜尾矿中的铁，还原球团磁选回收铁的技术，并考察了还原温度、还原剂用量、 还原时间、活化剂用量对选铜尾矿选择性还原回收铁的影响，得出最佳工艺条件：还原温度为1200℃，还原剂用量为原料质量 25%,还原时间为2h,活化剂用量为原料质量5%：在最佳工艺条件下，磁选精矿中铁质量分数超过90%，铁回收率大于95%. 借助X射线衍射仪、光学显微镜和扫描电子显微镜等检测手段对原料、还原球团、磁选矿的矿相组成和结构进行分析，揭示了 铁矿相还原及金属相生成/融合演变规律：升高温度促进金属相的还原、融合兼并和生长：增加还原剂用量使金属颗粒的融合 兼并变得更加普遍：延长还原时间促进金属粒子的融合和铁橄榄石相的还原：活化剂促进金属粒子的扩散和融合.金属颗粒 的兼并生长促使其粒度增大，粗粒金属颗粒在磁选工序裹夹带入磁选精矿的渣相量相对较少，磁选精矿铁含量显著提高. 关键词选铜尾矿：还原：矿相：金属颗粒：融合 分类号TF803.1 Process of the selective reduction and recovery of iron from copper tailings SHAO Shuang,XING Peng,ZHANG Wen-juan,MA Bao-zhong,WANG Cheng-yan,CHEN Yong-qiang,WANG Ling School of Metallurgical and Ecological Engineering.University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:bzhma@126.com ABSTRACT Copper tailings are potential resources rich in iron minerals and their long-term stockpiling not only cause resource waste but also bring serious pressure to the ecological environment.Therefore,the resource utilization of copper tailings has attracted considerable attention and becomes the key to the sustainable development of the copper industry.In this study,the technology of the selective reduction of iron from copper tailings at low temperature using coal and recovery of iron from reduction pellets using magnetic separation was proposed.The effects of several factors,such as reduction temperature,reducing agent dosage,reduction time,and ac- tivator dosage,on the selective reduction and recovery of iron from copper tailings were investigated.The following optimum process conditions are determined through single-factor experiments:the reduction temperature is 1200C,the reducing agent dosage is 25%of the mass of copper tailings,the reduction time is 2h,and the activator dosage is 5%of the mass of copper tailings.Under the optimum process conditions,the iron mass fraction of the magnetic concentrate exceeds 90%,and the iron recovery rate is greater than 95%. The composition and structure of copper tailings,reduction pellets,and magnetic ores were determined via X-ray diffraction,optical microscopy,and scanning electron microscopy.Moreover,the mechanism of mineral phase reduction and metal phase generation/mer- ging was revealed.The results show that increase in temperature is beneficial for the reduction,merging,and growth of the metal phase.Merging the metal particles becomes common by increasing the reducing agent dosage.Prolonging the reduction time promotes the merging of metal particles and reduction of fayalite.The activator promotes the diffusion and merging of metal particles.The mer- ging and growth of metal particles promote the increase in particle size.The amount of slag wrapped by coarse metal particles in the magnetic concentrate is relatively small in the magnetic separation process,and the iron grade of the magnetic concentrate is significant- 收稿日期：201901-16 基金项目：国家重点研发计划资助项目(2018Y℉C1900304):国家自然科学基金青年基金资助项目(51804029)：国家自然科学基金云南省联合 基金资助项目(U1802253):广西科技重大专项资助项目(2018AA21022）:北京市自然科学基金资助项目(2182040)工程科学学报，第 41 卷，第 6 期: 741--747，2019 年 6 月 Chinese Journal of Engineering，Vol． 41，No． 6: 741--747，June 2019 DOI: 10． 13374 /j． issn2095--9389． 2019． 06． 005; http: / /journals． ustb． edu． cn 从选铜尾矿中选择性还原回收铁 邵 爽，邢 鹏，张文娟，马保中，王成彦，陈永强，王 玲 北京科技大学冶金与生态工程学院，北京 100083  通信作者，E-mail: bzhma@ 126． com 摘 要 提出采用煤较低温度下选择性还原选铜尾矿中的铁，还原球团磁选回收铁的技术，并考察了还原温度、还原剂用量、 还原时间、活化剂用量对选铜尾矿选择性还原回收铁的影响，得出最佳工艺条件: 还原温度为 1200 ℃，还原剂用量为原料质量 25% ，还原时间为 2 h，活化剂用量为原料质量 5% ; 在最佳工艺条件下，磁选精矿中铁质量分数超过 90% ，铁回收率大于 95% ． 借助 X 射线衍射仪、光学显微镜和扫描电子显微镜等检测手段对原料、还原球团、磁选矿的矿相组成和结构进行分析，揭示了 铁矿相还原及金属相生成/融合演变规律: 升高温度促进金属相的还原、融合兼并和生长; 增加还原剂用量使金属颗粒的融合 兼并变得更加普遍; 延长还原时间促进金属粒子的融合和铁橄榄石相的还原; 活化剂促进金属粒子的扩散和融合． 金属颗粒 的兼并生长促使其粒度增大，粗粒金属颗粒在磁选工序裹夹带入磁选精矿的渣相量相对较少，磁选精矿铁含量显著提高． 关键词 选铜尾矿; 还原; 矿相; 金属颗粒; 融合 分类号 TF803. 1 收稿日期: 2019--01--16 基金项目: 国家重点研发计划资助项目( 2018YFC1900304) ; 国家自然科学基金青年基金资助项目( 51804029) ; 国家自然科学基金云南省联合 基金资助项目( U1802253) ; 广西科技重大专项资助项目( 2018AA21022) ; 北京市自然科学基金资助项目( 2182040) Process of the selective reduction and recovery of iron from copper tailings SHAO Shuang，XING Peng，ZHANG Wen-juan，MA Bao-zhong ，WANG Cheng-yan，CHEN Yong-qiang，WANG Ling School of Metallurgical and Ecological Engineering，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: bzhma@ 126． com ABSTＲACT Copper tailings are potential resources rich in iron minerals and their long-term stockpiling not only cause resource waste but also bring serious pressure to the ecological environment． Therefore，the resource utilization of copper tailings has attracted considerable attention and becomes the key to the sustainable development of the copper industry． In this study，the technology of the selective reduction of iron from copper tailings at low temperature using coal and recovery of iron from reduction pellets using magnetic separation was proposed． The effects of several factors，such as reduction temperature，reducing agent dosage，reduction time，and ac￾tivator dosage，on the selective reduction and recovery of iron from copper tailings were investigated． The following optimum process conditions are determined through single-factor experiments: the reduction temperature is 1200 ℃，the reducing agent dosage is 25% of the mass of copper tailings，the reduction time is 2 h，and the activator dosage is 5% of the mass of copper tailings． Under the optimum process conditions，the iron mass fraction of the magnetic concentrate exceeds 90% ，and the iron recovery rate is greater than 95% ． The composition and structure of copper tailings，reduction pellets，and magnetic ores were determined via X-ray diffraction，optical microscopy，and scanning electron microscopy． Moreover，the mechanism of mineral phase reduction and metal phase generation/mer￾ging was revealed． The results show that increase in temperature is beneficial for the reduction，merging，and growth of the metal phase． Merging the metal particles becomes common by increasing the reducing agent dosage． Prolonging the reduction time promotes the merging of metal particles and reduction of fayalite． The activator promotes the diffusion and merging of metal particles． The mer￾ging and growth of metal particles promote the increase in particle size． The amount of slag wrapped by coarse metal particles in the magnetic concentrate is relatively small in the magnetic separation process，and the iron grade of the magnetic concentrate is significant-