A semi-industrial experiment of suspension magnetization roasting technology for separation of iron minerals from red mud

Shuai Yuan; Xiao Liu; Peng Gao; Yuexin Han

doi:10.1016/j.jhazmat.2020.122579

A semi-industrial experiment of suspension magnetization roasting technology for separation of iron minerals from red mud

J Hazard Mater. 2020 Jul 15:394:122579. doi: 10.1016/j.jhazmat.2020.122579. Epub 2020 Mar 27.

Authors

Shuai Yuan¹, Xiao Liu², Peng Gao³, Yuexin Han³

Affiliations

¹ College of Resources and Civil Engineering, Northeastern University, Shenyang 110819, PR China; State Key Laboratory of Mineral Processing, Beijing 100070, PR China; National-Local Joint Engineering Research Center of High-Efficient Exploitation Technology for Refractory Iron Ore Resources, Shenyang 110819, PR China.
² College of Resources and Civil Engineering, Northeastern University, Shenyang 110819, PR China; State Key Laboratory of Mineral Processing, Beijing 100070, PR China; National-Local Joint Engineering Research Center of High-Efficient Exploitation Technology for Refractory Iron Ore Resources, Shenyang 110819, PR China. Electronic address: xiaoxiaoyangliu@163.com.
³ College of Resources and Civil Engineering, Northeastern University, Shenyang 110819, PR China; National-Local Joint Engineering Research Center of High-Efficient Exploitation Technology for Refractory Iron Ore Resources, Shenyang 110819, PR China.

PMID: 32283382
DOI: 10.1016/j.jhazmat.2020.122579

Abstract

Red mud is a type of solid waste derived from the alumina extraction process. It can be considered as a secondary resource for recovering iron values because of its high content of ferric oxide. In this study, an innovative technology called suspension magnetization roasting (SMR) was applied to treat red mud to recycle iron. Based on the lab-scale experimental basis, we adopted the single factor method to perform the semi-industrial scale experiments. Under the optimum conditions, the recovery and grade of iron in the iron concentrate were 95.22 % and 55.54 %, respectively. Chemical phase analysis, vibrating sample magnetometer, and XRD combined with Mössbauer spectroscopy were employed to assess the characteristics of red mud and roasted products. Occupancy of Fe content in magnetite was raised to 89.91 % in SMR products from 0.75 % in the red mud; saturation magnetization was enhanced from 0.40 A·m²/kg to 32.44 A·m²/kg; and the hematite and goethite phase were transformed into Fe₃O₄ (A), Fe₃O₄ (B) and γ-Fe₂O₃ phase. In addition, transmission electron microscopy analysis revealed that both magnetite and maghemite were found in the roasted product. This study demonstrates that SMR is a promising technology for the recovery of iron from red mud.

Keywords: Iron recovery; Magnetic separation; Phase transformation; Red mud; Suspension magnetization roasting.

Publication types

Research Support, Non-U.S. Gov't