This paper explores the effects of reductant type, flux, reduction temperature, and reduction time on coal-based direct reduction of iron ore tailings. A series of tests were designed and implemented on ore tailing samples containing 14.51% of iron. The results show that the most ideal coal reductant for the direct reduction of iron ore tailings should be rich in fixed carbon and poor in volatile matters; with anthracite as reductant and CaO as flux, the tailing samples roasted and magnetically separated for 180min at 1,300 oC yielded high iron content (90.12%) and iron recovery rate (72.21%). Then, the components of the product was analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). According to the XRD, SEM and EDX spectra, the product consists of lots of metallic irons and a few α-cristobalite and magnetite. The metallic irons were obtained through direct reduction, while the α-cristobalite and magnetite came from the secondary oxidization of metallic iron. The research findings shed new light on the reduction and recovery of iron in iron ore tailings
iron ore tailings, coal-based direct reduction, reductant type, roasting
This paper is made possible thanks to the generous support from China Postdoctoral Science Foundation (Grant No.: 2016M602082), Natural Science Foundation of Hebei Province (Grant No.: E2018402119), Science and Technology Research Project of Higher Education Universities in Hebei Province (Grant No.: ZD2016014; QN2016115), Shaanxi Key Laboratory of Comprehensive Utilization of Tailings Resources (Grant No.: 2017SKY-WK008), Handan Science and Technology Research and Development Plan Program (Grant No.: 1621211040-3), Jiangxi Postdoctoral Daily Fund Project (Grant No.: 2016RC30) and Jiangxi Postdoctoral Research Project (Grant No.: 2017KY19)
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