Iron Recovery from Iron Ore Tailings by Direct Hydrogen Reduction at Low Temperature and Magnetic Separation

Abstract

In this work, we describe a sustainable alternative to recover iron from two iron ore tailings (IOT) using hydrogen reduction at relatively low temperatures followed by magnetic separation. X-ray powder diffraction (XRD), inductively coupled plasma (ICP), atomic absorption (AA), Mössbauer, scanning electron microscopy (SEM/EDS), Raman and thermogravimetry (TG) analyses indicated that the Fe oxide present in the IOTs (sandy tailing (ST) and mud tailings (MT)), can be reduced with H2 at 500 ºC to produce α-Fe. Upon magnetic separation the mud tailing produced a 77 wt.% magnetic fraction increasing the Fe content from 19.2 to ca. 56 wt.% of Fe. On the other hand, the sandy tailing resulted in a 15 wt.% magnetic fraction increasing the Fe content from 19.2 to 70 wt.%. These results indicate that up to 86% of iron can be recovered from the IOT wastes already in the metallic form which can be very interesting for the steel industry.