High-efficiency extraction of iron from early iron tailings via the suspension roasting-magnetic separation

The high-efficiency extraction of iron from early iron tailings via the innovative suspension roasting-magnetic separation (SRMS) technology would be an important method to consolidate the available iron ore resources. In this study, the roasting effect and product characterizations of SRMS were investigated by the SRMS tests, X-ray diffraction, Fe chemical phase analyses, X-ray photoelectron spectroscopy, transmission electron microscopy, vibrating sample magnetometry, Brunauer-Emmett-Teller, and field emission scanning electron microscopy. The recommended conditions parameters were as follows: the roasting temperature was 600 degrees C, roasting time was 20 min, CO concentration was 30%, and grinding fineness 55.32 wt% passing 0.038 mm. The Fe grade and Fe recovery in the concentrate were 67.09% and 85.93%. The Fe content in magnetite was increased from 1.73% in the roasting feed to 98.42% in the SRMS products and the saturation magnetization was increased from 1.10 to 46.37 Am-2/kg. The analysis results exhibited the SRMS technology improved the porosity of the products and facilitated their grinding and separation. The results of this study demonstrated that SRMS could be an environmentally-friendly and clean technology for the recovery of iron from early iron tailings. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The high-efficiency extraction of iron from early iron tailings via the SRMS technology improved the porosity of the products and facilitated their grinding and separation. The recommended roasting conditions were temperature 600 degrees C, time 20 minutes, CO concentration 30%, and grinding fineness 55.32% passing 0.038 mm, with Fe grade in the concentrate at 67.09% and Fe recovery at 85.93%.