Comparing strategies for iron enrichment from Zn- and Pb-bearing refractory iron ore using reduction roasting-magnetic separation

Iron in refractory iron ore composed of 47.04% Fe, 0.39% Pb and 0.30% Zn was enriched through reduction roasting followed by magnetic separation in this work. The phase transformations occurring in iron ore during reduction roasting were investigated through XRD, VSM, and SEM-EDS. Results show reduction process of hematite follows Fe2O3 -> Fe3O4 -> FeO -> Fe. The quartz in iron ore reacts with FeO to form fayalite. At elevated temperatures, fayalite decomposes into metallic iron and cristobalite solid solution. The reductively roasted product (RRP) with main phases of magnetite and metallic iron has higher magnetization intensity than that with main phases of wustite and fayalite. Iron in RRP-800 degrees C and RRP-1150 degrees C is extracted by magnetic separation, and obtained concentrates have main minerals of magnetite and metallic iron, respectively. Elevated temperature decreases zinc and lead contents in concentrate. Thus, deep reduction-magnetic separation is more suitable for enriching iron from Zn- and Pb-bearing refractory iron ore. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Iron in refractory iron ore was enriched through reduction roasting and magnetic separation, with the deep reduction-magnetic separation method found to be more suitable for iron enrichment. Phase transformations during reduction roasting were investigated, revealing the formation of main phases of magnetite and metallic iron in the reductively roasted product.