Selective enrichment of iron from fine-grained complex limonite using suspension magnetization roasting followed by magnetic separation

Abstract

ABSTRACT A process of suspension magnetization roasting and magnetic separation, which is used to separate and recover iron from fine limonite, was investigated. Iron concentrates grade of 58.29 wt.% and recovery of 91.45 wt.% were obtained under conditions of roasting time of 20 min at 560°C, CO concentration of 30%, grinding fineness of 85 wt.% passing 38 µm and total gas volume of 500 ml/min. X-ray diffraction (XRD), vibration sample magnetometer (VSM), scanning electron microscope (SEM) revealed fine weak magnetic limonite was selectively transformed into strong magnetic magnetite, porous structure of iron ore caused by magnetization roasting was helpful for grinding and magnetic separation.