Green magnetization roasting technology for refractory iron ore using siderite as a reductant

In the present study, a green magnetization roasting process was proposed by using siderite (FeCO3) as the reductant. The influences of the siderite dosage, roasting temperature and roasting time on the magnetization roasting process were investigated. The saturation magnetization of roasted samples was analyzed by a vibrating sample magnetometer (VSM), and the phase transformation was investigated by in situ X-ray diffraction (XRD). The optimal roasting conditions were determined to be a siderite dosage of 40% with a roasting temperature of 700 degrees C and a roasting time of 10.0 min. The saturation magnetization of the roasted product under optimal conditions was 70.19 A m(2) kg(-1). The siderite (FeCO3) was transformed to magnetite (Fe3O4) with the intermediate product of wustite (FeO) in the decomposition process. In the meantime, the hematite (Fe2O3) was reduced to magnetite (Fe3O4) by the carbon monoxide released from the decomposition of siderite. (C) 2018 Elsevier Ltd. All rights reserved.