Siderite as a novel reductant for clean utilization of refractory iron ore

A creative method of using siderite (FeCO3) as a novel reductant for clean utilization of low-grade refractory iron ore by magnetization roasting and low-intensity magnetic separation technology was proposed. To verify the applicability of this route, typical refractory iron ore from Jiuquan Iron and Steel Co., Ltd, China was investigated. Magnetic concentrate of iron grade 61.48% and recovery 95.39% was obtained with siderite dosage of 20%, roasting temperature of 700 degrees C, and magnetic intensity of 104 kA/m. In addition, the roasted products were analyzed by X-ray diffraction analysis, Mossbauer spectroscopy, transmission electron microscope, and vibrating sample magnetometer. The analysis results indicated that both hematite (Fe2O3) and siderite were transformed into magnetite (Fe3O4) that exhibited a good crystallinity in this magnetization roasting process. Moreover, the 8.84% surviving wustite (FeO) was found by Mossbauer spectroscopy in the roasted product. The magnetism of the sample improved clearly during the magnetization roasting process and the roasted product with a saturation magnetization of 52.58 Am-2/kg, remanence of 8.70 Am-2/kg, and coercivity of 11.2 x 10(3) A/m can be obtained. (C) 2019 Elsevier Ltd. All rights reserved.