Effect of Thermal Oxidation Pretreatment on the Magnetization Roasting and Separation of Refractory Iron Ore

The effect of thermal oxidization pretreatment (TOP) on the magnetization roasting and separation of refractory iron ore was investigated. The TOP of raw samples was performed in a muffle furnace at 750 degrees C for 30 min. The magnetization roasting and separation experiments of the raw samples and TOP samples were performed, which revealed that TOP could decrease the optimal CO concentration required during the magnetization roasting process by 10% and increase the iron recovery by about 10%. Analysis results of X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) showed that there were many pores and cracks in the TOP samples, which were advantageous to the subsequent magnetization roasting, and promoted the sufficient conversion of specularite and siderite to magnetite, increasing the iron recovery significantly.