Recovery of Iron from Tailings with Fluidized Magnetization Roasting Followed by Magnetic Separation

In order to improve recovery efficiency of iron minerals from iron ore tailings and to reduce its associated environmental pollution, this article investigated the reducing roasting of iron ore tailings in a laboratory fluidized magnetization roasting reactor to optimize the roasting method and conditions. The examined parameters included roasting temperature, roasting time, and reducing atmosphere. The parameters evaluating magnetizing roast efficiency and theoretical value were determined. X-ray diffraction (XRD) analysis was utilized to investigate the conversion of iron phase after roasting. The results show that the best magnetizing roast conditions are a roasting temperature of 540℃, holding time of 15 min, and CO concentration of 20%. The magnetization conversion ratio of roasting products is over 80%; under the best magnetic separation condition, the concentrate grade of iron is 65.61%, and the recovery of iron is 83.77%. The XRD analysis reveals that Fe exists in hematite and siderite before roasting and in magnetite after roasting. This technique not only effectively recovers iron minerals from tailings with good economic benefits but also mitigates the environmental pollution caused by tailings accumulation.