Recovery of Iron from Bauxite Red Mud by Reduction Roasting Method

Red mud is an important solid tailing with strong alkalinity that is obtained during the extraction of alumina in the Bayer process. The global reserve of red mud is more than ۴ billion tons, and its disposal as tailing has always been a serious environmental problem. This tailing is considered as a potential source, due to its high content of valuable metal compounds including iron. In this research work, the extraction of iron in red mud is investigated by the method of reduction roasting. The main influencing factors are also investigated. These methods include reduction in muffle and tube furnace, and temperature, reduction agent, and additive type are as important factors. Reduction roasting of the samples in a tube furnace, with Argon gas and vacuum, a mixture of red mud, graphite, and sodium carbonate at ۷۰۰–۱۰۰۰ °C results in the formation of Fe۳O۴. Magnetic measurements indicate that saturation magnetization increases from ۰.۲۳۹ to ۳۸.۲۰۵ emu/g due to the formation of Fe۳O۴. Applying the magnetic field intensity of about ۱۰۰۰ Gauss results in the iron recovery of ۸۹.۹%.

Keywords:

Red Mud , Reduction-Roasting , Muffle furnace , Tube furnace , Vibrating Sample Magnetometer