Separate recycling of iron and aluminum from iron-rich red mud by coal gangue reduction to realize solid waste utilization

Iron-rich red mud is a typical solid waste in the aluminum industry. And coal gangue is generated during the coal selection process. The efficient treatment of these two kinds of large reserves of solid waste has important resource value and environmental value. In this study, the co-roasting of iron-rich red mud with coal gangue for iron and aluminum recycling was explored. The optimum conditions were 850 degrees C, 30 min, 30 % coal gangue, -37 mu m accounts for 85.88 %, and magnetic intensity of 132 x 10(3)A/m. Then the iron recovery, TFe grade, iron yield, Al2O3 content of iron concentrate were 70.14 %, 59.77 %, 49.14 %, and 8.26 %, separately. the Al2O3 content and recovery rate in Al-containing products were 16.90 %, and 64.35 %, separately. Based on the analysis of materials, hematite was transformed to magnetite, and diaspore was transformed into Al2O3 through co-roasting. Its saturation magnetization strength increased from nearly 0 A center dot m(2)center dot kg(-1) to 7.23 A center dot m(2)center dot kg(-1). Meanwhile, the sample changed from compact to porous honeycomb structure, and the newly formed small magnetite particles were densely distributed on the surface. Therefore, the co-roasting achieved tailings-free resource utilization of two types of solid waste, as well as co-roasting to effectively separate iron and aluminum from red mud and coal gangue. (c) 2024 Society of Powder Technology Japan Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.