Red mud is a waste generated during the Bayer process in the production of alumina. Recovery of metallic components of the red mud has both environmental and economic benefits. In this study, the effect of carbothermal reduction on the physical and chemical separation of red mud components, namely Ti, REEs, Fe, and Al, were investigated. At first, the impact of carbothermal reduction on the efficiency and selectivity of iron separation from the bulk material through magnetic separation was studied. At the optimum conditions of T = 1350 °C, using a ring-shaped mixing regime of coal and red mud, coal/red mud ratio of 3, t = 120 mins, and soda ash/red mud ratio of 0.2, the iron content of the red mud was effectively metalized and separated from Ti, REEs, and Al. Recovery of iron in the magnetic separation concentrate was 91%, with Fe content of 81%, while about 90% of Ti and Al and 80% of REEs were retained in the non-magnetic product. For the untreated sample, however, iron separation was insignificant mostly due to the low iron metallization. Finally, the dissolution behavior of Ti, REEs, Fe, and Al for both treated and untreated samples using H₂SO₄, HCl, and HNO₃ were studied. Different dissolution behavior of the REEs and Ti were observed and correlated to the mineralogical composition of the sample. Overall, carbothermal reduction has shown to positively affect the magnetic separation of iron but negatively affected the Ti and REEs dissolution efficiency.

赤泥是拜耳法在氧化铝生产过程中产生的废物。赤泥金属成分的回收具有环境效益和经济效益。在这项研究中，研究了碳热还原对赤泥成分，即 Ti、REE、Fe 和 Al 的物理和化学分离的影响。首先，研究了碳热还原对通过磁选从散装材料中分离铁的效率和选择性的影响。在 T = 1350 °C 的最佳条件下，采用煤和赤泥的环形混合方式，煤/赤泥比为 3，t = 120 mins，纯碱/赤泥比为 0.2，铁含量的赤泥被有效地金属化并与 Ti、REE 和 Al 分离。磁选精矿中铁的回收率为91%，Fe含量为81%，而大约 90% 的 Ti 和 Al 以及 80% 的 REE 保留在非磁性产品中。然而，对于未经处理的样品，铁分离并不显着，主要是由于铁金属化程度低。最后，使用 H 处理处理和未处理样品的 Ti、REEs、Fe 和 Al 的溶解行为_{研究了 2} SO ₄、HCl 和 HNO ₃。观察到 REE 和 Ti 的不同溶解行为，并与样品的矿物组成相关。总体而言，碳热还原已显示出对铁的磁分离有积极影响，但对 Ti 和 REE 的溶解效率有负面影响。