Bauxite residue (BR) is produced in vast quantities during the Bayer process for producing alumina and is typically landfilled.1,2 Although numerous valorisation pathways have been suggested,3,4,5 the utilisation is currently restricted to <3% of the 170 Mt/year generated and a total volume of 4 Gt has been accumulated.2,6 The alkaline character, the fine particle size, as well as the complex nature of the minerals in BR, are the main technical reasons for the low utilisation.2,4 One of the valorisation options is the recovery of metals, such as iron, aluminium, titanium, and rare earth elements (REEs), including scandium. Our study investigated the reduction of BR with NaOH at relatively low temperatures (400-700°C) using varying contents of hydrogen as a reducing agent: 5 vol% H2 + 95 vol% N2 and 100 vol% H2, both gas compositions with a flowrate of 20 L/h. A combined water leaching and wet-magnetic separation process was carried out for the recovery of Fe, Al, and Na. Unlike previous studies6,7,8, this study provides a comprehensive comparison of Fe, Al, and Na recovery and further, evaluates phase changes under various H2 concentrations, offering a novel contribution to the field.