phases indicate the inclusion of titanium bearing minerals and desilication products formed during the bauxite treatment in alkali solution. The mineralogical composition of refinery A, refinery B and refinery C are influenced by both the bauxite mineralogy and the refining conditions and post-processing transformations. 4. IMPLICATIONS FOR CRITICAL MINERAL STRATEGY AND MINERAL POLICY The results of this project have significant implications for the critical mineral strategy and mineral policy in economies which have limited access to natural resources and rely heavily on importing primary materials. There are considerable differences in terms of the chemical composition, mineralogy and morphology of red mud samples from various refineries. These differences demonstrate that red mud should not be viewed as a single, homogeneous industrial waste product. Rather, it should be viewed as a secondary resource located at each site. Therefore, its value as a strategic resource will depend upon the origin of the bauxite and the refining processes used at each refinery. Scandium has demonstrated the greatest level of enrichment in all samples with the greatest amount being in Refinery B. Therefore, red mud appears to represent a potential domestic source of valuable critical material; scandium is a critical metal that is important for advanced alloys, aerospace applications and renewable energy systems (Mitrica et al., 2021). As such, it represents a potential means to decrease reliance on imported primary resources. Other technological metals and rare earth elements and gallium and vanadium are also found in the red mud. Although these are present at relatively low concentrations, they contribute to strategic importance when the volume of residue produced is considered. These findings support the necessity of creating differential policy and regulation. The encouragement of refinery specific characterization and selective recovery is supported. Regulating red mud solely based on the focus of disposal will likely inhibit the utilization of the resource. Therefore, policies that incorporate secondary resources into national critical mineral road maps are necessary. Pilot scale recovery studies are needed to support this type of activity. Collaboration between the producers of alumina, research organizations and downstream users should be encouraged. Red mud valorization supports sustainability and circular economic objectives. Valorization can assist in reducing the long-term waste storage and environmental risks associated with the disposal of red mud. Resource efficiency throughout the alumina value chain can be enhanced. Recognition of red mud within critical mineral policy frameworks can enhance mineral security and promote better mining and metallurgical practice. 5. CONCLUSIONS The technical differences among the three red mud samples were found to be very significant and varied greatly based on the original raw materials used at the respective alumina refineries. The variation in the red mud samples was primarily based on the geochemical and 124
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