Life Cycle Assessment of Red Mud-Based Geopolymer Production at Industrial Scale

Nowadays the production of traditional building materials continues to be highly energy consuming and polluting. Therefore, the development of sustainable materials that allow the reuse of industrial waste could lead to a faster ecological transition of the construction industry. Among lab-scale developed materials, geopolymers are widely recognized as a future and sustainable alternative to traditional Portland cement, allowing to reuse various wastes from different industrial sectors. This paper aims to perform an environmental analysis of geopolymers large-scale production based on the use of red mud, a waste product from the aluminum supply chain. Previous studies on red mud-based geopolymers have focused mainly on optimizing the laboratory formulations, without analyzing their real environmental advantage over traditional building materials. Therefore, this study uses the life cycle assessment approach to verify the environmental benefit of the large-scale production for the circular economy. Starting from the literature analysis, a four-steps scale-up procedure was applied to identify a potential industrial production. Results showed a clear reduction in CO2 emissions compared to the production of conventional Portland cement and highlighted the need to reduce the use of alkaline activators in geopolymers production.