Life cycle assessment of hybrid alkali-activated cement production with red mud as an alkali activator.

Abstract

The production of hybrid alkali-activated cement (HAAC) has generated considerable interest in environmental issues. In this research, the environmental impacts of utilizing red mud (RM) as a partial activator of alkali-activated ground granulated blast furnace slag (GBFS) in HAAC production have been evaluated. A contribution analysis was carried out using life cycle assessment (LCA) to assess the environmental significance of six important substances in HAAC production. A comparative analysis of the environmental consequences of producing ordinary portland cement (OPC) and two HAACs using various activators in the same plant was conducted. The results showed that the calcination and preparation of alkali-activated cementitious materials are the two processes with the highest environmental impacts. Marine ecotoxicity was identified as the primary impact category, followed by freshwater ecotoxicity and fossil depletion. HAAC provides better benefits than OPC in most environmental impact categories. Additionally, the inclusion of RM as a partial alkali activator to HAAC results in even more pronounced environmental benefits when compared to NaOH alone, particularly in terms of cleaner production areas.