Is It Possible to Make Magnesia-Based Cement Environmentally\nFriendly?

Magnesia-based cement\nis recognized for its outstanding mechanical\nproperties, but its environmental impact has not been thoroughly evaluated.\nThis paper employs a comprehensive life cycle assessment methodology\nto systematically analyze the environmental effects of four kinds\nof MgO and 10 kinds of magnesia-based cements based on the data in\nthe literature. The impacts include CO<sub>2</sub> emissions, fossil\nfuel depletion potential, and overall environmental impact indicators.\nThe results indicate that using Salt Lake magnesium residue to prepare\nMgO, e.g., LB-MgO and DB-MgO, can reduce over 60% of CO<sub>2</sub> emissions, compared with traditional MgO (e.g., L-MgO and D-MgO)\nprepared with magnesite. Utilizing supplementary cementitious materials\n(e.g., fly ash and ground granulated blast-furnace slag) as substitutes\nfor clinker in basic sulfate magnesium cement (BMSC) and magnesium\nphosphate potassium cement (MKPC) can also reduce approximately 16\nand 45% of carbon emissions, respectively. In addition, carbonation-reactive\nmagnesium cement (CRMC), which involves carbonation curing and replacing\ntraditional MgO with Salt Lake magnesium residue, is the most environmentally\nfriendly magnesia-based cement with an overall environmental impact\nindicator of 0.00078.