Tan Yongshan, Liu Shichang, Achintha Mithila, Mi Renjie
College of Civil Science and Engineering, Yangzhou University, Yangzhou 225127, China.
School of Engineering, The University of Manchester, Manchester M13 9PL, United Kingdom.
ACS Sustain Chem Eng. 2024 Nov 6;12(46):16869-16883. doi: 10.1021/acssuschemeng.4c05985. eCollection 2024 Nov 18.
Magnesia-based cement is recognized for its outstanding mechanical properties, but its environmental impact has not been thoroughly evaluated. This paper employs a comprehensive life cycle assessment methodology to systematically analyze the environmental effects of four kinds of MgO and 10 kinds of magnesia-based cements based on the data in the literature. The impacts include CO emissions, fossil fuel depletion potential, and overall environmental impact indicators. The results indicate that using Salt Lake magnesium residue to prepare MgO, e.g., LB-MgO and DB-MgO, can reduce over 60% of CO emissions, compared with traditional MgO (e.g., L-MgO and D-MgO) prepared with magnesite. Utilizing supplementary cementitious materials (e.g., fly ash and ground granulated blast-furnace slag) as substitutes for clinker in basic sulfate magnesium cement (BMSC) and magnesium phosphate potassium cement (MKPC) can also reduce approximately 16 and 45% of carbon emissions, respectively. In addition, carbonation-reactive magnesium cement (CRMC), which involves carbonation curing and replacing traditional MgO with Salt Lake magnesium residue, is the most environmentally friendly magnesia-based cement with an overall environmental impact indicator of 0.00078.
镁基水泥因其出色的力学性能而受到认可，但其对环境的影响尚未得到全面评估。本文采用综合生命周期评估方法，根据文献中的数据，系统分析了四种氧化镁和十种镁基水泥的环境影响。这些影响包括二氧化碳排放、化石燃料消耗潜力和整体环境影响指标。结果表明，与用菱镁矿制备的传统氧化镁（如L-MgO和D-MgO）相比，使用盐湖镁渣制备氧化镁，如LB-MgO和DB-MgO，可减少60%以上的二氧化碳排放。在碱式硫酸镁水泥（BMSC）和磷酸镁钾水泥（MKPC）中，使用辅助胶凝材料（如粉煤灰和粒化高炉矿渣）替代熟料，也可分别减少约16%和45%的碳排放。此外，采用碳化养护并用盐湖镁渣替代传统氧化镁的碳化反应性镁水泥（CRMC）是最环保的镁基水泥，其整体环境影响指标为0.00078。
