The cement industry faces growing environmental pressures. These include fossil fuel depletion, raw material shortages, and massive accumulation of solid waste. Ordinary Portland cement production accounts for a large share of global carbon dioxide emissions. It also produces enormous amounts of solid waste. Against this background, low-carbon alternative cementitious materials have attracted extensive attention. They feature a smaller carbon footprint and excellent performance in solid waste immobilization. This review systematically analyzes three typical magnesia-based cements: magnesium oxychloride cement (MOC), magnesium oxysulfate cement (MOS), and magnesium phosphate cement (MPC). It summarizes their development history, hydration mechanisms, inherent performance drawbacks, and mainstream modification approaches. This work also highlights the latest research progress on applying the three cements to immobilize industrial and agricultural solid wastes. It provides insightful references for future research on sustainable cement-based solid waste recycling.
Li et al. (Fri,) studied this question.