Accelerated CO2 Mineralization Using Alkaline Solid Wastes as Feedstocks: Recent Research Progress

Carbon dioxide mineral sequestration offers a thermodynamically stable and permanent route for carbon storage, yet its large-scale deployment remains constrained by slow carbonation kinetics, high pretreatment costs, and limited process scalability. Alkaline industrial solid wastes are generated in vast quantities, widely available, and rich in Ca/Mg-bearing components that can participate in carbonation reactions, making them attractive alternatives to natural minerals. This review summarizes recent advances in accelerating CO 2 mineralization using representative alkaline wastes, including steel slag, fly ash, cementitious wastes, waste gypsum, blast furnace slag, and red mud. It focuses on the relationships among waste composition, Ca/Mg availability, mineralization pathways, and product utilization. Direct carbonation, indirect carbonation, and integrated absorption–mineralization processes are compared, with particular emphasis on key intensification strategies such as feedstock activation, chemical acceleration, biological enhancement, electrochemical assistance, and reactor optimization. The industrial value of carbonation products in construction materials, environmental remediation, and high-value chemicals is also highlighted. Finally, in light of current research bottlenecks, this review identifies several priorities for future work, including reagent recovery, long-term product stability, reactor scale-up, and standardized techno-economic and life-cycle assessments. Overall, this review provides guidance for advancing alkaline solid waste mineralization toward industrial CO 2 mitigation.