Research progress of CO₂ capture and mineralization based on natural minerals

Natural minerals, such as kaolinite, halloysite, montmorillonite, attapulgite, bentonite, sepiolite, forsterite, and wollastonite, have considerable potential for use in CO₂ capture and mineralization due to their abundant reserves, low cost, excellent mechanical properties, and chemical stability. Over the past decades, various methods, such as those involving heat, acid, alkali, organic amine, amino silane, and ionic liquid, have been employed to enhance the CO₂ capture performance of natural minerals to attain high specific surface area, a large number of pore structures, and rich active sites. Future research on CO₂ capture by natural minerals will focus on the full utilization of the properties of natural minerals, adoption of suitable modification methods, and preparation of composite materials with high specific surface area and rich active sites. In addition, we provide a summary of the principle and technical route of direct and indirect mineralization of CO₂ by natural minerals. This process uses minerals with high calcium and magnesium contents, such as forsterite (Mg₂SiO₄), serpentine Mg₃Si₂O(OH)₄, and wollastonite (CaSiO₃). The research status of indirect mineralization of CO₂ using hydrochloric acid, acetic acid, molten salt, and ammonium salt as media is also introduced in detail. The recovery of additives and high-value-added products during the mineralization process to increase economic benefits is another focus of future research on CO₂ mineralization by natural minerals.