Research progress on carbon dioxide mineralization sequestration technology by tailings
Lijie Guo, Xiaopeng Peng, Qianqian Wang, Yue Zhao, Lingling Xu, Shan Wu
Abstract
Carbon dioxide capture, utilization, and storage (CCUS) has become a focal point of research for scientists worldwide to address the global warming issue. Among these studies, utilizing mine tailings as CO 2 mineralization materials has emerged as a new research approach in recent years. This study reviews the research progress of using mine tailings for CO 2 mineralization and sequestration. The reaction mechanisms of CO 2 mineralization using tailings have been introduced first. Notably, ultramafic tailings containing divalent cations, such as Ca 2+ , Mg 2+ , and Fe 2+ , can react with CO 2 to produce carbonate precipitates. Furthermore, factors including the size of mineral particles, reaction temperature, and pressure will influence the mineralization reaction rate. The activation methods of tailings to accelerate mineral carbonation have been summarized. The activation of tailings for mineralization generally includes acid leaching, ammonium salt pH swing, and physical grinding. Newly developed methods, such as a combination of acid digestion and electrolysis of olivine, have also been introduced. Thereafter, the processes and technologies for CO 2 sequestration through tailings mineralization have been analyzed. The in-situ and ex-situ mineral carbonation processes have been introduced. The last part explores the technical approaches of synergistic mineralization and storage of CO 2 by cemented tailings backfill in underground mined-out areas, which is considered to be one of the key technological pathways for CCUS in the future. However, critical technical challenges must still be addressed for this process, including low-cost multiphase CO 2 storage in backfill plants, synergistic transportation of backfill slurries and CO 2 , and in-situ injection processes of CO 2 in mined-out stopes to produce suitable carbon curing environments. The research content of this article can provide valuable insights for studies on the mineralization and storage of CO 2 using tailings.