The fate of atmospheric carbon sequestrated through weathering in mine tailings.

• Reactive Mg-hydroxides and silicates in mine tailings offer vast sink for ambient CO 2. • Lower mineralization deep in tailings piles underuses storage capacity. • Climate, CO 2 availability, waste composition, and biotic agents are controlling factors. • Isotope analysis and geochemical modeling have become necessary tools to track CO 2. • Learnings from CO 2 sequestration in tailings are valuable for pedospheric-C sinks. Induced by fossil fuels combustion, GHGs emissions play a key role in the atmospheric CO 2 level elevation. Accordingly, many mitigation strategies have been proposed to uptake atmospheric CO 2. However, most of these methods demand industrial facilities, usually coming along with obstructive expenses. Residues produced from mining operations are among cheap and naturally occurring materials propounded for stable carbon sequestration through mineralization. Brucite and chrysotile are the major candidates for passive carbon mineralization in mining residues, belonging to magnesium hydroxide and magnesium silicates groups, respectively. This review paper critically explores available literature on mechanisms governing atmospheric CO 2 capture in the mining residues, with an emphasis on the mine tailings. Firstly, the overall image of carbon mineralization in mineral residues is discussed in this paper. This entails the occurrence and the mechanisms governing the carbonation in the surface and deep layers of the mining residue piles. Secondly, factors that likely affect the mineralization are illustrated. Then, two tools, carbon isotopes and geochemical modeling, utilized for discriminating atmospheric CO 2 and characterizing mineralization in the tailings are described, respectively. Finally, various conditions leading to different Mg-carbonates formation, carbonation rate estimations, and technologies proposed for enhancing carbonation in the mining residues are explored. [ABSTRACT FROM AUTHOR]