Influence of physicochemical properties

The study investigates the leaching behavior of Brazilian serpentinite rocks to enhance indirect CO2 mineral carbonation. The objective is to analyze how the physicochemical properties of these rocks influence their reactivity and leaching efficiency. Using two serpentinite types, S-GO and S-MG, various characterization methods assessed their surface area-to-volume ratio and metals-to-silicon ratio to establish a relationship with their leaching performance. Reactivity tests used specific reaction conditions, involving a particle size of 355–250 μm, 4 M HCl concentration, 100 °C, and a reaction time of 2 hours, to extract magnesium (Mg) and iron (Fe). Results indicate that S-GO demonstrates significantly higher reactivity with extraction rates of 94 ± 1% for Mg, while S-MG provided much lower extraction rates of 34% for Mg and 60% for Fe. Further reduction of the particle size of S-MG to 75–63 μm aimed to enhance its reactivity, but did not significantly improve extraction rates. The findings suggest that the mineralogical and surface properties critically affect the leaching efficiency and highlight the need for optimizing these parameters in CO2 sequestration processes.