Basalt mineralization with soda saline soil for enhanced CO₂ sequestration : An experimental study

Global warming, driven by rising CO₂ concentrations, demands urgent mitigation strategies. Among these, Basalt mineralization offers a promising method for large-scale carbon sequestration. Adding alkaline substances to the basalt mineralization reaction can expedite the process. Soil salinization, a widespread and severe problem in China, particularly in the northeastern regions, is characterized by the presence of soluble salts and high alkalinity. These soda saline soils could potentially enhance the efficiency of basalt mineralization. This study explores a novel enhancement approach: leveraging soda saline soils to accelerate basalt carbonation. A series of reactor experiments varying basalt-to-saline soil ratios, particle sizes, and solid-liquid ratios were conducted. The mineralization reaction mechanism of basalt in the presence of saline soil was investigated. The minerals of the reaction products were analyzed and the mineralization efficiency and sequestration capacity of each set of experiments were evaluated. The results showed that the saline soil enhanced the mineralization and carbon sequestration of basalt, increasing the efficiency by more than three times compared to basalt alone. This study demonstrates the potential of saline soil as a low-cost accelerant in carbon capture technologies.