Objective and Methods  The urgent need to reduce global greenhouse gas emissions has driven the development of CO₂ mineral trapping in basalts. To gain further insights into the microscopic mechanisms and reaction pathways of the mineral trapping, this study systematically reviews the geochemical reaction mechanisms involved, with a particular focus on the differences in reaction pathways between supercritical and dissolved CO₂ injection, the coupling between mineral dissolution and carbonate precipitation, and the key factors influencing these reactions.

Advances  In the case of supercritical CO₂ injection, CO₂ mineral trapping is achieved through multi-step coupling reactions in nanoscale hydration layers. Under dissolved CO₂ injection, the mineral trapping is primarily achieved through chemical dissolution and coordination reactions in the aqueous phase. In the geochemical reactions during CO₂ mineral trapping in basalts, minerals such as olivine and pyroxene play a dominant role in the release of metal cations, while carbonate minerals including calcite, magnesite, and ankerite precipitate sequentially under different temperature and pressure conditions. Calcite exhibits broad temperature adaptability, whereas magnesite and ankerite are commonly observed under moderately high temperature conditions. Factors such as pH, temperature, CO₂ partial pressure ( p_\textC\textO_\text2 ), fluid salinity, and rock heterogeneity exert significant impacts on reaction pathways and the evolution of minerals precipitated. Specifically, low pH accelerates the dissolution of primary minerals, while high pH creates favorable conditions for the precipitation of carbonate minerals. Elevated temperatures promote mineral dissolution, thus increasing the reaction rates. High CO₂ partial pressure can enhance the solubility and reactivity of CO₂, thereby accelerating mineral dissolution and carbonate formation. Fluid salinity affects the dissolution and precipitation processes of minerals by changing the ionic strength and chemical composition of solutions. Rock heterogeneity, including differences in mineral compositions and pore structures, affects fluid transport pathways and reaction efficiency. Furthermore, it facilitates localized precipitation and the formation of preferential flow channels, enabling sustained precipitation in low-flow and disconnected channels. It is necessary to investigate the impacts of rock heterogeneity on reservoir physical properties in the future. The abovementioned factors interact with each other, jointly determining the dynamic evolution of CO₂ mineral trapping.

Prospects  Future research directions are proposed in this study based on the review, including the establishment of parameter optimization frameworks, the construction of high-resolution coupling models, and the optimization of CO₂ injection strategies. These efforts will promote the large-scale applications and engineering implementation of CO₂ storage in basalts. Additionally, a thorough investigation into the mechanisms behind the synergy among the influential factors of reactions will lay a solid theoretical foundation for the optimization of CO₂ storage technology, thus further improving the efficiency and stability of CO₂ mineral trapping.