The precipitation of carbonate minerals through chemical reaction between injected CO₂ and reactive basaltic rocks can enable a long-term carbon storage solution (carbon mineralization). Magnesite is one of the most stable carbonate precipitates that can contribute to addressing the challenge of long-term carbon storage, and the chemical mechanism that can catalyze its formation is of great interest and practical significance. Here, using batch reactor experiments at 200 ºC and mineralogical characterization, we explore magnesite precipitation kinetics in injected fluids whereby the chemical impact of fluid pH, NaCl, and MgO nanoparticles is investigated. The results show that an alkaline or a saline environment significantly accelerates magnesite formation by enhanced phase transition of hydrated metastable magnesium carbonate to magnesite. Raised CO₃²⁻ activity in an alkaline environment may promote the transformation of hydromagnesite to magnesite. Competition for hydration water between background ions and magnesite building ions in the presence of NaCl can promote Mg dehydration and magnesite mineralization. Although MgO hydrophilic surfaces may retard magnesite formation at the early stage of the reaction, an alkaline pH environment can subsequently accelerate magnesite growth by enhanced replacement of hydromagnesite. This research provides new insights into the mechanism and kinetics of magnesite precipitation at mineral-fluid interfaces in a range of conditions, and can facilitate the deployment of carbon storage technologies and support defining strategies to accelerate underground CO₂ mineralization in deep basalt reservoirs.

_{通过注入的CO 2}之间的化学反应沉淀碳酸盐矿物和反应性玄武岩可以实现长期的碳储存解决方案（碳矿化）。菱镁矿是最稳定的碳酸盐沉淀物之一，有助于应对长期碳储存的挑战，其催化其形成的化学机制具有重要意义和实际意义。在这里，我们使用 200 ºC 的间歇反应器实验和矿物学表征，探索注入流体中的菱镁矿沉淀动力学，从而研究流体 pH、NaCl 和 MgO 纳米颗粒的化学影响。结果表明，碱性或盐碱环境通过增强水合亚稳态碳酸镁向菱镁矿的相变，显着加速了菱镁矿的形成。提高的 CO ₃ ²⁻在碱性环境中的活动可能会促进水菱镁矿向菱镁矿的转化。在 NaCl 存在下，背景离子和菱镁矿生成离子之间对水合水的竞争可以促进 Mg 的脱水和菱镁矿的矿化。尽管 MgO 亲水表面可能会在反应的早期阶段延缓菱镁矿的形成，但碱性 pH 环境随后可以通过增强水菱镁矿的置换来加速菱镁矿的生长。这项研究为一系列条件下矿物-流体界面处菱镁矿沉淀的机制和动力学提供了新的见解，并可以促进碳储存技术的部署，并支持确定加速深部玄武岩储层地下 CO _{2矿化的策略。}