Experiments of CO₂-Basalt-Fluid Interactions and Micromechanical Alterations: Implications for Carbon Mineralization

Abstract

Basalt rich in Ca, Mg and Fe enables fast CO 2 mineralization, making carbon storage in basalt an alternative technology for reducing carbon emissions. The Leizhou Peninsula in China holds great potential as a key region for basalt carbon storage. However, the scarcity of extensive research on basalt carbonation reactions and the resulting mechanical response poses a significant obstacle to the implementation of this technology. Therefore, a series of basalt carbonation experiments were carried out. The results showed that diopside had the highest dissolution rate and acted as the primary source of divalent cations. Within one month, smectite was formed, followed by the precipitation of carbonate minerals. Initially, aragonite and dolomite were the primary carbonation products, but over time, dolomite dominated with a higher percentage of Mg. The dissolution and precipitation of minerals also led to degradation of the micromechanical properties of the basalt. With the progress of the reaction, the average elastic modulus and hardness continuously decreased with maximum reduction rates of 87.66 and 84.38%, respectively. The dissolution-dominant reaction caused an increase in defects on the surface of the basalt sample. Furthermore, the newly formed carbonate and clay minerals exhibited weaker mechanical strength, exacerbating the overall mechanical performance. This mechanical weakness poses a long-term safety risk for carbon storage. This study can provide valuable insights for the implementation of CO

The Future of CO2 Geological Sequestration: An Overview of Mineralization in Aqueous and Supercritical States

“…Therefore, both processes are enhanced by reducing the particle size. This also explains why both CO 2 aqueous solution and scCO 2 experiments try to minimize the particle size, and even use artificial synthesis methods to prepare nanomagnesium olivine crystals for mineralization. , On the other hand, there are many rock minerals available for CO 2 mineralization research, such as basalt, peridotite, , plagioclase, potassium feldspar, basaltic glass, serpentine, olivine, pyroxene, wollastonite and many other minerals, which are all silicate ores rich in Ca 2+ or Mg 2+ . However, the content of Ca 2+ or Mg 2+ varies greatly among them .…”

“…In the process of geological sequestration, it is crucial to select a suitable site during the process of geological sequestration . Therefore, selecting silicate strata rich in calcium and magnesium ions or sandstone strata with more and smaller silicate mineral particles, would be more conducive to CO 2 mineralization. , …”

“…Consequently, modulating the flow rate can effectively mitigate wellhead plugging . Additionally, extensive precipitation in low flow rate zones may induce reactive fracturing, potentially enhancing CO 2 storage capacity . Nonetheless, the scarcity of field-scale mineralization storage pilot projects and a lack of enough experimental evidence remain challenges in this domain.…”

Accelerated Direct Mineralization of CO2 by Carbide Slag under Ambient Temperature and Pressure Reaction Conditions

“…CO 2 mineral storage, also known as CO 2 mineralization or CO 2 carbonation, is mainly based on the reaction between CO 2 and calcium and magnesium ions in minerals to generate carbonates, achieving storage of CO 2 , which is distinguished by its low cost, large scale, high reactivity, and long-term stability. , Compared with other CO 2 utilization conversions, the negative Gibbs energy of mineral storage indicates that the reaction can be carried out spontaneously, and the formed carbonate energy state is 60–180 kJ/mol lower than that of CO 2 , which is more thermodynamically stable. In terms of raw materials, the mineralized materials are alkaline industrial solid waste and CO 2 -containing flue gas discharged from emission sources, which can solve the problem of environmental pollution caused by exhaust gas and solid waste emissions at the same time.…”