Carbon Mineralization and Lithium Extraction in Phyllosilicates under Different Temperatures and CO<sub>2</sub> Pressures: Advancing Secure CO<sub>2</sub> Storage and Utilization Strategies
M. Abdalla, Qingsheng Wang
Abstract
High Resolution Image Download MS PowerPoint Slide The urgent need to mitigate anthropogenic CO 2 emissions necessitates the advancement of robust, scalable, and safe CCUS technologies. This study demonstrates rapid and stable carbonate formation in biotite-rich systems within just 24 h of CO 2 exposure. Through a series of controlled static reactor experiments, biotite samples were subjected to varying temperatures (18–40°C), pressures (6–74 bar), and reaction durations, revealing profound mineralogical transformations and geochemical dynamics. The interaction of biotite with CO 2 -rich brine conditions led to the release of cations─Mg, Fe, K, Ca, and Li─with the highest concentrations observed under supercritical CO 2 conditions. XRD and SEM analyses identified the formation of stable carbonate minerals, including calcite, siderite, and magnesite, directly evidencing rapid CO 2 mineralization. A discovery, first to be reported in the literature, was the formation of lithium deuteride and lithium fluoride, highlighting a novel pathway for lithium mineralization under mild conditions (30°C, 6 bar), where lithium, initially incorporated within the biotite structure (2038 mg/kg), becomes highly mobile during CO 2 -induced reactions. This finding opens a new geochemical pathway for lithium recovery from sedimentary formations, suggesting that vast lithium resources hosted in clay- and mica-rich siliciclastic deposits, such as those in the Thacker Pass lithium deposit in Nevada, could be effectively extracted through CO 2 -assisted geochemical treatments. In addition to lithium, the experiments revealed substantial mobilization of critical metals─Ni, Cu, Zn, and Cr, emphasizing both the potential for critical metal recovery and environmental risks associated with CO 2 leakage into shallow aquifers. These findings redefine the role of phyllosilicates from passive CO 2 containment structures to active carbon mineralization reactors, capable of facilitating permanent CO 2 sequestration at unprecedented rates. Furthermore, the cooccurrence of lithium mobilization and mineralization introduces a dual benefit─secure CO 2 sequestration coupled with sustainable lithium resource recovery, critical for the global energy transition.