Synthesis of multi-morphology anhydrous MgCO3 from brucite solid waste employing molecular effect on CO2 conversion via biodegradable chelating-system

Brucite solid waste generated during mining is challenging to utilize directly and is often discarded, occupying a substantial space and causing environmental damages. This study proposed a novel single-step method for synthesizing anhydrous MgCO3 via brucite solid waste carbonation with simultaneous carbon dioxide sequestration, aiming to mitigate environmental impact and enhance economic value. The Vitamin C was chosen as it is easily degraded to provide carbon source for mineralization. Results indicated multi-morphology anhydrous MgCO3 was obtained, and the highest carbon dioxide sequestration rate was 46.7 %. Vitamin C bound Mg2 + through-OH, inhibiting [Mg(H2O)6]2+ formation. Degradation-derived organic molecules adsorbed onto crystal surfaces, inducing the oriented growth and assembly of anhydrous MgCO3. Density functional theory calculations revealed the formation of O-Mg bonds between Vitamin C and Mg2+. O-Mg bonds, intermolecular hydrogen bonds, and van der Waals forces exist between organic molecules and anhydrous MgCO3. This method is anticipated to be an eco-friendly short-process technology for anhydrous MgCO3 synthesis, with implications for environmental sustainability and carbon utilization strategies. Additionally, anhydrous MgCO3 exhibits broad application potential in flame retardancy and electronic component enhancement, while the carbon spheres derived from Vitamin C degradation can be recycled for use as electrodes and adsorption materials.