Research Progress of CO2 Mineralization Using Carbide Slag
Carbide slag (CS), an alkaline industrial solid waste from acetylene production in the chlor-alkali industry, poses severe ecological risks due to long-term stockpiling. This review systematically examines CO2 mineralization pathways and applications of CS, leveraging its high reactivity dominated by Ca(OH)2. Direct gas-solid and liquid-solid carbonation mechanisms, alongside indirect ammonium salt cyclic leaching-carbonation, are elaborated. Process optimization via parameter regulation, amino acid modification, and multi-solid waste coordination significantly enhances reaction efficiency and product performance, enabling controlled synthesis of high-value calcium carbonate. Environmental and economic analyses confirm that CS mineralization achieves CO2 fixation with good economic feasibility, simultaneously addressing solid waste resource utilization and carbon emission reduction. Derived lightweight fillers and low-carbon cementitious materials exhibit both environmental and economic potential, providing theoretical and application support for a 'waste-to-waste' carbon reduction technology system.