钢渣基固碳储热材料的开发及热物性研究OA

This study investigates the conversion of steel slag into a carbon-sequestering matrix through accelerated mineral carbonation.The resulting CO2-fixing steel slag is combined with sodium nitrate phase-change material(PCM)using cold-press sintering,producing a dual-functional composite capable of simultaneous carbon sequestration and thermal energy storage.An orthogonal experimental design is employed to optimize carbonation parameters,with optimal conditions identified as 75℃,0.85 MPa CO2 pressure,a liquid-to-solid ratio of 35,and a stirring speed of 950 r·min-1.Further carbonation conducted at 95℃for 4 h under optimized conditions yields a carbon sequestration capacity of 294 kg CO2/t steel slag.Scanning electron microscopy analysis reveals homogeneous impregnation of sodium nitrate within the pore structure of the CO2-fixing steel slag.X-ray diffraction analysis demonstrates high chemical compatibility between the constituents,confirming the absence of chemical reactions and indicating purely physical interactions.Thermal characterization shows that the composite containing 50%CO2-fixing steel slag exhibits a melting temperature of 303.2℃,a latent heat capacity of 81.9 J/g,and a thermal conductivity of 0.866 W/(m·K).The composite also maintains stable thermal performance over 300 heating-cooling cycles.Compared with previously reported steel slag-sodium nitrate PCM composites,this system exhibits markedly enhanced thermal energy storage performance.Overall,this study proposes a sustainable dual-functional strategy for the high-value utilization of steel slag while providing systematic experimental validation for the development of high-performance composite PCMs.Furthermore,it demonstrates the technical feasibility of coupling carbon capture with thermal energy storage,offering a robust materials-level foundation for renewable energy storage technologies in the transition toward clean,low-carbon energy systems.