• • Water washing achieves 88%–95.5% chloride removal; at liquid-to-solid ratio 5 and 20 min washing, soluble chloride in the final aerated concrete is controlled below 1% (mass fraction), meeting HJ 1134-2020 limits and preventing durability degradation.
• • CO2 curing (65 °C, 0.6 MPa, 2 h) effectively immobilizes heavy metals by densifying the pore structure; leaching of Cr, Pb, Cd, and Zn decreases with lower fly ash content, but Cu leaching anomalously increases when fly ash is absent (0% content).
• • Adding 17.5% organic sulfur stabilizer (DTC) achieves superior heavy metal stabilization compared to Na2S, ensuring all heavy metal contents meet national standards without significantly affecting compressive strength (1.50 MPa) or carbonation efficiency.
• • Optimal formulation (bottom slag:fly ash:slag = 40:20:40, aluminum powder 0.04%, water-to-cement ratio 0.36) yields aerated concrete with compressive strength of 1.50 MPa, meeting A1.5, B03 grade requirements per GB/T 11968-2020.