57 / 2023-10-13 15:17:50

Investigation of waste alkali-activated cementing material using MSWI-fly ash and dravite as precursors

Keywords: MSWIFA; Semi-dry pressing; Mechanical properties; Heavy metal solidification; Long-term performance; On-site application

The proper treatment of municipal solid waste incineration fly ash (MSWIFA) is a crucial issue due to its hazardous nature and potential harm to the environment. To address this issue, this study utilized dravite and black liquor for the first time to solidify MSWIFA using the semi-dry pressing method, resulting in the production of MSWIFA-based cementing material. The compressive and flexural strength of this material reached 45.89 MPa and 15.58 MPa, respectively, and the heavy metal ions (Pb, Cr, Cu, Cd, and Zn) were effectively solidified in the MSWIFA-based cementing material. Furthermore, the MSWIFA-based cementing material exhibited excellent long-term performance with acceptable heavy metal leaching and minimal mechanical degradation. Through the experimental and theoretical analyses, the heavy metal solidification mechanism was also revealed, including chemical binding, ion substitution and physical encapsulation. Finally, the on-site application of MSWIFA-based cementing material was performed, proving the feasibility of the proposed material in meeting both environmental and strength requirements.