Abstract: To promote the full-component resource utilization of waste incineration ash and slag (WIS),this study employed
fly ash-based geopolymer (FAP) as the cementitious material,synergistically utilizing fine slag (0~ 2. 36 mm) and
coarse slag (2. 36 ~ 4. 75 mm). Lightweight aggregates were prepared via an ambient-temperature extrusion granulation
process. Orthogonal experiments were conducted to systematically investigate the influence of FAP content,fine-to-coarse slag
ratio,and water-to-binder ratio on the properties of the lightweight aggregates. The results show that the ambient-temperature
extrusion process enables the full-component resource utilization of WIS. The optimal mix proportion was determined as 40%
FAP content,a fine-to-coarse slag ratio of 5∶5,and a water-to-binder ratio of 0. 28. Under these conditions,the lightweight aggregate
achieved a cylinder compressive strength of 14. 1 MPa,a bulk density of 1 164 kg/ m3,and a water absorption of
8. 6%,meeting the requirements for the 1200 density grade,with a freeze-thaw mass loss rate of 17. 6%. Range analysis indicated
that the order of factors affecting the properties primary and secondary order was FAP content,fine-to-coarse slag ratio,water-
to-binder ratio. An appropriate amount of FAP forms a three-dimensional network gel that encapsulates slag particles,significantly
enhancing material compactness and strength. Suitable gradation and water-to-binder ratio play a crucial role in maintaining
structural stability. Under the optimal mix proportion,the leaching concentrations of Cr,Cd,Pb,and Ni were 4. 69 μg/ L,
0. 46 μg/ L,3. 62 μg/ L,and 1. 17 μg/ L,respectively. These values are all lower than the limits specified in the Identification
Standards for Hazardous Wastes and meet the Class Ⅱ limits of the Quality Standard for Groundwater (GB/ T 14848—2017),
confirming the significant solidification effect of FAP on heavy metal ions.

Key words: lightweight aggregate,waste incineration ash and slag,all solid waste,mechanical strength,heavy metal leaching