Recovery of Zn and Cu from municipal solid waste incineration fly ash by integrating ammonium leaching and ammonia removal

•Ammonium chloride leaching extracts Zn and Cu selectively from MSWI fly ash.•Impressive recovery rates from leachate: Zn 95.99%, Cu 98.90%.•Precipitate contains Zn (33.62%) and Cu (14.19%), ideal for smelting.•The process reduces fly ash mass and lowers chlorine content significantly. This study introduces an environmentally friendly process for recovering zinc (Zn) and copper (Cu) from municipal solid waste incineration (MSWI) fly ash using ammonium chloride leaching and ammonia removal. The leaching rates for Zn and Cu were 54.39% and 86.23%, respectively, with total recovery rates reaching 52.21% and 85.28%, respectively. The recovered precipitate demonstrated significant Zn (33.62%) and Cu (14.19%) contents, making it ideal for metal smelting. The ammonium leaching process also showcased effective reduction and dechlorination effects on the fly ash. The treated fly ash had a reduced mass of only 30.63% of the original, and chlorine content decreased from 26.23% to 0.84%. The results of this study support the sustainable utilization of MSWI fly ash by facilitating valuable resource recovery and promoting its conversion into construction materials.