Recent progress on the thermal treatment and resource utilization technologies of municipal waste incineration fly ash: A review

Incineration is becoming a promising and effective approach to dispose the increasing municipal solid waste, while the fly ash produced is another urgent problem needed to be addressed. Municipal solid waste incineration fly ash (MSWI-FA) contains heavy metals and organic pollutants, which exert huge threat to human health and environmental safety. This paper analyzed the current situation of MSWI-FA, summarized the technologies of hazard-free treatment and resourceful utilization, expounded its future development trend. The latest thermal detoxification technologies of MSWI-FA were reviewed, including melting/vitrification, hydrothermal treatment and thermal plasma technology. The organic pollutants can be efficiently decomposed during the thermal treatment process, and the heavy metals can be stabilized, which was currently the most effective hazard-free treatment technology. The resource utilization technologies of MSWI-FA related to thermal treatment, including the application of MSWI-FA in the production of asphalt, cement, and glass ceramics, were reviewed. The life cycle assessment of various MSWI-FA treatment technologies were summarized and compared. The main principle was to make full use of the physicochemical characteristics of MSWI-FA, with its purpose to realize value-added utilization, and to decompose and stabilize the hazardous components during high-temperature process. The mechanism and technical characteristics of treating MSWI-FA through thermal detoxification and resource utilization were deeply summarized, and the future research work that needs to be further strengthened was proposed, thereby promoting the safe and effective treatment of MSWI-FA and realizing the green and sustainable development of the city.