From waste to wealth: A review of green resource utilization and advanced processing of fly ash for high-value applications

As a natural source of carbon, coal has been extensively utilized in both industrial and domestic contexts. However, when coal-fired power is generated, it produces a large amount of solid waste. Among them, solid waste represented by fly ash is characterized by a large output and difficult treatment. Therefore, the comprehensive utilization of fly ash is becoming increasingly imperative. Fly ash contains abundant valuable components. Its distinctive physicochemical properties provide a solid foundation for its application. This paper reviews the current situation and research progress of fly ash utilization from two aspects: resource utilization and deep processing. Firstly, hazards and physicochemical properties of fly ash are summarized. Based on this, the development trends of fly ash in building materials and ecological restoration were discussed. Subsequently, the research progress of deep processing technologies on adsorbents and electrochemical energy storage materials is reviewed. The adsorption capacity of the modified fly ash material for Cd2 + reached 90.27 mg/g. The battery capacity of the fly ash-based electrode reaches 688 milliampere-hours per gram. This paper provides a reference for the dual utilization of fly ash resource recovery and deep processing, and is expected to become a key approach for the industrial utilization of fly ash.