Preparation of incineration fly ash mineral powder cementitious material

Incineration fly ash contains heavy metals and chlorides, which pose environmental hazards. However, its compositional characteristics endow it with the potential to activate the pozzolanic activity of mineral powder. The feasibility of incineration fly ash to activate mineral powder as a binding material was explored. In the experiments, solidified bodies were prepared with different proportions of incineration fly ash and mineral powder. The properties and mechanisms of action of these solidified bodies were analyzed by XRD, TG, isothermal calorimetry, and other means. The results showed that the properties of the solidified bodies first increased and then decreased with the increase of incineration fly ash. When the content of incineration fly ash was 40%, the early and late strength of the solidified bodies was the highest. It provided sufficient Ca2⁺ and SO₄2⁻ for the pozzolanic reaction of mineral powder, promoting the formation of C–S–H gel and C–A–S–H gel, and there was no risk of heavy metal leaching. However, when the content of incineration fly ash reached 80%, the strength of the solidified bodies significantly decreased, and the risk of heavy metal leaching exceeding the standard increased. An appropriate amount of incineration fly ash could activate the activity of mineral powder and enhance the properties of the solidified bodies. Which provided a new way for the resource utilization of incineration fly ash and the reduction of environmental pollution. However, the dosage should be controlled to ensure the mechanical properties and environmental safety of the solidified bodies.