In situ mechanochemical carbonation enables carbon-negative detoxification and upcycling of municipal solid waste incineration fly ash.

In situ mechanochemical carbonation of municipal solid waste incineration fly ash achieves 124 g/kg-FA CO2 absorption in 40 minutes, doubling conventional methods and enabling carbon-negative treatment.

• Why it matters: Detoxification and resource-upcycling of hazardous fly ash are hindered by its alkalinity, heavy metal enrichment, and high chloride content, posing global environmental challenges.
• What they did: The study applied additive-free mechanochemical carbonation combining ball milling with wet carbonation, reaching 83% of the theoretical CO2 absorption potential and significantly reducing chloride and heavy metal leaching.
• The result: This process demonstrates a carbon-negative potential with a net CO2 balance of -95.6 kg CO2 per ton of fly ash after 40 minutes, facilitating safer disposal and resource recovery.