A method for disposing of fly ash. After the fly ash has been processed using the method contained herein, this fly ash can be disposed of more easily because of the reduced toxicity of the final product. Also, this converted fly ash may be recycled and used as a material or aggregate in concrete. The method includes the treatment of dioxins found in fly ash found in waste incinerator flue from waste incineration power plants which includes collecting the fly ash, putting the fly ash into a hermetic device and treating the fly ash through various heating steps and thereafter lowering an environmental temperature in the hermetic heating device, which results in a significant reduction of dioxins in the fly ash.