Additive combination for treatment of heavy metals and dioxins in fly ash

Abstract

Provided is an additive combination for treatment of heavy metals and dioxins in fly ash. In the present disclosure, the fly ash is subjected to tertiary water washing and then separation by pressure filtration with a plate and frame filter press to obtain fly ash after the tertiary water washing. A low-temperature heat treatment is conducted on the fly ash after the tertiary water washing in a stirring reactor by adding the additive combination. Chlorine salts in the fly ash can be effectively removed by the tertiary water washing, which avoids the chlorination of a precursor in the fly ash to form the dioxins during the low-temperature pyrolysis, thereby improving a heat reduction efficiency of the dioxins in the fly ash. Moreover, the reduction of a chlorine content in the fly ash can also avoid deactivation of the additives and improve a solidification effect of the heavy metals.

Dependencies are inferred from the claim text.