Volcanic eruption-inspired co-melting treatment of municipal solid waste incineration fly ash

The resourceful disposal of municipal solid waste incineration fly ash (MSWI FA) is a major global challenge. Inspired by volcanic eruptions, a method to lower the melting point of MSWI FA and to promote heavy metal chlorination volatilization was proposed. The introduction of river mud transformed melting products from crystalline to amorphous, obtaining glass products with low heavy metal residues. The volatilization efficiencies of Cu, Zn, Pb, and Cd reached 82.67 %, 100 %, 100 %, and 100 %, respectively, the heavy metal and salts were enriched in secondary ash. Alkali metal oxide induced the transformation of bridging oxygen to non-bridging oxygen, providing binding site for Cl in the form of Ca-Cl coordination and increasing the chlorine content. Then chlorine reacted with CuO converted from Cu2S and promoted the Cu volatilization. The outcomes fundamentally solved the problem of heavy metal residues in MSWI FA melting treatment, supporting resourceful and harmless treatment of MSWI FA.