Copper smelter dust, a typical hazardous waste that is
abundant
in valuable heavy metals, holds the potential to be regarded as a
promising resource. This study introduces a new approach that integrates
chlorination roasting and cascade condensation to efficiently recover
heavy metals from copper smelter dust. The findings demonstrate the
successful separation of heavy metals (Cu, Pb, and Zn) as chlorides
at nearly 100% efficiency while also effectively converting trivalent
arsenic (As(III)) into pentavalent arsenic (As(V)) and immobilizing
it in the roasting residues, thereby reducing environmental risk.
Through the utilization of thermogravimetric mass spectrum analysis
and thermodynamic equilibrium calculations, the chlorination process
for heavy metals was investigated, revealing both direct and indirect
chlorination processes. Additionally, the study resulted in the development
of a CuO-based multiple-metals electrocatalyst from the oxidized roasting-recovered
heavy metal chlorides, exhibiting significantly enhanced catalytic
activity and faradaic efficiency for the electroreduction of CO
2
into CO and CH
4
compared to pure CuO electrocatalyst
under similar electrocatalytic conditions. Overall, this work presents
a sustainable and scalable method and new insights for addressing
environmental risks while repurposing copper smelter dust.