A green strategy toward extraction of cadmium(II) during the transformation from arsenic-rich flue dust to scorodite

This paper presents an eco-friendly method for recovery of cadmium by solvent extraction and stabilization of arsenic through one-pool treatment on arsenic-rich flue dust. The morphology-controlled scorodite can be realized by adjusting reaction temperature. It is worth emphasizing that the arsenic-immobilized scorodite precipitates have superior crystallinity which exhibit excellent safety for long-term storage. In addition, the advantage brought about by taking hydrogen peroxide as leaching agent is that leachate is weakly acidic, which removes the need to add a large amount of neutralizing agent and facilitates the synthesis of scorodite. The results show that 97.3% of arsenic was leached from arsenic-rich flue dust and then 92.8% of the leached arsenic was transferred into scorodite with the recovery of 81.5% of cadmium under the optimal conditions. We hope that this work will provide a facile and environmentally friendly protocol for those interested in developing a new strategy for simultaneously recovering and stabilizing toxic heavy metal ions from industrial dust.