Recovering harmful elements (As, Pb) and metals (Cu, Bi, Zn) from copper smelting flue dust (CSFD) is a critical subject and task for arsenic contamination control and resource sustainability. In this work, a two-step pyrometallurgical process was developed to preferentially separate arsenic and recover metals from CSFD. During the low-temperature roasting, arsenic-bearing waste acid (AWA) from copper industry was used as an additive and effective removal of arsenic (97.8 %) was obtained at 350 °C, which follows the idea of "treating waste with waste". Subsequently, the recovery and separation of metals were well-achieved based on the affinity between metals and sulfur in the second stage of roasting, by which 91.28 % of Pb and 95.65 % of Bi were recovered as an alloy (Pb 86.48 %, Bi 13.21 %), while 82.62 % of Cu was enriched in the matte. The migration rules of metal elements and phase transformation in the whole process were studied in-depth from theory and experiments. This process can realize the efficient removal of arsenic as well as effective recovery of metals via cooperative disposal of CSFD and AWA, and minimize the environmental impacts.
Keywords: Arsenic-bearing waste acid; Copper smelting flue dust; Metals recovery; Thermodynamic analysis; Two-step pyrometallurgical process.
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