Selective leaching of arsenic and copper in copper smelting dust (referred to as “soot”) was investigated by Na2S-NaOH leaching process with assistance of glow discharge plasma. Results showed that glow discharge plasma could enhance alkaline leaching capacity. The corresponding leaching ratios of arsenic and copper were reached to 92.52% and 7.76% at condition of 10 min discharge time

500 W discharge power

150 Pa discharge pressure

and 0.9 cm plate spacing. The leaching process reduced arsenic and copper content in soot from 7.11% to 0.45% and from 2.62% to 2.42%

respectively. XPS

XRD

and speciation analysis of heavy metals indicated that glow discharge plasma was able to oxidize As(Ⅲ) to As(Ⅴ) and Cu(Ⅰ) to Cu(Ⅱ)

which As(Ⅴ) was more easily leached than As(Ⅲ) under alkaline condition. In conclusion

glow discharge plasma assisted Na2S-NaOH leaching process proves to be an efficient way of removing both arsenic and copper from soot so the soot can be further utilized after toxic content reduction.