Abstract: In order to recycle zinc from zinc oxide of the waste galvanized sheet zinc-borne dust, two-stage neutral-acid continuous leaching process was conducted. Through the conditional tests, the optimal technical parameters for the neutral leaching were determined as the initial acid concentration 0 g/L, the ratio of liquid to solid 9 mL/g, stirring intensity of 200 r/min, the leaching temperature of 25 ℃ for 80 min, for the acid leaching as the starting acid concentration of 20 g/L, the ratio of liquid to solid 9 mL/g, stirring intensity of 500 r/min, the leaching temperature of 25 ℃ for 80 min. Then under the technical parameters above, a closed-circuit test was made by using the neutral leaching solution as output solution, and the acid leaching return to the neutral leaching solution. In the tests, Zn leaching rate reaches 90.36%. Zn content in leaching solution is 10.14 g/L, and iron content is 0.56 g/L only.

Key words: Waste galvanized sheet, Zinc-borne dust, Neutral-acid two-stage leaching, Final leaching pH