Recovery of Valuable Materials Based on Pb and Zn in the Hydrometallurgical Processing of Copper Shaft Furnace Dust

Copper shaft furnace (CSF) dust containing valuable metals with a composition of 44.02% Zn and 14.57% Pb, in the form of oxides (PbO and ZnO), was used for leaching in 1 mol/L sodium hydroxide lixiviant at a temperature of 80 °C. The leaching efficiency for lead removal was 98%. The leaching of CSF dust in sodium hydroxide was thermodynamically studied using Pourbaix diagrams for the Pb/Zn/-Na-H₂O system at temperatures of 25 °C and 80 °C. A suitable precipitating agent was 0.5 mol/L sulfuric acid at pH 3. The formation of lead sulfate as the final product was confirmed by SEM, EDX, and XRD analysis. Although increasing the temperature reduced the aging time required for the precipitation, it did not affect the amount of lead precipitated. The solution, after lead precipitation and containing zinc (Zn²⁺), was further treated with ammonium carbonate for zinc precipitation. Various analytical methods, including SEM, EDX, XRD, XRF, and AAS, were used to analyze the input samples and the final products obtained after alkali leaching of CSF dust and lead and zinc precipitation.