LAUSR

Abstract In this contribution, a hydrometallurgical process is specifically developed to recover zinc (Zn), manganese (Mn) and lead (Pb) from the pyrometallurgical sludge produced in the steel manufacturing industries. The optimum conditions for Zn and Mn selective leaching from the pyrometallurgical sludge of Pompey have been already found. This process consists of six unit operations: 1) Selective Zn leaching. At this stage, 80.8–100% of Zn is extracted. 2) Selective Mn leaching, with two reductive leaching steps: fixed pH range from 3.5 to 4.2 and redox potential lower than 400 mV, using H 2 SO 4 and Na 2 S 2 O 5 as the reducing agent. In this step, 77.6–95.9% of Mn is recovered. 3) Removal of aluminum (Al) and iron (Fe) from Zn leach liquor by chemical precipitation at pH 4.8 with NaOH. 4) Removal of Al, Zn and Pb by sulfide precipitation (Na 2 S) from Mn leach liquor (2) at pH 5.6. 5) Zn precipitation (as sphalerite) using twice the stoichiometry value of Na 2 S (considering the concentration of Zn). 6) Mn precipitation (as rhodochrosite) at pH 8.5 using Na 2 CO 3 as the precipitation agent. This process is tested with four different raw materials, which demonstrates its reliability.