Investigation of metal recovery methods from zinc plant residue

At present, with the decrease in high grade ores and the possibility of processing secondary deposits with new developed technology necessiate the need of recovering valuable minerals from mineral processing and metalurgical tailings.In this study, recovery of zinc, lead and silver from the Çinkur zinc plant residues by hidrometallurgical methods was investigated. To investigate the recovery methods of the residues, the structure of zinc ferrite contained in the residues was altered by sulfate roasting first, and followed by water leach tests. Empirical variables affecting the process were investigated in this study. To remove the iron from the leach solution (leachate), goethite and jarosite proseses were applied, however, iron was not able to be removed successfully by jarosite process. However, 99.99% of iron was removed from the leachate by goethite prosess. In addition to iron, manganese and cobalt can also be precipitated by geothite prosess using amonium peroxodisulfate. After the iron removing process, a modified cementation process was used to remove the metal ion impurities from the solution. Empirical variables affecting the cementation process, such as, zinc dust size and amount, temperature, duration, and mixing speed, were investigated and optimized in this study to determine cementation kinetics and mechanism.In addition, the most feasible method for the recovery of lead and zinc was shown to be treating the lead cake by NaCl.Recovery of zinc, lead and silver from leach tailings by hydrometallurgical metods was accomplished and based on the results of this investigation a flowsheet showinng the recovery steps was developed.