Zinc Recovery from Direct Leaching Sulfide Concentrate Residue in Pilot Scale

Document Type : Original Articles


1 sahand university of technology

2 university of Znjan


Direct leaching of sphalerite is a new production method that is considered in the Zinc industries. However, the main problem is relatively low recovery percent of Zn (less than 70%). The surveys show that zinc content in leaching residue is more than %25 and other precious metals (such as silver, nickel, copper, and cadmium) presence in there. In this study, a tubular reactor with 30 cm diameter, more than 9 m height and 440 liters’ volume were used to Zinc extraction from leach residue. The residual sulfide leaching conditions and the impact of factors such as the concentration of sulfuric acid, iron sulfate and sludge retention time on the recovery percentage were determined. The results show that increasing the ferrous sulfate concentration increases the zinc recovery percent but sulfuric acid hasn’t a significant effect on dissolution rate. Furthermore, with increasing temperature, the zinc recovery percent increases. The leaching reaction rate is controlled by the diffusion of the dissolution agent into the ash layer, according to the shrinking core model.


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