Return
Hydrometallurgical Recovery of Zinc and Silver from High-Iron Algerian Leach Residues: Jarosite Control, Dissolution Kinetics, and Process Optimization
B
DOI:10.1134/S1067821226600109.png)
Abstract
En 中文
This study proposes an integrated hydrometallurgical route for the valorization of high-iron jarosite leach residues generated during zinc production. The investigated residue contains significant amounts of zinc (approximate to 17.82 wt %) and iron (approximate to 20.82 wt % as Fe2O3), with trace silver (approximate to 409 ppm). Zinc extraction was first performed by controlled sulfuric acid leaching under systematically varied operating parameters using a mechanically agitated reactor. Under optimized conditions (pH = 1.8 +/- 0.1, T approximate to 70 degrees C, t approximate to 90 min, S/L = 0.10 g mL-1 and [H2SO4]0 = 250 g L-1), zinc recovery reached approximately 92%. Kinetic analysis revealed a two-stage dissolution mechanism characterized by an initial surface-reaction-controlled regime followed by diffusion limitation due to progressive jarosite passivation, consistent with the Shrinking Core Model (SCM). Silver recovery from the zinc-depleted residue was subsequently investigated using thiourea as a non-cyanide lixiviant. Ag extraction reached approximately 20% under the optimized flowsheet conditions and increased up to 35-42% when thiourea concentration was raised to 0.5-1.0 M in acidic medium. The results demonstrate the technical feasibility of combined Zn-Ag recovery from jarosite-rich residues, providing a practical and environmentally sustainable route for the valorization of hydrometallurgical wastes and offering a basis for future pilot-scale applications.
Keywords:
zinc recovery
silver leaching
jarosite
kinetics
shrinking core model
thiourea
hydrometallurgy
high-iron residues
Journal
R
IF:
0.9
Papers:
37
Citations:
0
