Brazilian Journal of Chemical Engineering Alkaline leaching in caustic soda solution is another process frequently used in the recovery of zinc from oxidized zinc ores and wastes

Production of ultrafine zinc powder from industrial wastes by electrowinning in alkaline solution was studied. Stainless steel and magnesium electrodes were used as anode and cathode, respectively. Morphology, size distribution and composition of the Zn particles were characterized by Scanning Electron Microscopy, Laser Particle Size Analyzer, and Inductive Coupled Plasma Emission Spectrometer. The required composition of the electrolyte for ultrafine particles was found to be 25–35 g/L Zn, 200–220 g/L NaOH and 20–40 mg/L Pb. The optimal conditions were a current density of 1000–1200 A/m and an electrolyte temperature of 30–40 °C. The results indicated that the lead additive exerted a beneficial effect on the refining of the particles, by increasing the cathodic polarization. Through this study, ultrafine zinc powder with a size distribution of around 10 μm could be produced, and considerably high current efficiencies (97–99 %) were obtained.

[1]  T. Havlík,et al.  Acidic leaching both of zinc and iron from basic oxygen furnace sludge. , 2011, Journal of hazardous materials.

[2]  A. Kermanpur,et al.  Effects of process parameters on synthesis of Zn ultrafine/nanoparticles by electromagnetic levitational gas condensation , 2010 .

[3]  P. Tsakiridis,et al.  Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD): part I: Characterization and leaching by diluted sulphuric acid. , 2010, Journal of hazardous materials.

[4]  M. F. D. Carvalho,et al.  Study of the influence of the polyalcohol mannitol on zinc electrodeposition from an alkaline bath , 2010 .

[5]  V. L. Barrio,et al.  Hydrometallurgical process development for the production of a zinc sulphate liquor suitable for electrowinning , 2010 .

[6]  K. Maweja,et al.  Zinc recovery from the water-jacket furnace flue dusts by leaching and electrowinning in a SEC-CCS cell , 2009 .

[7]  M. Bahrololoom,et al.  Electrodeposition of nanocrystalline nickel by using rotating cylindrical electrodes , 2008 .

[8]  François Lapicque,et al.  Investigation of optimal conditions for zinc electrowinning from aqueous sulfuric acid electrolytes , 2007 .

[9]  J. Nava,et al.  Current efficiency studies of the zinc electrowinning process on aluminum rotating cylinder electrode (RCE) in sulfuric acid medium: Influence of different additives , 2007 .

[10]  S. Tjong,et al.  Nanocrystalline materials and coatings , 2004 .

[11]  Ivan Ivanov,et al.  Increased current efficiency of zinc electrowinning in the presence of metal impurities by addition of organic inhibitors , 2004 .

[12]  S. Gürmen,et al.  A laboratory-scale investigation of alkaline zinc electrowinning , 2003 .

[13]  Z. Youcai,et al.  SELECTIVE SEPARATION OF LEAD FROM ALKALINE ZINC SOLUTION BY SULFIDE PRECIPITATION , 2001 .

[14]  Youcai Zhao,et al.  Production of Zn powder by alkaline treatment of smithsonite Zn–Pb ores , 2000 .

[15]  B. L. Gupta,et al.  Iron control in zinc plant residue leach solution , 1996 .

[16]  C. Cachet,et al.  Mechanism of zinc electrodeposition in acidic sulfate electrolytes containing Pb2+ ions , 1996 .

[17]  R. Winand.  Electrocrystallization: Fundamental considerations and application to high current density continuous steel sheet plating , 1991 .

[18]  J. St-Pierre,et al.  Electrowinning of zinc from alkaline solutions at high current densities , 1990 .

[19]  D. J. Mackinnon,et al.  The effect of lead on zinc deposit structures obtained from high purity synthetic and industrial acid sulphate electrolytes , 1979 .