Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD). Part II: Downstream processing and zinc recovery by electrowinning

J Hazard Mater. 2010 Jul 15;179(1-3):8-14. doi: 10.1016/j.jhazmat.2010.04.004. Epub 2010 Apr 10.

Abstract

The characterization and the agitation leaching of electric arc furnace dust (EAFD) by diluted sulphuric acid have been studied in Part I, as a separate article. The aim of the present research work (Part II) is the development of a purification process of the leach liquor for the recovery of high-purity zinc by electrowinning. The proposed hydrometallurgical process consists of the following four (4) unit operations: (1) Removal of iron as easily filterable crystalline basic sulphate salt of the jarosite type, at atmospheric pressure, by chemical precipitation at pH: 3.5 and 95 degrees C. (2) Zinc solvent extraction by Cyanex 272 at pH: 3.5, T: 40 degrees C, with 25% extractant concentration. (3) Stripping of the loaded organic phase by zinc spent electrolyte (62.5 g/L Zn(2+)) at T: 40 degrees C with diluted H(2)SO(4) (3 mol/L). (4) Zinc electrowinning from sulphate solutions (at 38 degrees C) using Al as cathode and Pb as anode. The acidity of the electrolyte was fixed at 180 g/L H(2)SO(4), while the current density was kept constant at 500 A/m(2).

MeSH terms

  • Dust / analysis*
  • Electrochemistry
  • Electrolytes / chemistry
  • Indicators and Reagents
  • Iron / isolation & purification
  • Metallurgy
  • Microscopy, Electron, Scanning
  • Phosphinic Acids
  • Solvents
  • X-Ray Diffraction
  • Zinc / isolation & purification*

Substances

  • Cyanex 272
  • Dust
  • Electrolytes
  • Indicators and Reagents
  • Phosphinic Acids
  • Solvents
  • Iron
  • Zinc