Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD). Part II: Downstream processing and zinc recovery by electrowinning.
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).
Tsakiridis
P E
PE
School of Mining and Metallurgical Engineering, Laboratory of Metallurgy, National Technical University of Athens, 9, Iroon Polytechniou Street, 157 80 Zografou, Athens, Greece. ptsakiri@central.ntua.gr
Oustadakis
P
P
Katsiapi
A
A
Agatzini-Leonardou
S
S
D004391:Dust / Q000032:analysis*; D004563:Electrochemistry; D004573:Electrolytes / Q000737:chemistry; D007202:Indicators and Reagents; D007501:Iron / Q000302:isolation & purification; D008669:Metallurgy; D008855:Microscopy, Electron, Scanning; D010721:Phosphinic Acids; D012997:Solvents; D014961:X-Ray Diffraction; D015032:Zinc / Q000302:isolation & purification*
C523127:Cyanex 272; D004391:Dust; D004573:Electrolytes; D007202:Indicators and Reagents; D010721:Phosphinic Acids; D012997:Solvents; D007501:Iron; D015032:Zinc