School of Mining and Metallurgical Engineering, Laboratory of Metallurgy, National Technical University of Athens, 9, Iroon Polytechniou Street, 157 80 Zografou, Athens, Greece.
J Hazard Mater. 2010 Jul 15;179(1-3):8-14. doi: 10.1016/j.jhazmat.2010.04.004. Epub 2010 Apr 10.
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).
在第一部分中，我们研究了用电弧炉粉尘（EAFD）经稀硫酸浸取的特性和浸取条件。本研究工作（第二部分）的目的是开发一种从浸出液中回收高纯锌的净化工艺，该工艺由以下四个单元操作组成：（1）在大气压下，通过化学沉淀法在 pH：3.5 和 95°C 下将铁转化为易过滤的晶状黄钾铁矾硫酸盐。（2）在 pH：3.5、T：40°C 下，用 25%浓度的 Cyanex 272 萃取剂萃取锌。（3）在 T：40°C 下，用含锌废电解液（62.5g/L Zn(2+)）对负载有机相进行反萃，用稀硫酸（3mol/L）。（4）在 38°C 下，用电解质（180g/L H(2)SO(4)）进行锌的电沉积，以 Al 为阴极，Pb 为阳极，电流密度保持在 500A/m(2)。
