Dipl.-Ing. Philipp Rädecker, Prof. Dr.-Ing. Christiane Scharf, M. Sc. Philipp Zürner, Juniorprof. Dr. Gero Frisch, Dipl.-Min. Gunther Pieplow, Dipl.-Ing. (FH) Doreen Lindner, Dr. Jörg Koch
Flue dusts from copper metallurgy are resources for base metals such as copper, zinc, tin or lead.
However, there is also a potential for the recovery of strategic elements like indium. At the moment
flue dusts are recirculated within the copper process, but residues are available from historic production
Hydrometallurgical processes seem to be a promising method to recover the base and strategic metals
from these fine-grained flue dusts. In preparation for further processing, the secondary material was
characterized by mineral liberation analysis (MLA) and electron probe micro analysis (EPMA). An
iron- and zinc-rich spinel phase (Zn,Fe,Mn)(Fe,Mn)2O4 was detected as the main phase (76 wt.-%) in
the flue dust. The chemical composition of the flue dust was analysed by X-ray fluorescence spectroscopy
(XRF spectroscopy). Leaching by sulfuric acid leads to precipitation of lead sulphate and calcium
sulphate, which remain in the residue. The level of some impurities in the solution can be controlled.
This work focuses on the selective recovery of copper and indium by solvent extraction from the
leaching solution. Preliminary synthetic solutions of copper, iron(III), zinc, indium and mixtures of
them were used for the investigations. The influence of pH value, concentration of acidic extractants,
extraction time, and phase ratio on the extraction of copper, iron(III), zinc, and indium were studied.
The results of the selective extraction of copper in the presence of iron(III) will be presented.