Characterization and Processing
of Residues from Hydrometallurgical
Zinc Smelters
J. Antrekowitsch and G. Hanke
Abstract Leaching residues out of primary zinc industry like the so-called jarosite,
move more and more into the focus of research and development, due to environmental reasons and the potential to recover zinc, lead, silver as well as other valuables.
Even though values of lead and zinc can be found in a range of 2–8% sometimes
accompanied by up to 500 ppm of silver, missing concepts for concentration, e.g. by
flotation, and failing hydrometallurgical approaches, make an economic treatment
difficult to realize. At the University of Leoben, together with associated R&Dcompanies, a pyrometallurgical process for jarosite treatment has been developed,
realizing a multi-metal recovery and the formation of slag, allowing utilization in
construction or cement industry. However, to avoid high specific energy consumption, at least a certain grade of concentration would be beneficial. The paper describes
the general process idea, the characterization of the material, and the first results of
mineral beneficiation trials and how they could influence the economy of the concept.
Keywords Recycling · Zinc · Lead · Mineral processing · Characterization
Introduction
Zinc ores nowadays often suffer from decreasing zinc and lead grades going along
with increasing iron contents. The iron, which follows the valuables into the concentrate, has to be removed during the leaching process, creating huge volumes of waste
which are, in the majority of cases, dumped worldwide. Considering that for every
ton of zinc produced in zinc smelters operating a jarosite or goethite precipitations,
600–1000 kg of leaching residue is generated alongside; globally, the amount of
slurry generated per year lies somewhere between 7 and 10 million tons.
J. Antrekowitsch (B)
Chair of Nonferrous Metallurgy, University of Leoben, Leoben, Austria
e-mail: juergen.antrekowitsch@unileoben.ac.at
G. Hanke
Chair of Geology and Economic Geology, University of Leoben, Leoben, Austria
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_38
437
of Residues from Hydrometallurgical
Zinc Smelters
J. Antrekowitsch and G. Hanke
Abstract Leaching residues out of primary zinc industry like the so-called jarosite,
move more and more into the focus of research and development, due to environmental reasons and the potential to recover zinc, lead, silver as well as other valuables.
Even though values of lead and zinc can be found in a range of 2–8% sometimes
accompanied by up to 500 ppm of silver, missing concepts for concentration, e.g. by
flotation, and failing hydrometallurgical approaches, make an economic treatment
difficult to realize. At the University of Leoben, together with associated R&Dcompanies, a pyrometallurgical process for jarosite treatment has been developed,
realizing a multi-metal recovery and the formation of slag, allowing utilization in
construction or cement industry. However, to avoid high specific energy consumption, at least a certain grade of concentration would be beneficial. The paper describes
the general process idea, the characterization of the material, and the first results of
mineral beneficiation trials and how they could influence the economy of the concept.
Keywords Recycling · Zinc · Lead · Mineral processing · Characterization
Introduction
Zinc ores nowadays often suffer from decreasing zinc and lead grades going along
with increasing iron contents. The iron, which follows the valuables into the concentrate, has to be removed during the leaching process, creating huge volumes of waste
which are, in the majority of cases, dumped worldwide. Considering that for every
ton of zinc produced in zinc smelters operating a jarosite or goethite precipitations,
600–1000 kg of leaching residue is generated alongside; globally, the amount of
slurry generated per year lies somewhere between 7 and 10 million tons.
J. Antrekowitsch (B)
Chair of Nonferrous Metallurgy, University of Leoben, Leoben, Austria
e-mail: juergen.antrekowitsch@unileoben.ac.at
G. Hanke
Chair of Geology and Economic Geology, University of Leoben, Leoben, Austria
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_38
437