Stefan Steinlechner

Characterization and process development for the selective removal of Sn, Sb, and As from anode slime obtained from electrolytic copper refining

The aim of this work was to develop a process for the removal of Sn, Sb and As from anode slime out of copper refinery to disburden a subsequent pyrometallurgical processing for precious metals refinement. For this reason, a detailed literature survey was conducted, followed by a characterization to find the present compounds/alloys and their morphology. A newly developed process concept for the separate extraction of the afore mentioned three target metals was developed and verified by leaching experiments, combined with thermodynamic calculations on their behavior under varying conditions. In this context, the influence of leaching temperature, alkalinity of leaching solution, and solid-liquid ration were evaluated on the extraction yields of Sn, As, and Sb, as well as how to exploit these findings to obtain separate streams enriched in the respective metals.

Thermodynamic Cons iderations Regarding the Volatilization Behavior of Silver and Indium from Jarosite by a Pyrometallurgical Treatment

Elements defined as critical by the European Commission, like platinum group metals (PGM), indium, cobalt, gallium, silver, gold, germanium and antimony are often contained in copper-, leadand zinc-ores. During the metal production process of the above-mentioned base metals different residues accumulate, which can contain these critical elements as well. By depositing thousands of tonnes of these residues from the metallurgical industry, the contained valuable metals are no longer available. Next to that the security of supply in Europe for especially those metals is bad. Due to these problems and an increased environmental awareness, the recovery of critical elements from residues gets more and more important. Because of carrying high amount of silver and indium, the precipitation residue jarosite or also neutral leaching residue from the hydrometallurgical zinc production are potentially interesting for reprocessing. By adding of different additives and a treatment at higher temperatures, critical elements as well as other valuable metals get vaporized in various chemical compounds. If the mentioned metals are recovered successfully during a recycling process it can contribute to the overall production economy. The paper summarizes carried out thermochemical calculations investigating a possible recovery of silver as well as indium in a pyrometallurgical process by selective vaporization.

Potential Contribution to the Supply of Silver by the Recycling of Industrial Residues from Zn, Pb and Cu Plants

The focus of recycling processes for industrial residues from lead, zinc and copper industry in the past was mainly on the recovery of the base metals. Silver, gold or also PGMs are well-known valuable side elements in the corresponding ores and with this significant contents can be found in some of the residues but were not recovered in the past. Therefore, the recovery of for instance silver is highly interesting, beside the above described base metals to contribute to the overall economy of a potential recycling process, although they occur in much smaller quantities in materials like tailings, sludge, slags or dusts. As an example, the annually produced and mainly dumped amount of zinc leach residues contains roughly 500 tons of silver beside lead, zinc and others. Therefore, the present paper tries to answer how recycling of such industrial residues can contribute for example to the supply of silver or also other precious metals.

Mini Mill Solutions in the Recycling of Electic Arc Furnace Dust — The 2SDR Process

High amounts of Steel Mill Dust is produced worldwide each year. Although the Waelz kiln is the preferred route for processing these wastes, significant amounts of this residue stays untreated. Very often, the unprocessed dust gets landfilled and therefore, it is lost for the recovery of zinc and further heavy metals accompanied in the waste. An alternative way with respect to treating Electric Arc Furnace Dust would be the so called 2sDR (Two step Dust Recycling) process, which allows the simultaneous recovery of high purity zinc oxide as well as iron and other heavy metals. This leads to a zero waste process, because the remaining slag is free of heavy metals which allows a utilization for e.g. construction purposes. The present publication should give an overview on the process set-up itself; moreover, achieved data from extended lab scale trials underlines the sustainability of this process.

Aktuelle Entwicklungstrends und zukünftige Herausforderungen im Bereich der Nichteisenmetallurgie

ZusammenfassungDer Umgang mit Rohstoffen und Energie ist für die industrielle Entwicklung Europas von großer Wichtigkeit. Dem Recycling kommt daher eine immer größere Bedeutung zu, wobei jedoch der gesamte Produktlebenszyklus betrachtet werden muss, sodass eine intensive Vernetzung von Rohstofftechnik, Metallurgie und Werkstoffwissenschaften in Zukunft einen wesentlichen Punkt darstellen wird. Darüber hinaus spielen Entwicklungstrends wie Industrie 4.0, Energiewende, E-Mobility, Wasserstofftechnologie usw. für die gesamte Nichteisenmetallurgie im Bereich der Prozesse und Produkte in den nächsten Jahren eine entscheidende Rolle.AbstractResources and energy have an essential importance for the industrial development in Europe. Especially the relevance of recycling processes will increase, which means that the life cycle of a product has to be considered. Therefore an intensive interaction of raw material technology, metallurgy, and material science will be necessary in the future. Furthermore, development trends, like “Industry 4.0”, alternative energy production, E-mobility, hydrogen technology, and more, will influence the nonferrous metallurgy in the field of processes and products within the next few years.

Optimization and Biomass Utilization in Heavy Metal Recycling

Environmental legislation, limited resources as well as high metal prices force the metallurgical industry more and more to make use of secondary materials. For this, also residues from metal production are nowadays considered as a possible resource. Due to their often complex structure and the presence of a multi-metal-system, efficient recycling of such materials is not easy to realize and suffers from various problems. The Christian Doppler Laboratory for Optimization and Biomass Utilization in Heavy Metal Recycling together with its partner companies Befesa R&D, voestalpine Stahl Linz, RHI, and Aurubis investigate alternative strategies and optimization possibilities for the considered residues. The achievements of three years’ activity in the major fields of the CDL, characterization of the complex input materials, upgrade of the product quality of recycling processes, utilization of biomass in the form of charcoal for use as a reducing agent and simultaneous recovery of valuable metals are described in the paper.ZusammenfassungUmweltauflagen, limitierte Ressourcen und hohe Metallpreise bewegen die metallurgische Industrie, verstärkt sekundäre Einsatzmaterialien zu nutzen. Dieser Notwendigkeit folgend, werden heute auch Rückstände der metallerzeugenden Industrie als mögliche Rohstoffe in Betracht gezogen. Aufgrund deren häufig komplexen Struktur sowie dem Vorhandensein eines Multimetall-Systems ist das Recycling entsprechender Materialien oft nicht einfach zu realisieren und leidet unter verschiedensten Problemen. Das Christian Doppler Labor für Optimierung und Biomasseeinsatz beim Recycling von Schwermetallen untersucht gemeinsam mit seinen industriellen Partnern, Befesa R&D, voestalpine Stahl Linz, RHI und Aurubis alternative Strategien und Optimierungsmöglichkeiten für die im Fokus befindlichen Rückstände. Die Erkenntnisse und Erfolge der bisher dreijährigen Tätigkeit in den Hauptbereichen des CDLs, Charakterisierung komplexer Einsatzmaterialien, Erhöhung der Produktqualität in Recyclingprozessen, Einsatz von Biomasse in Form von Holzkohle als Reduktionsmittel und die simultane Rückgewinnung von Wertmetallen sind im vorliegenden Beitrag beschrieben.

PGM Recycling from Catalysts in a Closed Hydrometallurgical Loop with an Optional Cerium Recovery

Today PGM-recovery from spent catalysts is a standard procedure. Nevertheless still big amounts of these materials remain untreated. Furthermore the state of the art process is a very expensive solution and does not offer a recovery of all valuable materials.