Die anthropogene Verbreitung der Edelmetalle durch die Nutzung vornehmlich als Katalysator in der chemischen Industrie und in Kraftfahrzeugen hat bereits zu messbaren Veraenderungen der Edelmetallgehalte in Umweltproben gefuehrt. Ein systematischer Ueberblick ueber die Veraenderungen und deren Auswirkungen auf Lebewesen ist noch nicht machbar, da zu wenige Untersuchungen vorliegen. Fuer das Element Platin sind, zumindest fuer die Verbreitung in der Umwelt, einige Aussagen verfuegbar. Fuer die Metalle Palladium, Rhodium und Iridium sind Untersuchungen nur ansatzweise zu finden. Praktisch keine Aussagen sind ueber die Bindungszustaende zu erhalten. Angaben ueber die vorkommenden Metallspezies sind aber fuer die Kenntnis der Wirkungsmechanismen dieser Metalle auf Lebewesen wichtig. Ziel des Projektes ist die Charakterisierung von Umweltproben, speziell biologischer Proben, bezueglich ihrer Gehalte an Edelmetallen und deren Spezies.
technologyComment of platinum group metal mine operation, ore with high palladium content (RU):
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technologyComment of platinum group metal, extraction and refinery operations (ZA):
The ores from the different ore bodies are processed in concentrators where a PGM concentrate is produced with a tailing by product. The PGM base metal concentrate product from the different concentrators processing the different ores are blended during the smelting phase to balance the sulphur content in the final matte product. Smelter operators also carry out toll smelting from third part concentrators. The smelter product is send to the Base metal refinery where the PGMs are separated from the Base Metals. Precious metal refinery is carried out on PGM concentrate from the Base metal refinery to split the PGMs into individual metal products.
Water analyses measurements for Anglo Platinum obtained from literature (Slatter et.al, 2009).
Mudd, G., 2010. Platinum group metals: a unique case study in the sustainability of mineral resources, in: The 4th International Platinum Conference, Platinum in Transition “Boom or Bust.”
Water share between MC and EC from Mudd (2010).
Mudd, G., 2010. Platinum group metals: a unique case study in the sustainability of mineral resources, in: The 4th International Platinum Conference, Platinum in Transition “Boom or Bust.”
technologyComment of treatment of automobile catalyst (RoW):
After collection and transportation to the intermediary dealer, the scrap is ground in a mill. The resulting material is fed to specialised refineries. The metallurgical step consists of an arc-furnace. Same refining process as in primary production assumed (selective precipitation)
technologyComment of treatment of automobile catalyst (RER):
The production process consists of three steps: Collection, Beneficiation and Refining.
COLLECTION:
Spoiled automotive catalysts are bought by specialised enterprises from different origins. Part of it originates from scrap dealer recycling end-of-life cars. Further more during the cars operating phase, defective catalysts are exchanged in garages. The third sources is the production waste, i. e. defective catalysts which do not reach market. In most cases, there are fix agreements between the different supplier and the intermediary trade. Although the trade with PGM containing scrap is risky. Motor car manufacturer built up their own internal recycling systems with their contractor garages and gained access to exchanged catalysts.
Emissions: Emissions during collection are gases from transportation and dust from dismantling. Also in this step the combustion leads to emissions of SO2. No serious water emissions are reported.
BENEFICIATION:
The catalysts are dismantled and then sold to refining companies. Refineries too have long-term contracts with the intermediary trade.
Emissions: Emissions during beneficiation are gases from transportation and dust from dismantling. Also in this step the combustion leads to emissions of SO2. No serious water emissions are reported.
REFINING:
The scrap first is shredded and then pyrometallurgicaly processed: The scrap is smelted in an electric arc furnace, and the ceramic wafer is slagged. The PGMs are concentrated in the collector metal, usually copper. Low-content PGM scrap is often smelted together with other non-ferrous metal matte. This is cheap, but effects a high loss in PGM. The collector matte from the furnace then is treated hydrometallurgically by re-precipitation. In this step usually production scrap from other industries (glass, chemical laboratories) is joined. The overall PGM-yield is 98 % for platinum and 85 % for rhodium.
Emissions: Dust and metals are generally emitted from incinerators and furnaces. VOC can be emitted from solvent extraction processes, while organic compounds, namely dioxins, can be emitted from smelting stages resulting from the poor combustion of oil and plastic in the feed material. All these emissions are subject to abatement technologies and controlling. Effluents from refining contain considerable amounts of metals and organic substances.
Waste: Solid residues from pyrometallurgical step are usually re-used in copper facilities, final residues generally comprise hydroxide filter cakes.
References:
Hagelücken C. (2001b) Die Märkte der Katalysatormetalle Platin, Palladium und Rhodium. In: Autoabgaskatalysatoren, Vol. 612. pp. 95-115. Expert Verlag, Renningen. Online-Version under: http://www.dmc-2.de/pmc_eng/Veroeffentlichungen_2/Die%20M%C3%A4rkte%20der%20Katalysatormetalle%20Pt%20Pd%20Rh.pdf.
technologyComment of treatment of precious metal from electronics scrap, in anode slime, precious metal extraction (SE, RoW):
Anode slime treatment by pressure leaching and top blown rotary converter. Production of Silver by Möbius Electrolysis, Gold by Wohlwill electrolysis, Palladium to further processing