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Deutsche verbrauchen zu viele Hi-Tech-Metalle

Rohstoffmangel bald Bremsklotz für die wirtschaftliche Entwicklung? Deutschland muss viel sparsamer mit seinen natürlichen Ressourcen und Rohstoffen umgehen, rät das Umweltbundesamt (UBA). „Mit einem Rohstoffverbrauch von 200 Kilo pro Kopf und Tag liegen die Deutschen weltweit mit an der Spitze. Das schadet nicht nur der globalen Umwelt - es ist auch gefährlich für unsere internationale Wettbewerbsfähigkeit. Schon heute liegen die Materialkosten im verarbeitenden Gewerbe bei rund 43 Prozent der Wertschöpfung. Wenn die Rohstoffpreise weiter in die Höhe schnellen, wird dieser Anteil auf Sicht weiter steigen“, sagte UBA-Präsident Jochen Flasbarth zur Eröffnung einer dreitägigen, internationalen Ressourcen-Konferenz in Berlin. Auch die wirtschaftliche Entwicklung könnte durch den weltweiten Rohstoffhunger unter die Räder kommen. Gerade die sogenannten seltenen Erden, dies sind spezielle Hi-Tech-Metalle wie Neodym werden knapper und teurer. Für den Elektromagneten eines modernen, getriebelosen Offshore-Windrades wird je nach Leistung bis zu eine Tonne Neodym benötigt. In den vergangenen sieben Jahren ist der Preis für Neodym von 25.000 Dollar pro Tonne auf rund 700.000 Dollar im Jahr 2012 gestiegen. Auch für die Elektromobilität sind Fahrzeughersteller auf große Mengen Neodym angewiesen. Über 97 Prozent der weltweiten Förderstätten für seltene Erden liegen derzeit in der Volksrepublik China. ⁠ UBA ⁠-Präsident Flasbarth hält es für kurzsichtig, für billige Rohstoffe allein auf gute Handelsbeziehungen zu Lagerstätten im Ausland zu setzen: „Wir brauchen den sparsamsten Einsatz von Rohstoffen bei uns in Deutschland und ein hochwertiges Recycling. Das ist aus Sicht des Umwelt- und Klimaschutzes und bei steigenden Weltmarktpreisen - gerade für viele Metalle - sowohl ein ökologisches wie auch ein ökonomisches Muss.“ Um den Rohstoffverbrauch zu senken, sind mehrere Ansätze möglich: „Warum machen wir es nicht wie im Bereich der Energieeffizienz und legen Mindeststandards für die Rohstoff- und Materialeffizienz von Produkten und Anlagen fest? Langlebige, wiederverwendbare, leicht zu wartende und gut recycelbare Produkte helfen uns, die Wertschöpfung bei sinkendem Ressourceneinsatz zu steigern. Denkbar wäre auch, das material- und rohstoffeffizienteste Gerät seiner Klasse zum Maßstab für alle Geräte zu machen. Das fördert technische Innovation, schont die Umwelt und senkt Kosten“, so Flasbarth. Die Verbraucherinnen und Verbraucher ermuntert das UBA, vor allem Elektrogeräte effizient zu nutzen und einer sachgerechten Entsorgung zuzuführen: „Wir schätzen allein den Materialwert der vielen Millionen Handys in Deutschland, die aussortiert in Schränken und Schubladen schlummern, auf mindestens 65 Millionen Euro. Das ist ein wahres Rohstofflager. Die Handyhersteller sollten ein Interesse haben, möglichst viele alte Handys zu recyceln, anstatt die Rohstoffe für jedes neue Gerät teuer auf dem Weltmarkt einzukaufen“, sagte Flasbarth. Auch die Umwelt würde entlastet - so spart jede Tonne Kupfer, die aus alten Handys zurückgewonnen wird, gegenüber dem Erstabbau über die Hälfte an Energie ein. Außerdem entsteht 50 Prozent weniger Schlacke. Die giftige Schwefelsäure für die Verarbeitung des rohen Kupfers fällt fast ganz weg. Neben Kupfer enthalten Handys und Smartphones auch Edelmetalle wie Gold, Silber und Palladium. Die Förderung und Aufbereitung von Silber oder Gold hat ebenfalls hohe Umweltwirkungen, so kommen gifte Zyanidlaugen zum Einsatz. Bei einzelnen Rohstoffen erreichen die Recyclingquoten in Deutschland bereits beachtliche Werte - so werden 45 Prozent des Stahls wiederverwendet, 50 Prozent der Nichteisen-Metalle und bis zu 94 Prozent bei Glas. Das drückt den Bedarf an neu abgebauten Rohstoffen deutlich, ist aber nicht genug. Vor allem für die Haushalte muss die Rückgabe von Produkten daher einfacher werden. Zwar können ausgediente Produkte schon heute kostenlos bei den Recyclinghöfen der Städte und Gemeinden abgeben werden - viele Menschen empfinden das aber als unpraktisch. Für alte und kranke Menschen ist es ohnehin kaum praktikabel. Deshalb landen immer noch viel zu viele Rohstoffe im privaten „grauen“ Restmüll, obwohl sie hochwertig recycelt werden könnten. Hier könnte eine möglichst haushaltsnahe Sammlung das Recycling attraktiver machen. Neben Metallen ist es vor allem der große Bedarf an Baurohstoffen, wie Steinen, Erden und Hölzern, der den Deutschen eine positivere Rohstoffbilanz pro Kopf verhagelt: „Unter Rohstoff-Gesichtspunkten ist es viel günstiger, ein altes Haus zu sanieren als ein neues zu bauen. Wer ein altes Gebäude saniert, spart rund zwei Drittel an Baumaterialien. Deutschland sollte daher seinen Gebäudebestand intensiver nutzen, anstatt neu zu bauen. Das geht, indem wir davon absehen, immer weitere Neubaugebiete auf der grünen Wiese auszuweisen, sondern die alten Stadtkerne attraktiver machen“, sagte UBA-Präsident Flasbarth. Damit wäre auch dem viel zu hohen Verbrauch der Ressource „Fläche“ Einhalt geboten - hier ist Deutschland „Spitze“: Jeden Tag werden fast 87 Hektar, das entspricht 124 Fußballfeldern, neu versiegelt. Weltweit werden jährlich fast 70 Milliarden Tonnen Rohstoffe gewonnen und eingesetzt. Dies entspricht rund einem Drittel mehr als im Jahr 2000 und doppelt so viel wie Ende der 1970er Jahre. Durch das weitere Ansteigen der Weltbevölkerung und das rasante Wirtschaftswachstum in den Schwellenländern wird die Nachfrage nach Ressourcen weiter zunehmen. Der Pro-Kopf-Konsum von Rohstoffen ist in Europa rund viermal so hoch wie in Asien und fünfmal so hoch wie in Afrika. Während die Industrienationen aber den Großteil der globalen Wertschöpfung erwirtschaften, treffen die ökologischen und sozialen Folgewirkungen der Ressourcennutzung überproportional die Entwicklungsländer. Die intensive Rohstoffnutzung führt zu erheblichen Umweltbeeinträchtigungen, die von der Freisetzung von Treibhausgasen über Schadstoffeinträge in Luft, Wasser und Boden bis zur Beeinträchtigung von Ökosystemen und ⁠ Biodiversität ⁠ reichen. UBA-Präsident Jochen Flasbarth: „Schon jetzt übersteigt die Nutzung von natürlichen Ressourcen die Regenerationsfähigkeit der Erde deutlich. Deshalb wird ein schonender und gleichzeitig effizienter Umgang mit natürlichen Ressourcen zu einer Schlüsselkompetenz zukunftsfähiger Gesellschaften. Eine Steigerung der Ressourceneffizienz wird die Umweltbelastungen begrenzen, die Wettbewerbsfähigkeit der deutschen Wirtschaft stärken, neue Arbeitsplätze schaffen und dauerhaft Beschäftigung sichern.“

Grüne Informationstechnik: ökologisch und ökonomisch überlegen

Zum Start der CeBIT: Neue Broschüre mit Verbraucher-Tipps Die Informations- und Kommunikationstechnik (IKT) ist das Rückgrat einer modernen Volkswirtschaft. Aber: Die Digitalisierung der Haushalte und Büros sowie das Internet verursachen einen erheblichen Strom- und Materialverbrauch. Allein in Deutschland sind rund zehn Kraftwerke nötig, um den Strombedarf der ITK in unseren modernen Haushalten zu decken. Ob Digitalkamera, Notebook, Spielkonsole, Handy oder Plasma-Fernseher, die ITK verursachte im Jahr 2007 rund 33 Millionen Tonnen des Klimagases Kohlendioxid (CO2) und damit mehr als der gesamte deutsche Luftverkehr. „Die Informations- und Kommunikationstechnik ist ein Wachstumsmarkt - und zwar auch beim Ausstoß klimaschädlicher Gase. Deshalb ist Klimaschutz hier besonders wichtig”, sagt Dr. Thomas Holzmann, Vizepräsident des Umweltbundesamtes (UBA). Zum Start der Computermesse CeBIT in Hannover am 3. März 2009 informiert das UBA in einer kostenlosen Verbraucher-Broschüre über Tipps und Kniffe beim Kauf energiesparender Computer, dem grünen Surfen und der umweltgerechten Aufrüstung alter Geräte. Computer mit gleicher Rechenleistung und Ausstattung verbrauchen leider oft unterschiedlich viel Energie. Wie bei Autos gibt es sowohl große Schlucker als auch Energiesparer. „Nicht nur Gigabyte und Pixel-Zahl sind beim Computerkauf entscheidend – auch auf den Energieverbrauch kommt es an. Jede Neuanschaffung legt den Energieverbrauch oft über Jahre fest. Wer beim Kauf genau hinschaut, wird belohnt”, erklärt Holzmann. Ein sehr effizienter Computer spart gegenüber einem ineffizienten Gerät zwischen 50 und 70 Prozent Strom. Dabei müssen sparsame Geräte nicht teurer sein als ineffiziente. Verbraucherinnen und Verbraucher sollten auch darauf achten, dass die neuen Geräte ihren individuellen Anforderungen entsprechen. Größer, schneller, stärker – kaum jemand will technisch zurückbleiben, wenn die neuen Geräte auf den Markt kommen. Aber: Was für die tatsächliche Nutzung überdimensioniert ist, braucht mehr Strom als nötig und ist meist teurer in der Anschaffung. „Und wer einen Rechner nur für Textverarbeitung und das Surfen nutzt, braucht sicher keinen Videoschnittplatz”, so der ⁠ UBA ⁠-Vizepräsident. „Grüne” Informationstechnik hört übrigens nicht beim Energiesparen auf. Auch der Aufwand zur Herstellung der Geräte ist enorm: Für die Produktion eines einzigen PC samt Monitor sind rund 1.500 Liter Wasser und 23 Kilo verschiedener Chemikalien nötig. In den elektronischen Bauteilen stecken zudem seltene Metalle wie Gold, Silber, Tantal oder Platin, deren Förderung die Umwelt und die natürlichen Ressourcen belastet. PCs, Handys oder Laptops enthalten zudem Blei, Quecksilber und Cadmium und andere Stoffe, die die Gesundheit schädigen können. Alte Elektrogeräte gehören daher nicht in den Hausmüll, sondern sind getrennt zu sammeln und zu verwerten. Für die Verbraucherinnen und Verbraucher ist das völlig kostenlos: Sie können die Geräte bei den Sammelstellen der Städte und Gemeinden zurückgeben. Unter dem Motto „Nachhaltigkeit in einer digitalen Welt” informiert vom 3. bis 8. März 2009 die Green IT World auf der Messe CeBIT in Hannover. Das Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit (⁠ BMU ⁠), der Bundesverband Informationswirtschaft, Telekommunikation und neue Medien (BITKOM) und das Umweltbundesamt (UBA) präsentieren gemeinsam mit zahlreichen Unternehmen ökologisch und ökonomisch erfolgreiche IT-Innovationen – von Strom sparenden Notebooks über energieeffiziente Rechenzentren bis hin zu modernsten Videokonferenz-Lösungen. Eine gedruckte Fassung gibt es kostenlos beim Umweltbundesamt c/o GVP, Postfach 30 0361, 53183 Bonn oder telefonisch zum Ortstarif unter (03018) 305 3355 Besuchen Sie uns auf der CeBIT in Hannover in Halle 8, der „Green IT World”. Dessau-Roßlau, 02.03.2009

Verantwortungsvolle Rohstoffgewinnung? Herausforderungen, Perspektiven, Lösungsansätze

Im Forschungsvorhaben "UmSoRess" wurden zunächst die Auswirkungen der Gewinnung von Gold, Kupfer, Aluminium, Seltenen Erden und Zinn auf Umwelt und Gesellschaft anhand von Fallstudien in 13 Ländern analysiert. In einem nächsten Schritt wurden 42 Standards zur Verbesserung der Umwelt- und Sozialsituation im Bereich der Rohstoffgewinnung untersucht - von internationalen Konventionen über staatliche Regelungen bis hin zu freiwilligen Zertifizierungsinitiativen und Best-Practice-Leitfäden. Schließlich wurden politische Handlungsempfehlungen zur Verbesserung von Umwelt- und Sozialstandards im Bergbau und zur Stärkung von Transparenz und Verantwortung in Rohstofflieferketten entwickelt. Veröffentlicht in Texte | 66/2017.

Public Eye Awards 2011

Am 28. Januar 2011 zeichneten die unabhängige entwicklungspolitische Organisation „Erklärung von Bern“ und Greenpeace Schweiz parallel zum Jahrestreffen des Weltwirtschaftsforums (WEF) in Davos zwei Unternehmen mit dem Public Eye Awards 2011 aus. Mit dem Schmähpreis werden Unternehmen, die exemplarisch für WEF-Mitglieder und Unternehmen stehen, für besonders menschen- und umweltverachtende Geschäftspraktiken prämiert. Der Publikumspreis ging via Internet-Voting an den finnischen Energiekonzern Neste Oil. Die Nichtregierungsorganisationen werfen dem finnischen Unternehmen Neste Oil vor, verantwortlich für Landnahme, Vertreibung von Menschen und die Zerstörung von Regenwald und Mooren vornehmlich in Malaysia und Indonesien ist. Den Jurypreis erhielt der südafrikanische Minenkonzern AngloGold Ashanti. Dem Bergbau-Unternehmen werfen die EvB und Greenpeace die Verschmutzung und Austrocknung von Flüssen sowie Vergiftung von Menschen und Land beim Goldabbau in Ghana und Menschenrechtsverletzungen vor.

Peru ruft Notstand wegen Quecksilber-Verschmutzung aus

Die peruanische Regierung hat in der Amazonasregion Madre de Dios einen Notstand ausgerufen. Bei Anwohnern seien erhöhte Quecksilberkonzentrationen nachgewiesen worden, 41 Prozent der regionalen Bevölkerung sind laut Umweltministerium betroffen. Die Verschmutzung gehe auf illegalen Bergbau zurück. In der Grenzregion zu Brasilien und Bolivien gibt es zahlreiche illegale Goldminen. Die Bergarbeiter verwenden das hochgiftige Quecksilber, um Gold aus Gestein zu lösen. Quecksilber verseuche das Wasser, die Luft und Erdablagerungen, heißt es in einem Bericht der Regierung. Der Notstand gilt zunächst für 60 Tage. Der illegale Bergbau ist in Peru seit Jahren ein Problem und gilt als eine Hauptursache für die Abholzung des Regenwalds. Nach Schätzungen des Umweltministeriums gibt es mehr als 70.000 informelle Bergarbeiter.

Brasilien gibt Naturschutzgebiet für Bergbau frei

Am 23. August 2017 veröffentlichte die brasilianische Regierung im Amtsblatt ein Dekret, das den Naturschutz-Status von mehr als vier Millionen Hektar Regenwald im Amazonas-Gebiet aufhebt. Künftig ist der Abbau von Rohstoffen dort erlaubt. Das von Präsident Michel Temer unterzeichnete Dekret betrifft das 1984 geschaffene Reservat Nacional do Cobre e Associados in der Grenzregion der Bundesstaaten Amapá und Para im Norden Brasiliens. In der Region werden große Gold-Vorkommen vermutet aber auch große Eisenvorräte, Kupfer und andere Erze. Zahlreiche illegale Minen existieren bereits in Oiapoque, Pedra Branca do Amapari, Tartarugalzinho, Mazagão und Calçoene. Ab sofort dürfen Kon­zes­sio­nen zum Abbau vergeben werden.

Bedrohter See des Jahres 2007: Pantanal, Brasilien, Paraguay und Bolivien

Die internationale Umweltstiftung Global Nature Fund (GNF) hat das südamerikanische Feuchtgebiet Pantanal zum Bedrohten See des Jahres 2007 ernannt. Der GNF macht damit auf die Zerstörung der Feuchtgebietsflächen durch Monokulturen, intensive Viehwirtschaft, die Gewinnung von Gold und Diamanten sowie die Ethanol-Herstellung aufmerksam.

Die zehn gefährlichsten Umweltgifte weltweit 2008

Die US-Umweltorganisation Blacksmith Institute und die Umweltorganisation Green Cross Schweiz legen mit dem Umweltgiftbericht 2008 eine Liste der zehn weltweit gefährlichsten Umweltgifte vor. Mit ihrem Bericht wollen die Organisationen die Öffentlichkeit auf die schwerwiegenden Folgen durch Umweltgifte auf die menschliche Gesundheit aufmerksam machen. Laut Bericht sind die zehn gefährlichsten Umweltgiftquellen weltweit: Goldabbau; Kontaminierte Oberflächengewässer; Kontaminiertes Grundwasser; Luftschadstoffe in Innenräumen; Metallschmelzen und –verarbeitung; Industrieller Bergbau; Radioaktive Abfälle und Abfälle aus dem Uranbergbau; Ungeklärte Abwässer; Städtische Luftverschmutzung; Recycling von Bleibatterien

Markt für Gold

technologyComment of gold mine operation and refining (SE): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. ORE AND WASTE HAULAGE: The haul trucks transport the ore to various areas for processing. The grade and type of ore determine the processing method used. Higher-grade ores are taken to a mill. Lower grade ores are taken to leach pads. Some ores may be stockpiled for later processing. HEAP LEACHING: The ore is crushed or placed directly on lined leach pads where a dilute cyanide solution is applied to the surface of the heap. The solution percolates down through the ore, where it leaches the gold and flows to a central collection location. The solution is recovered in this closed system. The pregnant leach solution is fed to electrowinning cells and undergoes the same steps as described below from Electro-winning. ORE PROCESSING: Milling: The ore is fed into a series of grinding mills where steel balls grind the ore to a fine slurry or powder. Oxidization and leaching: Some types of ore require further processing before gold is recovered. In this case, the slurry is pressure-oxidized in an autoclave before going to the leaching tanks or a dry powder is fed through a roaster in which it is oxidized using heat before being sent to the leaching tanks as a slurry. The slurry is thickened and runs through a series of leaching tanks. The gold in the slurry adheres to carbon in the tanks. Stripping: The carbon is then moved into a stripping vessel where the gold is removed from the carbon by pumping a hot caustic solution through the carbon. The carbon is later recycled. Electro-winning: The gold-bearing solution is pumped through electro-winning cells or through a zinc precipitation circuit where the gold is recovered from the solution. Smelting: The gold is then melted in a furnace at about 1’064°C and poured into moulds, creating doré bars. Doré bars are unrefined gold bullion bars containing between 60% and 95% gold. References: Newmont (2004) How gold is mined. Newmont. Retrieved from http://www.newmont.com/en/gold/howmined/index.asp technologyComment of gold production (US): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. UNDERGROUND MINING: Some ore bodies are more economically mined underground. In this case, a tunnel called an adit or a shaft is dug into the earth. Sort tunnels leading from the adit or shaft, called stopes, are dug to access the ore. The surface containing the ore, called a face, is drilled and loaded with explosives. Following blasting, the broken ore is loaded onto electric trucks and taken to the surface. Once mining is completed in a particular stope, it is backfilled with a cement compound. BENEFICIATION: Bald Mountain Mines: The ore treatment method is based on conventional heap leaching technology followed by carbon absorption. The loaded carbon is stripped and refined in the newly commissioned refinery on site. Water is supplied by wells located on the mine property. Grid power was brought to Bald Mountain Mine in 1996. For this purpose, one 27-kilometre 69 KVA power line was constructed from the Alligator Ridge Mine substation to the grid. Golden Sunlight Mines: The ore treatment plant is based on conventional carbon-in-pulp technology, with the addition of a Sand Tailings Retreatment (STR) gold recovery plant to recover gold that would otherwise be lost to tailings. The STR circuit removes the heavier gold bearing pyrite from the sand portion of the tailings by gravity separation. The gold is refined into doré at the mine. Tailing from the mill is discharged to an impoundment area where the solids are allowed to settle so the water can be reused. A cyanide recovery/destruction process was commissioned in 1998. It eliminates the hazard posed to wildlife at the tailings impoundment by lowering cyanide concentrations below 20 mg/l. Fresh water for ore processing, dust suppression, and fire control is supplied from the Jefferson Slough, which is an old natural channel of the Jefferson River. Ore processing also uses water pumped from the tailings impoundment. Pit water is treated in a facility located in the mill complex prior to disposal or for use in dust control. Drinking water is made available by filtering fresh water through an on-site treatment plant. Electric power is provided from a substation at the south property boundary. North-Western Energy supplies electricity the substation. Small diesel generators are used for emergency lighting. A natural gas pipeline supplies gas for heating buildings, a crusher, air scrubber, boiler, carbon reactivation kiln, and refining furnaces. Cortez Mine: Three different metallurgical processes are employed for the recovery of gold. The process used for a particular ore is determined based on grade and metallurgical character of that ore. Lower grade oxide ore is heap leached, while higher-grade non-refractory ore is treated in a conventional mill using cyanidation and a carbon-in-leach (“CIL”) process. When carbonaceous ore is processed by Barrick, it is first dry ground, and then oxidized in a circulating fluid bed roaster, followed by CIL recovery. In 2002 a new leach pad and process plant was commissioned; this plant is capable of processing 164 million tonnes of heap leach ore over the life of the asset. Heap leach ore production is hauled directly to heap leach pads for gold recovery. Water for process use is supplied from the open pit dewatering system. Approximately 90 litres per second of the pit dewatering volume is diverted for plant use. Electric power is supplied by Sierra Pacific Power Company (“SPPC”) through a 73 kilometre, 120 kV transmission line. A long-term agreement is in place with SPPC to provide power through the regulated power system. The average power requirement of the mine is about 160 GWh/year. REFINING: Wohlwill electrolysis. It is assumed that the gold doré-bars from both mines undergo the treatment of Wohlwill electrolysis. This process uses an electrolyte containing 2.5 mol/l of HCl and 2 mol/l of HAuCl4 acid. Electrolysis is carried out with agitation at 65 – 75 °C. The raw gold is intro-duced as cast anode plates. The cathodes, on which the pure gold is deposited, were for many years made of fine gold of 0.25 mm thickness. These have now largely been replaced by sheet titanium or tantalum cathodes, from which the thick layer of fine gold can be peeled off. In a typical electrolysis cell, gold anodes weighing 12 kg and having dimensions 280×230×12 mm (0.138 m2 surface) are used. Opposite to them are conductively connected cathode plates, arranged by two or three on a support rail. One cell normally contains five or six cathode units and four or five anodes. The maximum cell voltage [V] is 1.5 V and the maximum anodic current density [A] 1500 A/m2. The South African Rand refinery gives a specific gold production rate of 0.2 kg per hour Wohlwill electrolysis. Assuming a current efficiency of 95% the energy consumption is [V] x [A] / 0.2 [kg/h] = 1.63 kWh per kg gold refined. No emissions are assumed because of the purity and the high value of the material processed. The resulting sludge contains the PGM present in the electric scrap and is sold for further processing. OTHER MINES: Information about the technology used in the remaining mines is described in the References. WATER EMISSIONS: Water effluents are discharged into rivers. References: Auerswald D. A. and Radcliffe P. H. (2005) Process technology development at Rand Refinery. In: Minerals Engineering, 18(8), pp. 748-753, Online-Version under: http://dx.doi.org/10.1016/j.mineng.2005.03.011. Newmont (2004) How gold is mined. Newmont. Retrieved from http://www.newmont.com/en/gold/howmined/index.asp Renner H., Schlamp G., Hollmann D., Lüschow H. M., Rothaut J., Knödler A., Hecht C., Schlott M., Drieselmann R., Peter C. and Schiele R. (2002) Gold, Gold Alloys, and Gold Compounds. In: Ullmann's Encyclopedia of Industrial Chemistry. Online version, posting date: September 15, 2000 Edition. Wiley-Interscience, Online-Version under: http://dx.doi.org/10.1002/14356007.a12_ 499. Barrick (2006b) Environment: Performance Tables from http://www.barrick. com/Default.aspx?SectionID=8906c4bd-4ee4-4f15-bf1b-565e357c01e1& LanguageId=1 Newmont (2005b) Now & Beyond: Sustainability Reports. Newmont Mining Corporation. Retrieved from http://www.newmont.com/en/social/reporting/ index.asp technologyComment of gold production (CA): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. UNDERGROUND MINING: Some ore bodies are more economically mined underground. In this case, a tunnel called an adit or a shaft is dug into the earth. Sort tunnels leading from the adit or shaft, called stopes, are dug to access the ore. The surface containing the ore, called a face, is drilled and loaded with explosives. Following blasting, the broken ore is loaded onto electric trucks and taken to the surface. Once mining is completed in a particular stope, it is backfilled with a cement compound. ORE AND WASTE HAULAGE: The haul trucks transport the ore to various areas for processing. The grade and type of ore determine the processing method used. Higher-grade ores are taken to a mill. Lower grade ores are taken to leach pads. Some ores may be stockpiled for later processing. BENEFICIATION: In the Porcupine Mines, gold is recovered using a combination of gravity concentration, milling and cyanidation techniques. The milling process consists of primary crushing, secondary crushing, rod/ball mill grinding, gravity concentration, cyanide leaching, carbon-in-pulp gold recovery, stripping, electrowinning and refining. In the Campbell Mine, the ore from the mine, after crushing and grinding, is processed by gravity separation, flotation, pressure oxidation, cyanidation and carbon-in-pulp process followed by electro-winning and gold refining to doré on site. The Musselwhite Mine uses gravity separation, carbon in pulp, electro¬winning and gold refining to doré on site. REFINING: Wohlwill electrolysis. It is assumed that the gold doré-bars from both mines undergo the treatment of Wohlwill electrolysis. This process uses an electrolyte containing 2.5 mol/l of HCl and 2 mol/l of HAuCl4 acid. Electrolysis is carried out with agitation at 65 – 75 °C. The raw gold is intro-duced as cast anode plates. The cathodes, on which the pure gold is deposited, were for many years made of fine gold of 0.25 mm thickness. These have now largely been replaced by sheet titanium or tantalum cathodes, from which the thick layer of fine gold can be peeled off. In a typical electrolysis cell, gold anodes weighing 12 kg and having dimensions 280×230×12 mm (0.138 m2 surface) are used. Opposite to them are conductively connected cathode plates, arranged by two or three on a support rail. One cell normally contains five or six cathode units and four or five anodes. The maximum cell voltage [V] is 1.5 V and the maximum anodic current density [A] 1500 A/m2. The South African Rand refinery gives a specific gold production rate of 0.2 kg per hour Wohlwill electrolysis. Assuming a current efficiency of 95% the energy consumption is [V] x [A] / 0.2 [kg/h] = 1.63 kWh per kg gold refined. No emissions are assumed because of the purity and the high value of the material processed. The resulting sludge contains the PGM present in the electric scrap and is sold for further processing. WATER EMISSIONS: Effluents are discharged into the ocean. REFERENCES: Newmont (2004) How gold is mined. Newmont. Retrieved from http://www.newmont.com/en/gold/howmined/index.asp Renner H., Schlamp G., Hollmann D., Lüschow H. M., Rothaut J., Knödler A., Hecht C., Schlott M., Drieselmann R., Peter C. and Schiele R. (2002) Gold, Gold Alloys, and Gold Compounds. In: Ullmann's Encyclopedia of Industrial Chemistry. Online version, posting date: September 15, 2000 Edition. Wiley-Interscience, Online-Version under: http://dx.doi.org/10.1002/14356007.a12_ 499. Auerswald D. A. and Radcliffe P. H. (2005) Process technology development at Rand Refinery. In: Minerals Engineering, 18(8), pp. 748-753, Online-Version under: http://dx.doi.org/10.1016/j.mineng.2005.03.011. technologyComment of gold production (AU): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. UNDERGROUND MINING: Some ore bodies are more economically mined underground. In this case, a tunnel called an adit or a shaft is dug into the earth. Sort tunnels leading from the adit or shaft, called stopes, are dug to access the ore. The surface containing the ore, called a face, is drilled and loaded with explosives. Following blasting, the broken ore is loaded onto electric trucks and taken to the surface. Once mining is completed in a particular stope, it is backfilled with a cement compound. ORE AND WASTE HAULAGE: The haul trucks transport the ore to various areas for processing. The grade and type of ore determine the processing method used. Higher-grade ores are taken to a mill. Lower grade ores are taken to leach pads. Some ores may be stockpiled for later processing. LEACHING: The ore is crushed or placed directly on lined leach pads where a dilute cyanide solution is applied to the surface of the heap. The solution percolates down through the ore, where it leaches the gold and flows to a central collection location. The solution is recovered in this closed system. The pregnant leach solution is fed to electrowinning cells and undergoes the same steps as described below from Electro-winning. ORE PROCESSING: Milling: The ore is fed into a series of grinding mills where steel balls grind the ore to a fine slurry or powder. Oxidization and leaching: Some types of ore require further processing before gold is recovered. In this case, the slurry is pressure-oxidized in an autoclave before going to the leaching tanks or a dry powder is fed through a roaster in which it is oxidized using heat before being sent to the leaching tanks as a slurry. The slurry is thickened and runs through a series of leaching tanks. The gold in the slurry adheres to carbon in the tanks. Stripping: The carbon is then moved into a stripping vessel where the gold is removed from the carbon by pumping a hot caustic solution through the carbon. The carbon is later recycled. Electro-winning: The gold-bearing solution is pumped through electro-winning cells or through a zinc precipitation circuit where the gold is recovered from the solution. Smelting: The gold is then melted in a furnace at about 1’064°C and poured into moulds, creating doré bars. Doré bars are unrefined gold bullion bars containing between 60% and 95% gold. REFINING: Wohlwill electrolysis. It is assumed that the gold doré-bars from both mines undergo the treatment of Wohlwill electrolysis. This process uses an electrolyte containing 2.5 mol/l of HCl and 2 mol/l of HAuCl4 acid. Electrolysis is carried out with agitation at 65 – 75 °C. The raw gold is intro-duced as cast anode plates. The cathodes, on which the pure gold is deposited, were for many years made of fine gold of 0.25 mm thickness. These have now largely been replaced by sheet titanium or tantalum cathodes, from which the thick layer of fine gold can be peeled off. In a typical electrolysis cell, gold anodes weighing 12 kg and having dimensions 280×230×12 mm (0.138 m2 surface) are used. Opposite to them are conductively connected cathode plates, arranged by two or three on a support rail. One cell normally contains five or six cathode units and four or five anodes. The maximum cell voltage [V] is 1.5 V and the maximum anodic current density [A] 1500 A/m2. The South African Rand refinery gives a specific gold production rate of 0.2 kg per hour Wohlwill electrolysis. Assuming a current efficiency of 95% the energy consumption is [V] x [A] / 0.2 [kg/h] = 1.63 kWh per kg gold refined. No emissions are assumed because of the purity and the high value of the material processed. The resulting sludge contains the PGM present in the electric scrap and is sold for further processing. WATER EMISSIONS: Water effluents are discharged into rivers. REFERENCES: Newmont (2004) How gold is mined. Newmont. Retrieved from http://www.newmont.com/en/gold/howmined/index.asp Renner H., Schlamp G., Hollmann D., Lüschow H. M., Rothaut J., Knödler A., Hecht C., Schlott M., Drieselmann R., Peter C. and Schiele R. (2002) Gold, Gold Alloys, and Gold Compounds. In: Ullmann's Encyclopedia of Industrial Chemistry. Online version, posting date: September 15, 2000 Edition. Wiley-Interscience, Online-Version under: http://dx.doi.org/10.1002/14356007.a12_ 499. Auerswald D. A. and Radcliffe P. H. (2005) Process technology development at Rand Refinery. In: Minerals Engineering, 18(8), pp. 748-753, Online-Version under: http://dx.doi.org/10.1016/j.mineng.2005.03.011. technologyComment of gold production (TZ): The mining of ore from open pit and underground mines is considered. technologyComment of gold refinery operation (ZA): REFINING: The refinery, which provides a same day refining service, employs the widely used Miller Chlorination Process to upgrade the gold bullion it receives from mines to at least 99.50% fine gold, the minimum standard required for gold sold on the world bullion markets. It also employs the world’s leading silver refining technology. To further refine gold and silver to 99.99% the cost-effective once-through Wohlwill electrolytic refining process is used. MILLER CHLORINATION PROCESS: This is a pyrometallurgical process whereby gold dore is heated in furnace crucibles. The process is able to separate gold from impurities by using chlorine gas which is added to the crucibles once the gold is molten. Chlorine gas does not react with gold but will combine with silver and base metals to form chlorides. Once the chlorides have formed they float to the surface as slag or escape as volatile gases. The surface melt and the fumes containing the impurities are collected and further refined to extract the gold and silver. This process can take up to 90 minutes produces gold which is at least 99.5% pure with silver being the main remaining component. This gold can be cast into bars as 99.5% gold purity meets the minimum London Good Delivery. However some customers such as jewellers and other industrial end users require gold that is almost 100% pure, so further refining is necessary. In this case, gold using the Miller process is cast into anodes which are then sent to an electrolytic plant. The final product is 99.99% pure gold sponge that can then be melted to produce various end products suited to the needs of the customer. WOHLWILL PROCESS - The electrolytic method of gold refining was first developed by Dr. Emil Wohlwill of Norddeutsche Affinerie in Hamburg in 1874. Dr. Wohlwill’s process is based on the solubility of gold but the insolubility of silver in an electrolyte solution of gold chloride (AuCl3) in hydrochloric acid. Figure below provide the overview of the refining process (source Rand Refinery Brochure) imageUrlTagReplace7f46a8e2-2df0-4cf4-99a8-2878640be562 Emissions includes also HCl to air: 7.48e-03 Calculated from rand refinery scrubber and baghouse emmission values Metal concentrators, Emmision report 2016 http://www.environmentalconsultants.co.za/wp-content/uploads/2016/11/Appendix-D1.pdf technologyComment of gold refinery operation (RoW): REFINING: The refinery, which provides a same day refining service, employs the widely used Miller Chlorination Process to upgrade the gold bullion it receives from mines to at least 99.50% fine gold, the minimum standard required for gold sold on the world bullion markets. It also employs the world’s leading silver refining technology. To further refine gold and silver to 99.99% the cost-effective once-through Wohlwill electrolytic refining process is used. MILLER CHLORINATION PROCESS: This is a pyrometallurgical process whereby gold dore is heated in furnace crucibles. The process is able to separate gold from impurities by using chlorine gas which is added to the crucibles once the gold is molten. Chlorine gas does not react with gold but will combine with silver and base metals to form chlorides. Once the chlorides have formed they float to the surface as slag or escape as volatile gases. The surface melt and the fumes containing the impurities are collected and further refined to extract the gold and silver. This process can take up to 90 minutes produces gold which is at least 99.5% pure with silver being the main remaining component. This gold can be cast into bars as 99.5% gold purity meets the minimum London Good Delivery. However some customers such as jewellers and other industrial end users require gold that is almost 100% pure, so further refining is necessary. In this case, gold using the Miller process is cast into anodes which are then sent to an electrolytic plant. The final product is 99.99% pure gold sponge that can then be melted to produce various end products suited to the needs of the customer. WOHLWILL PROCESS - The electrolytic method of gold refining was first developed by Dr. Emil Wohlwill of Norddeutsche Affinerie in Hamburg in 1874. Dr. Wohlwill’s process is based on the solubility of gold but the insolubility of silver in an electrolyte solution of gold chloride (AuCl3) in hydrochloric acid. Figure below provide the overview of the refining process (source Rand Refinery Brochure) imageUrlTagReplace7f46a8e2-2df0-4cf4-99a8-2878640be562 Emissions includes also HCl to air: 7.48e-03 Calculated from rand refinery scrubber and baghouse emmission values Metal concentrators, Emmision report 2016 http://www.environmentalconsultants.co.za/wp-content/uploads/2016/11/Appendix-D1.pdf technologyComment of gold-silver mine operation with refinery (PG): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. ORE AND WASTE HAULAGE: The haul trucks transport the ore to various areas for processing. The grade and type of ore determine the processing method used. Higher-grade ores are taken to a mill. Lower grade ores are taken to leach pads. Some ores may be stockpiled for later processing. HEAP LEACHING: The recovery processes of the Misima Mine are cyanide leach and carbon in pulp (CIP). The ore is crushed or placed directly on lined leach pads where a dilute cyanide solution is applied to the surface of the heap. The solution percolates down through the ore, where it leaches the gold and flows to a central collection location. The solution is recovered in this closed system. The pregnant leach solution is fed to electrowinning cells and undergoes the same steps as described below from Electro-winning. ORE PROCESSING: Milling: The ore is fed into a series of grinding mills where steel balls grind the ore to a fine slurry or powder. Oxidization and leaching: The recovery process in the Porgera Mine is pressure oxidation and cyanide leach. The slurry is pressure-oxidized in an autoclave before going to the leaching tanks or a dry powder is fed through a roaster in which it is oxidized using heat before being sent to the leaching tanks as a slurry. The slurry is thickened and runs through a series of leaching tanks. The gold in the slurry adheres to carbon in the tanks. Stripping: The carbon is then moved into a stripping vessel where the gold is removed from the carbon by pumping a hot caustic solution through the carbon. The carbon is later recycled. Electro-winning: The gold-bearing solution is pumped through electro-winning cells or through a zinc precipitation circuit where the gold is recovered from the solution. Smelting: The gold is then melted in a furnace at about 1’064°C and poured into moulds, creating doré bars. Doré bars are unrefined gold bullion bars containing between 60% and 95% gold. WATER SUPPLY: For Misima Mine, process water is supplied from pit dewatering bores and in-pit water. Potable water is sourced from boreholes in the coastal limestone. For Porgera Mine, the main water supply of the mine is the Waile Creek Dam, located approximately 7 kilometres from the mine. The reservoir has a capacity of approximately 717, 000 m3 of water. Water for the grinding circuit is also extracted from Kogai Creek, which is located adjacent to the grinding circuit. The mine operates four water treatment plants for potable water and five sewage treatment plants. ENERGY SUPPLY: For Misima Mine, electricity is produced by the mine on site or with own power generators, from diesel and heavy fuel oil. For Porgera Mine, electricity is produced by the mine on site. Assumed with Mobius / Wohlwill electrolysis. Porgera's principal source of power is supplied by a 73-kilometre transmission line from the gas fired and PJV-owned Hides Power Station. The station has a total output of 62 megawatts (“MW”). A back up diesel power station is located at the mine and has an output of 13MW. The average power requirement of the mine is about 60 MW. For both Misima and Porgera Mines, an 18 MW diesel fired power station supplies electrical power. Diesel was used in the station due to the unavailability of previously supplied heavy fuel oil. technologyComment of gold-silver mine operation with refinery (CA-QC): One of the modelled mine is an open-pit mine and the two others are underground. technologyComment of gold-silver mine operation with refinery (RoW): The mining of ore from open pit mines is considered. 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 primary zinc production from concentrate (RoW): The technological representativeness of this dataset is considered to be high as smelting methods for zinc are consistent in all regions. Refined zinc produced pyro-metallurgically represents less than 5% of global zinc production and less than 2% of this dataset. Electrometallurgical Smelting The main unit processes for electrometallurgical zinc smelting are roasting, leaching, purification, electrolysis, and melting. In both electrometallurgical and pyro-metallurgical zinc production routes, the first step is to remove the sulfur from the concentrate. Roasting or sintering achieves this. The concentrate is heated in a furnace with operating temperature above 900 °C (exothermic, autogenous process) to convert the zinc sulfide to calcine (zinc oxide). Simultaneously, sulfur reacts with oxygen to produce sulfur dioxide, which is subsequently converted to sulfuric acid in acid plants, usually located with zinc-smelting facilities. During the leaching process, the calcine is dissolved in dilute sulfuric acid solution (re-circulated back from the electrolysis cells) to produce aqueous zinc sulfate solution. The iron impurities dissolve as well and are precipitated out as jarosite or goethite in the presence of calcine and possibly ammonia. Jarosite and goethite are usually disposed of in tailing ponds. Adding zinc dust to the zinc sulfate solution facilitates purification. The purification of leachate leads to precipitation of cadmium, copper, and cobalt as metals. In electrolysis, the purified solution is electrolyzed between lead alloy anodes and aluminum cathodes. The high-purity zinc deposited on aluminum cathodes is stripped off, dried, melted, and cast into SHG zinc ingots (99.99 % zinc). Pyro-metallurgical Smelting The pyro-metallurgical smelting process is based on the reduction of zinc and lead oxides into metal with carbon in an imperial smelting furnace. The sinter, along with pre-heated coke, is charged from the top of the furnace and injected from below with pre-heated air. This ensures that temperature in the center of the furnace remains in the range of 1000-1500 °C. The coke is converted to carbon monoxide, and zinc and lead oxides are reduced to metallic zinc and lead. The liquid lead bullion is collected at the bottom of the furnace along with other metal impurities (copper, silver, and gold). Zinc in vapor form is collected from the top of the furnace along with other gases. Zinc vapor is then condensed into liquid zinc. The lead and cadmium impurities in zinc bullion are removed through a distillation process. The imperial smelting process is an energy-intensive process and produces zinc of lower purity than the electrometallurgical process. technologyComment of processing of anode slime from electrorefining of copper, anode (GLO): Based on typical current technology. Anode slime treatment by pressure leaching and top blown rotary converter. Production of Silver by Möbius Electrolysis, Gold by Wohlwill electrolysis, copper telluride cement and crude selenium to further processing. technologyComment of silver-gold mine operation with refinery (CL): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. BENEFICIATION: The processing plant consists of primary crushing, a pre-crushing circuit, (semi autogenous ball mill crushing) grinding, leaching, filtering and washing, Merrill-Crowe plant and doré refinery. The Merrill-Crowe metal recovery circuit is better than a carbon-in-pulp system for the high-grade silver material. Tailings are filtered to recover excess water as well as residual cyanide and metals. A dry tailings disposal system was preferred to a conventional wet tailings impoundment because of site-specific environmental considerations. technologyComment of silver-gold mine operation with refinery (RoW): Refinement is estimated with electrolysis-data. 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

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technologyComment of gold mine operation and refining (SE): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. ORE AND WASTE HAULAGE: The haul trucks transport the ore to various areas for processing. The grade and type of ore determine the processing method used. Higher-grade ores are taken to a mill. Lower grade ores are taken to leach pads. Some ores may be stockpiled for later processing. HEAP LEACHING: The ore is crushed or placed directly on lined leach pads where a dilute cyanide solution is applied to the surface of the heap. The solution percolates down through the ore, where it leaches the gold and flows to a central collection location. The solution is recovered in this closed system. The pregnant leach solution is fed to electrowinning cells and undergoes the same steps as described below from Electro-winning. ORE PROCESSING: Milling: The ore is fed into a series of grinding mills where steel balls grind the ore to a fine slurry or powder. Oxidization and leaching: Some types of ore require further processing before gold is recovered. In this case, the slurry is pressure-oxidized in an autoclave before going to the leaching tanks or a dry powder is fed through a roaster in which it is oxidized using heat before being sent to the leaching tanks as a slurry. The slurry is thickened and runs through a series of leaching tanks. The gold in the slurry adheres to carbon in the tanks. Stripping: The carbon is then moved into a stripping vessel where the gold is removed from the carbon by pumping a hot caustic solution through the carbon. The carbon is later recycled. Electro-winning: The gold-bearing solution is pumped through electro-winning cells or through a zinc precipitation circuit where the gold is recovered from the solution. Smelting: The gold is then melted in a furnace at about 1’064°C and poured into moulds, creating doré bars. Doré bars are unrefined gold bullion bars containing between 60% and 95% gold. References: Newmont (2004) How gold is mined. Newmont. Retrieved from http://www.newmont.com/en/gold/howmined/index.asp technologyComment of primary lead production from concentrate (GLO): There are two basic pyrometallurgical processes available for the production of lead from lead or mixed lead-zinc-sulphide concentrates: sinter oxidation / blast furnace reduction route or Direct Smelting Reduction Processes. Both processes are followed by a refining step to produce the final product with the required purity, and may also be used for concentrates mixed with secondary raw materials. SINTER OXIDATION / BLAST FURNACE REDUCTION: The sinter oxidation / blast furnace reduction involves two steps: 1) A sintering oxidative roast to remove sulphur with production of PbO; and 2) Blast furnace reduction of the sinter product. The objective of sintering lead concentrates is to remove as much sulphur as possible from the galena and the accompanying iron, zinc, and copper sulphides, while producing lump agglomerate with appropriate properties for subsequent reduction in the blast furnace (a type of a shaft furnace). As raw material feed, lead concentrates are blended with recycled sinter fines, secondary material and other process materials and pelletised in rotating drums. Pellets are fed onto sinter machine and ignited. The burning pellets are conveyed over a series of wind-boxes through which air is blown. Sulphur is oxidised to sulphur dioxide and the reaction generates enough heat to fuse and agglomerate the pellets. Sinter is charged to the blast furnace with metallurgical coke. Air and/or oxygen enriched air is injected and reacts with the coke to produce carbon monoxide. This generates sufficient heat to melt the charge. The gangue content of the furnace charge combines with the added fluxes or reagents to form a slag. For smelting bulk lead-zinc-concentrates and secondary material, frequently the Imperial Smelting Furnace is used. Here, hot sinter and pre-heated coke as well as hot briquettes are charged. Hot air is injected. The reduction of the metal oxides not only produces lead and slag but also zinc, which is volatile at the furnace operating temperature and passes out of the ISF with the furnace off-gases. The gases also contain some cadmium and lead. The furnace gases pass through a splash condenser in which a shower of molten lead quenches them and the metals are absorbed into the liquid lead, the zinc is refined by distillation. DIRECT SMELTING REDUCTION: The Direct Smelting Reduction Process does not carry out the sintering stage separately. Lead sulphide concentrates and secondary materials are charged directly to a furnace and are then melted and oxidised. Sulphur dioxide is formed and is collected, cleaned and converted to sulphuric acid. Carbon (coke or gas) and fluxing agents are added to the molten charge and lead oxide is reduced to lead, a slag is formed. Some zinc and cadmium are “fumed” off in the furnace, their oxides are captured in the abatement plant and recovered. Several processes are used for direct smelting of lead concentrates and some secondary material to produce crude lead and slag. Bath smelting processes are used: the ISA Smelt/Ausmelt furnaces (sometimes in combination with blast furnaces), Kaldo (TBRC) and QSL integrated processes are used in EU and Worldwide. The Kivcet integrated process is also used and is a flash smelting process. The ISA Smelt/Ausmelt furnaces and the QSL take moist, pelletised feed and the Kaldo and Kivcet use dried feed. REFINING: Lead bullion may contain varying amounts of copper, silver, bismuth, antimony, arsenic and tin. Lead recovered from secondary sources may contain similar impurities, but generally antimony and calcium dominate. There are two methods of refining crude lead: electrolytic refining and pyrometallurgical refining. Electrolytic refining uses anodes of de-copperised lead bullion and starter cathodes of pure lead. This is a high-cost process and is used infrequently. A pyrometallurgical refinery consists of a series of kettles, which are indirectly heated by oil or gas. Over a series of separation processes impurities and metal values are separated from the lead bouillon. Overall waste: The production of metals is related to the generation of several by-products, residues and wastes, which are also listed in the European Waste Catalogue (Council Decision 94/3/EEC). The ISF or direct smelting furnaces also are significant sources of solid slag. This slag has been subjected to high temperatures and generally contains low levels of leachable metals, consequently it may be used in construction. Solid residues also arise as the result of the treatment of liquid effluents. The main waste stream is gypsum waste (CaSO4) and metal hydroxides that are produced at the wastewater neutralisation plant. These wastes are considered to be a cross-media effect of these treatment techniques but many are recycled to pyrometallurgical process to recover the metals. Dust or sludge from the treatment of gases are used as raw materials for the production of other metals such as Ge, Ga, In and As, etc or can be returned to the smelter or into the leach circuit for the recovery of lead and zinc. Hg/Se residues arise at the pre-treatment of mercury or selenium streams from the gas cleaning stage. This solid waste stream amounts to approximately 40 - 120 t/y in a typical plant. Hg and Se can be recovered from these residues depending on the market for these metals. Overall emissions: The main emissions to air from zinc and lead production are sulphur dioxide, other sulphur compounds and acid mists; nitrogen oxides and other nitrogen compounds, metals and their compounds; dust; VOC and dioxins. Other pollutants are considered to be of negligible importance for the industry, partly because they are not present in the production process and partly because they are immediately neutralised (e.g. chlorine) or occur in very low concentrations. Emissions are to a large extent bound to dust (except cadmium, arsenic and mercury that can be present in the vapour phase). Metals and their compounds and materials in suspension are the main pollutants emitted to water. The metals concerned are Zn, Cd, Pb, Hg, Se, Cu, Ni, As, Co and Cr. Other significant substances are fluorides, chlorides and sulphates. Wastewater from the gas cleaning of the smelter and fluid-bed roasting stages are the most important sources. References: Sutherland C. A., Milner E. F., Kerby R. C., Teindl H. and Melin A. (1997) Lead. In: Ullmann's encyclopedia of industrial chemistry (ed. Anonymous). 5th edition on CD-ROM Edition. Wiley & Sons, London. IPPC (2001) Integrated Pollution Prevention and Control (IPPC); Reference Document on Best Available Techniques in the Non Ferrous Metals Industries. European Commission. Retrieved from http://www.jrc.es/pub/english.cgi/ 0/733169 technologyComment of primary zinc production from concentrate (RoW): The technological representativeness of this dataset is considered to be high as smelting methods for zinc are consistent in all regions. Refined zinc produced pyro-metallurgically represents less than 5% of global zinc production and less than 2% of this dataset. Electrometallurgical Smelting The main unit processes for electrometallurgical zinc smelting are roasting, leaching, purification, electrolysis, and melting. In both electrometallurgical and pyro-metallurgical zinc production routes, the first step is to remove the sulfur from the concentrate. Roasting or sintering achieves this. The concentrate is heated in a furnace with operating temperature above 900 °C (exothermic, autogenous process) to convert the zinc sulfide to calcine (zinc oxide). Simultaneously, sulfur reacts with oxygen to produce sulfur dioxide, which is subsequently converted to sulfuric acid in acid plants, usually located with zinc-smelting facilities. During the leaching process, the calcine is dissolved in dilute sulfuric acid solution (re-circulated back from the electrolysis cells) to produce aqueous zinc sulfate solution. The iron impurities dissolve as well and are precipitated out as jarosite or goethite in the presence of calcine and possibly ammonia. Jarosite and goethite are usually disposed of in tailing ponds. Adding zinc dust to the zinc sulfate solution facilitates purification. The purification of leachate leads to precipitation of cadmium, copper, and cobalt as metals. In electrolysis, the purified solution is electrolyzed between lead alloy anodes and aluminum cathodes. The high-purity zinc deposited on aluminum cathodes is stripped off, dried, melted, and cast into SHG zinc ingots (99.99 % zinc). Pyro-metallurgical Smelting The pyro-metallurgical smelting process is based on the reduction of zinc and lead oxides into metal with carbon in an imperial smelting furnace. The sinter, along with pre-heated coke, is charged from the top of the furnace and injected from below with pre-heated air. This ensures that temperature in the center of the furnace remains in the range of 1000-1500 °C. The coke is converted to carbon monoxide, and zinc and lead oxides are reduced to metallic zinc and lead. The liquid lead bullion is collected at the bottom of the furnace along with other metal impurities (copper, silver, and gold). Zinc in vapor form is collected from the top of the furnace along with other gases. Zinc vapor is then condensed into liquid zinc. The lead and cadmium impurities in zinc bullion are removed through a distillation process. The imperial smelting process is an energy-intensive process and produces zinc of lower purity than the electrometallurgical process. technologyComment of treatment of electronics scrap, metals recovery in copper smelter (SE, RoW): Conversion of Copper in a Kaldo Converter and treatment in converter aisle. technologyComment of treatment of scrap lead acid battery, remelting (RoW): The referred operation uses a shaft furnace with post combustion, which is the usual technology for secondary smelters. technologyComment of treatment of scrap lead acid battery, remelting (RER): The referred operation uses a shaft furnace with post combustion, which is the usual technology for secondary smelters. Typically this technology produces 5000 t / a sulphuric acid (15% concentration), 25’000 t lead bullion (98% Pb), 1200 t / a slags (1% Pb) and 3000 t / a raw lead matte (10% Pb) to be shipped to primary smelters. Overall Pb yield is typically 98.8% at the plant level and 99.8% after reworking the matte. The operation treats junk batteries and plates but also lead cable sheathing, drosses and sludges, leaded glass and balancing weights. From this feed it manufactures mainly antimonial lead up to 10% Sb, calcium-aluminium lead alloys with or without tin and soft lead with low and high copper content. All these products are the result of a refining and alloying step to meet the compliance with the designations desired. The following by products are reused in the process: fine dust, slag, and sulfuric acid. References: Quirijnen L. (1999) How to implement efficient local lead-acid battery recycling. In: Journal of Power Sources, 78(1-2), pp. 267-269.

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