Die Studie beinhaltet umfangreiche Informationen zu Bedarf und Verfügbarkeit eisenhaltiger Flockungsmittel, die auf Befragungen von deutschen und europäischen Wasserversorgungsunternehmen sowie Herstellern basieren. Die Marktsituation wurde analysiert, inklusive der Konsequenzen für Wasserversorgungsunternehmen und chemisch-technischer Möglichkeiten der Aufreinigung dieser Aufbereitungsstoffe sowie möglicher Produktalternativen. Veröffentlicht in Umwelt & Gesundheit | 09/2023.
technologyComment of cobalt production (GLO): Cobalt, as a co-product of nickel and copper production, is obtained using a wide range of technologies. The initial life cycle stage covers the mining of the ore through underground or open cast methods. The ore is further processed in beneficiation to produce a concentrate and/or raffinate solution. Metal selection and further concentration is initiated in primary extraction, which may involve calcining, smelting, high pressure leaching, and other processes. The final product is obtained through further refining, which may involve processes such as re-leaching, selective solvent / solution extraction, selective precipitation, electrowinning, and other treatments. Transport is reported separately and consists of only the internal movements of materials / intermediates, and not the movement of final product. Due to its intrinsic value, cobalt has a high recycling rate. However, much of this recycling takes place downstream through the recycling of alloy scrap into new alloy, or goes into the cobalt chemical sector as an intermediate requiring additional refinement. Secondary production, ie production from the recycling of cobalt-containing wastes, is considered in this study in so far as it occurs as part of the participating companies’ production. This was shown to be of very limited significance (less than 1% of cobalt inputs). The secondary materials used for producing cobalt are modelled as entering the system free of environmental burden. technologyComment of platinum group metal mine operation, ore with high palladium content (RU): imageUrlTagReplace6250302f-4c86-4605-a56f-03197a7811f2 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 processing of nickel-rich materials (GLO): Based on typical current technology. technologyComment of smelting and refining of nickel concentrate, 16% Ni (GLO): Extrapolated from a typical technology for smelting and refining of nickel ore. MINING: 95% of sulphidic nickel ores are mined underground in depths between 200m and 1800m, the ore is transferred to the beneficiation. Widening of the tunnels is mainly done by blasting. The overburden – material, which does not contain PGM-bearing ore – is deposed off-site and is partially refilled into the tunnels. Emissions: The major emissions are due to mineral born pollutants in the effluents. The underground mining operations generate roughly 80 % of the dust emissions from open pit operations, since the major dust sources do not take place underground. Rain percolate through overburden and accounts to metal emissions to groundwater. Waste: Overburden is deposed close to the mine. Acid rock drainage occurs over a long period of time. BENEFICIATION: After mining, the ore is first ground. In a next step it is subjected to gravity concentration to separate the metallic particles from the PGM-bearing minerals. After this first concentration step, flotation is carried out to remove the gangue from the sulphidic minerals. For neutralisation lime is added. In the flotation several organic chemicals are used as collector, frother, activator, depressor and flocculant. Sometimes cyanide is used as depressant for pyrite. Tailings usually are led to tailing heaps or ponds. As a result, nickel concentrates containing 7 - 25% Ni are produced. Emissions: Ore handling and processing produce large amounts of dust, containing PM10 and several metals from the ore itself. Flotation produce effluents containing several organic agents used. Some of these chemicals evaporate and account for VOC emissions to air. Namely xanthates decompose hydrolytically to release carbon disulphide. Tailings effluent contains additional sulphuric acid from acid rock drainage. Waste: Tailings are deposed as piles and in ponds. Acid rock drainage occurs over a long period of time. METALLURGY AND REFINING: There are many different process possibilities to win the metal. The chosen process depends on the composition of the ore, the local costs of energy carrier and the local legislation. Basically two different types can be distinguished: the hydrometallurgical and the pyrometallurgical process, which paired up with the refining processes, make up five major production routes (See Tab.1). All this routes are covered, aggregated according to their market share in 1994. imageUrlTagReplace00ebef53-ae97-400f-a602-7405e896cb76 Pyrometallurgy. The pyrometallurgical treatment of nickel concentrates includes three types of unit operation: roasting, smelting, and converting. In the roasting step sulphur is driven off as sulphur dioxide and part of the iron is oxidised. In smelting, the roaster product is melted with a siliceous flux which combines with the oxidised iron to produce two immiscible phases, a liquid silicate slag which can be discarded, and a solution of molten sulphides which contains the metal values. In the converting operation on the sulphide melt, more sulphur is driven off as sulphur dioxide, and the remaining iron is oxidised and fluxed for removal as silicate slag, leaving a high-grade nickel – copper sulphide matte. In several modern operations the roasting step has been eliminated, and the nickel sulphide concentrate is treated directly in the smelter. Hydrometallurgy: Several hydrometallurgical processes are in commercial operation for the treatment of nickel – copper mattes to produce separate nickel and copper products. In addition, the hydrometal-lurgical process developed by Sherritt Gordon in the early 1950s for the direct treatment of nickel sulphide concentrates, as an alternative to smelting, is still commercially viable and competitive, despite very significant improvements in the economics and energy efficiency of nickel smelting technology. In a typical hydrometallurgical process, the concentrate or matte is first leached in a sulphate or chloride solution to dissolve nickel, cobalt, and some of the copper, while the sulphide is oxidised to insoluble elemental sulphur or soluble sulphate. Frequently, leaching is carried out in a two-stage countercurrent system so that the matte can be used to partially purify the solution, for example, by precipitating copper by cementation. In this way a nickel – copper matte can be treated in a two-stage leach process to produce a copper-free nickel sulphate or nickel chloride solution, and a leach residue enriched in copper. Refining: In many applications, high-purity nickel is essential and Class I nickel products, which include electrolytic cathode, carbonyl powder, and hydrogen-reduced powder, are made by a variety of refining processes. The carbonyl refining process uses the property of nickel to form volatile nickel-carbonyl compounds from which elemental nickel subsides to form granules. Electrolytic nickel refineries treat cast raw nickel anodes in a electrolyte. Under current the anode dissolves and pure nickel deposits on the cathode. This electrorefining process is obsolete because of high energy demand and the necessity of building the crude nickel anode by reduction with coke. It is still practised in Russia. Most refineries recover electrolytic nickel by direct electrowinning from purified solutions produced by the leaching of nickel or nickel – copper mattes. Some companies recover refined nickel powder from purified ammoniacal solution by reduction with hydrogen. Emissions: In all of the metallurgical steps, sulphur dioxide is emitted to air. Recovery of sulphur dioxide is only economic for high concentrated off-gas. Given that In the beneficiation step, considerable amounts of lime are added to the ore for pH-stabilisation, lime forms later flux in the metallurgical step, and decomposes into CO2 to form calcite. Dust carry over from the roasting, smelting and converting processes. Particulate emissions to the air consist of metals and thus are often returned to the leaching process after treatment. Chlorine is used in some leaching stages and is produced during the subsequent electrolysis of chloride solution. The chlorine evolved is collected and re-used in the leach stage. The presence of chlorine in wastewater can lead to the formation of organic chlorine compounds (AOX) if solvents etc. are also present in a mixed wastewater. VOCs can be emitted from the solvent extraction stages. A variety of solvents are used an they contain various complexing agents to form complexes with the desired metal that are soluble in the organic layer. Metals and their compounds and substances in suspension are the main pollutants emitted to water. The metals concerned are Cu, Ni, Co, As and Cr. Other significant substances are chlorides and sulphates. Wastewater from wet gas cleaning (if used) of the different metallurgical stages are the most important sources. The leaching stages are usually operated on a closed circuit and drainage systems, and are therefore regarded as minor sources. In the refining step, the combustion of sulphur leads to emissions of SO2. Nitrogen oxides are produced in significant amounts during acid digestion using nitric acid. Chlorine and HCl can be formed during a number of digestion, electrolytic and purification processes. Chlorine is used extensively in the Miller process and in the dissolution stages using hydrochloric acid and chlorine mixtrues respectively. 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. Large quantities of effluents contain amounts of metals and organic substances. Waste: Regarding the metallurgical step, several co-products, residues and wastes, which are listed in the European Waste Catalogue, are generated. Some of the process specific residues can be reused or recovered in preliminary process steps (e. g. dross, filter dust) or construction (e. g. cleaned slag). Residues also arise from the treatment of liquid effluents, the main residue being gypsum waste and metal hydroxides from the wastewater neutralisation plant. These residuals have to be disposed, usually in lined ponds. In the refining step, quantities of solid residuals are also generated, which are mostly recycled within the process or sent to other specialists to recover any precious metals. Final residues generally comprise hydroxide filter cakes (ironhydroxide, 60% water, cat I industrial waste). References: Kerfoot D. G. E. (1997) Nickel. In: Ullmann's encyclopedia of industrial chemis-try (ed. Anonymous). 5th edition on CD-ROM Edition. Wiley & Sons, London. technologyComment of smelting and refining of nickel concentrate, 7% Ni (CN): The nickel concentrate (6.78% beneficiated - product of the mining and beneficiation processes) undergoes drying, melting in flash furnace and converting to produce high nickel matte. The nickel matte undergoes grinding-floating separation and is refined through anode plate casting and electrolysis in order to produce electrolytic nickel 99.98% pure. Deng, S. Y., & Gong, X. Z. (2018). Life Cycle Assessment of Nickel Production in China. Materials Science Forum, 913, 1004-1010. doi:10.4028/www.scientific.net/MSF.913.1004 technologyComment of treatment of metal part of electronics scrap, in copper, anode, by electrolytic refining (SE, RoW): Production of cathode copper by electrolytic refining.
Alkylphenolethoxylate (APEO) sind nicht-ionische Tenside, die in Industrie und Technik vielfältig eingesetzt werden Einige ihrer Ausgangs- und Abbauprodukte sind in der Umwelt persistent, bioakkumulierend, endokrin wirksam und hochtoxisch für aquatische Organismen. Seit dem Verzicht der deutschen Industrie auf APEO in Reinigungsmitteln in den Jahren 1986 und 1992 ist die Belastung von Brassen aus Rhein, Elbe und Saar mit APEO und ihren Abbauprodukten deutlich gesunken. Miesmuscheln aus Nord- und Ostsee wiesen im Allgemeinen niedrigere Konzentrationen auf, die im Untersuchungszeitraum weiter abnahmen. Die wirtschaftlich bedeutendsten Alkylphenole und Alkylphenolethoxylate sind die 4-Nonyl- und 4-Octylverbindungen. In Kläranlagen werden die Ethoxylate sukzessive zu kürzerkettigen Homologen und schließlich zu den entsprechenden Alkylphenolen abgebaut. Wegen ihrer negativen Effekte auf die Umwelt verzichtet die deutsche Industrie seit 1986 bzw. 1992 auf den Einsatz von APEO in Haushalts- und Industriereinigern. Auf europäischer Ebene folgten entsprechende Maßnahmen in Bezug auf Nonylphenolethoxylate in den Jahren 1995 (Haushaltsreiniger) und 2000 (Industriereiniger). Darüber hinaus werden seit 2002 europaweit keine APEO-haltigen Flockungsmittel mehr in Kläranlagen eingesetzt. Um die Belastung aquatischer Organismen zu erfassen und die Wirksamkeit der regulatorischen Maßnahmen zu überprüfen, wurden Brassen aus deutschen Fließgewässern und Miesmuscheln aus Nord- und Ostsee auf 4-Nonylphenol (4NP), 4-Nonylphenolmonoethoxylat (4NP1EO), 4-tert-Octylphenol (4tOP)und 4-tert-Octylphenolmonoethoxylat (4tOP1EO) untersucht. Entsprechend dem höheren Marktanteil der NPEO-Produkte im Vergleich zu den OPEO-Produkten war die Belastung der Fische durch Nonylverbindungen höher als durch Octylverbindungen (Faktoren von 5 bis 93). Von den hier untersuchten Flüssen ist die Exposition mit AP und APEO in der Saar am höchsten. Besonders auffällig sind die hohen 4NP1EO-Konzentrationen in Fischen von der Staustufe Güdingen, die sich im Untersuchungszeitraum 1992 bis 2001 über einen Bereich von 29 - 324 ng/g Frischgewicht (FG) erstreckten. Brassen aus Rhein und Elbe wiesen deutlich niedrigere Gehalte auf, die teilweise auch unterhalb der Bestimmungsgrenzen lagen. Im Untersuchungszeitraum nahm die Belastung an allen Probenahmeflächen ab. Miesmuscheln aus der südlichen Nordsee (Eckwarderhörne) wiesen höhere Belastungen auf als Muscheln aus dem Schleswig-Holsteinischen Wattenmeer und der Ostsee. Die 4NP-Gehalte in Muscheln aus Eckwarderhörne lagen im Bereich von unterhalb der Bestimmungsgrenze (< 2 ng/g) bis zu 9,7 ng/g FG. Im Untersuchungszeitraum 1986 bis 2001 konnte eine deutliche Abnahme beobachtet werden: nach 1997 lagen die Konzentrationen unterhalb der Bestimmungsgrenze. 4NP1EO wurde bereits seit 1990 nicht mehr in Muscheln nachgewiesen. Die Gehalte an 4tOP waren generell gering (< 0,2 bis 0,5 ng/g FG) und 4tOP1EO konnte zu keinem Zeitpunkt quantifiziert werden. Die Untersuchungen belegen den Erfolg der verschiedenen freiwilligen Maßnahmen zur Verminderung der Alkylphenolethoxylat- und Alkylphenol-Einträge in Oberflächengewässer. Eine Umrechnung der Gewebekonzentrationen auf Wasserkonzentrationen ergibt, dass im Jahr 2001 die Nonylphenol- und Octylphenolkonzentrationen unterhalb der im Rahmen der Wasserrahmenrichtlinie abgeleiteten Umweltqualitätsnormen für 4-Nonylphenol (0,3 µg/L) und für 4-tert-Octylphenol (0,1 µg/L Binnengewässer bzw. 0,01 µg/L sonstige Oberflächengewässer) lagen und somit nicht von einer Gefährdung der aquatischen Umwelt durch diese Stoffe auszugehen war. Aktualisiert am: 12.01.2022 Datenrecherche Datenrecherche Datenrecherche Datenrecherche Datenrecherche Datenrecherche Datenrecherche Datenrecherche Datenrecherche
This production mix is fully based on the related exploitation of copper ore. technologyComment of copper mine operation and beneficiation, sulfide ore (CA, CL, CN, RU, US, RoW): Based on typical current technology. Mining is done 70% open pit and 30% underground, followed by joint beneficiation of copper and molybdenite trough flotation, where considerable amounts of agents are added. Overburden is disposed separate to sulfidic tailings near the mining site. No dewatering (or other pre-treatment) of the tailings of is assumed as this is considered a treatment activity that occurs only at selective sites and is therefore modelled separately. technologyComment of molybdenite mine operation (GLO): imageUrlTagReplacead2d66f4-3a0d-4ae6-a5ca-e63fd821a4fc Mining. Sulphidic copper ores are mined only 30% underground, the major part is mined in large open cut operations. The ore mined in 1900 in the U.S. had a high content of 3.4% and was mined entirely underground. Open pit mining permits the use of very large equipment. Resulting economies of scale enable the exploitation of lower grade disseminated (porphyry) ores – the ores now mainly mined. The major emissions are due to mineral born pollutants in the effluents. Open cut mining generates large quantities of dust, which contains elevated contents of metals and sulphur. Rain percolates through overburden and accounts to metal emissions to groundwater. Overburden is deposed close to the mine. No overburden is refilled. imageUrlTagReplace47e24476-56f3-4016-9151-88908e3e0072 Beneficiation. After mining, the ore is first ground. In a next step it is subjected to gravity concentration to separate the metal-bearing particles from the unwanted minerals. After this first concentration step, flotation is carried out to remove the gangue from the sulphidic minerals. For neutralisation lime is added. In the flotation several organic chemicals ( such as collectors (xanthate or aerofloat) and frothing reagent (eg. Methyl Isobutyl Carbinol)) are used as collector, frother, activator, depressor and flocculant. Sometimes cyanide is used as depressant for pyrite. Tailings usually are led to tailings heaps or ponds. As a result, copper concentrates containing around 30% Cu are produced. Molybdenite concentrate are further ground and purified. It leaves the process as co-product with a concentration of 90 – 95 % Molybdenum disulphide. The concentrated ore is fed to the metallurgy, which is assumed to be on-site. Ore handling and processing produce large amounts of dust, containing PM10 and several metals from the ore itself. Flotation produces effluents containing several organic agents used. Some of these chemicals evaporate and account for VOC emissions to air. Namely xanthates decompose hydrolytically to release carbon disulphide. Tailings effluent contains additional sulphuric acid from acid rock drainage. Tailings are deposed as piles and in ponds. In the sulphidic tailings occurs acid rock drainage (ARD) over a long period of time. Reserves and resources: Molybdenum and Copper are coexisting in porphyry deposits of the copper-molybdenum type, as molybdenite (MoS2) and chalcopyrite (CuFeS2). About half of the world-wide produced molybdenum is a co-product of the primary copper industry while for another substantial part copper is the co-product. Hence almost all of the molybdenum is produced in a process similar to the copper primary production. Molybdenum secondary production – mainly from spent petroleum catalysts – is not remarkable, and no secondary production is considered in this study. It's estimated that 30% of the molybdenum is re-used in the form of the molybdenum content steel alloys which are recycled to the foundries. Secondary production of copper from scrap plays an important role. The resources of primary copper are limited, a continuous depletion within 60 years is estimated. Land-based resources of copper are estimated to be 1.6 billion tons , and resources in deep-sea nodules are estimated to be 700 million tons. A detailed overview over the global refinery production and a statistic on US use and production of copper is available in the online version of the USGS “Mineral Commodity Summary”. The world-wide mine estimated reserves by country are listed in Tab. 1. Exploitable reserves of recoverable copper were estimated at about 100 million tons in 1935; new discoveries raised this to 212 million tons in 1960. Reserves grew again sharply to 340 million metric tons (MMT) in 1984, but since then they have declined slowly to 321 MMT in 1990 and 310 MMT in 1994. Estimates vary according to prices and assumptions. Total potential resources have increased somewhat over the same period, from 500 MMT to around 590 MMT. As a matter of interest, cumulative global production of copper between 1970 and 1996 was 216 MMT. With the actual mine production of around 13.5 MMT/a, the reserves would last 36 years and the reserve base 70 years. Reserves of molybdenite in the market economy countries have been estimated in a survey evaluating identified ore bodies, i.e., those which have been explored as well as those which have been exploited. The results indicate the following amounts of recoverable molybdenum: United States, 4100 kt; Chile, 1770 kt; Canada, 928 kt; Mexico, 306 kt; Peru, 288 kt; other countries, 356 kt. Ore bodies producing primarily molybdenum contain 55 % of the reserves identified; only 29 % of these ore bodies were being exploited at the time of the survey (January 1985). Operations producing molybdenum as a byproduct contained the remaining 45 % of reserves and 67 % of them were producing molybdenite. The estimated total recoverable molybdenum from primary and byproduct reserves is listed in Tab. 2. References: Krauss et al. (1999), Sebenik et al. (1997), USGS (2003), Ayres et al. (2002).
technologyComment of cobalt production (GLO): Cobalt, as a co-product of nickel and copper production, is obtained using a wide range of technologies. The initial life cycle stage covers the mining of the ore through underground or open cast methods. The ore is further processed in beneficiation to produce a concentrate and/or raffinate solution. Metal selection and further concentration is initiated in primary extraction, which may involve calcining, smelting, high pressure leaching, and other processes. The final product is obtained through further refining, which may involve processes such as re-leaching, selective solvent / solution extraction, selective precipitation, electrowinning, and other treatments. Transport is reported separately and consists of only the internal movements of materials / intermediates, and not the movement of final product. Due to its intrinsic value, cobalt has a high recycling rate. However, much of this recycling takes place downstream through the recycling of alloy scrap into new alloy, or goes into the cobalt chemical sector as an intermediate requiring additional refinement. Secondary production, ie production from the recycling of cobalt-containing wastes, is considered in this study in so far as it occurs as part of the participating companies’ production. This was shown to be of very limited significance (less than 1% of cobalt inputs). The secondary materials used for producing cobalt are modelled as entering the system free of environmental burden. technologyComment of copper mine operation and beneficiation, sulfide ore (AU, CA, CL, CN, ID, KZ, RU, US, ZM, RoW): Based on typical current technology. Mining is done 70% open pit and 30% underground, followed by joint beneficiation of copper and molybdenite trough flotation, where considerable amounts of agents are added. Overburden is disposed separate to sulfidic tailings near the mining site. No dewatering (or other pre-treatment) of the tailings of is assumed as this is considered a treatment activity that occurs only at selective sites and is therefore modelled separately. technologyComment of gold-silver mine operation and beneficiation (CA-QC): The ore is mined in an underground mine and transported by trucks to the mill for further processing. The ore is then fed into a series of grinding mills where steel balls grind the ore. Then follows the steps of flotation of copper and zinc, concentrate handling, cyanide destruction and backfilling of the tailings, refining of gold by electro-winning and melting in furnace to produce the gold and silver ingots. 20% of the tailings produce are sent underground to be used as backfill; sulfidic tailing is managed on site in tailings ponds. technologyComment of molybdenite mine operation (GLO): imageUrlTagReplacead2d66f4-3a0d-4ae6-a5ca-e63fd821a4fc Mining. Sulphidic copper ores are mined only 30% underground, the major part is mined in large open cut operations. The ore mined in 1900 in the U.S. had a high content of 3.4% and was mined entirely underground. Open pit mining permits the use of very large equipment. Resulting economies of scale enable the exploitation of lower grade disseminated (porphyry) ores – the ores now mainly mined. The major emissions are due to mineral born pollutants in the effluents. Open cut mining generates large quantities of dust, which contains elevated contents of metals and sulphur. Rain percolates through overburden and accounts to metal emissions to groundwater. Overburden is deposed close to the mine. No overburden is refilled. imageUrlTagReplace47e24476-56f3-4016-9151-88908e3e0072 Beneficiation. After mining, the ore is first ground. In a next step it is subjected to gravity concentration to separate the metal-bearing particles from the unwanted minerals. After this first concentration step, flotation is carried out to remove the gangue from the sulphidic minerals. For neutralisation lime is added. In the flotation several organic chemicals ( such as collectors (xanthate or aerofloat) and frothing reagent (eg. Methyl Isobutyl Carbinol)) are used as collector, frother, activator, depressor and flocculant. Sometimes cyanide is used as depressant for pyrite. Tailings usually are led to tailings heaps or ponds. As a result, copper concentrates containing around 30% Cu are produced. Molybdenite concentrate are further ground and purified. It leaves the process as co-product with a concentration of 90 – 95 % Molybdenum disulphide. The concentrated ore is fed to the metallurgy, which is assumed to be on-site. Ore handling and processing produce large amounts of dust, containing PM10 and several metals from the ore itself. Flotation produces effluents containing several organic agents used. Some of these chemicals evaporate and account for VOC emissions to air. Namely xanthates decompose hydrolytically to release carbon disulphide. Tailings effluent contains additional sulphuric acid from acid rock drainage. Tailings are deposed as piles and in ponds. In the sulphidic tailings occurs acid rock drainage (ARD) over a long period of time. Reserves and resources: Molybdenum and Copper are coexisting in porphyry deposits of the copper-molybdenum type, as molybdenite (MoS2) and chalcopyrite (CuFeS2). About half of the world-wide produced molybdenum is a co-product of the primary copper industry while for another substantial part copper is the co-product. Hence almost all of the molybdenum is produced in a process similar to the copper primary production. Molybdenum secondary production – mainly from spent petroleum catalysts – is not remarkable, and no secondary production is considered in this study. It's estimated that 30% of the molybdenum is re-used in the form of the molybdenum content steel alloys which are recycled to the foundries. Secondary production of copper from scrap plays an important role. The resources of primary copper are limited, a continuous depletion within 60 years is estimated. Land-based resources of copper are estimated to be 1.6 billion tons , and resources in deep-sea nodules are estimated to be 700 million tons. A detailed overview over the global refinery production and a statistic on US use and production of copper is available in the online version of the USGS “Mineral Commodity Summary”. The world-wide mine estimated reserves by country are listed in Tab. 1. Exploitable reserves of recoverable copper were estimated at about 100 million tons in 1935; new discoveries raised this to 212 million tons in 1960. Reserves grew again sharply to 340 million metric tons (MMT) in 1984, but since then they have declined slowly to 321 MMT in 1990 and 310 MMT in 1994. Estimates vary according to prices and assumptions. Total potential resources have increased somewhat over the same period, from 500 MMT to around 590 MMT. As a matter of interest, cumulative global production of copper between 1970 and 1996 was 216 MMT. With the actual mine production of around 13.5 MMT/a, the reserves would last 36 years and the reserve base 70 years. Reserves of molybdenite in the market economy countries have been estimated in a survey evaluating identified ore bodies, i.e., those which have been explored as well as those which have been exploited. The results indicate the following amounts of recoverable molybdenum: United States, 4100 kt; Chile, 1770 kt; Canada, 928 kt; Mexico, 306 kt; Peru, 288 kt; other countries, 356 kt. Ore bodies producing primarily molybdenum contain 55 % of the reserves identified; only 29 % of these ore bodies were being exploited at the time of the survey (January 1985). Operations producing molybdenum as a byproduct contained the remaining 45 % of reserves and 67 % of them were producing molybdenite. The estimated total recoverable molybdenum from primary and byproduct reserves is listed in Tab. 2. References: Krauss et al. (1999), Sebenik et al. (1997), USGS (2003), Ayres et al. (2002). 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 smelting and refining of nickel concentrate, 16% Ni (GLO): Extrapolated from a typical technology for smelting and refining of nickel ore. MINING: 95% of sulphidic nickel ores are mined underground in depths between 200m and 1800m, the ore is transferred to the beneficiation. Widening of the tunnels is mainly done by blasting. The overburden – material, which does not contain PGM-bearing ore – is deposed off-site and is partially refilled into the tunnels. Emissions: The major emissions are due to mineral born pollutants in the effluents. The underground mining operations generate roughly 80 % of the dust emissions from open pit operations, since the major dust sources do not take place underground. Rain percolate through overburden and accounts to metal emissions to groundwater. Waste: Overburden is deposed close to the mine. Acid rock drainage occurs over a long period of time. BENEFICIATION: After mining, the ore is first ground. In a next step it is subjected to gravity concentration to separate the metallic particles from the PGM-bearing minerals. After this first concentration step, flotation is carried out to remove the gangue from the sulphidic minerals. For neutralisation lime is added. In the flotation several organic chemicals are used as collector, frother, activator, depressor and flocculant. Sometimes cyanide is used as depressant for pyrite. Tailings usually are led to tailing heaps or ponds. As a result, nickel concentrates containing 7 - 25% Ni are produced. Emissions: Ore handling and processing produce large amounts of dust, containing PM10 and several metals from the ore itself. Flotation produce effluents containing several organic agents used. Some of these chemicals evaporate and account for VOC emissions to air. Namely xanthates decompose hydrolytically to release carbon disulphide. Tailings effluent contains additional sulphuric acid from acid rock drainage. Waste: Tailings are deposed as piles and in ponds. Acid rock drainage occurs over a long period of time. METALLURGY AND REFINING: There are many different process possibilities to win the metal. The chosen process depends on the composition of the ore, the local costs of energy carrier and the local legislation. Basically two different types can be distinguished: the hydrometallurgical and the pyrometallurgical process, which paired up with the refining processes, make up five major production routes (See Tab.1). All this routes are covered, aggregated according to their market share in 1994. imageUrlTagReplace00ebef53-ae97-400f-a602-7405e896cb76 Pyrometallurgy. The pyrometallurgical treatment of nickel concentrates includes three types of unit operation: roasting, smelting, and converting. In the roasting step sulphur is driven off as sulphur dioxide and part of the iron is oxidised. In smelting, the roaster product is melted with a siliceous flux which combines with the oxidised iron to produce two immiscible phases, a liquid silicate slag which can be discarded, and a solution of molten sulphides which contains the metal values. In the converting operation on the sulphide melt, more sulphur is driven off as sulphur dioxide, and the remaining iron is oxidised and fluxed for removal as silicate slag, leaving a high-grade nickel – copper sulphide matte. In several modern operations the roasting step has been eliminated, and the nickel sulphide concentrate is treated directly in the smelter. Hydrometallurgy: Several hydrometallurgical processes are in commercial operation for the treatment of nickel – copper mattes to produce separate nickel and copper products. In addition, the hydrometal-lurgical process developed by Sherritt Gordon in the early 1950s for the direct treatment of nickel sulphide concentrates, as an alternative to smelting, is still commercially viable and competitive, despite very significant improvements in the economics and energy efficiency of nickel smelting technology. In a typical hydrometallurgical process, the concentrate or matte is first leached in a sulphate or chloride solution to dissolve nickel, cobalt, and some of the copper, while the sulphide is oxidised to insoluble elemental sulphur or soluble sulphate. Frequently, leaching is carried out in a two-stage countercurrent system so that the matte can be used to partially purify the solution, for example, by precipitating copper by cementation. In this way a nickel – copper matte can be treated in a two-stage leach process to produce a copper-free nickel sulphate or nickel chloride solution, and a leach residue enriched in copper. Refining: In many applications, high-purity nickel is essential and Class I nickel products, which include electrolytic cathode, carbonyl powder, and hydrogen-reduced powder, are made by a variety of refining processes. The carbonyl refining process uses the property of nickel to form volatile nickel-carbonyl compounds from which elemental nickel subsides to form granules. Electrolytic nickel refineries treat cast raw nickel anodes in a electrolyte. Under current the anode dissolves and pure nickel deposits on the cathode. This electrorefining process is obsolete because of high energy demand and the necessity of building the crude nickel anode by reduction with coke. It is still practised in Russia. Most refineries recover electrolytic nickel by direct electrowinning from purified solutions produced by the leaching of nickel or nickel – copper mattes. Some companies recover refined nickel powder from purified ammoniacal solution by reduction with hydrogen. Emissions: In all of the metallurgical steps, sulphur dioxide is emitted to air. Recovery of sulphur dioxide is only economic for high concentrated off-gas. Given that In the beneficiation step, considerable amounts of lime are added to the ore for pH-stabilisation, lime forms later flux in the metallurgical step, and decomposes into CO2 to form calcite. Dust carry over from the roasting, smelting and converting processes. Particulate emissions to the air consist of metals and thus are often returned to the leaching process after treatment. Chlorine is used in some leaching stages and is produced during the subsequent electrolysis of chloride solution. The chlorine evolved is collected and re-used in the leach stage. The presence of chlorine in wastewater can lead to the formation of organic chlorine compounds (AOX) if solvents etc. are also present in a mixed wastewater. VOCs can be emitted from the solvent extraction stages. A variety of solvents are used an they contain various complexing agents to form complexes with the desired metal that are soluble in the organic layer. Metals and their compounds and substances in suspension are the main pollutants emitted to water. The metals concerned are Cu, Ni, Co, As and Cr. Other significant substances are chlorides and sulphates. Wastewater from wet gas cleaning (if used) of the different metallurgical stages are the most important sources. The leaching stages are usually operated on a closed circuit and drainage systems, and are therefore regarded as minor sources. In the refining step, the combustion of sulphur leads to emissions of SO2. Nitrogen oxides are produced in significant amounts during acid digestion using nitric acid. Chlorine and HCl can be formed during a number of digestion, electrolytic and purification processes. Chlorine is used extensively in the Miller process and in the dissolution stages using hydrochloric acid and chlorine mixtrues respectively. 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. Large quantities of effluents contain amounts of metals and organic substances. Waste: Regarding the metallurgical step, several co-products, residues and wastes, which are listed in the European Waste Catalogue, are generated. Some of the process specific residues can be reused or recovered in preliminary process steps (e. g. dross, filter dust) or construction (e. g. cleaned slag). Residues also arise from the treatment of liquid effluents, the main residue being gypsum waste and metal hydroxides from the wastewater neutralisation plant. These residuals have to be disposed, usually in lined ponds. In the refining step, quantities of solid residuals are also generated, which are mostly recycled within the process or sent to other specialists to recover any precious metals. Final residues generally comprise hydroxide filter cakes (ironhydroxide, 60% water, cat I industrial waste). References: Kerfoot D. G. E. (1997) Nickel. In: Ullmann's encyclopedia of industrial chemis-try (ed. Anonymous). 5th edition on CD-ROM Edition. Wiley & Sons, London. technologyComment of zinc mine operation (GLO): The technological representativeness of this dataset is considered to be high as mining and concentration methods for zinc are consistent in all regions. Mining The mining of zinc ore includes underground and open cast mining processes. Within the global zinc industry, about 80% of zinc ore comes from underground mines and 20% from open pit or combination mines. - Underground Mining: Access is via vertical shafts or inclined roadways. There are usually two access routes (one for mining personnel and materials, and one for the ore) for safety and for ease of ventilation (fresh air comes in one and is then exhausted out of the other). These are permanent structures and therefore require strong roof supports (often including "bolts" into the rock to tie the layers together for strength). Once at the correct depth has been reached, horizontal tunnels are driven to reach the ore deposit. These are often temporary, so the support requirements are less substantial. Transport for personnel and materials can be by train, truck or conveyor belts. The largest share of the consumed fuels is diesel followed by electricity. Other major inputs include explosives and water. - Open Pit Mining: Hard-rock surface mining usually includes drilling, blasting, or a combination of both processes, and then lifting of the broken ore either into trucks or onto conveyors for transportation to the processing plant. This lifting is usually by excavator (electric or hydraulic; with shovel or backhoe configuration) or front-end loader. Benefication (Comminution and Flotation) Zinc ore is milled and mixed with water to recover a fine concentrate by gravity and elutriation techniques, creating a slurry. The separation process of the metal from the slurry is realized through the addition of various floatation chemicals.
In der Trinkwasseraufbereitung werden eisenhaltige Flockungsmittel eingesetzt, deren Reinheitsanforderungen in Produktnormen (DIN EN 888, 889, 890, 891) festgelegt sind. Von der zuständigen europäischen Working Group des CEN wurden im Sommer 2020 europäische Entwürfe dieser Normen mit deutlichen Verschlechterungen der Reinheitsanforderungen vorgelegt. Von Herstellerseite wurde die Verschlechterung mit einer Harmonisierung der Reinheitsanforderungen der vier Normen begründet. Dies könne eine Vereinfachung in der Anwendung darstellen. Nach Einsprüchen wurde die Argumentation angepasst. Durch die Änderungen werden Produkte mit den â€Ìaltenâ€Ì Reinheitsanforderungen zukünftig nicht ausreichend verfügbar sein. Die allgemeine Verschlechterung der Reinheiten normkonformer Produkte steht nicht im Einklang mit den Vorgaben der EU-Trinkwasserrichtlinie (Artikel 12 RL(EU) 2020/2184) und dem Minimierungsgebot nach § 6 der Trinkwasserverordnung (TrinkwV 2001 mit letzter Änderung 22.09.2021), die Mitgliedstaaten und Wasserversorger erfüllen bzw. beachten müssen. Aufgabe der Studie war zu prüfen, ob eine Verschlechterung der Reinheitsanforderungen gerechtfertigt ist, ob sie aufgrund von Mechanismen des freien Marktes unabwendbar ist und in welcher Weise Reinheitskriterien in den Produktnormen geändert werden können oder sollten. Die Studie beinhaltet umfangreiche Informationen zu Bedarf und Verfügbarkeit eisenhaltiger Flockungsmittel, die auf Befragungen von deutschen und europäischen Wasserversorgungsunternehmen sowie Herstellern basieren. Die Marktsituation wurde analysiert, inklusive der Konsequenzen für Wasserversorgungsunternehmen und chemischtechnischer Möglichkeiten der Aufreinigung dieser Aufbereitungsstoffe sowie möglicher Produktalternativen. Quelle: Forschungsbericht
Das Projekt "Alkalische Laugung von Blei/Zinn/Zinkflugstaeuben" wird vom Umweltbundesamt gefördert und von Technische Hochschule Aachen, IME, Metallurgische Prozesstechnik und Metallrecycling durchgeführt. Fuer die Aufarbeitung von Pb/Sn/Zn-Flugstaeuben, die bei der Stahlherstellung aus Schrotten sowie bei der Gewinnung von NE-Metallen entstehen, soll ein generelles Schema hydrometallurgischer Verfahren entwickelt werden. Ausgehend von der jeweiligen Zusammensetzung der Flugstaeube (vorwiegend Zink- und andere Metalloxide) wurden folgende Loesungsalternativen untersucht: 1) Laugung mit Wasser und schwach alkalischer Loesung zur Entfernung der Cl- und SO4-Gehalte sowie auch von Alkali, eventuell von Blei. 2) Laugung mit starker Natronlauge zur Loesung von Zink und Blei. 3) Laugung mit Schwefelsaeure zur Loesung von Zink. 4) Reinigung der Laugenloesungen durch Zementation mit Zn-Pulver. 5) Absetzverhalten und Filtrationsverhalten der Trueben ohne und mit Flockungshilfsmitteln sowie Filtration. Dabei wurden folgende Ergebnisse erzielt. 1) Bei der Wasserlaugung erreicht man eine maximale Entfernung von 90 Prozent Cl und Alkali und etwa 4 Prozent SO4 nach 60 Min. Laugung bei 90 Grad C, so dass auf diese Weise Chlorid und Alkali selektiv abgetrennt werden koennen. 2) Der Zusatz von NaOH zum Wasser erhoeht nicht nur die Loeslichkeit des Cl auf 95 Prozent sondern auch die des SO4 auf bis zu 95 Prozent und die des Pb zu etwa 80 Prozent. Nach einer Wasserlaugung kann so auch Sulfat selektiv abgetrennt werden. 3) Bei der stark alkalischen Laugung erreicht man unter optimalen Bedingungen eine Aufloesung von fast 100 Prozent des Bleis und 90 Prozent des Zinks. Kupfer und Zinn zeigen dagegen eine nur niedrige Loeslichkeit von max. 40 Prozent Cu und max. 10 Prozent Sn. 4) Bei der sauren Laugung unter optimalen Bedingungen (200 g/l H2SO4 und 150 g/l Feststoff) gehen...
Das Projekt "Teil II" wird vom Umweltbundesamt gefördert und von Abfallwirtschaft GmbH Halle-Lochau durchgeführt. 1. Zielsetzung: Optimierung des Verfahrens zur Deponiesickerwasseraufarbeitung auf der Deponie Halle-Lochau durch Einsatz von Membranverfahren wie Hochdruck-Umkehrosmose und Nanofiltration in Kombination mit Faellung / Flockung, Kristallisation und Filtration. 2. Arbeitsprogramm: - Untersuchungen zum Einsatz der Hochdruck-Umkehrosmose (bis 200 bar) bei der Aufarbeitung von Sickerwasserkonzentraten; - Einsatz einer Nanofiltrationsanlage mit DTF-Modulen (Rochem) zur Vorbehandlung der Sickerwasserkonzentrate; - Durchfuehrung von Versuchen zur Faellung / Flockung in Kombination mit nachgeschalteten Membranverfahren (RO, NF); - Versuche zur Sulfatreduzierung im Sickerwasserkonzentrat mittels Kristallisation.
Das Projekt "INCOPA LCA Study: Carbon footprint and LCA study for different coagulants produced from INCOPA member companies" wird vom Umweltbundesamt gefördert und von Karlsruher Institut für Technologie, Institut für Wasser und Gewässerentwicklung, Bereich Siedlungswasserwirtschaft und Wassergütewirtschaft (IWG-SWW) durchgeführt. Carbon foot-printing, the basic scope of this study, is a sub-set of a full lifecycle assessment (LCA). While LCA is a method of systematically assessing the environmental impacts associated with a product over its entire lifetime - from cradle to grave -, the proposed enhanced study focuses on a cradle to gate LCA, where the gate is defined as the entrance to the wastewater treatment plant. In accordance to DIN EN ISO 14040:2009-11 and DIN EN ISO 14044:2006-10 a carbon labeling for coagulants (PAC, Al2(SO4)3, Fe2(SO4)3, Fe2SO4, FeClSO4, NaAl(OH)4) will be performed using SimaPro LCA software. The outcome of this study will be the amount of carbon dioxide equivalents per mole of active ingredient (kg CO2 eq./ mole Fe3+ or Al3+).
Das Projekt "Waste to Airlaid" wird vom Umweltbundesamt gefördert und von Sächsisches Textilforschungsinstitut e.V. An-Institut der Technischen Universität Chemnitz durchgeführt. Kurzfasern im Längenbereich zwischen 1 mm und 12 mm bilden die Rohstoffbasis von nach dem Airlaid-Verfahren hergestellten Wirrvliesstoffen. Als klassischer Rohstoff sind gebleichte Weichholzkurzfasern (Fluff-pulp) zu bezeichnen, die im Industriemaßstab zu saugfähigen, voluminösen oder papierartigen Strukturen verarbeitet werden. Kurzfasern verschiedenster Arten fallen aber auch bei Recyclingprozessen oder als Produktionsabfälle an. Die Verknüpfung des Recyclinggedankens mit einem hochproduktiven Verfahren zur Kurzfaserverarbeitung stellt die wesentliche Motivation des abgeschlossenen Projektes dar. Die wesentliche Zielsetzung besteht in der erstmaligen Applikation des Airlaid-Vliesbildungsverfahrens auf die Verarbeitung von mit geeigneten Mitteln aus unterschiedlichsten Textilglas-Abfällen aufbereiteten Textilglas-Rezyklatfasern. Die Kombination des Verfahrens und der damit herstellbaren speziellen Wirrvliesstruktur mit den funktionellen Eigenschaften bisher nicht oder nur schwer verwertbarer Faserstoffe ist Grundlage für die Entwicklung von innovativen Produktideen außerhalb der heute für Airlaid-Produkte üblichen oben genannten Produktbereiche. Technische Basis ist eine Airlaid-Versuchsanlage, die nach dem M&J-Prinzip arbeitet. Ursprünglich als Versuchsstand geplant, konnte im Rahmen einer Projekterweiterung die Integration in eine bereits bestehende Airlay-Anlage eine quasi kontinuierliche Arbeitsweise realisiert werden. Die Produktmäßige Zielstellung bestand in einer Dämmtapete auf Basis von rezyklierten Glaskurzfasern mit durch den Zusatz anderer Fasern einstellbaren Funktionalitäten wie Feuchteaufnahmevermögen und Schwerentflammbarkeit. Die Zumischung thermoplastischer Schmelzklebefasern mit angepasster Schnittlänge bildet die Voraussetzung der anschließenden Vliesverfestigung mittels Thermofusion. Funktionsmuster in verschiedenen Zusammensetzungen konnten im Flächenmassebereich von 400 g/m2 bis 700 g/m2 und Dicken von 4 mm bis 6 mm hergestellt und erprobt werden. Der erreichte Wärmedurchgangs-widerstand ist höher als der eines handelsüblichen Vergleichsmusters ist. Die Kaschierung mit einem Deckvlies (Malervlies) kann direkt bei der Vliesbildung oder in einem zweiten Arbeitsgang erfolgen und ergibt eine malerfertige Oberfläche. Synergien wurden anorganischen und organischen Kurzfasern wie Flusen aus der Altreifenaufbereitung, Schleifstäube aus der klassischen Filzherstellung oder, Basalt und Aluminium nachgewiesen. Die Projektergebnisse sind Grundlage bereits angelaufener Anschlussprojekt und einer Reihe von Kundenversuchen. Für eine Ergebnisumsetzung im großtechnischen Maßstab bedarf es neben weitergehenden Untersuchungen vor allem der Verfügbarkeit entsprechender Anlagenkapazitäten für die Herstellung von für Testreihen ausreichenden Versuchsmengen.
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