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.
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 zinc production from concentrate (CA-QC): Hydrometallurgical process Sulphide concentrates are roasted first in fluidized bed roasters to produce zinc oxide (calcine) and sulphur dioxide. Roasting is an exothermic process and no additional fuel is used to sustain the reaction, the heat generated is recovered to produce steam. Calcine is then sent to the leaching step. Roaster gases are treated in hot electrostatics precipitators to remove dust. The remaining dust and volatile metals such as mercury and selenium are removed in the wet section of the acid plant through a cooling tour, a mist precipitator and a mercury tower (Boliden mercury removal processs). The sulphur dioxide is then converted to sulphuric acid in a conventional recovery system (converted and absorbing tower). Leaching of the calcine is carried out in a number of successive stages using a gradually increasing strength of hot sulphuric acid. The initial stages dissolve the major part of the zinc oxide and the other stages dissolve the zinc ferrite (ZnO.Fe2O3) and convert iron into Jarosite (sodium Jarosite). Zinc sulfate (ZnSO4) entering the electrolysis stage produce electrolyte (H2SO4) that is returned to leaching plant. Other metals are also dissolved during the process and are removed after leaching. Iron is the major impurity, which is precipitated in the form of Jarosite. Overall waste: The production of metals is related to the generation of several by-products, residues and wastes. Relatively large quantities of iron based solids, depending on the iron content, are generated by the leaching process (6.14E-1 kg Jarosite/kg zinc). Cement is added to the Jarosite to produce Jarofix (an inert waste). Solid residues also arise as the result of the liquid effluents treatment. The main waste stream is gypsum (CaSO4) and metal hydroxides that are produced at the wastewater neutralization plant. Mercury and selenium residues arise from the weak acid bleed treatment from the acid plant. Selenium can be recovered from these residues depending on the market demand for this metal. Overall emissions: The emissions to air can either be stack emissions or fugitive emissions. Stack emissions are normally monitored continuously (SO2) or periodically (other emissions) and reported. The main emissions to air from zinc production are sulphur dioxide (SO2) and particulate matters including metals. Main emissions to water are metals and their compounds. The monitored metals are zinc, cadmium, lead, mercury, selenium, copper and arsenic. 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.
Das Projekt "Advanced bipolar membrane processes for remediation of highly saline waste water streams (NEW ED)" wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Aachener Verfahrenstechnik, Lehrstuhl für Chemische Verfahrenstechnik durchgeführt. Objective: NEW ED aims at closing industrial water cycles and reducing the amount of waste water streams with highly concentrated salt loads stemming from a broad range of industrial production processes by exploiting the waste components (salts) and transforming them to valuable products. This will be achieved by developing new micro- to nano-porous bipolar membranes for bipolar electrodialysis (BPMED), a new membrane module concept and by integrating this new technology into relevant production processes. The bipolar membrane process produces acids and bases from their corresponding salts by dissociating water at the interface within the bipolar membranes. However, BPMED so far has been applied only in niche markets due to limitations of the current state of membrane and process development. Major drawbacks of the classic BPMED process are low product purity, limited current density and formation of metal hydroxides at or in the bipolar membrane. The objective of this project is to overcome these limitations by developing a new bipolar membrane and membrane module with active, i.e. convective instead of diffusive water transport to the transition layer of the bipolar membranes, where water dissociation takes place. The key feature of the innovative new bipolar membranes is a nano- to micro-porous and at the same time ion conducting intermediate transition layer, through which water is convectively transported from the side into the transition layer. The porous transition layer may have either the character of a cation or an anion exchanger. Several promising intermediate layer materials together with different monopolar ion-exchange layers will be tested and characterized. Membrane manufacturing and new module concepts will be investigated to exploit the full potential of the new bipolar membrane technique. Integration of the developed membranes and modules into relevant production processes is an essential part of the project.
Das Projekt "Kernprojekt B 3: Rolle des Redoxmilieus für die Aufbereitungswirkung der Uferfiltration" wird vom Umweltbundesamt gefördert und von Technische Universität Berlin, Institut für Technischen Umweltschutz, Fachgebiet Wasserreinhaltung durchgeführt. Im Rahmen des Projektes B3 wurde der Einfluss des Redoxmilieus auf die Reinigungsleistung des Untergrunds bei der Trinkwasseraufbereitung untersucht. Der Schwerpunkt der Arbeiten bezog sich dabei auf den Einfluss von verschiedenen Mangan(hydr)oxiden die in der Literatur als mögliche Oxidationsmittel im Untergrund diskutiert werden. Neben den Eisen(hydr)oxiden sind sie die wichtigsten Metall(hydr)oxide des Bodens (maximaler Anteil: 0 2 ppm) und mit ihren hohen Redoxpotentialen interessante Komponenten. Die Versuche mit Mangan(hydr)oxiden, die in Batchreaktoren und in Festbettfiltern durchgeführt wurden konzentrierten sich zum Einen auf verschiedene Wässer (Trinkwasser, Oberflächenwasser, vorgereinigtes Abwasser) sowie einzelne organische Substanzen aus dem Bereich der phenolischen und Carbonsäurearomaten, die im Molekülgerüst der Huminstoffe vorkommen. Zusätzlich wurden die Spurensubstanzen Iopromid, Sulfamethoxazol und drei verschiedene Naphthlindisulfonsäuren auf ihre Abbaubarkeit mit Mangandioxid getestet. Alle Versuche wurden bei unterschiedlichen pH-Milieus und Redoxbedingungen bestritten auch der Einfluss der Temperatur wurde untersucht. Als wichtigste Ergebnisse lassen sich eine recht deutlich vorhandene Reaktivität der Manganoxide mit phenolischen Komponenten sowie eine nur geringe Oxidierbarkeit von carbonsäurehaltigen Aromaten hervorheben, die Umwandlung von Huminstoffbestandteilen in kleinere Kompartimente ist insgesamt gering, aber dennoch vorhanden. Dabei spielt die Oberflächenbeschaffenheit der Mangan(hydr)oxide eine entscheidende Rolle. Bei den untersuchten Spurenstoffen konnten keinerlei Oxidationsprodukte gefunden werden.
Das Projekt "Entwicklung eines Membranverfahrens zur Regeneration von Saeuren bei der Oberflaechenbehandlung von Metallen" wird vom Umweltbundesamt gefördert und von Gesellschaft für Umweltschutz und Verfahrenstechnik durchgeführt. Gesamtziel des Vorhabens. Durch die verschaerften Umweltschutzbestimmungen im Rahmen der Abwassergesetzgebung ist es bei Oberflaechenbehandlungsverfahren notwendig, Aufbereitungs- und Recyclingverfahren einzusetzen. Bei der Oberflaechenbehandlung von Metallen durch Einsatz von Mischsaeuren entstehen verbrauchte Beizloesungen und saeurehaltige Daempfe. Die darin enthaltenen Schadstoffe, wie z.B. Metalle und Metallverbindungen, Fluoride und Nitrate, muessen aufbereitet und deponiert werden. Bisher wurden die saeurehaltigen Abwaesser mit geeigneten Neutralisationsmitteln (Natronlauge oder Kalkmilch) neutralisiert und die vorhandenen Metallverbindungen als Metallhydroxid ausgefaellt. Die anfallenden Feststoffe wurden aus dem neutralisierten Abwasser abgetrennt und entwaessert. Durch den Einsatz eines Regenerationsverfahrens in Form einer Elektrodialyse ist eine funktionelle und wirtschaftliche Verfahrensverbesserung gegeben.
Das Projekt "Abiotische Umwandlung anthropogener organischer Zusammensetzungen in Boeden: Kinetik der oberflaechen-induzierten Hydrolyse von Phosphorestern bei Vorliegen ausgewaehlter Ton- und Metallhydroxid-Minerale" wird vom Umweltbundesamt gefördert und von Haus der Technik e.V. durchgeführt. Soils and aquifers are increasingly polluted by anthropogenic organic substances. The interaction with the solid matrix plays an important part in the fate of the chemicals. The importance of abiotic transformations at the solid-liquid interface, the most prominent of which are hydrolysis and redox reactions, has so far been underestimated. The objective of this project was to study the kinetics of heterogeneous hydrolysis of pesticides in the presence of oxides and clay minerals. Reactions were studied under batch as well as steady-state conditions. For the analysis of the data the numerical steady-state reaction model STEADYQL was combined with a curve-fitting routine on the basis of the Levenberg-Marquardt algorithm and implemented under the name Steady Fit. The program allows the simultaneous determination of kinetic and equilibrium reaction constants from experimental data obtained under steady-state conditions. The experimental system was successfully tested using the hydrolysis of phenylpicolinate by titan dioxide as a test system. Finally the hydrolysis of the carbamate pesticide carbosulfan was investigated in suspensions with montmorillonite, titan dioxide, manganese dioxide and the clay-silt fractions of two acidic soils. Montomorillonite had the stongest effect, acceleration hydrolysis up to several orders of magnitude in the neutral pH range in which homogeneous hydrolysis was slowest.
Das Projekt "Teilprojekt 2: Brikettierung und Verhüttung" wird vom Umweltbundesamt gefördert und von BGH Edelstahl Freital GmbH durchgeführt. Das Ziel des Verbundvorhabens ist die Rückgewinnung und Wiederverwertung des Nickels aus deponierten Neutralisationsschlämmen der Edelstahlindustrie. Ausgehend von einer neuen selektiven Laugung der Neutralisationsschlämme sollen als Recyclingwege die Brikettierung von gefälltem Nickelhydroxid für den Einsatz in Schmelzaggregaten zur Edelstahlherstellung sowie die Extraktion mit anschließender elektrolytischer Abscheidung von Nickel bzw. Nickelsalzherstellung entwickelt und die Anwendbarkeit im Technikumsmaßstab zweifelsfrei demonstriert werden. Ausgehend von einer Katastererstellung zur Deponiesituation von Neutralisationsschlämmen der Edelstahlindustrie und der notwendigen Spezifikationen der erzeugten Produkte werden die einzelnen Prozessschritte in Laborversuchen untersucht und optimiert. Aufbauend auf den Laborversuchen erfolgen Bau und Inbetriebnahme einer Technikumsanlage mit anschließenden Technikumsversuchen. Abschließend erfolgt eine technische und wirtschaftliche Bewertung der Recyclingwege.
Das Projekt "Teilvorhaben: Charakterisierung, Fabrikations- und Realwassertests" wird vom Umweltbundesamt gefördert und von Leibniz-Institut für Polymerforschung Dresden e.V. durchgeführt. Das Ziel des WATER-LEGO-Projekts ist es, innovative, erschwingliche und umweltfreundliche Materialien zu entwickeln, welche sich LEGO-ähnlich zusammenfügen und für die Tiefenentkeimung von Wasser aus toxischen Gemischen oder Mikroverunreinigungen nutzen lassen sowie in sequentiellen Sorptionsfiltern lokaler Wasseraufbereitungsanlagen oder beim Endverbraucher eingesetzt werden können. Eine große Vielfalt hochporöser, organischer, anorganischer und hybrider Sorptionsmaterialien (z.B. Polymer/Calciumcarbonat, Metallionen/Polymer, Metallhydroxid/Polymer) mit spezifischen Sorptionseigenschaften wird für die Entfernung von Pharmazeutika, gelösten organischen Stoffen, Oxyanionen, ausgewählte Schwermetallionen und Bor synthetisiert, charakterisiert und analysiert. Die realen Wassertests mit Wasser aus Flüssen und Wasserentsalzungsanlagen zielen auf die Abtrennung bzw. Rückgewinnung von Schadstoffgemischen ab, um den LEGO-Ansatz zu validieren. Die Hauptaspekte zur Neuartigkeit des Projekts sind (i) der innovative LEGO-Ansatz zum Design von Sorptionssystemen, (ii) die 'grüne' (umweltfreundliche) Synthese von porösen Materialien in wässrigen Medien, (iii) die 'grüne' (umweltfreundliche) Synthese neuer Komposite mit komplexen Architekturen auf Basis von CaCO3, (iv) die Synthese neuer poröser Metall-Polymer-Sorbentien für Antibiotika und Bor (nicht triviale Schadstoffe) sowie (v) die Durchführung von Realwassertests, orientiert an regionalen Problemstellungen und grundlegende Untersuchungen der Materialeigenschaften zur Entfernung von Schadstoffspuren.
Das Projekt "Teilvorhaben Verfahrenstechnik und Prozessentwicklung für Hochtemperaturreaktionen" wird vom Umweltbundesamt gefördert und von Deutsches Zentrum für Luft- und Raumfahrt e.V., Institut für Technische Thermodynamik durchgeführt. 1. Vorhabensziel Ziel des Vorhabens ist es, das Potenzial der chemischen Energiespeicherung unter spezieller Berücksichtigung bestehender Probleme und Einschränkungen für technische Anwendungen nutzbar zu machen. Die Speicherdichte soll bei gleichzeitig verbesserter Entladeleistung auf 400 bis 800 kWh/m3 (Faktor 5 bis 8 im Vergleich zu Wasser) erhöht werden. Untersucht werden die Langzeitspeicherung von Solar- oder KWK-Wärme für die Klimatisierung und Heizung im Hausenergiebereich sowie Hochtemperaturspeicherung im Kraftwerksbereich und industrieller Prozesswärme. Besonders viel versprechende Reaktionstypen sind die Dehydratisierung von Metallhydroxiden und Salzhydraten und Decarboxilierung von Metallkarbonaten. 2. Arbeitsplanung Identifizierung der optimalen Reaktionssysteme mit Reaktions-Gleichgewichtstemperaturen im Bereich 200 - 400 C (Hochtemperatur-Reaktionssysteme). Erstellung eines Simulationsmodells zur Auslegung des thermochemischen Speichers (Reaktors) unter Berücksichtigung von Stoff- und Wärmetransport. Umsetzung im Labormaßstab zum Nachweis der verfahrenstechnischen Machbarkeit und Verifizierung der entwickelten Auslegungsmodelle. Entwicklung eines verfahrenstechnischen Leitkonzepts für ein thermo-chemisches Speichersystem. 3. Ergebnisverwertung Die Projektergebnisse werden in Fachzeitschriften und auf Fachkongressen einer breiten Öffentlichkeit präsentiert. Neue Ergebnisse und Ansätze werden patentrechtlich gesichert, gemeinsame Projektergebnisse von DLR und ITW werden als Gemeinschaftspatent angemeldet. Hiermit soll die Basis geschaffen werden, um mit substantieller Beteiligung industrieller Komponentenhersteller und Systemlieferanten eine nachfolgende Technologieentwicklung zielgerecht durchführen zu können.
Das Projekt "Beurteilung der Alkaliempfindlichkeit von Betonzuschlagstoffen aus Thueringen und Sachsen" wird vom Umweltbundesamt gefördert und von Forschungsinstitut der Zementindustrie durchgeführt. 1) Alkaliempfindliche kieselsaeurehaltige Bestandteile des Betonzuschlags reagieren mit den in der Porenloesung des Betons geloesten Alkalien zu hygroskopischen Alkalisilikatgelen unter Volumenvergroesserungen. Fuer Ausloesung, Ablauf und Ausmass sind in erster Linie Art, Menge und Korngroessenverteilung des alkaliempfindlichen Zuschlags, der Alkaligehalt der Porenloesung und Feuchtigkeit verantwortlich. 2) Durch die Untersuchungen soll geklaert werden, ob Grauwacken, Quarzporphyre und Kieselschiefer den potentiell alkaliempfindlichen Zuschlagesteinen zuzurechnen sind und ob sie zu einer schaedigenden Reaktion im Beton fuehren koennten. 3) Aus 3 Zementen mit unterschiedlichen Alkaligehalten und 10 Zuschlaegen wurden Pruefkoerper 4x4x16cm aus 325 verschiedenen Betonmischungen hergestellt, an denen das Dehnverhalten im Vergleich zu Proben aus Normsand und Quarzkies ermittelt wurde. Die Untersuchungen des Einflusses der Zuschlagmenge fuehrten bei den Quarzporphyten und beim Phonolith nur bei konstant hohem Zementgehalt von 600 kg/m3 und bei Verwendung des alkalireichsten Portlandzements zu einem sehr schwach ausgepraegten Pessimum. Bei den Grauwacken wurde kein Pessimum ermittelt. Die Dehnungen lagen bei 0,8mm/m. Mit Duranglas wurden die bekannten hohen Dehnungen von ueber 2mm/m bestaetigt. Die Untersuchungen haben insgesamt zu dem Ergebnis gefuehrt, dass die geprueften Zuschlaege eine vergleichsweise geringe chemische Alkaliempfindlichkeit aufweisen. Sie ist so gering, dass von ihr allein unter den hier gewaehlten Versuchsbedingungen keine schaedigende Alkali/Zuschlag-Reaktion ausgehen kann. Der Frage, ob ein physikalischer Quellmechanismus eine massgebende Rolle spielt, muss weiter nachgegangen werden. 4) Der wesentlich volkswirtschaftliche Nutzen besteht in einer moeglichen Senkung der Schadensquote durch Verbesserung der Dauerhaftigkeit von Beton.