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Markt für Blei

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.

Wärmeversorgung für die Stadt Schwandorf

Das Projekt "Wärmeversorgung für die Stadt Schwandorf" wird vom Umweltbundesamt gefördert und von Stadt Schwandorf durchgeführt. Objective: To use the heat contained in the condenser cooling water of the power plant of the Bayernwerk AG at Schwandorf to cover the need for space heating in parts of the town. General Information: Condenser cooling water from the power plant of the Bayernwerk AG is used as the heat source for the heat pumps of the city heating system of Schwandorf. The water is diverted from the power plant's cooling water system before the entry into the cooling tower and is pumped to the heat pump station of the city heating system. After the water has been cooled down in the heat pump evaporators, it is discharged into the river Naab. The cooling of the condenser cooling water in the evaporators and the heat generated by the heat pumps and recovered from the waste heat of the heat pump gas motors yield a total heating power of 4.1 MW. The heating water of 60 deg.C to max. 75 deg.C is fed via heat exchangers into the heating installations of the users (public buildings). The heat pumps are capable of coping with outside temperature of above 4 deg.C. Below this temperature level, boilers are used to cover the missing heat generation capacity. In total 14 users are connected with the city heating network: 2 swimming pools, a hospital, 5 schools and 6 other large public buildings. The capacity of the system is 4.100 KW, producing annually 15.877 MWh at a cost of DM 773.759 p.a. (excluding the cost of capital) against DM 1,191,525 for a conventional system using fuel at DM 0.65/l, saving therefore DM 417.766 p.a. This saving represents a 14.2 year payback of the additional investment (DM 5.0930.617) compared to a conventional heating system. Achievements: The project was finished in 1985. From that time until the final report no changes were made. The final report was submitted in January 1989. The outcome achieved was not good because expected sales could not be achieved. The average annual sale was 10.000 MWh so a considerable loss was incurred. As the expected supply of 15.877 MWh could never be achieved, less district heating was supplied and it was only with this that energy could have been saved. The loss in the financial year 1990 amounted to DM 880.000. The previous year yielded similar results. Prime Contractor: Grosse Kreisstadt Schwandorf; Schwandorf; Germany.

Middle temperature drying of extracted sugar beet pulp by using secondary energy

Das Projekt "Middle temperature drying of extracted sugar beet pulp by using secondary energy" wird vom Umweltbundesamt gefördert und von Elektronenstrahltechnik Nord GmbH & Co. (ETN) durchgeführt. Objective: Aims to demonstrate a sugar beet convection dryer that uses waste heat within a sugar refinery. Heat from evaporators, condensers and surplus steam is used to pre-heat ambient air entering the dryer. The dryer consists of several circular horizontal sieve plates which are fixed to a rotating shaft. This is contained by Asilo like structure. Air fed into the dryer is 70-90 degree of Celsius. The beet pulp is transferred from one plate to another to the base of the dryer. The process is 82 per cent more efficient, saving 1.28 t/h oil, about 2272 t/y oil. The process technology of this project is innovatory.

Gasmotorgetriebene Waermepumpe mit Waermeextraktion aus dem Boden fuer die Raumheizung

Das Projekt "Gasmotorgetriebene Waermepumpe mit Waermeextraktion aus dem Boden fuer die Raumheizung" wird vom Umweltbundesamt gefördert und von Kreis Warendorf, Kreisdirektor durchgeführt. Objective: The aim of the project is to demonstrate the use of a gas compression heat pump with the soil as heat source in the heating range power above 1 000 kW. Energy savings of 50 per cent compared with a conventional boiler plant are envisaged. General Information: The heating plant of the district building in Warendorf consists of a combination of two gas heat pump units with three gas boilers to cover the peak load and produce hot water. The heat pumps are dimensioned for coverage of the transmission heat demand of 1 150 kW, two soil heat exchangers (6 800 m2, 2 100 m2) are used as heat source for the heat pumps, the heat exchangers consist of pe-tubings in parallel one besides the other in plane, they are installed in 2 depths of 0.8 and 1.8 beneath the soil surface. The building under consideration having 17.700 square m. of heated area, was designed to have a K value of 0.2 W/square m.K. and the load was calculated under 21 Deg. C inside and 12 Deg. C outside design temperatures. The infiltration coefficient was taken as 9,4 cubic m/h sq. m. of window surface, corresponding to an air charge of 1 time per hour. At present energy price levels the heat pump heating capacity was designed to be about 60 per cent of the total transmission heat demand. The construction of the plant implies the combination of both heat pumps connected to a common evaporator and condenser. Each screw compressor used, being slide valve regulated, is directly coupled to gas-Otto 6 cylinder drive engine rated at 13 kW output. The refrigerant R-12 is evaporated in a flooded type evaporator of 440 kW capacity, at 10 Deg. C evaporating temperature. The condenser is an ordinary bundle type condenser, rated as 680 kW, at 55 Deg. C condensing temperature. Heat is extracted from soil and rain water using a brine circuit operating at 2 to 5 Deg. C lower than corresponding soil temperature, and 5 Deg. C temperature differential across the evaporator. The maximum heat absorption coefficient amounts to 49 W/sq. m. of soil area. Heating water flows first through a low temperature circuit operating at 50.9 Deg. C, and consisting of the oil-coolers, condenser and gear coolers. A partial flow of the heating water is then passed through the high temperature circuit operating at 63.5 Deg. C, consisting of the motor jacket heat exchanger and waste gas heat exchangers. A buffer store integrated into the heat pump system stores the high temperature heat and supplies the impulses for switching on and off the heat pumps and the boiler. A special characteristic of this installation is that the mechanical room is located in the attic of the building and sound proofing is ascertained by a proper design. Saving of 51.5 per cent versus 55 per cent expected. Achievements: During the heating periods 1982/83 and 83/84 there were longer non-availability periods of the plant mainly due to damage of the soil heat exchangers, corrosion problems in motor heat exchangers, motors failures etc. ...

Use of the variance-covariance method in radiation protection

Das Projekt "Use of the variance-covariance method in radiation protection" wird vom Umweltbundesamt gefördert und von Universität Würzburg, Biozentrum, Institut und Lehrstuhl für Humangenetik durchgeführt. General Information: Reductions of the dose limits in radiation protection and changes of the quality factor for densely ionizing radiations will require increased precision in area monitoring and in personal dosimetry. Tissue equivalent proportional counters are increasingly employed for this purpose. However, their routine use in radiation protection requires the variance-covariance method which is an extension of the pulse height determination in two ways: it is not restricted to radiation fields of extremely low dose rate and, unlike the variance methods, it is applicable in the time varying radiation fields that are frequently encountered in radiation protection practice. Achievements: Measurements in the field of a diagnostic X-ray tube have been performed with a 2 pulse generator. The beam was filtered with 1 mm of aluminium. The twin detector consists of 2 cylindrical proportional counters. The plastic detector walls have a thickness equivalent to 13 mm of tissue. The detector currents are integrated on capacitors. The voltage at the capacitors is digitized and the results stored on a computer. Calibration of the proportional counters was performed with an americium-241 alpha source. As a side product to this the Townsend coefficients for methane based tissue equivalent gas have been determined for a broad range of reduced field strengths. In further measurements variations of the dose averaged lineal energy, y d, during the 10 ms time interval of the high voltage pulse of the X-ray tube have been determined. In a theoretical analysis the inherent possibilities of the variance covariance method for suppression of noise and electric pickup have been examined. Several types of disturbances have been considered. Preliminary measurements have been performed in the photon and electron fields of a 20 MV linear accelerator. To cope with the high dose rate 2 improvements of the instrumentation are necessary. Increased sampling frequency will reduce the dose per sampling interval and smaller detectors will reduce the current delivered. In the experimental system, the signal processing has been improved by the implementation of faster and more accurate analogue to digital conversions (ADC) and the mechanical device for pressure stabilization in the gas flow system has been replaced by an electronic pressure control. In addition the gas flow is now adjusted by a mass flow control. Work is being done to transform a system designed for variance covariance measurements in pulsed therapeutic X-ray and electron fields into one appropriate for measurements in continuous cobalt-60 beam, regarded as an intermediate step before measuring in diagnostic X-rays. The proportional counters were found to be unsuitable for continuous beam measurements so it has been decided to apply new detectors. Ionization chambers and charge integration have been chosen to achieve a more satisfactory calibration. 2 Keithley 617 programmable electrometers together with a ...

Teilprojekt 4

Das Projekt "Teilprojekt 4" wird vom Umweltbundesamt gefördert und von Fachhochschule Stralsund, Institut für Regenerative EnergieSysteme durchgeführt. Das Vorhabenziel beinhaltet die Erarbeitung des Konzeptes und der Spezifikationen eines Brennstoffzellensystems, das als Funktionsprototyp mit photokatalytisch erzeugtem Wasserstoff betrieben wird. Die netzunabhängige Stromversorgungseinheit verstromt dabei den diskontinuierlich in spezifischen Qualitäten bereitgestellten Wasserstoff in einem Anwendungsfall, dessen konkrete Einsatzbedingungen im Ergebnis einer Marktanalyse durch die WtI-MV zur Projektlaufzeit fixiert werden. Das Demonstrationssystem ist mit direkter Umsetzung des Wasserstoffs ohne Zwischenspeicherung als Hybridsystem mit einem elektrischen Energiespeicher in einem Leistungsbereich von 10 - 100 Wel vorgesehen. Insbesondere ist für das bei variierenden Lastverhältnissen, Wasserstoff- und Oxydanzfeuchten zuverlässig arbeitende Brennstoffzellensystem ein Diagnostik-System für die Wasserbalance zu entwickeln und in das Steuerungskonzept zu integrieren. Die Parametertoleranz des Brennstoffzellensystems ist hinsichtlich der zum Einsatz kommenden Wasserstoff- und Luftgemische zu ermitteln und für die Auslegung der Gasaufbereitung bereitzustellen. Auf Basis einer Modellierung des Hybridsystems mit Matlab/Simulink werden Anforderungen an den Stack, den Speicher und die Ladeelektronik abgeleitet. Schlüsselparameter des Systems werden an Einzelkomponenten verifiziert. Der Feuchtehaushalt wird mit der Impedanzspektroskopie untersucht. Die Membrane werden unter den konkretisierten Einsatzbedingungen charakterisiert.

Gegendrucksteuerung von Hochoefen durch Einsatz einer Kopfggas-Druckentlastungsturbine

Das Projekt "Gegendrucksteuerung von Hochoefen durch Einsatz einer Kopfggas-Druckentlastungsturbine" wird vom Umweltbundesamt gefördert und von Thyssen Stahl durchgeführt. Objective: To install and test a top gas pressure relief turbine to use the pressure drop in the blast furnace after waste gas cleaning to generate electrical power (13,480 kW) to achieve annual energy saving of 7,760 TOE at project level. Assuming average power plant efficiency, this should correspond to primary energy saving of +- 27,000 TOE/y. General Information: Top-gas pressure allows appreciably higher specific outputs for a given furnace volume. Longer gas residence time in the blast furnace leads top gas flow homogenisation and reduced coke consumption. While a low fraction of gas pressure (0.25 Bar max.) is required for the downstream gas cleaning system, residual pressure 2 Bar max. is lost through throttling, equivalent to +- 30 per cent of energy used for blast compression. In order to utilize the pressure drop in the top gas after waste gas cleaning it was decided to install a pressure recovery turbine which is located downstream of the scrubbers in the already existing gas purification facilities at Schwelgern. It was decided to install a double-flow, four stage axial type reaction turbine designed to generate 13.5 MWh from a gas throughput of 587,000 m3/h, admission temperature of 45 deg C and a differential pressure of 1.8 Bar. The cast steel turbine casing is 3,870 mm in length, 3,500 mm maximum height. The rotor is 6,055 mm long, of1,692 mm maximum diameter and weighs 75 Tons. The admission guide blades of the first stage are variable to attain a regular top-gas pressure. In addition, they ensure identical efficiency over a broad operating range. Coupled to the turbine is a 14 MWh self-excited asynchronous generator of 1,500 rpm output speed. When switching to the power network, the self-excitation mode precludes any voltage drop. By connecting capacitors to the generator terminals, cover for the no-load reactive power is guaranteed. Gas pressure within the network is 0.2 Bar. All operational sequences are predetermined, executed and monitored by a control and regulating system. Turbine start-up and shut-down is automatic with no appreciable effect on top gas pressure. Licences can be obtained from Zimmermann and Jansen. Achievements: To perform the test programme, 60 measuring points were logged. An electronic digital measuring point logging system was also put into operation in parallel with the conventional analogue one. Most of these measuring points were equipped with a buffer amplifier to prevent signal interference. The turbine output depends primarily on pressure drop, inlet temperature and mass flux i.e. on factors influenced by the operational mode of up and down stream facilities. In order to take account of these variables, the following influencing parameters were examined: - increasing inlet pressure; - reducing outlet pressure; - increasing gas inlet temperature; - reducing scrubber water temperature; - gas flow rate; - top gas composition. A total of three main trials and preliminary tests were conducted ...

Teilvorhaben 1: Konzeptentwicklung und Planung einer Pilotanlage für das Recycling von Tantal

Das Projekt "Teilvorhaben 1: Konzeptentwicklung und Planung einer Pilotanlage für das Recycling von Tantal" wird vom Umweltbundesamt gefördert und von Fraunhofer-Institut für Silicatforschung (ISC), Projektgruppe für Wertstoffkreisläufe und Ressourcenstrategie (IWKS) durchgeführt. Das Übergangsmetall Tantal ist ein Element mit zahlreichen Anwendungsmöglichkeiten in der modernen Technik. Sein sehr hoher Schmelzpunkt von ca. 3000 °C und seine Korrosionsbeständigkeit machen es zu einem begehrten Werkstoff in der chemischen Industrie und der Medizintechnik. Das Hauptanwendungsgebiet liegt jedoch im Bereich Elektronik. Als namensgebender Bestandteil in Tantal-Kondensatoren ermöglicht das Übergangsmetall durch seine besonderen elektrischen Eigenschaften die Konstruktion von Bauteilen, die bei geringem Volumen eine sehr hohe elektrische Kapazität besitzen. Der Einsatz von Tantal-Kondensatoren erlaubt deshalb die Miniaturisierung von Elektrogeräten. Allerdings erfolgt die Förderung von Tantal zu erheblichen Teilen aus der politisch instabilen 'Große-Seen-Region' in Afrika und der Tantal-Abbau wird hier teilweise zur Finanzierung von kriegerischen Auseinandersetzungen genutzt. Deshalb wird dieses Tantal von der US-Börsenaufsichtsbehörde SEC als konfliktfördernd eingestuft. Um unbedenkliches Tantal verwenden zu können, muss entsprechend zertifiziertes - wie z.B. durch die OECD und die Conflict-Free Sourcing Initiative - erworben werden. Außerdem liegt die Recyclingquote von Tantal aus Altgeräten bei unter einem Prozent, da es auf dem herkömmlichen Kupferrecyclingweg verloren geht. Das Projekt IRETA, 'Entwicklung und Bewertung innovativer Recyclingwege zur Rückgewinnung von Tantal aus Elektronikabfällen', das mit rund 700.000 Euro im Rahmen der 'KMU-Innovationsoffensive Ressourcen- und Energieeffizienz' des BMBF gefördert wird, erforscht deshalb Recyclingwege, bei denen vollkommen neue Prozesswege im Zusammenhang mit Tantal zur Anwendung kommen. Dadurch soll eine Sekundärproduktion aufgebaut werden, die den Importbedarf von Tantal entsprechend senken wird. Dies bringt ökonomische Vorteile für die Industrie und trägt entscheidend zur Versorgungssicherheit Deutschlands bei. Der geplante Recyclingweg startet damit, dass die Tantal-Kondensatoren über eine optische Erkennungssoftware auf den Platinen von Elektroaltgeräten identifiziert und anschließend vollautomatisch demontiert werden. Anschließend folgt eine mechanische Aufbereitung der Kondensatoren zu einem Pulver. Mit drei verschiedenen innovativen Recyclingwegen, die auf chemischem Transport, funktionalisierten Nanopartikeln und elektrochemischer Abscheidung basieren, wird das Tantal aus diesem Pulver in Reinform wiedergewonnen. Eine vergleichende Bewertung der Recyclingwege unter ökonomischen und ökologischen Aspekten soll Aufschluss darüber geben, welcher dieser drei Prozesse für den Aufbau einer Pilotanlage infrage kommt.

Kompression von Abdampf mithilfe eines gasmotorgetriebenen Schraubenverdichters in einer Brauerei

Das Projekt "Kompression von Abdampf mithilfe eines gasmotorgetriebenen Schraubenverdichters in einer Brauerei" wird vom Umweltbundesamt gefördert und von MAN Technologie GmbH durchgeführt. Objective: To demonstrate that vapor compression by means of a gas engine driven screw compressor shows high reliability and considerably reduces the energy consumption of the brewing process. General Information: By means of an internal combustion engine driven vapor compression plant the energy consumption in a brewery can be considerably reduced. The energy saving is achieved by increasing the temperature of the waste vapor during compression and subsequent release of the heat back to the wort and by using the waste of the combustion engine in the brewery. The demonstrated vapor compression plant is installed in a brewery with an annual output of 1200000 hl of beer. The waste vapor (5.4 t/y, 1 bar, 100 deg. C) coming from the wort copper (normally exhausted to the air) is pumped by the screw compressor driven by a gas engine (187 kW) up to 1.3 bar and 110 deg. C. The hot vapor is condensated in the vapor thermostar by heating the wort (3.3 MW). The hot condensate leaving the vapor condenser is cooled down by an additional heat exchanger (462 kW). This heat is used together with the usable waste heat from the gas engine (450 kW) for hot water production needed in the brewery. With a primary energy input (natural gas) of 550 kW and the usable heat output of 4,212 kW a primary energy ratio of 7.65 is yielded. Achievements: The plant runs successfully and is distinguished by high reliability with minimum costs for operation and maintenance. Numerous measurements have shown that in the field less fouling of the vapor condenser occurs than had been assumed. The condenser is only cleaned once a week, without any appreciable increase in the condensate pressure being noted towards the end of the week. The screw compressor, which is subject to only slight fouling, has so far not needed any cleaning. The integration of the vapor compression system in the brewing process has had no influence on the process as a whole. Energy measurements of the system have yielded the high primary energy ratio (usable heat/gas energy input) of 6.95 (with respect to the gross calorific value of natural gas) and 7.65 (with respect to the net calorific value). The annual saving in energy is about 1 million cubic meters of natural gas. This means an energy saving of 89 per cent. Unfortunately the efficiency of the screw compressor is less than expected and therefore the brake horse power higher than calculated. Presumably the water injection, which keeps the vapor output temperature down, has a greater influence in reducing efficiency than had previously been assumed. The electromagnetic clutch is the chief cause of vibrations. With the help of suitable balancing experiments, however, vibration can be reduced to an acceptable level. Economic feasibility calculations show that vapor compression plants have good market prospects in breweries with more than 1,400 brews per year (at present gas prices). In designing a brewery, this number can be achieved by a proper layout of ...

LiBr absorption chiller for builings air conditioning with efficient flexible operation

Das Projekt "LiBr absorption chiller for builings air conditioning with efficient flexible operation" wird vom Umweltbundesamt gefördert und von Bayerisches Zentrum für Angewandte Energieforschung e.V. durchgeführt. General Information:/Project Objectives and Scientifical Targets: Development of a European alternative for large gas fired or exhaust gas co-generated LiBr absorption chiller heater to be integrated into buildings with following competitive advantages: Thermal efficiency Through modifications introduced into the standard thermal cycle: - 25 per cent improvement of the COP with subsequent primary energy saving - high efficiency operation from 10 per cent to 100 per cent load Water consumption Through separation of the absorber and condenser cooling circuits, development of a hybrid cooling tower: - 50 per cent reduction of water consumption Benign impact on the environment - 25 per cent reduction of C02 emission at full load operation related to primary energy saving, - down to 50 per cent reduction of C02 emission at partial load, - no water vapor wreath. Integrability - adaptable to cogeneration applications, - adaptable to various chilled water circuits conditions, - minimised overall dimensions, - improved integrability of cooling water tower, - conformity to European standards for buildings. 2/PARTNERS AND MAIN TASKS Organisation Type Role Country 1) ENTROPIE Ind1 C FR 2) ZAE Ror2 P DE 3) CATHERINE Ind1 P FR 4) BG/PLC Ind7 P GB 5) GN Ind6 P ES Company activity RTD function in project 1) Engineering Study, system design, tests 2) Research laboratory Study, model, tests 3) Manufacturer Detailed design, manufacturing 4) Gas distributor North Basic design LiBr regenerator 5) Gas distributor South Basic design hybrid tower 3/ SCHEDULE AND BUDGET Schedule: 30 months Total budget: 2025 kECUs, 187.5 man-months and 83 kECUs equipment 4/ EXPECTED ECONOMICAL IMPACTS AFTER 5 YEARS Partners: 26.6 kECUs, Others: 12.65 MECUs + 7.5 MECUs gas sales. Prime Contractor: Entropie SA; Saint-Germain-en-Laye; France.

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