Program Organizer: Ms. Pragna N.H. Bhakta, U.S. Bureau of Mines, 810 7th St., MS 6204, Washington, D.C. 20241
Monday, AM Room: A6
February 5, 1996 Location: Anaheim Convention Center
Session Chairperson: Pragna Bhakta, U.S. Bureau of Mines, 810 7th St., MS 6204, Washington, D.C. 20241
SOLID ELECTROLYTE BASED SENSOR FOR MONITORING THE MAGNESIUM LEVEL DURING RECLAMATION OF ALUMINUM SCRAP: Jeffrey W. Fergus, Shiqiang Hui, Materials Research and Education Center, 201 Ross Hall, Auburn University, AL 36849
Aluminum alloy scrap often contains excess magnesium which must be removed during recycling by a process referred to as "demagging". The efficiency of this process could be improved with an in-situ magnesium sensor, which could be used to optimize the process parameters to the changing magnesium content. The sensor developed in this work consists of galvanic cell with a magnesium fluoride (MgF2) solid electrolyte and a molten magnesium reference electrode. The voltage output of the sensor changes by about 100 mV for the change in magnesium contents which occur during the demagging process (5 wt% to 0.1 wt%) and is in excellent agreement with thermodynamic measurements using molten chloride electrolytes. Although the best response is provided using a molten magnesium reference electrode, a solid reference electrode could be used to produce a completely solid-state sensor.
RECOVERY AND SEPARATION OF HIGH VALUE PLASTICS FROM DISCARDED HOUSEHOLD APPLIANCES: D. E. Karvelas, B.J. Jody, B. Arman, J. Pomykala and E.J. Daniels, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439
This paper presents the results of research, being conducted at Argonne National Laboratory, to develop a cost-effective and environmentally acceptable process for the separation of high value plastics from discarded household appliances. The process under development has separated high-purity (greater than 99.5%) acrylonitrile-butadiene-styrene from commingled plastics generated by appliance-shredding and metal-recovery operations. The process consists of size-reduction steps for the commingled plastics, followed by a series of gravity-separation techniques to separate materials of different densities. Individual plastics of similar densities are further separated by using a chemical solution. By controlling the surface tension of the chemical solution, we are able to selectively float plastic materials that have different surface energies. This separation technique has proven to be highly effective in producing high-purity plastic materials from household appliances. A conceptual design of a continuous process for separating high-value plastics from discarded household appliances will be presented. In addition to plastics separation research, Argonne National Laboratory has also been conducting research to develop cost-effective techniques for improving the mechanical properties of the recovered plastics. Results from this research will also be presented.
EUREKA PACK-EE - PACKAGING AND ENVIRONMENT IN EUROPE-AUTOMATED SORTING OF ALUMINUM FROM DOMESTIC WASTE: Y. Bertaud, R. Guilermet, H. Lemaire-Pechiney CRV, BP 27, 38340 Vorepe (France) G. Nijhof-Hoogovens Groep-P.O. Box 10000, 1970 CA IJmuiden (The Netherlands) H. Rossel-VAW Aluminum AG, Postfach 2468, 53014 Bonn (Germany).
Argonne National Laboratory has been developing a process to recycle automobile shredder residue (ASR). We built and tested a field demonstration plant for recycling polyurethane foam, and produced several thousand pounds of recyclable foam. Several 300 pound samples were sent for evaluation, and were found to be of marketable quality. We are also in the process of preparing for a large scale test in which about 200 tons of fines (<0.25 inch) derived from ASR, will be used as a raw material in cement making. Small samples of fines prepared in the laboratory were evaluated by a major cement company and were found to meet their requirements, as a substitute for iron ore or mill scale. This paper presents a brief discussion of the process as a whole, and summarizes the results obtained from the field work on foam and fines recycling.
EUREKA-Project: PACK-EE: G. Nijhof, Y. Bertaud, R. Guillermet, Hoogovens Groep, P.O. Box 10000, 1970 CA 1Jmuiden, The Netherlands
A large research project with this title has been started in June 1993. The project carries out research and innovation into collection, soding and valorisation of types of packaging, with improvements to sorting procedures capabie of meeting the needs of the recovery and recycling industries. The project includes studies of consumer behaviour concerning wastes, which will influence the choice of sorting techniques. Materials involved are: aluminium, glass, paper, and plastic. In the Alumlnium Group the participants are: Hoogovens Groep, Pechiney and VAW. The following subjects of research will be discussed; 1) improvements of the collection of waste packagings, 2) improvements of the Eddy Current equipment 3) separation optimization and efficiency, 4) economic balance.
10:10 am BREAK
EVALUATION OF RECYCLABILITY OF USED AUTOMOTIVE OIL FILTERS AS FERROUS SCRAP: Darrell E. Roberts, Kent D. Peaslee, University of Missouri-Rolla, Department of Metallurgical Engineering, 218 McNutt, Rolla, MO 65401
Over 425 million used automotive oil filters are discarded in the U.S. each year. Only about 10% are currently recycled as ferrous scrap and the remainder are typically landfilled. Oil filter scrap is not being used by many operations because of concerns with scrap consistency and quality. Consistent scrap quality depends both on the content of the used oil filters and the processing technique used to produce the scrap. This paper investigates the content of used oil filters and compares the recyclability of different oil filter designs and manufacturing methods. Included is a model that predicts the scrap yield, chemistry, and energy effects of various oil filter designs in combination with different recycling methods.
INVESTIGATIONS ABOUT THERMAL SEPARATION OF ALUMINUM PACKAGING: H. Rossel, D. Mackenstedt, VAW Aluminum AG, Postfach 2468, 53014 Bonn, (Germany) B. Fillon, Y. Bertaud, Y. Caratini, Pechiney CRV, BP 27, 38340 Voreppe-France, J.C. Templier-CEA Cadarache, 13106 Saint Paul Les Durance Cedex (France)
Aluminium packaging scrap are combined with a lot of other materials, like plastics, paper, varnish, glue, colors and ink. In addition the scrap can be contaminated with residues of the packaged goods (cosmetics, food etc.). Most of the non aluminium components would be removed by incineration during the melting procedure. The local increase in temperature resulting from the combustion process and mixing with carbonaceous residues decreasss the metal yield and produces non aceptable emissions of hydrocarbons. Low temperature pyrolysis, i.e. endothermic cracking of organics in short gaseous chains recovered and/or burnt (energy recovery), is the only solution. The investigation has been divided in design experiments and model calculations and pilot scale experiments. The research is largely focused on controlling the thermal cracking profile to avoid the formation of soot while degrading a maximum number of compounds at low temperatures. Special attention is being paid to all technological requirements, mechanical pretreatment, monitoring, automation of the thermal steps, collection and treatments of the gases given off by the thermal degradation of the organics.
PURIFICATION OF REMELTED ALUMINUM PACKAGING: G. Nijhof, H.M van der Donk, Y. Bertaud, S. Bouvet, Hoogovens Groep, P.O. Box 10000, 1970 CA 1Jmuiden, The Netherlands
Remelting of aluminium requires only 5% of the energy required for primary smelting. Therefore it is important to keep aluminium in the materials cycle as long as possible. Making new packaging from production scrap or waste packaging is thus very important. Remelted scrap may contain an amount of undesired alloying elements, this amount must be reduced. State of the art is to mix in molten scrap with purest material to reach the required composition. Future aim is to use less primary metal, thus technologies for the removal of these undesired elements, particularly iron, are necessary. Investigations are focused of intermetallic compounds, by adding other elements to the melt it is possible to form intermetallic compounds, which can be removed from the melt by: gravity segregation, partial solidification or filtering. Having accurate knowledge of the thermodynamic reactions and the phase diagrams, it is possible to predict the amount of material to be added to achieve a final composition. The results will be discussed.
LEAD REMOVAL FROM BRASS AND BRONZE SCRAP: Frederick J. Dudek, Dwight R. Diercks, Edward J. Daniels, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439
The brass and bronze ingot manufacturing industry melts lead-bearing
copper-base scrap and casts specification alloy ingots for sale and conversion
into a wide range of products, including plumbing fixtures. Under proposed
regulations limiting the lead content of plumbing fixtures, the industry could
not use current technology to recycle a large fraction of the scrap stream. To
provide for the continued and most economic use of lead bearing scrap, a
process is needed that selectively removes lead from copper-base melts and/or
scrap. Several alternatives for selective lead removal from copper based scrap
are liquation, slagging, precipitation of intermetallics, vacuum distillation,
and chemical leaching of selected portions of the scrap stream. This paper
reviews an effort to identify and assess the technical and economic feasibility
of options for selective lead removal from brass and bronze melts and/or scrap.
Results of experimental screening are presented.
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