Final Report on Scrap Management, Sorting and Classification of Magnesium. S. Bell, B. Davis, A. Javaid and E. Essadiqi. Report No.

Transcription

1 Final Report on Scrap Management, Sorting and Classification of Magnesium S. Bell, B. Davis, A. Javaid and E. Essadiqi Report No (CF) June 2002 Enhanced Recycling, Action Plan 2000 on Climate Change, Minerals and Metals Program The Government of Canada Action Plan 2000 on Climate Change Minerals and Metals Program, managed by the Minerals and Metals Sector of Natural Resources Canada, is working towards reducing Canada s greenhouse gas (GHG) emissions from the minerals and metals sector. By matching funds with other partners, this program supports initiatives that enhance recycling practices and provide GHG emission reductions.

2 DISCLAIMER Natural Resources Canada makes no representations or warranties respecting the contents of this report, either expressed or implied, arising by law or otherwise, including but not limited to implied warranties or conditions of merchantability or fitness for a particular purpose.

3 i CONTENTS Page INTRODUCTION 1 AUTOMOTIVE APPLICATIONS 1 SOURCES OF MAGNESIUM SCRAP 3 DIE-CASTING SCRAP 3 POST-CONSUMER SCRAP 4 COLLECTION AND DISMANTLING THE END OF LIFE VEHICLE 5 Shredders 6 EXISTING MAGNESIUM SORTING TECHNOLOGIES 8 JAPAN 8 EUROPE 9 NORTH AMERICA 11 NEW MAGNESIUM SORTING TECHNOLOGIES 12 EUROPE 12 NORTH AMERICA 14 APPENDIX 1 - MAGNESIUM SCRAP CLASSIFICATION SYSTEM 15 REFERENCES 16

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5 1 FINAL REPORT ON SCRAP MANAGEMENT, SORTING AND CLASSIFICATION OF MAGNESIUM by Stacy Bell *, Boyd Davis *, Amjad Javaid ** and Elhachmi Essadiqi ** INTRODUCTION The increasing need for low-density structural materials for both air and land travel has spurred the development of lightweight materials technology. The use of magnesium, the lightest structural metal, has increased tremendously since its origin in the nineteenth century. The first commercial production of magnesium was recorded in Germany in 1916 by electrolysis of fused magnesium chloride (1), however, a lack of markets caused the world production of magnesium to be a meager 300 tonnes (2). It was not until the Second World War that the magnesium industry developed significantly. At that time, magnesium was used in many military aircraft parts such as wheels, fuselages and control panels, as well as other military applications including incendiary bombs and tent support poles. By the end of 1943, magnesium production had increased to 237,000 tonnes worldwide (2). Two years later, magnesium consumption had dropped dramatically to 50,000 tonnes (2). It took another 30 years for the annual production of magnesium to recover to the 1945 level, and in the year 2000, 366,900 tonnes of magnesium was consumed. With the increasingly wide-spread use of magnesium in society, there is a growing need for an efficient and integrated magnesium scrap handling and recycling system. AUTOMOTIVE APPLICATIONS Volkswagen stimulated the growth of the magnesium industry from the 1940s to 1970s, by incorporating more then 20 kg of magnesium into each of the 30 million Beetles produced worldwide (3). Magnesium parts included die-cast fuel pumps, wheels, dashboards, and engine and transmission castings. During this time Volkswagen represented the single largest user of magnesium in the world, consuming close to metric tons per year (4). However, from 1973 to 1986, the price of magnesium quadrupled, causing the demand for magnesium to decrease sharply. Magnesium applications decreased significantly, and production was flat until the late 1980s. During the last two decades, consumer emphasis on comfort and safety caused the average car to become quite heavy, thereby increasing fuel consumption dramatically. High-fuel-consumption cars increased the production of greenhouse gases and other pollutants that contribute to the deterioration of the environment. Increasing government pressure on automotive manufacturers * Davis Laboratories, Kingston, Ontario ** Materials Technology Laboratory CANMET, Ottawa, Ontario

6 2 to produce a more environmentally friendly vehicle led to the development of the first 3-litre sub-compact cars. In order for this to be possible, the weight of the vehicle needed to be reduced. To minimize the weight of the automobile, single automotive castings such as engines, seat components, rims, rear flaps, reflectors, steel wheels and gearboxes have been manufactured with much lighter materials. Since magnesium is 33% lighter than aluminum, 100% recyclable, and has the highest strength-to-weight ratio of any of the commonly used metals, it has been chosen as a substitute for many of the components in Table 1 (5). The demand for these components has increased the production of magnesium die castings over the last decade at an annual rate of 15% as shown in Fig. 1 (6). Nearly 70% of all magnesium die-casting alloys are for automotive applications (3). The recent development of high purity, corrosion-resistant alloys allows magnesium castings to compete with other automotive metals in general surface corrosion testing. Thus, this growth is expected to continue for the next decade (6). Cast alloys Table 1. Magnesium alloy designations, compositions, and applications. Composition (%) Company Application AZ 91 Al 8.0 to 9.5 Zn 0.3 to 1.0 Mn 0.1 to 0.3 Mg Residual AM50 Al 4.5 to 5.3 Mn 0.28 to 0.5 Zn 0.20 Mg Residual AM60 Al 5.5 to 6.5 Mn 0.1 to 0.4 Mg Residual Alfa Romeo Audi, VW Ford Daimler Benz Volvo McLaren Motors Daimler Benz Fiat Porsche AG Honda Motor Oil pan, coupling casing, engine cover, rim (4.5 kg) Gear casing (12 kg), steering wheel frame Injection casing (8 kg), steering wheel frame Instrument panel carrier, oil pan Gear casing, steering wheel frame, engine block (50 kg) Camshaft housing, valve cover, wheels etc. Seat frame (8.5 kg) Instrument panel (3.4 kg), steering wheel frame Wheels (53 kg), rim (9.8 kg), top system (2.5 kg) Rim (7.4 kg)

7 Tonnes (000) Aluminum Alloying Die Casting Desulphurization Other Applications Fig. 1. World use of magnesium. Another issue facing the automotive industry is recycling. Close to 52 million cars are manufactured each year and, considering their relatively short service time (between nine and thirteen years), their disposal has a significant impact on the environment (7). As it did with the development of the 3-litre sub-compact car, government pressure has led to dramatic changes in this aspect of the automotive industry. For example, the British government recently signed an agreement with the Society of Motor Manufactures and Traders, the Motor Vehicle Dismantlers and the British Metals Federation, among others, to increase automobile recycling to 85% of the average vehicle weight by 2005 (8). In order to achieve this goal, separation of automobile component materials must be improved to minimize contamination of the metal streams during recycling. Clean, well-sorted scrap is crucial to cost-efficient recycling. Due to more strict environmental legislation, the European recycling industry, especially in Germany, has been in the forefront of sorting and recycling technologies. DIE-CASTING SCRAP SOURCES OF MAGNESIUM SCRAP The amount of waste from the die-casting process has been estimated to be as much as 50% (9). The International Magnesium Association reported in 1999 that 41% of the magnesium lost in a typical die-casting operation is Type 1 scrap, 5% as dross, 5% returns, and 36% gates, runners

8 4 and trim scrap [see Appendix 1] (9). A typical flow sheet for a die-casting operation is shown in Fig. 2 (10). Natural Resources Canada estimated in 1999 that 36% of all primary magnesium produced in the world was used in the die-casting industry (11). This represents approximately 135,180 tonnes of magnesium (11). Using the figures stated in the previous paragraph, it can be determined that 55,482 tonnes of Type 1 magnesium scrap, 6,759 tonnes of magnesium dross, 6,759 tonnes of magnesium returns, and 48,664 tonnes of magnesium gates, runners, and trim scrap was produced worldwide in 1999 alone. Most die-casting operations found it necessary to implement their own in-house recycling operation because of the high volume of Type 1 magnesium scrap produced. Fig. 2. Typical flow sheet for die-casting process. POST-CONSUMER SCRAP Post-consumer scrap includes material from the automotive, electronics, telecommunications, audio and computer industries. Due to the recent increase in the use of magnesium in the vast automotive market, the amount of post-consumer magnesium scrap is growing rapidly. For this reason, only post-consumer scrap produced by the automotive industry will be discussed further in this report. Until recently, recycling of magnesium from scrapped, or end-of-life, cars has not been well developed. In 1992, magnesium from automotive shredder scrap was not recycled in Japan, and no quantitative statistics were available in Germany on the subject (12). Inefficiency and high costs have been cited as the two major reasons for this lack of magnesium recycling from shredder scrap. This is because most magnesium recycling has been done by handpicking, and the use of magnesium coatings for corrosion protection limits metal recovery. In order for magnesium recycling from automotive scrap to be economical, it is vital for magnesium to be sorted correctly. This report reviews established magnesium sorting

9 5 technologies for automotive shredder scrap and explores new technologies. Knowledge of sorting technologies can benefit the magnesium-finishing industry, as well as magnesium recyclers and die casters (7). There are also issues that arise prior to sorting that should be discussed. Some of these issues are: dismantling, shredding, and separation of magnetic fraction. COLLECTION AND DISMANTLING THE END OF LIFE VEHICLE End-of-life vehicles enter the recycling path when they are brought to a scrap collection and dismantling yard. The main source of income for dismantlers is from the sale of certain vehicle parts that have been removed from end-of-life vehicles and reconditioned. Which components are removed depends on their condition and potential marketability. Dismantlers across North America are networked through a state-of-the-art computer parts database that can locate any existing part within the network. If removal of a part is not economically viable, it is usually left on the hulk (i.e. scrapped body). The parts that are usually removed include the entire front and rear ends, engines and transmissions (less than hundred thousand kilometers), alternators, doors, body panels, glass and other components shown in Fig. 3 (13). It is also mandatory for dismantlers to remove items such as batteries, fuel, fluids, refrigerants, etc., for safety reasons. Fig. 3. Material flow in dismantling of automobiles.

10 6 In the dismantling yard, parts totaling approximately 50% of the original weight of the vehicle are removed. A weight description of each dismantled part is shown in Fig. 4 (13). The remaining hulk is then transferred to the press for volume reduction. Flattening is required in order to get the maximum number of hulks onto a flat bed trailer for transportation to the regional shredder. Once the hulk is pressed there is no chance of further dismantling. Scrapped Automobile 980 kg Dismantling Plant Dismantled Parts and Materials 500 kg Engine 180 kg Cell-Dynamo 4 kg Tires 75 kg Axles, etc. 150 kg Radiator 3.5 kg Wire-harness 1.5 kg Batteries 8 kg Parts, oil, fluids, etc. 78 kg Scrapped Body (Hulk) 480 kg Fig. 4. A break-down of scrapped vehicle components by weight. Shredders The flattened hulks are then sold to a shredder plant. A typical shredder would operate anywhere between HP hammer mills so that an entire hulk is reduced to pieces four inches or less in size, in 45 seconds (14). The principle of the shredder is shown in Fig. 5 (15). Input rollers flatten the hulk and help feed it into the rotor housing. There, flexible hammers shred the car into pieces until they are small enough to fit through the top grid of the shredder. The size of the grid openings is usually four inches. This facilitates the release of single materials and makes the material separation more cost effective. Any components that cannot be shredded to pieces smaller than four inches are expelled from the shredder through the heavy particle flap. Dust, fluff, foam, paper, rubber and some wire are pulled out of the shredder through the de-duster by air suction. The remaining material is fed onto a conveyor belt and sent to the sorting stages of the shredder plant.

11 7 Fig. 5. Illustration of a typical shredder. At the shredder facility, the pieces undergo several sorting stages to separate the magnetic from the nonmagnetic metal shredder fraction (NMSF). This is accomplished using magnetic separation. The most common piece of equipment used for this separation step is a magnetic drum separator (Fig. 6) (14). As shown in Fig. 6, a stationary drum, half the surface of which is lined with NdFeB magnets, is housed in a rotating cylinder that is set up as a conveyor belt (14). Here, almost all of the iron and steel pieces are separated, and they are then sold back to the steel-making operation. This portion represents 72% of the input material (15). Fig. 6. Magnetic separator. The NMSF is then introduced to several air-separation steps. One such step is a suction nozzle above the conveyor belt that is used to remove the light non-metals, such as plastics, rubbers, foams and fibers, from the heavier metallic fraction. Other techniques include the use of an elutriator or air knife. In an elutriator, the pieces are dropped through an upward flow of air causing very light pieces to be removed. An air knife is similar to an elutriator but does not use an upward flow of air to remove the low-density materials. The materials removed in these steps amount to approximately 22% of the input feed and are known as the shredder residue (15).

12 8 The remaining NMSF is sent to the third and final sorting step at the shredder facility - eddy current separation (ECS). The ECS repels nonmagnetic, electrically conducting metal particles out of the residue. A more detailed explanation of ECS technology will be discussed later in this report. The end product is a wt % metallic NMSF (16). Current analysis of the metallic fraction of the NMSF in North America estimates the composition to be 70% aluminum, 10% zinc, 7% copper, 8% brass, 4% stainless steel, and 1% lead (14). Although there are no data available on the amount of magnesium in the metallic portion of the NMSF in North America, 44 shredders in Germany estimate Mg to be less than 0.5% (12). The resulting NMSF is then typically sold to wet sink-float plants. JAPAN EXISTING MAGNESIUM SORTING TECHNOLOGIES Fig. 7. Flow diagram of scrapped car in Japan. In Japan, the two main participants in recycling end-of-life vehicles are the dismantling and shredding companies. In 1992, there were four large-scale combined dismantling and shredding facilities in service (12). Figure 7 clearly shows the recycling path of automotive magnesium (12). Handpicking is the only method available to separate magnesium from the other metals in the shredder scrap. However, in Japan the amount of magnesium scrap is very minimal, making handpicking a slightly more cost effective and efficient method. Only 2000 tons of magnesium metal is die cast in Japan each year (12).

13 9 EUROPE The current sorting system for mass recycling of magnesium from NMSF in Europe is shown in Fig. 8 (12). If the magnesium parts are not dismantled before they reach the shredder, they are sorted by the shaded path in this illustration. The NMSF is first screened into two different portions. In Europe, the screened fraction that is larger then 13 mm in size is fed directly to the first heavy media stage. The smaller particles are collected and shipped to Southeast Asia for handpicking. The larger fragments are then subjected to flotation separation. The first flotation solution has a density of 2.2 g/cm 3 and consists of a mixture of water and ferrosilicon powder (12). Note that there are differences in the density and media mixture used in sink-float plants throughout Europe. During this stage, most of the non-metallic and magnesium alloys are floated. The floated fraction is then rinsed to remove unnecessary media, and fed to an eddy-current separator (ECS). The densities of some common materials found in NMSF can be seen in Table 2 (17). The ECS method separates magnesium alloys from other non-metallic materials. The main principle behind ECS is the repulsion of nonmagnetic, electrically conductive metallic particles, when they are exposed to an external magnetic field. When this type of particles enters a magnetic field, a counter-acting current is produced inside the particles to protect and repel them away from the magnetic field. The overall effect is the production of a forward thrust (F) and torque (T) on the particles, which causes them to be ejected out of the stream of non-metallic materials (14). Figure 9 illustrates this force and the moment acting on a non-magnetic, metallic particle in the magnetic field of a standard eddy current rotor (14). Fig. 8. European sorting system based on existing technique.

14 10 Table 2. Density values of common automotive materials. Material Density (g/cm 3 ) Foam plastics Wood Natural rubber Polypropylene 0.90 H.D. polyethylene 0.96 Polystyrene Polyvinyl chloride 1.40 Magnesium and alloys Hollow aluminum Aluminum and alloys Zinc and alloys Stainless steels Brass and bronze Copper and alloys Lead and alloys Fig. 9. Non-magnetic metallic particle in the magnetic field of eddy current rotor. The rotor is lined axially with alternating rows of north and south poles of NdFeB magnets thus producing the magnetic field (14). The rotor is inserted into a nonmetallic outer shell that, in turn, acts as a conveyor head pulley bringing in the mixed metal and nonmetal material (14). Varying the speed of the rotor causes the magnetic field to change with time. By using this technology it is possible to successfully separate over 95% of the magnesium contents (12).

15 11 However, ECS is dependent on the shape of the particles since the separation is based on the generation of a magnetic repulsion force within the material. Therefore, some shapes, especially foils and wires, cannot be sorted effectively since they are not eddy current creators. NORTH AMERICA The recycling system in North America is fairly extensive with an estimated 6000 scrap collection and dismantling yards, 200 shredders and 10 sink-float plants (16). The path for recycling magnesium from NMSF is very similar to the European method described above, with only a few minor differences. Flotation and eddy current separation are still the two methods used to sort the magnesium from the other materials. However, North America utilizes a threestep sink-float separation method rather than a two-step method. The three-step sink-float separation technology uses liquid media with densities of 1, 2.5, and 3.5. Water is used as the first medium to float paper, wood, foam and textiles from the NMSF. Magnetite is then added to the water to produce the correct medium density for the second step. In a medium with a density of 2.5, rubber, light plastic, magnesium and hollow aluminum float. The floated fraction is then rinsed off to remove the residual magnetite, and the remaining material is processed through an ECS system. This separates the magnesium and hollow aluminum from the other non-metals. Additional separation of the two metals can be achieved by using colour sorters. This technology was developed by Huron Valley Steel Corporation (HVSC), the world s largest nonferrous scrap sorter. The company is located in Belleville, Michigan, USA, and processes roughly tonnes of non-ferrous metal each year - equivalent to the non-ferrous fraction from at least 5 million scrap cars (18). Colour sorting has been used for the last decade by HVSC to sort zinc, copper, brass and stainless steel. It is one of the first computer-automated sorting processes to be used industrially. In colour sorting, an image of each metallic piece is made, and a computer detects its corresponding colour. The computer then controls a mechanical device that directs the particles of a specific colour out of the feed material. In order for this to occur, a singling mechanism is used to produce a chain-like profile of scrap particles before the image detector. The colour sorters used by HVSC are able to effectively sort magnesium and aluminum from each other, creating almost pure (greater then 99%) alloy mixes for both metals (16). The main reason for such a high degree of accuracy in sorting is because the mechanism used for physically separating the particles is not a function of particle size or shape (14). Figure 10 represents the sorting path for magnesium from the 2.5 SG float fraction (13). Fig. 10. Separation of Al and Mg by eddy currents and colour sorting.

16 12 NEW MAGNESIUM SORTING TECHNOLOGIES The industrial sorting technologies currently used for recycling magnesium from NMSF has a few flaws. First, flotation and eddy current separation equipment is very cost intensive, requiring a large initial investment. Secondly, the media used to produce the correct specific gravity within the flotation tanks can contaminate the scrap and require mandatory additional cleaning steps to produce a final high-quality product. These problems are driving the search for a completely dry, automated process that produces individual metal fractions of the highest quality possible. In order for this to be achieved most effectively, the metals must be sorted not only according to their primary constituent, but also into their specific alloy groups. This will, in turn, make it more efficient to recycle the metal and produce a high-quality product for direct resale back into the market. Over the last decade, two companies, Metallgesellschaft and Huron Valley Steel Corporation (HVSC), have enhanced the sorting technology of NMSF by focusing on the chemical composition of each piece for more complete separation. EUROPE To overcome the problems associated with the existing magnesium-sorting technologies, Metallgesellschaft, in Germany, developed and built a new separation system in the early 1990s. New sorting technologies incorporated in this system include a rubber separation technique that utilizes a difference in coefficients of friction, a wire and rolling component separator, and an automatic sorting section. A conceptual picture of the new sorting system can be seen in Fig. 11 (12). Fig. 11. New sorting system technique.

17 13 In this new system, the NMSF would first be exposed to a screening step to separate fine and coarse scrap from the remainder of the feed. Only particles of mm advance to the preseparation stages. The coarse material, >65 mm, is sent to an on-site shredder for further breakdown (12). The pre-separation stages remove any non-metallic material from the NMSF using the coefficient of friction difference between the two groups. A specific wire separator, as well as a rolling and long component separator, is also installed to ensure the best-feed material for the automatic sorting machine. The automatic sorting machine utilizes a singling mechanism, a detector section, and a sorting section to perform a complete analysis on each particle. Figure 12 shows the procedure required to produce a singling mechanism that organizes the shredded pieces into a single file structure (12). This step controls the spacing of the scrap and thus, the system throughput. It is very important that the presentation of the scrap pieces to the analyzer be precise for correct analysis. Atomic emission spectroscopy is used to identify the metals. Since the scrap is not 100% metallic at this point, the electronic conductivity of each particle is first measured to separate the last non-metallic fraction. Only the pieces that record a conductivity reading will be analyzed. The actual detection process can be seen in Fig. 13 (19). Fig. 12. Singling mechanism for automatic sorting machine. Fig. 13. Detection system.

18 14 A trigger laser first acknowledges the presence of the particle followed by a pulse laser that illuminates ~1 x 2 mm of the surface of the metal, producing an atomic emission. The chemical composition of the material can be obtained by a spectral detector through a spectral filter. Using an optical fiber, a polychromator, a photodiode detector and a computer system, the resulting emission can be adapted to a sorting signal (12). The processing rate of the sorter is roughly 100 pieces per second with a reported 98% accuracy when processing general NMSF (12). The sorting signal then activates a mechanical device that forces each identified piece to be placed in a particular sorting bin. Thus, complete separation of the scrap particles into individual metal fractions (i.e., Mg, Cu, Zn, stainless steel, etc.) and alloy groups (i.e., AM, AE, AZ, etc.) is achieved. At a processing speed of 100 pieces per second, 3-5 tons per day of NMSF can be sorted with an accuracy of 96% (12). However, Metallgesellschaft discontinued this project in the late 1990s and licensed the technology to Sortech (14). The reasons for abandoning this system, according to HVSC, were material handling problems and direct competition from a more efficient sorting system developed by HVSC (14). It is unsure whether Sortech has advanced the sorting technology and produced a more marketable product for industrial sorting applications. NORTH AMERICA In 1993, HVSC began its research on determining the elemental chemical composition of nonferrous metals for sorting applications. The technology is much the same as that developed by Metallgesellschaft. The application of a laser on the surface of a metallic particle produces an atomic emission. Using optical emission spectroscopy methods, the chemical composition of the metal is identified, and the particles are sorted based on this information. The main difference between the two processes developed by HVSC and Metallgesellschaft is the configuration of the system and the use of several HVSC proprietary technologies and techniques for handling and analyzing material at high speed and volume. These technologies and techniques were developed during the decade-long use of colour sorting technology whereby a vast amount of experience and education was gained in the application of automatic systems. The majority of the research has been focused on the composition analysis of solid aluminum shred particles and is currently being tested on a pilot plant scale, but HVSC has tested other types of scrap, including magnesium, and seen no theoretical differences. Therefore, this technology has great potential for sorting AM, AE and AZ magnesium alloys. Other new sorting technologies being researched by HVSC include an ECS machine that separates different types of material rather than just removing non-metallic pieces. Also, an Alcoa practice is being used in conjunction with HVSC s colour sorters to produce a method able to sort different alloys of the same primary metal. In this process, the metallic pieces are etched to tint the surface of the particles. The actual tint colour depends on the composition of the metal and can be isolated using a colour sorter. However, this technology is in pilot-scale development and is strictly based on aluminum alloys.

19 15 APPENDIX 1 - MAGNESIUM SCRAP CLASSIFICATION SYSTEM (7) Magnesium Scrap Classes Class 1A Characterization High grade clean scrap without impurities (e.g., scrap castings, biscuits etc.) Class 1B Class 2 Clean scrap with a high surface area in proportion to the weight Clean scrap with aluminum or steel inserts No copper or brass impurities Class 3 Class 4 Class 5 Clean, dry, and uncontaminated turnings and swarfs Flux-free residues (e.g., dross, sludge) Painted or coated scrap with/without aluminum or steel inlays No copper or brass impurities Class 6 Class 7 Oily and/or wet turnings and swarfs Unclean and contaminated metal scrap (e.g., post consumer scrap) may contain: Silicon (Al alloys, shot blasting) Cu-contaminated alloys Ni coating Non-magnesium sweepings Class 8 Flux-containing residues from Mg Recycling Note: Other classifications do exist. The above classification system was produced by Hydro Magnesium. Magnesium Elektron has a similar classification but is based on a 6-class system.

20 16 REFERENCES 1. C. Wilson, K. Claus, M. Earlam, and J. Hillis, Magnesium and Magnesium Alloys, A Digest of Useful Technical Data from the Kirk-Othmer Encyclopedia of Chemical Technology, The International Magnesium Association, McLean, PA, (1995), p M. Henstock, The Recycling of Non-Ferrous Metals, International Council on Metals and the Environment, Ottawa, ON (1996) p S. Erickson, Magnesium Gaining in Automotive Acceptance, Die Casting Engineer, 35 (1991), H. Wentz and L. Ganim, Recycling: The Catchword of the 90s: Recycling of Magnesium, Light Metal Age, Feb. (1992), C. Scharf and A. Ditze, Present State of Recycling of Magnesium and its Alloys, Proceedings from the International Conference on Magnesium Alloys and Their Applications, Wolfsburgh, Germany, (1998), A. Luo, Magnesium: Current and Potential Automotive Applications, Journal of Metals, 54 [2] (2002), G. Hanko, H. Antrekowitsch, and P. Ebner, Recycling Automotive Magnesium Scrap, Journal of Metals, 54 [2] (2002), N. Shahmanesh, The Waste Line, Automotive Engineer, 23 [4] (1998), R. Brown, Magnesium Recycling Yesterday, Today, and Tomorrow, Proceedings from the Fourth International Symposium on Recycling of Metals and Engineered Materials, Pittsburgh, Pennsylvania (2000), J. King, Environmentally Acceptable Recycling In Europe, Magnesium Elektron Company Report, (1995), pg Natural Resources Canada, Magnesium, Canadian Minerals Yearbook, (1999), H. Sattler and T. Yoshida, Recycling of Magnesium from Consumer Goods after Use, Proceedings from the International Conference on Magnesium Alloys and Their Applications, Garmisch-Parenkirchen, Germany, (1992), M. Suzuki, A. Nakajima, and S. Taya, Recycling Scheme for Scrapped Automobiles in Japan, Proceedings from the Third International Symposium on Recycling of Metals and Engineered Materials, Point Clear, Alabama, (1995), A. Gesing, C. Stewart, R. Wolanski, R. Dalton, L. Berry, Scrap Preparation for Aluminum Alloy Sorting, Proceedings from the Fourth International Symposium on Recycling of Metals and Engineered Materials, Pittsburgh, Pennsylvania, (2000),

21 S. Wolf, Recycling of Aluminum from Obsolete Cars-Economic, Technical and Ecological Aspects, Conference on Treatment and Recycling of Solid Waste Material, Aachen, Germany. 16. A. Gesing and R. Wolanski, Recycling Light Metals from End-of-Life Vehicles, Journal of Metals, 53 [11] (2001), M. Ashby and D. Jones, Engineering Materials 1: An Introduction to Their Properties and Applications, Butterworth-Heinemann, Jordan Hill, Oxford (1996) 2 nd Ed., p W.L. Dalmijn and J.A. Van Houwelingen, New Developments in the Processing of the Non-Ferrous Metal Fraction of Car Scrap, Proceedings from the Third International Symposium on Recycling of Metals and Engineered Materials, Point Clear, Alabama, (1995), H.P. Sattler and T. Yoshida, New Sorting System for Recycling of Magnesium and Its Alloy After Use, Proceedings from the First International Conference on Process Materials for Properties, Honolulu, Hawaii, (1993), p 864.