EFFICIENT USE OF ALUMINUM SCRAP IN BATCHING SECONDARY ALLOYS AND POTENTIAL FOR SENSOR-BASED SORTERS TO IMPROVE RECYCLING SYSTEM EFFICIENCY

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1 EFFICIENT USE OF ALUMINUM SCRAP IN BATCHING SECONDARY ALLOYS AND POTENTIAL FOR SENSOR-BASED SORTERS TO IMPROVE RECYCLING SYSTEM EFFICIENCY Adam G G C Hartmut Harbeck TiTech GmbH

2 Contents Current light metal recycling system Markets for secondary alloys Recycling system needs and sustainability issues Scrap separation and sorting technologies Desirable separations that make financial sense

3 Aluminum production and recycling RSI Prime smelter Casting scrap Oxides Salts Dross processor Dross Remelt and ingot cast house Shredder residues EoL & mixed metal scrap Foils Chips Turnings Contaminated scrap Shredder Sorter Scrap dealer Al shred Handsorted Al scrap Mixed manuf scrap Assembly scrap EoL scrap Semifabricator Component manufacturer Assembler Use Fab scrap Manuf scrap Shape caster Reject components Landfill Waste

4 Post-consumer light-metal recycling Primary steel shredders process ELVs commingled with other metal-containing scrap Light-metal scrap can be effectively separated from the shredder residue as nonmagnetic metal concentrate (NMMC) Mg is not separated from light metals at the shredder Only a portion of the NMMC is treated by dense-media plants producing Al and Al + Mg alloy mixes Remaining Mg scrap stays commingled with Al shred and is chlorinated out of Al foundry alloys Al + Mg mix is handsorted in Asia and Mg desulphurizes Chinese steel New particle-sorting technologies and processes under development have the ability to complete metal scrap separation by parent metal and by alloy

5 Post-consumer light-metal scrap sources Scrap source Scrap type LM in EoL products LM commingled in shredded scrap LM scrap products Curbside recycling and recycling depots Municipal waste dirty MRFs and RDF plants C&D MRFs WEEE recycling depots Scrap yards and ELV de-pollution dismantlers Steel shredders Dense media sink-float plants Alloy sorting/batching plants UBC Packaging foil Consumer durables appliances Building scrap, siding, windows, doors Scrap machinery, process vessels & piping Electronic scrap Al and Mg housings Flattened ELV hulks Handsorted & baled, categorized LM scrap NMMC (nonmagnetic metal concentrate) LM concentrate Al and Mg-Al mixes from shredder LM concentrate Al or Mg alloys batched from alloy mix Post-consumer scrap diverted from landfill and recycled reduces demand for the prime metal by secondary alloys and frees up prime for use in high-performance prime alloys

6 Light metals in the car recycling system Car in use ELV Car repair remanufactured parts Remanufacturing scrap scrapped parts used consumer scrap used industrial scrap Scrap yard direct to remelt categorized scrap Remanufacture steel scrap demolition scrap appliance scrap mixed metal scrap nonmetal residue nonmagnetic metal concentrate reusable components Steel shredder Mg / Al(Mg) in nonmetal residue Sink-float media plant dense metals wire Mg+Al mix Deregistration Depollution Dismantling Flattening Flattening flattened ELV hulk Al+(Mg). Al(Mg) + Al(SiCuZn) Al casting scrap fluids refrigerants catalysts toxics steel shred Si Zn Cu Al refiner Al 38X & 319 foundry ingot Al shape Al casting shape casting Al castings Al new & old scrap Al prime ingot Cl 2 MgCl 2 in dross

7 Primary shredding plant ELVs white goods mixed metal dealer scrap CDW MSW oversize 5,000-15,000 HP hammer mill drum magnet Oversize 5, 30 mm screens steel Cyclone & baghouse light SR Z-box elutriator <5 mm fines (nonmetal) >5<30 mm >30<100 mm Overbelt magnet Eddy current rotor circuit Nonmetal lead, wire stainless steel Light SR steel Al + Mg concentrate metal NMMC nonmagnetic metal concentrate Eddy current coil particle sorter circuit Stainless steel Nonmetal Nonmetal fines Steel

8 Nonmagnetic shredder fraction NA supply ~1,000 kt of NF metal/year, growing quickly 20-95% metal 60-70% Al in metal (~600 kt/year) 30-50% wrought in Al (~200 kt/year)

9 Sink-float dense-media plant NMMC = Nonmagnetic metal concentrate Process water treatment HP hammer mill Oversize NMMC from SDF 100 mm 3 mm screens Overbelt magnet NMMC from SLF dense Dewatered sludge float 2.0 g/cc magnetite slurry >9 mm 1.0 g/cc wash 9 mm screen steel fines 3 mm screen Overbelt magnet Al +Mg mix Eddy current rotor circuit Nonmetal Fe attach. headpulley magnet 3.5 g/cc ferrosilicon slurry Dense metal mix float Eddy current rotor and shape sort circuit Jig dense <9 mm metal Insul. mix Wire Nonmetal Al +Mg Al alloy rock grain mix light Eddy current rotor circuit Nonmetal grain steel Nonmetal fines & dust Cyclone separator & baghouse light foam paper foil textile

10 Al mix from HMF

11 Market Main markets for secondary Al and the most popular alloys for these markets Secondary alloy Compatible scrap sources Al packaging Building Al Automotive Al Steel deoxidants 3X04 can body sheet 3105 painted sheet 38X.x casting alloys 319.x casting 95% Al Old cans, can manufacturing scrap Non-can wrought manufacturing scrap Al- and Mg-based scrap mix from 2 g/cc float fraction of a dense-media sink-float plant Old Al siding Al siding and extrusion construction scrap Mixed wrought manufacturing Al scrap with low copper content Old wrought scrap Some 38X alloys can accept a mixture of the most common old scrap varieties without dilution, providing the Mg concentration is controlled by chlorination Tighter concentration limits on 319 increase the dilution requirement and limit the types of old scrap that can be added to a 319 alloy batch This specification can be met by many mixtures of old wrought alloy scrap

12 Secondary die castings AA38X - Al Si9% Cu4% Zn3% Fe Low Mg Mg chlorinated out

13 Alternative uses for primary Al ingot & recycled Al Al in Mg AZ91 particlebatched old shred Al in Mg alloysegregated ingot and shape casting scrap Al in Mg alloysegregated ingot casting fabrication & manufacturing scrap Al in Mg alloysegregated billet casting fabrication & manufacturing scrap Primary Al ingot Al alloysegregated billet casting fabrication & manufacturing scrap Al 5/6XXX particle batched old shred Al alloysegregated ingot casting fabrication & manufacturing scrap Al 3/5/6XXX particle batched old shred Al 3XX particle batched old shred Al 3XX alloysegregated casting & manufacturing scrap Al machining chips & turnings UBC Mg +Al particle mix old shred from light media float Al 3X04 particle batched old shred Al dross and skim Fe contaminated scrap Al machining chips & turnings Mg shape casting remelt Mg sheet mill remelt Mg extrusion mill remelt Al extrusion mill remelt Al sheet mill remelt Al shape casting remelt Al UBC remelt All good uses for Al-containing scrap; All free up prime Al for prime alloy applications Al secondary smelter Mg Al Fe deoxidant

14 For least-cost, sustainable recycling you need: a complete recycling system markets for all scrap-derived products recyclable, relatively pure, PRIME alloys Few, high volume SECONDARY alloys with high recycled content low-cost technology and system for managing alloying elements in scrap and using these elements to alloy new metal unrestricted flow of metal scrap between markets

15 Scrap flows between markets Use of automotive scrap in automotive alloys Old wrought Al scrap in auto shred is batched into foundry alloys Use of scrap from other sources in automotive alloys Auto shred Al, the most common scrap stream used in automotive foundry alloys, is a mixture of scrap from ELVs, C&D and appliances Mixed clips scrap category, a mixture of new scrap from any sheet product or market, is often used in diluting automotive foundry alloys Old sheet, a mixture of old scrap from any sheet product or market, is used in batching automotive 38X foundry alloys Use of automotive scrap in other alloys 3105 building sheet batched from Al auto shred

16 Aluminum recycling system non issues The current market for Al secondary alloys exceeds the total supply of post-consumer Al scrap. Al scrap shortfall is supplied by prime and new scrap. There is no current recycling system need to: develop new Al secondary alloys, or new markets for these alloys, or divert post-consumer scrap to alloys currently batched from prime and new segregated scrap

17 Key Issues Increasing light-metal content of new automobiles Increasing proportion of Mg Interference by Mg in Al recycling system Key required actions Separate Mg from Al scrap

18 Strategy for efficient light-metal scrap recycling Maximize scrap collection and eliminate metal scrap losses to landfills Maximize the efficiency of metal liberation and segregation Minimize process losses in recycling Work with and improve upon the existing global material recycling system and scrap markets Promote cross-market trade in light-metal scrap Start with recycling to existing secondary markets and alloys Develop new secondary alloys and markets for scrap that does not have an existing destination in the current system Develop low-cost technology to manage alloying elements in scrap and use this scrap to alloy new metal

19 Belt type particle sorter Unsorted particle feed 2 Scanning and processing 3 Diversion

20 Finder Eddy current coil sensor sorter Find metal in residue and/or Mixed feed ECC sensor Sorted Products separate stainless steel Conveyor Air jet ejection

21 CombiSense Color and ECC sensor sorter Separate Cu, brass, Zn, stainless steel, nonmetal or Mixed feed Illumination Color sensor Sorted Products Al, Mg and nonmetal Conveyor ECC sensor Air jet ejection

22 X-Tract dual energy x-ray transmission sensor sorter Identify contaminants attachments, Mixed feed X-ray illumination Sorted Products products Separate light metals from dense metals Conveyor DE sensor Air jet ejection

23 DE-XRT identification of Al and Mg

24 LIBS elemental concentration sensor sorters Mixed feed LASER OE illumination spectrometer XYZ scanner Camera Sorted Products products Conveyor Air jet ejection Alloy sort or batch based on analysis of all major alloying elements, light and dense

25 Alloy sorting and Alloy batching Sorters with three diversion blowbars are already successfully operating in commercial applications. Such sorters can separate the feed into four output streams typically: two sorted products a recycle-to-feed stream still-mixed residue Mix of two or a maximum of three alloys can be sorted in a single pass through the sorter.

26 Alloy sorting and Alloy batching When more alloys are present in the sorter feed stream, one has the option of: re-running the mixed output stream through the sorter to recover two more sorted alloys or to batch new alloys, i.e. combine the feed alloys in a right proportion to make two new output alloys A sorter batches these alloys on line, particle by particle. The result of batching is a small number of useful product alloys that have a ready market. Old post-consumer scrap contains a large variety of alloys and their particular variants. Sorting of old scrap by alloy really is not a practical option. It is batching that enables upgrading of complex mixtures of both old and new scrap.

27 Competition: Sorting table vs Sorting circuit

28 Sorting circuit 0 Product grade (%) 100 Sorter Circuit Optimum optimum performance Performance curve Curve Feed mix Prepare feed PS product Clean product mix PS Clean residue mix 0 Component recovery (%) 100

29 Sorting circuit In order to provide sorted products with an acceptable combination of recovery and product purity, sorters are arranged in a circuit with auxiliary unit operations. A typical dry sorting circuit for light-metal scrap might include following unit operations: Particle sizing size reduction and size separation Clean and dry removing cutting fluids and forming lubricants from new scrap Sort out non-al contaminants from Al-alloy mix Sort mix by alloy or batch target alloy(s) from the mix

30 Shredder residue dry sorting plant NMMC = Nonmagnetic metal concentrate NMMC from SDF NMMC from SLF 3 mm screen Overbelt magnet contaminated HP hammer mill Oversize >3<9 mm Oversize 30 mm 9 mm fines screens >9<30 mm >30<100 mm dense Cyclone separator & baghouse light <3 mm fines Overbelt magnet steel DE x-ray sensor particle sorter circuit >9<100 mm metal mix Headpulley magnet Eddy current rotor circuit nonmetal magnetic Alalloy mix Mgalloy mix Dense Wire metal mix Eddy current coil particle sorter circuit >3<9 mm metal mix Stainless steel Nonmetal Steel foam paper foil textile Nonmetal fines & dust Contents

31 LM alloy batching/sorting plant Mg Mg + Al Contaminated DE x-ray sensor particle sorter circuit HP hammer mill Oversize >3<9 mm Oversize 30 mm 9 mm fines screens >9<30 mm <3 mm fines >30<100 mm Al-alloy mix Mg-alloy mix Clean LIBS sensor elemental composition particle sorter circuit >9<100 mm Mg / Mg+Al / Al Overbelt magnet Headpulley magnet Eddy current rotor circuit steel attached steel stainless steel Dense Metals Al alloy 1 Al alloy 2 Alalloy mix Mg Mg Mgalloy >3<9 mm alloy 1 alloy 2 Al mix mix >3<9 mm Mg mix Nonmetal steel Al fines Mg fines

32 Desirable separations in LM recycling system that make financial sense Recovery of recyclables from landfilled post-consumer waste Residual metal removal from shredder residue Al dross processing Separation of bare and painted scrap Separation of nonmetal contaminants and attachments Contaminant removal from nominally source-segregated manufacturing alloy scrap Sorting of mixed-alloy manufacturing scrap Separation of free Mg from Al scrap Separation of Al alloys with high Mg content from those with high Si, Cu or Zn in Al scrap Batching of value-added secondary alloys from post-consumer Al scrap twitch, old sheet and cast

33 Recovery of recyclables from landfilled post-consumer waste Landfilled in USA in ,000 kt of Al cans + 1,500 kt of other Al in 140,000 kt MSW and 100,000 kt of CDW In municipal recycling facilities (MRFs), thousands of sensor-based sorters already pick out the residual metals missed by magnets and EC rotors sort out plastics and sort paper and cardboard by grade from curbside collected recyclables. These sensor-based sorters could also deal with recyclables from landfilled waste.

34 Residual metal removal from shredder residue Primary shredder feed consists of steel containing ~25% nonmetallic and 5-10% nonmagnetic metals. Even a small concentration of nonmagnetic metal in the nonmetallic residue can represent significant loss of recovery of the nonmagnetic metals. Eddy current coil (ECC) sensor sorters inspect and recover the residual metal from nonmetallic residue. The dual energy x-ray transmission (DE-XRT) sensor could separate light from dense metals, replacing the function of the dense-media sink-float plants. Dual sensor ECC and DE-XRT sensors have the resolution and capability to inspect shredder fines residue that still contains small copper wires and small Al particles.

35 Al dross processing USGS data for 2006 reports over 600 kt of metal recovered from dross and skimmings. The US residue consists of more than 1,500 kt of nonmetallics containing up to 30 kt of metal. Prior to being remelted in rotary furnaces, Al metal is typically concentrated by crushing dross and eddy current rotor separation (ECS). This mechanical separation is sometimes repeated for the rotary furnace dross or saltcake. Dual sensor ECC and DE-XRT sorters have the resolution and capability to inspect crushed oxides and saltcake for residual metal.

36 Separation of bare and painted scrap Al from old post-consumer scrap is a mixture of bare and painted items. Decoating of bare scrap is a waste of effort and energy, while melting of painted scrap results in excessive melt losses. US Al smelters in 2006 consumed 215 kt of non-ubc wrought old scrap and 155 kt of cast old scrap. Much of this scrap could benefit from bare/painted separation and decoating of the painted fraction. A particle sorter equipped with a color camera sensor could separation after the material is shredded and sized. Reduction in melt losses is more than adequate to offset the additional processing costs.

37 Separation of nonmetal contaminants and attachments Wire and PCBs are difficult segregate from Al by bulk sorting. They represent losses of valuable resources and contaminate the melt. Metal attachments dissolve to contaminate the product melt. Residual paper, plastic and rubber particles and attachments in Al scrap burn during remelting, leading to oxidation and melt losses. Inorganics react with metal, contaminating it, and end up as dross. The 190 kt of Al recovered from shredder metal concentrate and consumed in US in 2006 could have been melted with lower melt losses and contamination if the residual contaminants were sorted out of the furnace feed. Another 1,000 kt of other Al old scrap consumed in US in 2006 would need to be shredded to permit removal of contaminants and attachments. A particle sorter equipped with a DE-XRT sensor is up to this task.

38 Contaminant removal from nominally source-segregated manufacturing alloy scrap A remelt facility equipped with a DE-XRT sensor particle sorter could: remove contaminants from purchased manufacturing scrap identify particles that differ in thickness, shape, or have significantly different average atomic numbers This may enable remelt operator to buy back sourcesegregated manufacturing scrap from its customers or from scrap dealers.

39 Separation of Mg-based scrap from Al scrap products Without Al-Mg separation, 200 kt of Mg diecastings that have entered the automotive market in 2008 will in the future contaminate over 5,000 kt of Al automotive Al scrap and will lead to losses of the 200 kt of Mg and similar amounts of Al in refining by chlorination. In the near future, Al-Mg separation will become imperative to maintain the efficiency and sustainability of the light-metal lifecycle. Options for Al-Mg segregation are either density separation in a dense-media plant or sensor-based sorting. Only a few media plants are left in North America and no new ones are being built. This leaves sensor-based particle sorting, where a combination of color and DE-XRT sensors can do the sort.

40 Sorting of mixed-alloy manufacturing scrap New mixed-alloy clips is among the largest traded Al scrap categories. A remelt facility equipped with a LIBS sensor particle sorter could sort mixtures of manufacturing clips of known composition. This would expand a remelt operator s freedom to buy back a lower cost mixed-alloy scrap and use it in batching wrought alloy or alloys in its range of products.

41 Separation of Al alloys with high Mg content from those with high Si, Cu or Zn in Al scrap The current level of refining by chlorination and the associated losses can be substantially reduced by sorting out Al-alloy particles rich in Mg and batching them into secondary wrought alloys. 3X04 can body sheet and 3105 building sheet are suitable candidate alloys. The second output stream will be high in Si, Cu and Zn and low in Mg, giving it an added value when batching foundry alloys. Such batching can be performed by a LIBS sensor. The first industrial plant based on this technology was commissioned in 2004 by Huron Valley Steel Corp. in Belleville, MI, and has been successfully operating since then on a feed of Al recovered from shredder metal concentrate.

42 Batching of value-added secondary alloys from postconsumer Al scrap twitch, old sheet and cast A secondary smelter equipped with a LIBS sensor particle sorting circuit has the freedom to buy post-consumer Al scrap from scrap dealers, which includes shredder product plus old sheet, extrusion and cast categories. Through elemental particle analysis, a LIBS sensor could batch value added two alloys at a time from this lower cost scrap. The key to such batching process economics is the price margin between the LME 380 alloy ingot and the price that the smelter can obtain for the value-added products and recovery of the feed in these products.

43 Scrap sorting plant (current technology) Dense metal mix (dense media sink) Dense metal mix (dry sort) Al + Mg (light media float) >9<100 mm metal mix DE X-ray sensor particle sorter circuit Dense metal mix Color sensor particle sorter circuit Red Whit XRF sensor e elemental composition particle sorter circuit HP hammer mill Oversi ze >3<9mm Scale and radiation detector Oversize 30 mm 9 mm fines screens >9<30 mm Overbelt magnet Headpulley magnet Eddy current rotor circuit >3<9 mm metal mix >30<100 mm <3 fines steel attached steel stainless steel Nonmetal lead wire stainless steel Eddy current coil particle sorter circuit DE X-ray sensor particle sorter circuit attached steel reshred Al Mg Cu red brass yellow brass Zn stainless steel lead wire nonmetal steel

44 Conclusions Transportation costs to Asia and wages in Asia are rising Unfair incentives are being phased out Sensor based sorters can now batch on line. Task that is not possibly by handsorting. Sensor-based sorters are now well proven industrially in large volume recycling, food inspection and mining applications. There is profit to be made by smartly selecting light metal scrap upgrading and secondary alloy batching applications. Time is right to apply sensor-based sorters to increase the efficiency of the light metal recycling system.

45 The competition

46 Thank you Manufacturing Construction Assembly Consumer Semi-product fabrication Collection & de-pollution Material production Mechanical segregation Feedstock production Energy recovery