Line design: aluminum and non-ferrous metal
Setting the splitter on an eddy current separator
The splitter is the adjustable edge that divides the metal an eddy current separator throws from everything that drops. Start it where your maker's manual says, move it in small steps, and check both output streams against your buyer's spec after each move.
- Aluminum and non-ferrous
- Ferrous
- Fiber
- Glass
- Film
- Other and residue
1What the splitter does
An eddy current separator throws conductive metal forward off the head of its belt. Non-metal such as glass, plastic and paper gets no push and drops off the end of the belt, closest to the head. Sources: IFE, Eddy current separators brochure, 2026 (the push); IMI, service manual and Settimo, Bevilacqua and Rem, 2004 (the drop). How the rotor does it: eddy current separation.
The splitter is the adjustable edge between the two paths. What lands beyond it is the product. What falls short of it is the residue.
- 1Belt. Carries one layer of mixed material toward the head.
- 2Shell. Non-metallic, so the field passes through. Turns with the belt.
- 3Rotor. Magnets of alternating polarity.
- 4Rotor drive. Spins the rotor much faster than the shell.
- 5Eddy currents in a conductive piece push it away from the head.
- 6Metal path. Thrown forward, over the splitter, into the product.
- 7Non-metal path. Drops off the end of the belt into the residue.
- 8Splitter. The setting this page is about: how far its edge sits from the rotor.
- 9Steel is attracted, not thrown. Magnets ahead of the separator keep it out (section 6).
Where the edge sits sets the trade between recovery and purity. Move it toward the rotor and more weakly thrown metal reaches the product, with more non-metal beside it. Move it away and the reverse happens. Both terms are defined in the aluminum recovery guide.
The splitter is one of three settings that interact. Industrial Magnetics (IMI) says belt speed, rotor speed and the splitter are separate settings that must be tuned together, and that rotor speed, once set, usually needs no change. Source: IMI, service manual. The two speeds: designing the line, section 4.
What moves the right setting
IMI lists what changes where the splitter should sit:
- the mix of metal and non-metal in the feed
- the mass on the belt
- the spread of metal sizes
- grease, oil and dirt on the pieces
- how much pieces stick to each other
- the type and grade of the metal
Source: IMI, service manual.
Size comes first. IMI says particle size is very important in setting the splitter and belt speed, and that the two must be set together for consistent recovery. Source: IMI, service manual. Bunge's monograph on bottom ash adds that coarse and fine pieces separate at different splitter settings, and that the right one is found by test. Source: Bunge, 2019.
So if the feed spans a wide size range, one splitter position has to serve all of it. Narrowing the range: screening ahead of separation.
2Where to start
Start from your own separator's manual, not from another machine's figure. Eriez publishes starting distances. IMI publishes a method.
| Machine | Starting distance | Method |
|---|---|---|
| Eriez RevX-E (eccentric rotor), on municipal waste or mixed recyclables | 20 in, with the rotor near full forward. Typical for beverage cans: 20 to 24 in. | Or run the material with the rotor off, and set the splitter 1 to 2 in in front of its path. |
| Eriez REA cartridge machines, same streams | 12 in. Typical gaps for cans depend on the rotor's magnets (section 3). | Measured the same way as the RevX-E figure. The same rotor-off method is in this manual too. |
| IMI | No distance given. | Run with no metal, and adjust belt speed until the non-metal lands 1 to 2 in below the upper edge of the first vane. Then set the vane so the metal clears it. |
Eriez measures each distance horizontally from the rotor surface, at the height of the rotor's centre, and suggests that a factory representative set the splitter at start-up. Sources: Eriez, RM-99 RevX-E manual, 2015; Eriez, SM-780-1 REA manual, 2010; IMI, service manual.
Eriez's rotor-off method and IMI's method both start from where the non-metal falls. With the rotor off, or with no metal on the belt, nothing is thrown, so the path you see is the path the residue takes. The splitter then goes just beyond it.
IMI's method needs a belt speed you can change. On IMI's separator a variable-frequency drive sets it: 384 ft/min at 60 Hz, on a drive that runs from 0 to 72 Hz. Source: IMI, service manual. Eriez's REA manual says belt speed is fixed or variable, depending on the options bought. Source: Eriez, SM-780-1 REA manual, 2010. If yours is fixed, ask the maker how it sets the splitter on that machine.
Start-up settings on the affiliate's own separators: [start-up splitter setting for cans on the affiliate's separators, and whether the splitter can be moved with the guards closed: pending the shop's answer]
3Magnet type and the gap
The magnets in the rotor change how far the same can is thrown. Eriez's REA manual gives typical splitter gaps for aluminum cans by magnet type.
| Rotor magnets | Typical gap for cans | Note |
|---|---|---|
| Ferrite | About 12 in | Eriez lists its ferrite rotors for light-duty MRF work. |
| REM (Eriez's label for a third magnet type; not spelled out in its manual) | 15 to 18 in | |
| Rare earth (RE) | 20 to 24 in | The same range Eriez gives for cans on its RevX-E. |
Sources: Eriez, SM-780-1 REA manual, 2010; Eriez, RM-99 RevX-E manual, 2015.
On these figures, a rare earth rotor puts the splitter for cans 8 to 12 in farther out than a ferrite rotor does. So a gap figure from one machine says little about a machine with different magnets.
Where the field sits
On an eccentric rotor the magnets sit off-centre, and on several machines their position can be adjusted. Eriez's RevX-E indexes its rotor forward or back. STEINERT says its fines machine can vary where the field acts. IMI sets a "magnetic hot spot", usually at the highest point of the shell or toward the discharge. Sources: Eriez, RM-99 RevX-E manual, 2015; STEINERT, EddyC FINES, undated; IMI, service manual.
Eriez gives its 20 in figure with the rotor near full forward, so treat it as the starting point for that rotor position only. What each maker claims for each rotor layout: concentric and eccentric rotors.
4Adjusting from the starting point
Small moves matter. In plant and lab tests on 1 to 6 mm incinerator bottom ash, a 10 mm shift in splitter distance can change metal recovery by about 10% and grade by about 18%. Those were ash fines, not cans, but they show how sensitive the setting can be. Source: Rahman and Bakker, 2013.
Recovery and product mass move together. In a 2004 study, moving the splitter changed both the metal recovered and the total mass reaching the product. That trial ran on a wet-feed separator, not a conventional dry machine. Source: Settimo, Bevilacqua and Rem, 2004.
A routine built from the makers' steps and the study above
- Set the starting point by your maker's method (section 2). Eriez suggests a factory representative do this at start-up. Source: Eriez, RM-99 RevX-E manual, 2015.
- Run normal feed and sample both streams (section 6).
- If belt speed needs changing, change it before you move the splitter, as IMI does. IMI says a faster belt throws all material farther, metal or not, and does not necessarily separate better. After any change to belt speed, check the splitter again. Source: IMI, service manual.
- Move the splitter in small steps, and sample both streams after each one. Source: Rahman and Bakker, 2013.
- Note the setting with the feed it was set on. IMI's list in section 1 shows the right position moves when the feed changes. Source: IMI, service manual.
When recovery drops
Eriez's troubleshooting list for poor recovery includes checks of the splitter setting, belt speed, rotor speed and belt thickness, among others. Source: Eriez, RM-99 RevX-E manual, 2015.
Wet feed costs recovery too. Very wet feed lowered recovery in the same ash tests. Source: Rahman and Bakker, 2013. Moisture and sticky feed: designing the line, section 7. Small pieces: recovering fine non-ferrous metal.
5Splitter options
Makers sell splitters that do more than make one cut. The table lists what each maker's own material describes.
| Option | What the maker lists | Listed by |
|---|---|---|
| Double vane | Makes two non-ferrous cuts from one separator. | IMI |
| Three-product splitter | Adds a third cut, for stainless steel. | IFE, as an option on its VIOS model and its static-bar ENOS |
| Automatic control | A laser grid watches the discharge zone, and the control adjusts belt speed itself. STEINERT gives the reason as the varying moisture, grain shape and conductivity of bottom ash. | STEINERT, SplitControl |
| Splitter type | A knife edge, a tube or a motorised splitter. | Magnapower |
| Adjustment | The splitter moves on a rack and pinion. | Eriez |
| Plate material | Non-conductive board for light streams; manganese steel for abrasive ones. | Goudsmit, EddyFines |
| Anti-caking splitter | Cuts caking and build-up on the blade with wet fines such as bottom ash. | STEINERT, EddyC FINES |
Ask each maker which of these it offers on the model it quotes; the RFQ checklist carries the splitter questions. Sources: IMI, service manual; IFE, brochure, 2026; STEINERT, SplitControl, undated; Magnapower, Eddy current separators, undated; Eriez, Eddy current separators, undated; Goudsmit, EddyFines, undated; STEINERT, EddyC FINES, undated.
Who publishes this. Recyclers Guide is published by [LLC name], an affiliate of Remcon Equipment, Inc. Remcon designs and builds conveyors and eddy current separator systems around rotors or complete separators made by others, builds overhead magnet units, magnetic head pulleys and trommels, resells screens and feeders, and integrates equipment discussed on this site.
Two metal products from one separator
A second cut works because metals fly different distances. IMI says aluminum is thrown farther than copper, zinc, brass and lead, and aluminum sheet farther than cast aluminum. Source: IMI, service manual. IFE lists copper-lead granules among the jobs its separators do. Source: IFE, brochure, 2026. Why each metal flies as it does: eddy current separation, section 5.
The split gets harder as pieces get smaller. Bunge reports that below about 2 mm air drag dominates: a 2 mm copper piece flies about as far as a 2 mm aluminum piece, and at 1 mm copper can fly farther. Source: Bunge, 2019.
A cut by throw distance is not a high-purity split by metal. ReMA's Twitch grade, with limits of 1% each on free zinc, free magnesium and iron, comes from wet or dry media separation, which sorts by density. Its stainless-rich grade, Zurik, comes from sensor sorting. Source: ReMA, ISRI Specifications, July 2026. Splitting metals by what they are made of: sensor-based sorting for metals, and eddy current against sensor sorting.
On the affiliate's machines
On the separator shown on the site of Remcon Equipment, the publisher's affiliate, the splitter sits in a hood that contains the thrown aluminum, and the drawing shows extra holes for moving it. That is one builder's arrangement: how the publisher's affiliate builds one. Source: Remcon Equipment, Eddy Current Separators for Aluminum Recycling, undated.
6Checking both streams against the buyer's spec
The splitter is set for a buyer, so start with the buyer's written spec. ReMA's grade for baled cans, Taldon, sets no aluminum percentage; it lists what must not be in the bale. Source: ReMA, ISRI Specifications, July 2026. Two can-sheet mills' specs say each load is inspected on arrival and can be downgraded or rejected. Sources: Novelis, UBC spec, Rev 7; Tri-Arrows and Logan, UBC spec, 2020. Each grade and each mill's list: aluminum scrap grades and what buyers accept.
Then check both sides of the splitter. Metal in the residue is recovery lost. Anything in the product that the buyer does not accept costs purity, and can cost a downgrade or a rejected load.
| Stream | What to look for | What it points to |
|---|---|---|
| Residue | Aluminum and other non-ferrous pieces | Lost recovery. Moving the splitter toward the rotor recovers more, and lets more non-metal into the product. If the lost pieces are small or wet, look at size and moisture first (sections 1 and 4). |
| Product | Paper, plastic, glass, rocks and dirt | Lower purity. All are on the can mills' lists of contaminants. Moving the splitter away from the rotor lets less of them in. |
| Product | Foil, pie pans, food cans and other non-beverage cans | The separator's product is not cans only: other non-ferrous metal comes with it. One mill takes clean, dry, label-free aluminum food cans, pet-food cans included, up to 10% of a bale by volume; the other treats them as grounds for downgrade or rejection. Some MRFs staff a quality-control station to clean the product. |
| Product | Cans with plastic sleeves, caps or tops | Both mills' lists count plastic built into the can, such as label sleeves and plastic caps. The plastic rides on the can, so it follows the can over the splitter. |
| Product | Steel | The magnets ahead of the separator, not the splitter (below). |
| Product | Water | Above 4% moisture, both mills may reject the load or deduct weight, and both advise against storing or processing cans outdoors. |
Sources: Novelis, UBC spec, Rev 7, sections 2.2, 2.3 and 2.5; Tri-Arrows and Logan, UBC spec, 2020, sections 8 and 9; GBB for CMI, 2020 (the product and quality-control stations); Settimo, Bevilacqua and Rem, 2004 (recovery and mass move together).
Steel in the product
Taldon, Taldack, Talcred and Taldork call for magnetically separated material, and Zorba must have passed one or more magnets. Source: ReMA, ISRI Specifications, July 2026. So steel in the product points to the magnets ahead of the separator.
This guide follows the separator makers' manuals: magnets go ahead of the separator, and the separator is not relied on to remove steel.
What a product sample can show
Oregon's 2011 study took ten samples of the aluminum product leaving five Oregon sorting facilities. By weight it was 79.5% beverage cans, 14.6% foil and pet-food cans, 2.2% steel cans, about 1.5% paper, about 1.4% plastics including film and 0.3% glass. Source: Oregon DEQ, 2011, Table 6. It is a small sample from one state in 2011, and Oregon has a container deposit.
What a residue sample can show
A residue sample taken at the separator shows what the splitter loses. It does not show cans lost before the separator. GBB reports that most separator vendors guarantee to capture at least 95% of the cans on the container line, and that a separator can only recover the cans that reach it. Source: GBB for CMI, 2020. Where else cans go: aluminum recovery on MRF container lines.
Bale weight alone overstates can recovery. The separator also captures roughly a quarter of the other aluminum in the stream, so comparing incoming cans with outgoing bales counts that metal as cans. Source: GBB for CMI, 2020.
How much to sample, and how often: [sample size and frequency for each stream: no published test method found; a buyer's own sampling rule or a standard method would fill it]
Purity targets in practice: [the product purity MRF operators aim for, and how they check it: pending the affiliate shop's answer]
7Questions
How far from the rotor is the splitter set for cans?
It depends on the machine and its magnets. On Eriez machines, typical gaps for aluminum cans run from about 12 in on ferrite rotors to 20 to 24 in on rare earth rotors, measured horizontally from the rotor surface at the height of the rotor's centre. Industrial Magnetics (IMI) publishes a method instead of a distance, so start from your own machine's manual. Sources: Eriez, REA manual SM-780-1, 2010; Eriez, RevX-E manual RM-99, 2015; Industrial Magnetics, manual 900505, undated.
Should I change belt speed or the splitter first?
IMI sets belt speed first. It runs the separator with no metal, adjusts belt speed until the non-metal lands 1 to 2 in below the upper edge of the first vane, then sets the vane so the metal clears it. A faster belt throws everything farther, so check the splitter again after any change to belt speed. On a machine with a fixed belt speed, ask the maker how it sets the splitter. Sources: Industrial Magnetics, manual 900505, undated; Eriez, REA manual SM-780-1, 2010.
How much does a small splitter move change recovery and purity?
Enough to matter. In plant and lab tests on 1 to 6 mm incinerator bottom ash, a 10 mm shift in splitter distance can change metal recovery by about 10% and grade by about 18%. Move the splitter in small steps, and check both output streams after each move. Source: Rahman and Bakker, 2013.
Can one eddy current separator make two non-ferrous products?
To a degree. IMI offers a double-vane splitter that gives two non-ferrous cuts, and IFE offers a three-product splitter with a cut for stainless steel on two of its models. The split relies on metals flying different distances, and below about 2 mm air drag upsets that order. A cut by throw distance is not a high-purity split by metal. Sources: Industrial Magnetics, manual 900505, undated; IFE, Eddy current separators brochure, 2026; Bunge, 2019.
Can the splitter be set automatically?
Some makers offer automatic control. STEINERT's SplitControl watches the discharge with a laser grid and adjusts belt speed itself, because moisture, grain shape and conductivity vary in bottom ash. Magnapower lists a motorised splitter among its options, without saying what controls it. Ask each maker what its control measures and what it adjusts. Sources: STEINERT, SplitControl, undated; Magnapower, Eddy current separators, undated.
8Sources
Every source below was read on 2026-10-06. Manufacturers' figures are their own claims about their own machines; nothing here was tested by the publisher.
- IFE Aufbereitungstechnik, Eddy current separators brochure, 03/2026 (manufacturer). https://www.ife-bulk.com/fileadmin/user_upload/ife-bulk/Produkte/Wirbelstromscheider/IFE-eddy-current-separators_web.pdf. Read 2026-10-06.
- Industrial Magnetics, Inc. (IMI), Eddy Current Separator Service Manual, endless belt, manual 900505, undated (manufacturer). https://assets.magnetics.com/assets/files/manuals/900505_ECS_Service_Manual_Endless_Belt.pdf. Read 2026-10-06. Industrial Magnetics supplies eddy current separators and magnets to Remcon Equipment, the publisher's affiliate.
- Bunge R., Recovery of metals from waste incinerator bottom ash, UMTEC, OST Eastern Switzerland University of Applied Sciences, June 2019 (technical monograph). https://www.ost.ch/fileadmin/dateiliste/3_forschung_dienstleistung/institute/umtec/fachartikel/2019/19-03_recovery_of_metals_from_waste_incinerator_bottom_ash.pdf. Read 2026-10-06.
- Eriez, RM-99 RevX-E Eddy Current Separator installation, operation and maintenance manual, April 2015 (manufacturer). https://www.eriez.com/Documents/Literature/IOMs/Metals-Recycling/RM-99-Eriez-RevXE-Eddy-Current-Separator-IOM.pdf. Read 2026-10-06.
- Eriez, SM-780-1 Eddy Current Separator REA Cartridge Design installation, operation and maintenance manual, 2010 (manufacturer). https://www.eriez.com/Documents/Literature/IOMs/Metals-Recycling/SM-780-1-Eriez-Eddy-Current-Separator-REA-Cartridge-Design-IOM.pdf. Read 2026-10-06.
- STEINERT, EddyC FINES, product page, undated (manufacturer). https://steinertglobal.com/us/sorting-systems/magnetic-separation/eddy-current-separators/steinert-eddyc-fines/. Read 2026-10-06.
- Rahman M.A., Bakker M.C., Sensor-based control in eddy current separation of incinerator bottom ash, Waste Management 33(6):1418-1424, 2013 (peer-reviewed; abstract read). https://pubmed.ncbi.nlm.nih.gov/23490354/. Read 2026-10-06.
- Settimo F., Bevilacqua P., Rem P., Eddy current separation of fine non-ferrous particles from bulk streams, Physical Separation in Science and Engineering 13(1):15-23, 2004 (peer-reviewed). https://repository.tudelft.nl/record/uuid:a219d415-14cf-47ee-84de-719786333cdb. Read 2026-10-06.
- STEINERT, SplitControl, product page, undated (manufacturer). https://steinertglobal.com/us/sorting-systems/magnetic-separation/eddy-current-separators/steinert-splitcontrol/. Read 2026-10-06.
- Magnapower, Eddy current separators, product page, undated (manufacturer). https://magnapower.com/separators/eddy-current-separators/. Read 2026-10-06.
- Goudsmit Magnetics, EddyFines eddy current separators, product page, undated (manufacturer). https://www.goudsmitmagnetics.com/en-us/products/belt-conveyor-magnetic-separators/eddyfines-eddy-current-separators. Read 2026-10-06.
- Recycled Materials Association (ReMA), ReMA's ISRI Specifications, July 2026 (Taldon, Taldack, Talcred and Taldork, p. 8; Twitch and Zorba, p. 11; Zurik, pp. 15 and 17) (industry association standard). https://www.isrispecs.org/wp-content/uploads/2026/09/2026-July-ReMA_ISRI_Specifications.pdf. Read 2026-10-06.
- Remcon Equipment, Inc. (the publisher's affiliate), Eddy Current Separators for Aluminum Recycling, undated, with its general-arrangement drawing (affiliate's own site). https://www.remconequipment.com/eddy-current-aluminum-separators. Read 2026-10-06.
- Novelis, NNA Recycling: UBC Product Quality Specification, REF-04146, Rev 7, file dated July 2021, posted May 2026 (can-sheet producer and can buyer). https://novelis.com/wp-content/uploads/2026/05/NNA-UBC-Spec_v7_REF-04146.pdf. Read 2026-10-06.
- Tri-Arrows Aluminum and Logan Aluminum, Used Beverage Cans (UBC) Specification, April 28, 2020 (can-sheet producer and can buyer). https://www.loganrawmaterials.com/wp-content/uploads/2020/04/UBC-Printable-PDF.pdf. Read 2026-10-06.
- Gershman, Brickner & Bratton (GBB) for the Can Manufacturers Institute, Aluminum Beverage Can: Driver of the U.S. Recycling System, 2020-06-23 (commissioned report). https://www.cancentral.com/wp-content/uploads/2023/03/GBB-Report-Aluminum-Can-Drives-U.S.-Recycling-System-Final-2020-0623.pdf. Read 2026-10-06.
- Oregon Department of Environmental Quality, Composition of Commingled Recyclables Before and After Processing, report 11-LQ-014, March 2011 (government). https://www.oregon.gov/deq/FilterDocs/CommingledRecyclablesBAProcessing.pdf. Read 2026-10-06.
- Eriez, Eddy current separators, product page, undated (manufacturer). https://www.eriez.com/Products/Metals-Recycling/Nonferrous-Recovery/Eddy-Current-Separators. Read 2026-10-06.
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