Boosting profits: productivity gains and metals recovery remain the focus of auto shredder improvements.

Auto shredders are well established as important processing systems for the recycling of automobiles, large appliances and other obsolete metallic scrap.

Although the basic technology has now been around for several decades, recyclers and their equipment suppliers continue to examine new approaches to maximizing the amount of metal (and the extent of profits) that can be recovered from the shredder stream.

PULLING METALS FROM FLUFF. Three new pieces of equipment from SGM Magnetics, Sarasota, Fla., are helping an Ohio shredder operator recover more metal.

Youngstown Iron and Metal Inc., Youngstown, Ohio, purchased a 60-inch SGM SIS eddy current separator in 2001 to compliment its existing downstream system.

"This unit has significantly increased recovered metal units on our shredder," says Youngstown Iron and Metal's Marry Wilhelm, who was impressed enough to make additional SGM purchases. "This summer we took delivery of a 40-inch SGM VIS fines separator to recover half-inch-minus nonferrous metals from shredder fluff," he remarks.

"In June, we placed an order for a new SGM EMS (electro magnetic sensor) for recovery of stainless steel and other metals from shredder fluff," says Wilhelm. The unit uses magnetic sensors coupled with embedded technology to identify and effectively remove marketable metal that does not react to eddy currents.

"We expect a quick pay-off from this unit," says Wilhelm, who notes that high value stainless steel that had formerly been landfilled as part of the residue stream will now he recovered.

Wendt Corp., Tonawanda, N.Y., is distributing a new line of equipment geared toward recovering stainless steel and other, metals that some recyclers are allowing to head to the landfill.

According to Wendt Corp., several types of metals that other eddy current machines and pickers might miss can be mined from mixed streams, including stainless steel, copper windings and insulated and bare copper wire.

"This new technology will recover lost revenue from your waste streams and promises to be a significant advancement to the shredding industry, like the introduction of eddy current separators in the 1990s," says Tom Wendt of Wendt Corp.

"The process is the next logical step for nonferrous downstream systems and picks up where eddy current separators leave off," he continues. Rather than using magnetic strength, this technology utilizes a high frequency magnetic sensor to detect metals with a high-speed computer that fires an array of compressed air nozzles to eject metals from the waste stream.

The technology has been created by Separation Systems Engineering GmbH (SSE), located in Wedel, Germany.

Innovative Recycling Systems, Solon, Ohio, has also introduced what it calls a magnetic innovation for ferrous separation. According to the company's Paul Popovich, the system still uses three rotating drum magnets with axial pole design, but includes only one feed pan. "We are using gravity to help separate the ferrous product, instead of fighting gravity," says Popovich.

Popovich notes that in this configuration, as mixed material falls from the pan, the magnet pulls the ferrous product sideways instead of lifting it vertically. "It is much easier for a magnet to move material sideways and even slightly magnetic, or heavy dense pieces, call be deflected sideways to the magnet," he remarks.

Also, because the gap between the magnet and pan edge is greater, and the material is flee falling, there is no rolling of material during surges, he claims. "This same process is used from magnet to magnet," Popovich comments. "After all three magnets, the ferrous product is very clean and passes onto a picking conveyor for hand picking copper or any entrapped waste. All of the waste and nonferrous metals is collected in a single hopper and is taken away by a conveyor for further eddy current separation."

Texas Shredder Inc. (TSI), San Antonio, Texas, in cooperation with Resource Recycling LLC, St. Petersburg, Fla., has sold a third-generation Steinert Induction Sorting System (ISS) unit to scrap recycler Davis Industries of Lorton, Va.

The ISS is designed to recover the nonferrous materials and stainless steel from a mixed stream passing through an eddy current system. This is accomplished with specially designed sensors that recognize the metals and activate air jets that "pop" the metals from the mixed stream.

The ISS will eliminate the need for manual picking and increase the nonferrous metals recovered, according to a TSI news release.

PRE-SHRED STEPS. Scrap metal recyclers are creating a renewed market for baler/loggers as a way to prepare collected scrap for shipment to auto shredder plants.

"Logs are now more acceptable to operators of the large shredders," John Sacco of Sierra International Machinery, Bakersfield, Calif., told attendees of the Steel Scrap 101 event, held in St. Louis earlier this year.

Sacco said that baler/loggers that can process from 25 to 250 tons per day of ferrous scrap are being used in areas that are somewhat distant from the nearest shredder yard as a means of preparing obsolete scrap for shipment to a shredder. "It can increase the trailer weight," he said, as opposed to shipping loose scrap.

He also remarked that are several reasons why some recyclers would rather create logs that are shipped to shredder plants rather than preparing a grade for direct shipment to a steel mill.

Logging can compress from 30 percent to 50 percent more material in a time period than haling (though not as densely), so recyclers are able to ship more material. From a cash flow viewpoint, recyclers will probably be paid more quickly by a shredder operator, and there is less chance of a load being rejected by a shredder operator compared to a rain, Sacco commented.

Preparing material for further processing at shredder plant also provides a home for material that may previously been packaged as number two heavy melt--a grade that many recyclers find is facing a dwindling demand scenario.

The Steel Scrap 101 Seminar was co-hosted by the Institute of Scrap Recycling Industries Inc. (ISRI) mid the Steel Manufacturers Association (SMA), both Washington-based trade associations.

A SPIDER SPOTTING

Metso Minerals Metal Recycling's North American operations, based in Cedar Rapids, Iowa, recently installed one of its "spider-style" rotors at a shredder plant.

Advanced Recycling of Concord, N.H., purchased the rotor, which incorporates Metso Minerals' four-pin spider design featuring fully capped protection of the spiders and end discs. The rotor will be installed in Advanced Recycling's Metso Minerals 6080 Scrap Shredder.

Company engineers say the benefits of the fully capped design include increased rotor longevity and that no welding is required throughout the lifetime of the rotor.

Bill Tigner, North American vice president and general manager, remarks, "This rotor assembly delivers 500,000 to 1 million tons or more of rotor life to many Metso Minerals Metal Recycling customers--much more than competitive designs available on today's market."

The manufacturer claims it is the most aggressive, most easily fed rotor design available on the market today. Spider rotors can process through unshreddables that can leave some other rotors with broken grates, stretched bearing studs or other types of damage.

Besides complete replacement rotors, Metso Minerals also offers a line of shredder parts including hammers, spider caps, grates and liners.