Large scale: large shredding plants and intense sorting systems are becoming the norm at auto shredding sites.

Automobile shredders began growing in size not long after they were introduced to the scrap metal market. As with most things in business, economies of scale drove many business owners and managers to explore the merits of increased production.

When the scrap market revved up earlier this decade after a prolonged slump, the pent-up demand for new processing equipment included plans by many companies to upgrade their existing shredding plants or, in some cases, for new companies to enter the shredding arena.

The result has been a series of boom years for makers of automobile shredders and the companion conveying, sorting and separating equipment that makes up a complete system. And in many cases, these new shredders and systems are skewing toward the largest, highest-production end of the shredding spectrum.

SUPER-SIZE IT. With the world's steelmakers and foundries hunger for shredded scrap metal increasing, recyclers have had few reservations about making the necessary capital investments to churn out these secondary commodities.

Among those committing large sums to large shredding plants is Schnitzer Steel Industries Inc., Portland, Ore., which has been installing newer, larger shredding plants at its Portland, Boston and Oakland yards.

The company is installing a 122x108 Metso Texas Shredder unit equipped with a 7,000-hp motor at its Portland facility--one of the largest shredder models available. The company and its supplier estimate that the giant shredding plant will be able to produce more than 450,000 tons of processed metal through the plant each year.

Metal Management Inc., Chicago, has also been upgrading its shredding capacity, with a 98x104 model on order from Wendt Corp. for its Memphis, Tenn., location and a Newell Riverside 120x104 mega shredder with a 6,000 hp-electric motor installed earlier this decade in Phoenix.

Scrap processing giant OmniSource Corp., Fort Wayne, Ind., will also be investing in shredder upgrades, having struck a deal this March with American Pulverizer and Hustler Conveyor to purchase three 98x104 heavy-duty scrap shredding and recovery systems. OmniSource already had one such model at work in Jackson, Mich., and plans to put the first of the three new shredders in Indianapolis.

PSC Metals Inc., Cleveland, has also been upgrading shredder plants, including the installation of a Wendt Corp. 106 "Heavy" model underway this year in Canton, Ohio. Wendt Corp. has also sold two of its largest shredding plants--the 130 Heavy model--to customers Camden Iron & Metal, Camden, N.J., and Sturgis Iron & Metal, Sturgis, Mich.

And the Alter Scrap Processing subsidiary of Alter Trading, St. Louis, has been installing or upgrading shredding plants at five of its locations, with an agreement struck with Metso Texas Shredder to supply models ranging in size from 80x104 to 98x104.

A massive 7,000-hp shredder built by The Shredder Co. with the model number 124SXS was installed at a Houston facility formerly known as Northwest Recycling. The facility is now owned by the David J. Joseph Co. and operates under the name Texas Port Recycling.

The Harris Shredder division of the long-time shear and baler maker based in Georgia has also sold and installed high-production units, including a super-sized HS125x125 being installed in Kansas City for Midwest Scrap Management.

Makers of shredding plants and their accompanying components have been performing installations at a hectic pace as this decade has progressed. At the same time the massive systems are being put in place to churn out more metal, recyclers are also eager to upgrade the quality of the scrap being produced.

IT'S COMPLICATED. Perhaps just as impressive as the scale of the newest shredding plants in North America is the complexity and thoroughness of the downstream systems and the monitoring systems that keep plants operating at peak efficiency.

In addition to offering more power and production, shredder manufacturers have also been competing to offer more automation and monitoring capability in shredder control booths.

Such systems are designed to save energy and to minimize the use of water or mist for dust suppression, among other cost-saving and quality-monitoring functions.

Complexity really starts to set in, however, in the downstream portion of plants, where record high nonferrous scrap prices have caused recyclers to pay close attention to the non-magnetic post-shredding stream.

The level of investment in downstream equipment has caused some in the industry to speculate that off-site heavy media separation is in its declining years as an ongoing practice, as sorting equipment that can quickly yield a return on investment is purchased by an increasing number of shredding plant operators.

Leaps in technology, availability and affordability have been coupled with healthy scrap markets that have given shredding plant owners the types of checking account balances that are allowing them to make the purchases to install high-capacity, high-yield downstream systems.

The technology has moved beyond eddy currents to include induction, X-ray and optical sorting and separating machinery. (See "Interest Earned," starting on p. 40 the April 2006 issue of Recycling Today or on the Web at www. RecyclingToday.com.)

Just as noteworthy, the capital investment climate seems to be moving the scrap recycling community quickly from demonstration of such technology at one or two locations to widespread adoption. Active competition among equipment suppliers has helped fuel recycler's interest in these technologies while also providing the capacity to install the requested systems.

As with shredder upgrades, the largest scrap companies have been among those committing to add additional downstream equipment. Metal Management Inc. has made major purchases from SteinertUS of not only its drum magnets and eddy current sorters, but also of induction sorting devices designed to capture additional stainless steel and red metal scrap.

PSC Metals has purchased magnetic equipment from Steinert as well as from Wendt Corp., which markets separation equipment made by Germany's SSE. A Wendt/SSE "Finder" unit that specializes in extracting stainless steel from the post-shredder stream was purchased by PSC for its Canton facility.

It is not only the largest recycling companies making these downstream commitments. Youngstown Iron & Metal, Youngstown, Ohio, has been working with SGM Magnetics throughout the decade to deploy SGM technology to maximize the yield and quality of the nonferrous metals it pulls from its shredded scrap stream.

A variation on downstream upgrades has involved the use of bulk analyzers at shredding facilities to conduct quality and chemistry assessments of the ferrous scrap to be marketed.

River Metals Recycling, a scrap processing subsidiary of the David J. Joseph Co. (DJJ), Cincinnati, has installed analyzers made by Gamma-Tech LLC at three Kentucky shredding plants while another DJJ subsidiary, Trademark Metals Recycling, is also adding the bulk analyzers at some of its Florida locations. PSC Metals, Cleveland, has also installed one of the units at its Nashville, Tenn., auto shredding facility.

Units made by Gamma-Tech are designed to provide an analysis of the presence of nonferrous metals such as copper or molybdenum in the ferrous shred stream. Shredder operators who can document low levels of such "tramp elements" in ferrous scrap can earn a premium on the product they ship to steel mills.

Technology addressing the metals portion of the shredding stream has attracted the attention and willing investment of scrap recyclers, but industry observers are now curious to see if the plastic portion can ever hope to attract the same attention.

TRASH TO TREASURE? Through several decades of auto shredding, the nonmetallic portion of the post-shredding stream has been referred to as "fluff" or residue and has generally been relegated to the landfill or, at best, used as landfill daily cover.

Recyclers who see an opportunity in the residue (or who just hate to see material landfilled) have studied this portion of the stream throughout that time and, as of late, have seen lofty petro-chemical prices provide an additional incentive to recover the polymers that make up a healthy portion of this auto shredder residue (ASR) stream.

In the European Union, requirements of the End-of-Life Vehicle Directive have helped spur considerable research into how to best recover these plastics, with several different approaches having been attempted.

A system developed by Germany's SiCon GmbH is able to recover plastics in the form of what the company calls "shredder granules" and "shredder fibers." According to a write-up prepared by SiCon, "The most preferred utilization of shredder granules is [their] injection into a blast furnace as a reducing agent to replace heavy oil or pulverized coal."

The shredder fibers, which consists of polyurethane foams, carpet and interior casing materials, can be used in municipal wastewater sludge treatment, according to SiCon.

Gasification and energy recovery figure into an ASR system developed by ILS (Innovative Logistics Solutions) Partners, Palm Desert, Calif., and Pyromex AG of Switzerland.

According to Herb Teague of ILS, this technology has proven commercially viable and has been in use in Europe for five years and can be configured to work at any auto shredding plant site in North America.

An American working to recover the plastics portion of ASR for years has been Michael Biddle of MBA Polymers, Richmond, Calif.

MBA has recently constructed two joint venture plants, one in China and the other in Austria, to re-process post-shredder residue into marketable secondary plastic resins.

In the two plants, the post-shredder residue has not specifically come from auto shredding plants, but rather from shredder locations where appliances and electronics are processed.

The MBA Polymers' system takes in a highly complicated mix of materials that can include metal, wire, circuit board fragments and rubber as well as the full spectrum of plastics resins.

Using a complex series of automated size reduction, cleaning, sorting and separating steps, MBA can produce plastic flakes and pellets that can be used by makers of automotive components and other manufacturers in a "closed-loop" fashion that is closer to achieving the type of recyclability common in the metals industry.

Although regulations in the European Union and other parts of the world have been one incentive for recovering the plastics portion of the shredding stream, global commodity demand, scarcity and pricing may provide the ultimate incentive for researchers and recyclers alike to re-capture this material.

A REAL DUST-UP

Shredder operators have a number of ways to suppress and minimize the dust that is produced by the shredding process, a necessary step for health and safety reasons.

MinTech, a subsidiary of Atlanta-based Momar Inc., markets additives that the company says provide benefits beyond what water alone can do in terms of dust and smoke suppression and explosion impact reduction.

The company's Autotrol 20 and Autotrol 80 products are odorless, biodegradable foams designed to reduce not only the amounts of dust and blue smoke emanating from shredding plants but also to muffle explosions and help shredder operators comply with environmental regulations and local ordinances.

X-RAY VISION 

Equipment suppliers have begun to deploy X-ray technology as a sorting technique for materials traveling through the post-shredder stream.

Wendt Corp. has installed its first X-tract units this year. The devices use X-ray detection on the mixed metals Zorba stream to identify metals by atomic density and then use a series of air jet nozzles to separate the materials after they are identified (See "Interest Earned," starting on p. 40 the April 2006 issue of Recycling Today.)

Another supplier offering an X-ray device is Austin AI of Austin. Texas. The company's QXR-M is "an automated X-ray fluorescence spectrometer-based sorting system [designed] to complement and improve upon eddy current and induction sorting capabilities." according to a write-up prepared by the firm.

Austin Al says its system was evaluated by one of the largest aluminum processors and scrap metal brokers in the United States and that the company subsequently purchased a system for its high-volume (more than 5 tons per hour) scrap aluminum sorting needs.

The QXR-M uses energy-dispersive X-ray fluorescence (EDXRF) a technique that employs X-rays to stimulate fluorescence, which provides information on which elements are contained in objects that make up the passing stream. "The technique is ideal for real-time measurements of moving materials--being fast, non-contacting and, in most cases, equally accurate on clean, wet, dry, dirty or painted material," the company states.

The QXR-M consists of a conveyor-mounted XRF spectrometer with integrated infrared (IR) camera. The camera determines the presence of material, while the XRF device determines elemental composition. The results actuate a paddle-type diverter downstream from the spectrometer, which directs the materials to the appropriate collection bins or take-away conveyors.

Austin Al says its device "works best on pre-sized materials" ranging from 1/2-inch to 4-to-8 inches in size. Additionally, "QXR-M selection parameters are easily modified to perform new selections based ors market conditions." says Austin Al President Rick Comtois. "While cooper, aluminum with low alloying zinc, or graded stainless steel may be of interest today in the future it could be a different metal or alloy grade," he remarks.

The author is editor of Recycling Today and can be contacted via e-mail at [e-mail].