Deep Impact

Advances in technology are allowing shredding plant operators to dig deeper into their residue for profits. 

Four years ago, as managing director of SGM Magnetics Corp., I communicated to our sales force that the time had come for us to offer innovative metal separation solutions to the auto shredding industry.

This was about five years after SGM Magnetics had started promoting its lifting magnets to steel mills and steel service centers in the United States. The SGM Magnetics sales force reacted by asking: "Why now and to offer what?"

My immediate explanation was that the market increasingly had been signalling that some automobile shredder operators were realizing that they may not have been getting all the metals out of their nonferrous downstream process and that more could be done.

IDENTIFYING THE CULPRITS. The answer to the question of what to offer was, "We’ll provide equipment to extract fines and stainless steel."

At that time at most auto shredder sites, residue fines (smaller than 1 inch or even 1 1/2 inches) were simply screened out and sent directly to the landfill. As far as stainless steel was concerned, in the best cases, some of it was recovered by pickers doing the best they could when confronted with the huge flow of residue they saw streaming past them.

U.S. Shredder and Castings Group Announces Shredder Project

The U.S. Shredder and Castings Group, based in Brookhaven, Miss., has announced that it is working on a new automobile/scrap shredder design.

"The project is significant because it will complete our product offerings to the scrap shredding industry," U.S. Shredder’s President Bill Tigner says. "We already supply and have supplied everything from the infeed conveyors, motors, castings, ferrous and nonferrous cleaning systems as well as rotors (both spider and disc)."

The design focuses on three primary criteria, according to Tigner: structural integrity for longevity, ease of maintenance and efficient production cost. He adds that the shredder line will be competitively priced, with production completed at the end of the first quarter of 2007.

U.S. Shredder and Castings Group was formed in June 2006 by a number of industry veterans and suppliers. The company currently builds shredder system components, with the exception of the shredder box itself.

More information is available at www.usshredder.com.

– DeAnne Toto

The higher density of the fines residue looks like a minority fraction of the total residue. However, metals are not sold by volume, rather by weight. And, in terms of weight, fines residue typically represents about 50 percent of the total amount with a metal content typically roughly 5 percent.

A fines line solution from SGM Magnetics that is composed of a Dynamic SRP separator that liberates the metals, followed by a high-frequency eddy current separator that recovers them has quickly been adopted at several shredding plants, by way of example.

Thanks to the help of early adopters who accepted visitors at their sites and who have spread the word on the merit of this technique, this fines recovery process has become increasingly popular among scrap processors.

GAZING INTO THE FUTURE. Having observed advances in auto shredding systems during in the past few years, I have developed several expectations of where processing is headed.

My first expectation is that within two to three years, the shredder yards that have not recently replaced at least one separation line for the recovery of metals from their fines residue will be rare exceptions.

The automatic sorting of stainless steel from auto shredder residue is related to advances in sensor sorting technology available now compared to what was being marketed to the industry about four or five years ago.

Initial sensor technology generated a lot of enthusiasm among operators, but it also caused the potential for disillusionment if the units that were supplied were not particularly successful. Five years later, the understanding of the technology has become more mature. Operators have learned about the technology’s potential. They also have a better understanding of how to determine if the technology will be economically worthwhile for their operations.

Many operators followed the common-sense approach for purchasing expensive equipment, which consists of buying an initial separator and waiting for the positive return on the investment before considering investing in a second one.

But, by adopting this approach, some operators were faced with a disappointing experience. For instance, some of the first sensor separators that were developed recovered some stainless, but in an unsuitable concentration that resulted in a product that possessed little value.

The operators who found success with that technology are the ones who have added a second sensor separator following the first one and who have assigned one sensor separator line to each of their eddy current lines.

Steinert Offers
Wider Eddy Current

Citing a trend toward higher throughputs and larger scale recycling plants, German equipment maker Steinert has begun to offer the NES 250, an eddy current separator with a working width of 98 inches.

The model also offers an increase in "the belt drum diameter of more than 60 centimeters," a Steinert news release states.

The 2.5-meter (98-inch) wide NES 250 eddy current separator offers an alternative to splitting material flows, according to the company. Many recyclers currently operate two eddy current separators with 1.25- or 1.5-meter working widths in parallel—with the associated duplication of conveyor systems, the problem of splitting the material flow into two equal parts and the doubled maintenance requirement, the company notes.

"Effective immediately, one single plant can be operated with a high throughput of approximately 130 cubic meters per hour," according to the company. Steinert contends that recyclers can save on both costs and space by using the new model.

Steinert, based in Cologne, Germany, has sold nearly 2,000 eddy current separators to recyclers and other materials processors. Its North American affiliate SteinertUS is based in Clearwater, Fla.

– Brian Taylor

Equipment makers have now developed a sensor separator line consisting of two different and complementary separators. The first sensor separator is designed to optimize the recovery of the metals left in the residue after the eddy current, while the second sensor separator works on the metal stream after it has passed under the first sensor and is designed to concentrate the metals to more than 90 percent to transform it into a salable commodity.

The extent of investment in sensor separators is often considerable, but with the price of nickel at record levels, market conditions have created an ideal time to invest in this technology.

CHANGES AFOOT. My second expectation is that within two to three years, most of the shredder sites with a monthly throughput of 5,000 tons or more will invest in sensor separators, since they will recoup their investment within one year.

My third expectation is related to a major change in the attitude of the shredding plant operators, who have traditionally been willing to buy shredding plants and nonferrous downstream systems from their shredder supplier. Instead, such buyers may consider the merits of researching each part of the system separately and working with two specialist corporations.

Historically, the two very different processes were purchased from the corporation manufacturing the shredder because the roots of these scrap companies often traced back primarily to the iron and steel scrap industry.

Working with a shredder supplier who outsourced the downstream system to another corporation was acceptable, as many of these buyers gave secondary importance to the nonferrous metals portion of the stream and considered the downstream system an auxiliary investment to the shredder itself.

Today, though, shredding plant operators are much more attuned to obtaining the best value for their residue to increase their profitability. Profitability—boosted by nonferrous scrap recovery and sales—is an important way to strengthen their capability of buying large quantities of scrap in a market that is increasingly competitive with the arrival of new and larger shredders.

An increased depth of knowledge among scrap processors regarding the specific technologies of the downstream systems has also allowed them to become more prepared and receptive to buying their shredder from a corporation specializing in shredders and their downstream system from a corporation specializing in nonferrous metals separation.

From their perspective, shredder manufacturers and downstream systems manufacturers are collaborating together in the best interest of their common customers, with each manufacturer responding from its own perspective, using its own expertise.

Last but not least, all these new technologies require operators to be prepared and motivated to properly service and maintain them. Without a doubt, the return that can be realized from these new technologies justifies their increased presence.

The author is managing director of SGM Magnetics Corp. and can be contacted via e-mail at didier.haegelsteen@SGM-magnetics.com.

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