Non-ferrous metal recovery builds

Click to Enlarge - ASR en route to the eddy current separators at the Upstate Shredding plant in Owego, New York. E-mail the author

Scrap metal processors are becoming increasingly clever at wringing out the last dollar from their waste stream. That includes recovering cleaner, greater weights of high value nonferrous metals. Ben Davis, manager of the magnetics division at Huron Valley Steel Corporation is considered by many in the industry as the dean of non-ferrous recovery. He had this to say about the state of the business, “A lot of shredders today have gotten away from autos and are going to smaller, low speed shredders for white goods because the volume of autos has gone down. The other major development over the past few years was development of image technology that senses and separates various non-ferrous by shape and color.”

Huron, the largest processor of nonferrous in the world, buys from shredders in Canada and all over the United States except for some of the west coast states due to transportation costs and because west coast shredders export most of what they produce to Pacific rim countries, mostly to China. Headquartered in Trenton, Michigan, Huron operates recovery and recycling facilities in Belleville, Michigan and Anniston, Alabama, and has a joint-venture with HVF West in Tucson, Arizona.   

In addition to processing nonferrous, Huron has been designing and manufacturing eddy current separation equipment for nearly 30 years, both for its own use and for sale to nonferrous recovery operations. It also provides consulting services to shredders, municipal recyclers and landfills to maximize nonferrous yields. “I do more consulting work than anything else. My main job is to empty the shredder and not send anything to a landfill … showing them how to arrange their material to get maximum recovery,” said Davis.

Bill Close, sales engineer for Wendt Corporation, one of the world’s largest shredder manufacturers, gave his opinion of the state of non-ferrous recovery. “There have been some pretty significant improvements in sensor based sorting equipment over the past few years, including optical, x-ray, near infrared and electromagnetic in terms of recovering products from a waste stream. It’s a very competitive industry and looking for improvements in processes to raise revenues is mission critical.”

Coaxing non-ferrous out of a waste stream has always been a challenge and has been traditionally as much an art as a science. But science is playing a continually larger role. Investing in new technologies and incremental improvements in old ones can pay off. At least that is the business plan of Adam Weitsman, president of Upstate Shredding in Owego, New York.

Upstate Shredding’s plant in Owego, New York.

In August, Upstate completed the first phase of a $20 million dollar upgrade to its in-line auto shredder and added a new auto shredder residue (ASR) processing plant designed to maximize non-ferrous recovery. Weitsman is confident that this investment for downstream nonferrous recovery will pay off quickly. “Our financial objective is to take all the non-ferrous out of the waste stream and get any marketable product we can. It should increase our net revenue by approximately $20 million a year, basically by recovering material that we now landfill as well as having higher quality commodities to sell.”

Upstate Shredding and its sister company Ben Weitsman & Son has scrap yards in Owego, Binghamton and Ithaca, just acquired land in Syracuse for a new facility and is planning another yard in Scranton, Pennsylvania. From this feeder system as well as from scrap dealers in Canada, New England and the Mid-Atlantic states, vehicle bodies and other scrap metals come to Upstate’s Owego mega-shredder, currently a 6,000 h.p. M-120-104 unit by Riverside Engineering. Working seven days per week, Upstate processes approximately 600,000 tons per year and is New York State’s largest scrap metal processor. Approximately 90 percent of its production goes overseas to China, India and Turkey.

“Adam’s going from a yard that did not have much separation to one that has a great deal of separation and recovering metals he was not able to do before. It’s really nice,” said Rusty Manning, Riverside’s new equipment sales manager. Early next year Riverside will install its latest 10,000 h.p., 450 ton per hour, M-122 mega shredder at Upstate – a more durable machine with tougher wear-parts that will cost Upstate less per ton to process. It will include Riverside’s latest iteration of its Shredder Cruise Control, a feed roll platform that automatically adjusts the feed rate to maximize output while reducing power consumption and the need for operator interaction.

By the end of this year, Riverside will add SGM Magnetics Polishing Drum Magnets to Upstate’s downstream shredder that will automatically produce a less than 0.18 percent copper content ferrous frag and facilitate the recovery of “meatballs,” electric motors containing valuable copper armatures. The move is designed to minimize manual picking, which will reduce labor costs and increase productivity. “This new technology was developed over the past few years and we are incorporating it into our separation system,” said Manning. After high-strength magnets remove the ferrous shred, lower-strength magnets attract the ferrous components of the motors such as housings and steel shafts and remove the copper bearing motors from the stream. “This hasn’t caught on very well, but more and more people are beginning to look at this technology when considering upgrades,” Manning added.

According to Didier Haegelsteen, SGM Magnetics’ managing director, SGM Magnetics added this polishing drum magnet technology an exclusive development allowing the drum magnets to always feature the same attraction force that is compulsory to perform an accurate separation.

Adam Weitsman worked closely with SGM Magnetics to design his downstream ASR recovery plant that incorporates SGM’s latest ideas and separation technologies. “I would say it ranks as one of the highest technology plants in the world. I don’t know of anyone else who has done this before. There are not many automobile shredders that take residue and have all of the eddy currents, sensors and also have the dry media plant all under one roof,” said Haegelsteen.

Being under a roof is also new for Upstate. The entire 200,000 sq. ft. facility is being roofed over and enclosed. “We are doing this to conform to New York State Department of Environmental Conservation storm water regulations related to run off from iron and ASR. We also built a storm sewer system and an on-site, sand filter water treatment plant to remove heavy metals, solvents, and other substances,” said Weitsman.

The residue plant starts with a screening process splitting the ASR material into four streams: -.63”; from .63” to 1.25”; from 1.25” to 5”. Anything over 5” is sent back to the shredder. The two first fines fractions are processed by dynamic ferrous separators before passing on high frequency eddy current separators, while the large fraction (>1.25” to 5”) is processed by a drum magnet before passing on a standard eddy current separator still spinning at 3,000 rpm. The next separation step implemented by Upstate for the two fractions over .63” is passing over inductive sensor separators to recover the typical 1 to 2 percent metals missed by the eddy current separators, made of predominately stainless steel, but also including insulated copper wire, copper, aluminum, magnesium, nickel, tin and zinc. This commodity, predominately stainless steel, produced by the new inductive sensor technology is classified as Zurik by ISRI.

The eddy current processes, as well as the induction sensor separation processes aim at recovering the maximum quantity of metals in the ASR while the next processes bring further added value to the Zorba recovered by the eddy current separators. Zorba is the ISRI spec for the mix of metals recovered by eddy current separators processing ASR that is predominately made of aluminum (about 70 percent). Zorba, as such, can be sold to either China or to domestic heavy media plants. The idea is to look for extra value by separating the aluminum from Zorba as well as separating the red and yellow metals from the heavies. The benefit comes not only from the extra value the market pays for separated single metal commodities, but also offers disposal alternatives to China and domestic heavy media plants by selling the aluminum to aluminum smelters, and the red and yellow metals to either brass or copper smelters.

At Upstate, Zorba produced by the eddy current working on material from 1.25” to 5”, is sent to a dual-energy x-ray separator that identifies particles by atomic density and segregates the aluminum from the heavier metals, typically zinc, copper and brass. “Thanks to a different program on the x-ray separator, a further possible added value can be brought to the aluminum by discriminating the sheet from the cast aluminum as we have already proven in Europe.” said Haegelsteen.

X-ray detection technology is not dependent on particle sizes, however, the smaller the material the lower the productivity of the x-ray separators. This is why at Upstate the x-ray is only dedicated to the process of particles that are 1.25” to 5”.

For Zorba less than 1.25”, SGM supplied Upstate with four Sandjet separators. The Sandjet consists of a dry media plant that works on the same principle as a wet media plant, but instead of using ferro silicium to bring the liquid density up to that of aluminum, Sandjet uses sand fluidized through air jets to bring the density down to that of aluminum and sinks the heavier zinc, copper, brass and stainless. Fluidized sand works on a shifting mechanism and the vibration carries the aluminum particles off by inertia. SGM claims that separation is better or equal to wet media separation at less operational cost because it eliminates the sludge recycling process. “The Sandjets take the copper out of the aluminum. We had been selling copper at the aluminum price because it was mixed in,” said Weitsman.

A new SGM Optic Color Sort System further segregates yellow and red metals coming off the Sandjet. Upstate installed six units, each employing multiple, ultra high-speed, high resolution CCD cameras covering a 48” belt width. Particle images are fed into a computer that uses a proprietary algorithm that discriminates between individual metal particles and either accepts or rejects a particle based its shape and color. After passing under the cameras, accepted particles are automatically air ejected.

According to Haegelsteen, the fact that all these technologies are dry and easy to operate (x-ray, Sandjet and Color Sorter) makes it convenient for shredder operators producing upwards of 5,000 tons of Zorba per month.

Currently under contract, and coming soon to Upstate is an $8 million dollar ASR insulated wire recovery line. “I’ve been throwing away about 40,000 pounds of insulated wire every day for 11 years. In the big picture when you are buying two to three thousand tons a day, 40,000 pounds is not a lot. It’s a heavy investment to make it work on site, but with the newer technology that senses the plastic from the copper we are going to make it work,” said Weitsman. “Our next goal is to recover glass and plastic as soon as we can find the technology that does it efficiently.”