When it comes to metals recovery, no job is too small for Eriez

The global market for scrap metal has continued to show an appetite for nearly any grade that can be extracted from downstream sorting systems at auto shredding plants.

Eriez has long recognized this and, for several decades, has conducted research, testing and product development efforts focused on harvesting both ferrous and nonferrous fines—pieces of metal smaller than 1 inch in size for ferrous scrap and smaller than one-half inch in size for nonferrous metals.

“Smaller metals were the most difficult to recover [downstream],” says Chris Ramsdell, product manager - separation and recycling at Eriez, but two products in particular have helped overcome this challenge.

“By working with Eriez, processors can increase metals recovery from ASR, adding even more value.” – Chris Ramsdell

In the ferrous stream, most iron and steel scrap is captured by the primary drum magnets, but Ramsdell says operating gaps set at around 12 inches will allow for the large nonmagnetic materials to pass through to the nonferrous side of the plant while ferrous pieces smaller than 1 inch often are missed at this stage.

This fine ferrous material can be pulled by a magnet positioned within that nonferrous stream, and Eriez customers have found optimal results when that magnet is a Dynamic Pulley Separator (DPS). The DPS is positioned upstream from an eddy current and, Ramsdell says, “uses a permanent rare earth magnet pulley rotating at an off-set speed from the belt, creating an agitating magnetic field.”

A DPS in the right place will improve ferrous recovery while debulking the auto shredder residue (ASR) to provide a cleaner feedstock to the downstream equipment, where zorba quality will be improved as a result.

Within that nonferrous stream, Eriez’s custom-designed Ultra High-Frequency (UHF) eddy current separator (ECS) has been found to reliably recover micro-fine zorba and bare wire from ASR fines.

“Before this most recent generation of eddy current separators, ASR plant operators were unable to reliably recover bare wire and fine cast aluminum,” Ramsdell says.

The UHF benefits not just volume, but also quality. “Because the UHF ECS can recover bare copper wires, the zorba package produced by this machine is very high in red metals content (up to 20 percent reds),” Ramsdell adds. “This high copper content makes the product more desirable in the market, often garnering prices 10 to 15 percent higher than standard fine zorba packages, depending on market conditions.

“These unrecovered metals were often lost to landfill,” he says of the era before devices like the DPS and UHF ECS could be deployed. “By working with Eriez, processors can increase metals recovery from ASR, adding even more value, and by increasing their fine zorba recovery, processors are reducing their ASR landfill costs at the same time.”

Descriptions of the Eriez product line for metal recyclers can be found at www.eriez.com/Recycling.