p-rex scrap drum illustration
Illustration courtesy of Eriez

Eriez's continual development of its P-Rex has expanded its capabilities

The scrap drum has been used in a growing number of applications.

November 25, 2021

Eriez introduced its P-Rex (Permanent Rare Earth Xtreme) scrap drum 11 years ago. The company’s Recycling Market Manager Mike Shattuck says Erie, Pennsylvania-based Eriez has continued to develop this product. “While we initially marketed P-Rex mainly for scrap recycling, today it is found in a variety of other successful applications and features many improvements,” he says.

The P-Rex’s magnetic circuit is up to 40 percent stronger than electromagnetic drums and can move ferrous scrap at twice the distance, according to the company, which says it also facilitates more agitation to remove ferrous from debris, providing a cleaner ferrous product.

Eriez says its research and development staff set out to design a drum to recover electric motors (known as “meatballs”) and spheres from the scrap recycling process as a means to keep these dangerous materials out of the fluff, thereby reducing the opportunity for fires.

“Although P-Rex is extremely effective for this purpose, we soon became convinced that we could further harness the power of this drum in additional ways and incorporate improvements,” Shattuck says.

That led Eriez to combine the P-Rex with the Shred1 ballistic metal separator. The P-Rex provides more copper-bearing material to the Shred1. This greatly increases the copper pickings, resulting in increased revenue, the company says.  

“By utilizing the P-Rex in conjunction with the Shred1, copper pickings from many yards went from 6 to 8 pounds per ton to as high as 12 pounds per ton of shred,” Shattuck says.

Eriez also developed the “under flow” process, which uses the P-Rex scrap drum and its multiple agitations, to provide a cleaner ferrous product. The ferrous is passed under the drum instead of over the top, allowing fluff to fall directly to the nonferrous conveyor instead of back into the line of feed, the company says. The multiple agitations of the P-Rex and the traction plate technology that keeps ferrous from bunching up on the drum surface deliver a cleaner ferrous product.

Shattuck says, “The huge field of the P-Rex and its extraordinary strength make it ideal for waste to energy plants where a large gap is required. The raw strength also lends itself to slag recycling operations where trace amounts of ferrous may be attached to large pieces of nonferrous.”