Equipment makers say they are advancing the science of metals separation, including metallic fines.

Pictured above, from left: Didier Haegelsteen of SGM Magnetics, Tim Shuttleworth of Eriez and Robert Broughton of SteinertUS

Valuable bits and pieces of metal have long been created by auto shredding plants, and equipment companies say they are getting increasingly better at harvesting these smaller units. Three vendor representatives spoke at a session on advancements in metals recovery at ISRI2017, the annual convention of the Washington-based Institute of Scrap Recycling Industries (ISRI).

Tim Shuttleworth, CEO of Pennsylvania-based Eriez, said increasingly powerful magnets are helping ensure shredder operators capture as close to 100 percent of the iron and steel content as possible.

Recyclers and vendors alike are refining their techniques to use a combination of drum, suspended and pulley magnets to harvest ferrous scrap from fist-sized chunks to the smallest fines. Shuttleworth said operators also have learned how to spread material out onto conveyors so they are “using the full width of the separation equipment” being deployed to collect metal.

The Eriez CEO said his company’s Stainless Steel Separator has been designed with “many thousands of gauss” to operate downstream from the other ferrous magnets to attract stainless steel pieces.

Didier Haegelsteen of Italy-based SGM Magnetics said eddy current separators are being refined and upgraded to address the “30 to 40 percent” of shredded output considered as “fines,” or pieces below 3/8-inch in size.

Along with specialized magnetic equipment, Haegelsteen said gravity separation processes “can be a fantastic complement, if properly used” to help shredder operators capture more metal.

He said a three-stage downstream system developed by SGM consists of preconcentration, concentration and polishing stages to help produce metals streams of high value. Haegelsteen said such a system focusing on fines can yield $70 to $74 per ton off additional saleable materials at spring 2017 commodity prices.

Robert Broughton of Kentucky-based SteinertUS said the use of sensors in downstream shredder applications “have come a long way in the last decade,” noting that X-ray, induction, infrared and other technologies can now all be deployed to help identify and harvest metallic units.

Broughton said specialized equipment designed by Steinert can help capture commodities such as “angel-hair zurik and very small wire” that formerly slipped through. He also said plastic circuit board pieces that can potentially contaminate zorba and other mixed metals can be captured via optical equipment designed to identify plastic.

Eriez’s Shuttleworth summarized the work of vendors such as the ones on the ISRI2017 panel by saying they are “trying to move the word from hand sorting to a more automated approach.”

ISRI2017 was in at the Ernest N. Morial Convention Center in New Orleans April 22-27, 2017.

The law, currently in effect, requires motorists to slow down and safely change lanes when passing a stopped waste truck.

The cleanup grapple acts as a claw to pick up material.

Lynx turbofiner can be used to produce rubber powder without the need to add cooling agents such as nitrogen.

Pallmann Industries, Clifton, New Jersey, has introduced the PLMW Turbofiner Lynx, which the company says can produce fine rubber powder from scrap tires without the need to add nitrogen as a cooling agent.

PLMW Turbofiners are used to finely grind precut rubber chips from truck and car tire treads and produce material that can be as fine as 425 microns. According to the company, the special design of the machine means that even hard-to-grind or temperature-sensitive products can be ground at ambient temperature without the need to add nitrogen as a cooling agent.

A vibratory feeder or rotary value continuously feeds precut material ranging in size from 2 millimeters to 4 millimeters to the Lynx. Contamination is removed with a solenoid coil or air sifter before the material is ground. The grinding process is aided by the quick-running rotor, which produces whirls of air between the beater plates that cause the rubber particles to collide, the company says.

The ground material is pneumatically conveyed to a downstream filter that separates the material by particle size. Larger particles that do not met the desired fineness are automatically reintroduced to the grinding process.

The new beater plate geometry and the high circumferential speed of the PLMW Lynx rotor allow the machine to produce particle sizes that previously were not achievable with traditional ambient grinding processes, Pallmann Industries says.

The resulting material can be used for new rubber applications.  

More information is available by visiting www.pallmannindustries.com or emailing recycling@pallmann.eu. 

Hanford Site contractors recycled 85 percent of nonhazardous material and 59 percent C&D debris last year.