Electronic Separation Equipment by Mark Henricks

—View a list of manufacturers at the bottom of the page

Electronics waste seems to have it all: glass, plastic, rubber and a variety of metals. “The electronics waste stream is rich with valuable, reusable materials,” says Terry Ward, director of sales at SSI Shredding Systems, Inc. in Wilsonville, Oregon.

Extracting that value is a complex job, however. “Electronic processing works like a decision tree,” says David Weitzman, vice president at RRT Design and Construction, a systems integrator in Melville, New York. “As material comes in the door, the question is first, ‘Can I sell it?’ and then, “if I can’t sell it as it is, can I pull some parts from it?’”

More and more, the answers to both questions are yes. That’s due in part to market volatility. As the price of copper skyrockets, for example, computer cables and cords are becoming more valuable. And as technology becomes more sophisticated in screening and sorting electronic waste toward mechanized approaches, the industry is slowly moving away from hand disassembly and sorting.

“Improvements in size reduction and sorting and separation technology are allowing electronics recyclers to handle larger volumes of material cost-effectively and create higher value end products, making an e-scrap recycling facility a more profitable venture than in the past,” says Ward. Separation technologies in use today employ magnetics, air, static electricity, optical sorters, eddy current separators, electrostatic separation and flotation techniques.

Electronics is the world’s fastest growing waste stream and much of it is not recycled. More than 3.2 million tons of electronics goes into landfills each year, and that number will face pressure to increase as consumers discard 3 billion discarded units by 2010. Meanwhile, regulators and activists are pushing to ban the export, landfilling and incineration of electronics waste as well as to stop use of prison labor for demanufacturing, a popular practice in some countries.

At General Kinematics in Crystal Lake, Illinois, regional sales manager Ron Zorn sells vibratory destoners for electronics separation applications. “The design was originally designed to take rock out of wood; that’s where the name came from,” Zorn says.

A vibratory pan spreads and moves material through a section where air blowing up through perforated holes fluidizes the particles and prepares them for the air knife, which is more air blowing up through a slot. Heavy particles fall through the slot to a conveyer while lighter materials remain aloft and pass over the gap. “In electronics, you may have a very heavy piece of thick glass from a big screen, while the light is the plastic product,” Zorn explains. General Kinematics destoners vary from 18 inches up to 72 inches wide and 12.5 feet to 40 feet long.

At Steinert US LLC in Clearwater, Florida, separators position metal detectors over streams of moving recyclable material. The detectors use a variety of means, including magnetic and x-ray to determine the nature of metals in the material stream. A system of individually programmed air jets firing under the material as it falls off the conveyor ejects metals from the stream. “We can automate the process of getting all the recoverable metals out of the stream,” says sales manager Dennis Ciccotelli. “Materials can be as low as one-half of one percent of metal by weight.” An ISS 120 separator capable of doing 8 to 10 tons per hour.

Some separators meet very specific needs. MBA Polymers, Inc., a Richmond, California, specialist in plastics recycling, provides a low-cost, modular recycling system called an Mbox that helps recycling facilities increase separation results for shredded materials with finer separation between plastics and metals, such as ferrous and nonferrous materials, circuit boards and wires. “Often electronics recyclers are seeking to recover more metal in addition to upgrading or concentrating their plastics in order to increase its value. The equipment can help suppliers meet export/import regulations beyond normal plastic buyer concerns such as yield,” says Darren Arola, global director of product development and sales at MBA Polymers. The MBox system can be easily integrated into an existing process line either as a stand-alone unit or combined with size reduction and/or screening and air classification systems to tackle other items such as dirt, paper, wood, and foam,” Arola stated.

Separating glass from electronic waste is another niche. At Andela Products Ltd., a Richfield Springs, New York, manufacturer of glass recycling systems, its high production E-Vantage unit shreds, separates and reduces whole machines, from computers and printers to washers and dryers. Materials move on a conveyor toward pulverizers and magnetic and eddy current separators to remove metals. A dust collection component ensures that phosphorous or lead residue doesn’t get released into the work atmosphere.

President Cynthia Andela says the system offers an improvement over methods that relied on brute force and gravity. “We took a look and said there has to be a better way than people dropping and crushing CRT tubes mostly because of the hazards it poses,” she says. “Recyclers wanted something with dust collection that was more people friendly and didn’t have OSHA or environmental issues.”

Other techniques to assist electronics separation are on the way. In Europe, where more aggressive regulatory efforts are underway to increase electronic waste recycling, manufacturers are testing a new solvent designed to dissolve brominated flame retardants in plastics. Researchers hope successful testing will produce a new source for industrial bromine and a recycled plastic with less than 0.1 percent of retardant, the maximum allowed by the European Union’s reuse standards.