Mining Recyclables

Landfill mining, while not always highly profitable because of the digging involved, is an intriguing concept. But what if you were able to extract the valuable components—especially metals—before they even got into the landfill and buried under dirt?

Several companies are beginning to incorporate separation and recycling strategies at transfer stations as well as at landfills prior to disposal. This can involve pulling out cardboard and segregating the metal fractions. At landfills, it includes looking at inbound trucks more carefully for loads that might be worth diverting to a sorting station, where the load can be picked for recycling.


Diversion Strategy
One successful project is the collaboration between Shoosmith Bros. Inc. and Hartsville, S.C.-based Sonoco Recycling Inc. An affiliate of Virginia Waste Services, the Shoosmith landfill re-uses and recycles 200,000 tons of material per year near Chester, Va. With the opening of The Recycling Center this summer, the company will handle mixed material loads for recycling. Commercial and industrial customers can recycle unsorted and mixed loads that previously would have gone to landfills, the company says.

The effort got underway about two years ago with a Sonoco pilot project. In June, Sonoco and Shoosmith Bros. started to ramp up a program to recover, reclaim and mine the landfill.

“We figure it will take 400 tons of raw material per month for us to break even,” says Ray Howard, director of operations with Sonoco Recycling Inc. “This gives products a second shot at life.”

The system is capable of sorting 2,000 tons per month. Right now, the companies are still on the learning curve and targeting 1,000 pounds per month. By mid-July, the project was expanding from 28 tons to 40 tons per day. “We are slowly moving up as we train people to see what percentage of recyclables there is in each load,” Howard explains.

Currently, 12 people are involved, including the office manager. Howard says he expects a total of 15 to 20 people to staff the sorting and packaging line once the operation is fully running. These people eyeball all incoming loads. Typically, they find the recyclables fraction runs between 25 percent and 50 percent of incoming loads. Howard says that range holds true no matter where Sonoco has done its studies.

Although the project began by looking for OCC (old corrugated containers) and paper, the facility will sort and process metal and plastics, too. Some of the recovered paper will go to Sonoco’s Richmond, Va., paper mill, 12 miles away, lowering the facility’s carbon footprint and offering a secure source of supply, according to Sonoco. In fact, much of the reclaimed material stays under the Sonoco corporate umbrella.


Money from Dirt
Recyclers can even make money reclaiming dirt. A recent success story that earned Kroeker Demolition/Kroeker Recycling, Fresno, Calif., an Environmental Excellence Award from the National Demolition Association was the mining of the Clovis, Calif., landfill.

The project did not seek quantities of UBCs (used beverage cans) or plastics. Instead, dirt was being reclaimed at the landfill, and it was quite profitable.

“It would have cost the city $20 million to buy cover for the new section of the landfill,” Rodney Ainsworth, general manager of Kroeker Inc., says.

Kroeker processed 2.5 million cubic yards of material, extending the life of the Clovis landfill. (Ainsworth and the city figure the project added 30 years to the facility’s life.) It also mitigated groundwater contamination, and the soil recovery eliminated the need to import millions of tons of new soil for ongoing operations.

The city’s landfill has been in operation since the 1950s, Ainsworth says. The city moved to lined cells once that technology became available. Officials wanted to remove the trash from the old section and move it to the new, lined portion of the landfill. In addition, they wanted to retrieve the dirt used in the old section for future cover in the new area.

Kroeker excavated the facility’s buried material, which it then sorted and screened, saving the soil for re-use and returning the screened waste to the landfill’s active face.


Keep it Simple
Reclamation efforts do not have to be complex to be successful. At their Ironton, Ohio, location, Rumpke Consolidated Cos. Inc. pulls out the cardboard fraction at the company’s transfer station. The Cincinnati-based firm has a buy-back station there where it accepts plastics, glass and aluminum from the public. However, only the fiber is removed from incoming waste at this particular site.

“When a load comes into our facility, we can easily see the wood, cardboard and metal,” says Amanda Pratt, Rumpke Consolidated Cos. director of corporate communications. “This visual inspection gives us a good opportunity to evaluate the recycling potential of certain customers, similar to a waste audit. Then we reach out to those customers and encourage them to add a separate container for recycling at their businesses.”

As is to be expected, some contamination issues arise with OCC that is recovered from the waste stream, Pratt adds.
Most of the recyclable materials at Rumpke’s Ironton facility arrive from buy-back and commercial collection routes, Pratt says. At the same time, the transfer station averages 5,590 tons of waste per month. Of that, small percentages of metal, wood and cardboard are removed from certain loads for recycling.

A complex list of considerations is associated with these operations. Economics, waste volumes, sorting space, available technology, health and safety, compliance and product quality are among them. Pratt says Rumpke is open to proven practices. “Right now our Ohio Valley facility provides the luxury of getting to evaluate an array of opportunities in one place,” she says.


How to Succeed
The secret to successful separation of valuable fractions, such as aluminum, says Steven M. Viny, CEO of Envision Waste Services, Cleveland, is an eddy current separator that is well-designed and well-maintained.

Recyclers need to get the ferrous material out of the stream first and get the material burden depth as thin as possible to successfully recover material with an eddy current separator, Viny says.

The typical eddy current separator uses thin, strong exotic materials for the belts and rare-earth magnets on a spinning shaft to separate materials. After the ferrous component is grabbed first using magnets, material moves to the eddy current. Then, the remaining material moves across a vibratory pan feeder.

“Keep the eddy current separator clean,” Viny advises. “Be certain to remove abrasive debris,” he cautions operators who have not used the equipment before. While the system is made of high-strength materials, it is quite thin. “Glass between the belt and the outer shell will abrade the sorter,” he says. Likewise, a food can lid will cut like a knife.

The Sonoco operation also relies on an automated sorting system that does the job with minimal human contact. Although the company started by looking for fiber in loads destined for the landfill, as more loads come in from the same office parks and other locations, the company found enough other good material to make a full recovery effort worthwhile.

Viny says grabbing aluminum is always profitable. “Aluminum is singularly the highest value material you will recover, pound for pound,” he says, though that picture changes over time.

Part of the reason is that aluminum manufacturers are quite adept at thin-walling their beverage cans. Viny counted 25 UBCs to the pound when he started in the business. Now that figure is 39 UBCs to the pound, he says.

Despite the use of automated separation and sorting equipment, foreign material may be present in finished bales. “We bale the material as-is,” Viny says. “It isn’t a perfect bale of aluminum cans, like you might get from the Boy Scouts, but it is still very salable in the market.”

Location, of course, contributes to success. “The proximity of the transfer station and recycling facilities and the smaller size of Rumpke’s Ohio Valley facility provide an opportunity to identify recyclable materials coming from specific customers. The company then reaches out to those customers to offer a comprehensive waste solution that involves a recycling component and, therefore, offers an opportunity to obtain more pre-sorted material,” Pratt says.


Where Mining Works
“Projects like ours are definitely available at other places,” says Ainsworth. “It’s just a matter of whether they want to do them,” he adds.

“Projects like this work well for everyone. Everyone wins,” Ainsworth continues. “The city saved money. We made money. The environment won.”

At Rumpke’s Ohio Valley facility, the recycling and trash are processed under one roof. The facility has a recycling buy-back center, with initial processing and baling equipment, and a transfer station.

“We collect trash and we also have recycling collection routes, which can be single-stream, office paper or cardboard collection routes,” Pratt says. The recyclables are pre-sorted, baled and sent to Rumpke’s larger material recovery facilities (MRFs). Material from the Ohio Valley facility is usually transported to Columbus. The waste material is shipped to larger regional disposal facilities.

The Ohio Valley facility provides Rumpke with a unique opportunity to observe incoming trash to determine if material can be diverted for recycling.

Beyond typical commercial recycling practices (like MRF and landfill mining), Rumpke weaves re-use and recycling into daily operations. The company has been doing this since the 1940s, when its founders set up conveyors to remove metals, rags and glass from the stream.

“Today, at our landfills, we work to recycle construction materials, such as concrete, plastic liners and water,” Pratt says. “We repurpose equipment and parts and recover landfill gas for public use as natural gas energy.”

The landfill gas recovery helps cash flow at the Shoosmith site, too.  Shoosmith generates 16 megawatts of electricity from landfill gas at the Chester landfill, enough energy to power 10,000 homes per year.

Many companies aim to implement best practices for waste reduction and recycling. “We continually search for ways to utilize the waste that cannot be re-used or recycled in an environmentally friendly way,” Pratt says.

Rumpke has added compressed natural gas trucks to its fleet and also shreds and processes tires for use as drainage material in landfills.

Sonoco’s Howard lists three keys to success: choosing a good partner, doing a waste characterization study to determine the contents of various loads and getting equipment designed for the recycling process.

At the Chester site, for example, fiber is quite important, and screens remove OCC and newsprint automatically, in addition to the more common eddy currents and magnets.

Howard says Sonoco’s process is not predicated on high-priced recyclables.

“We started this project two years ago,” he says. Back then, prices were only a fraction of what they are today. Howard says Sonoco put together a business case based on making money in that market. “By the time we got the operation ramped up, we were able to pay for it,” he adds.

However, Howard says, the project is not simply an effort to be green. “We certainly plan to make money on it for our stockholders,” he adds.

Landfill-bound loads in most localities will yield a similar percentage—25 to 50—of recyclables, sources say. While one site might be a bit higher in plastics and another in fiber, generally the effort should prove profitable, according to sources. In fact, Sonoco says it is looking to expand its landfill operation to other sites in the Mid-Atlantic and Southeast, a sign that the company likes the results of its early efforts.



The author is contributing editor to Recycling Today and can be reached at curt@curtharler.com.