Operations focus: A better way

Mechanical mixed C&D sorting systems often are designed to separate out “the good stuff” from mixed loads of material. Cardboard, wood, concrete, metals and plastics are among the salable products that are sorted by one of these complex systems, but in Cary, Illinois, Lowe Enterprises decided to try a different approach for one of its commodities.

The company’s General Kinematics’ finger screen had been playing the role of separating mixed C&D loads for the company since about 2007. Part of those mixed loads running across the picking line included asphalt shingles. After about a year into processing C&D, Superintendent Kerry Lowe recalls seeing workers hand picking heavy shingles off of the line and thinking, “There has to be a better way.”
 

Role reversal

Kerry says, “To me it made more sense to do it reverse. Just pull the light stuff out of the shingles and do it opposite from C&D and pick out the nonrecyclables.”

Often shingles that arrive at the facility have nails, wood and plastic stuck to them. Kerry says by running the shingle loads separately from other mixed C&D loads, “The finger screen shakes out the little splinters of wood that are hard to hand pick out.”

The small pieces of wood go into a separate pile and the shingles continue up the line. “We pull off the light stuff and let the shingles fall into the trailer, so then you are not trying to hand pick heavy shingles,” explains Kerry.

Shingle loads are treated differently than mixed C&D loads going across the line. “We do the opposite,” Kerry describes. “Instead of pulling the recyclables out, we pull the stuff that is not recyclable at the shingle plant. We kind of reverse pick it.”

Shingles are piled in a separate area from C&D debris. “We have a ramp that can work from either side of our finger screen plant,” Kerry says. “We keep the shingles on one side, the construction debris on the other, and instead of picking out all the recyclables for the construction debris and letting the waste fall out at the end, we pick out all the unusable [materials] and let the shingles fall off the end.”

Those working the line pick out plastic and wood from the shingle loads and the screens help shake out what they can’t get, including roofing nails.

“It was a better solution for us,” says Kerry of changing up the process.

The cleaned-up shingles are loaded directly onto a truck and hauled to two nearby shingle processors where they are further processed and ground, then sold to end markets.

“The recyclers that recycle the shingles receive a better product because all of the little fines and nails are out of it,” says Kerry, noting, “It is not 100 percent clean, but a lot of the stuff shakes out. You are able to get them a lot cleaner than if you were to hand sort them.”
 

Learning curve

Kerry’s father, Marshall Lowe, is president of Lowe Enterprises, which began in the early 1990s recycling concrete and asphalt, and as he puts it “gravitated to construction debris.”

“We were already part of the C&D product stream, so we just went for the rest of it,” says Marshall. Lowe Enterprises is certified in the state of Illinois as a gravel producer. The company also operates roll-off and excavating businesses. He admits mixed C&D recycling has been a learning experience.

When building the mixed C&D plant seven years ago, the Lowes also thought outside of the box. The mixed C&D plant was built extra high, says Marshall, at about 15 feet off of the ground. It is covered by a metal enclosure, which is heated to keep workers warm in the winter. Instead of bunkers below the sorting line, the material falls directly into 13-foot trailers positioned underneath equipment. Cardboard goes into a compactor also below the sorting equipment. The plant employs about 10 people.

Marshall explains the idea behind the design: “I didn’t want to handle that material a second time,” he says. “Our conveyors are cantilevered out enough that we can load the semis. The material falls off the conveyor belt onto the semi.”

Lowe Enterprises processed 4,800 tons of material in September 2014, says Marshall. Of that, 630 tons were shingles. He says 2014 has been a good year for business, although he expects the usual winter slowdown. Shingles in particular have been flooding the facility. “All of a sudden we were just inundated with shingles,” he says. “Roofers started coming to us. It has picked up dramatically this year.”

Despite starting a mixed C&D recycling facility amidst the construction downturn, Marshall says he has no regrets about expanding into the business. “It is incredible,” he says. “You have to diversify, and I am certainly glad that I did. It’s been good to us.”

The author is managing editor of Construction & Demolition Recycling and can be reached at ksmith@gie.net.