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Dem-Con looks to Rotochopper™ for asphalt shingle recycling equipment

0591by Mary Weaver

photos by William Weaver

Dem-Con Companies is a rapidly growing, third-generation recycler that began as the Louisville Landfill in the 1960s. In 2001, Mark Pahl and Jason Haus together purchased that business from Pahl’s father (and Haus’s father in-law), becoming Dem-Con companies. Today, Haus serves as CEO of the operation while Pahl is COO. Dem-Con currently processes material through a group of five business units, all under the Dem-Con Companies umbrella. These operations include Dem-Con Recovery & Recycling (DCRR), Dem-Con Materials Recovery (DCMRF), Dem-Con Shingle Processing (DCSP), Dem-Con Landfill (DCL), and Dem-Con Metal Recycling (DCMR).

Located in the metropolitan Minneapolis, MN area, Dem-Con’s site is a considerable asset, now that the southwestern metro area has grown up around it since the nineteen sixties, when the site was considered beyond the city limits. Today, their 120 acre, full-service environmental campus is equipped to recycle, process and dispose of materials, conveniently. It is near a major highway where customers can reach Dem-Con quickly.

Dem-Con Shingle Processing

In 2006, Dem-Con helped pioneer a process to collect, clean, and grind tear-off asphalt shingles and shingle manufacturer’s waste to market recycled asphalt shingles (RAS) to the hot mix asphalt industry in Minnesota. Working with MnDOT, Dem-Con played an integral role in developing a specification for post-consumer RAS in hot-mix asphalt. During that time, Dem-Con worked with Rotochopper, hot asphalt companies and MnDOT, to produce a ground shingle product that features a high degree of consistency in both product size and product quality.

Today, Dem-Con uses a wheeled portable RG1 Rotochopper Horizontal Grinder for shingle grinding and a Wildcat model 622 Cougar Trommel to screen the material once it is ground. “We began working with Rotochopper early on,” noted Haus. “We have developed a strong relationship with them.”

“Meeting product specifications and maintaining product integrity have been important to the growth of Dem-Con’s shingle processing business,” said Ben Wetzell, Waste Services Manager. “MnDOT’s standard for material post grind is that 100% must pass through a ½ inch sieve and 90% must pass through a #4 screen. At the same time, there must be less than .5% deleterious material. By today’s MnDOT HMA standards, the maximum allowable RAS in a mix is 5%.”

As a part of meeting MnDOT specs, samples taken by trained technicians are lab-tested for asbestos. These are taken from every 250 tons the company grinds. “We have years and years of data that show consistently that there is no asbestos in the shingles,” explained Wetzell.

Dem-Con recycles approximately 25,000 tons of shingles annually, but the company continues to look for additional outlets for recycled shingles. There is not enough demand from hot mix asphalt to use all the inbound material the company receives. As a result, not all shingles are recycled.

“There are new technologies on the horizon, though, to capitalize on the value of the raw materials from which shingles are manufactured,” said Wetzell. “Recently a new company called Recovery Technology Solutions has opened nearby in Shakopee, MN, and has begun to accept manufactured shingle waste. The company is using extrusion technology to extract the asphalt from the shingles and markets the different components of the shingle.”

In 2011, Dem-Con received Minnesota’s Governor’s award for pollution prevention. Dem-Con’s partnership with hot mix producers and MnDOT led to the award by Governor Mark Dayton titled, “Roofs to Road- A Successful Partnership.”

Other Companies under the Dem-Con Umbrella

One of their newer business units includes a single-stream recovery facility. Dem-Con’s Material Recovery Facility is an award-winner. The facility opened in 2013, and recently, it was awarded the “2015 SWANA GOLD AWARD FOR RECYCLING SYSTEMS” by the Solid Waste Association of North America. This MRF is a 70,000 square foot state-of-the art processing facility that has the capacity to recycle 20 tons of material per hour. Their process includes a proprietary screening technique to separate all fibers, an MSS Aladdin Optical Sorter to separate various types of plastics, and an eddy current separator to remove non-ferrous materials. Sorted material is baled using two IPS balers, one a two-ram unit.

The system includes several specialized screens including a glass breaker screen, from which glass is sent to the glass clean-up system. It has a screen to sort 2D and 3D mixed paper; an ONP (old newspaper) screen with rotating rubber star discs; and a rotating drum magnet, from which ferrous metals are sent to the metals silo.

Although many of the MRF’s being built across the nation have their own fleet of garbage trucks, Dem-Con has never chosen to pursue hauling. “We made this calculated decision because it made sense, given our situation and the needs of our customers,” said Wetzell. “We are a merchant style facility, which is somewhat unique. We want to grow with our customers and meet their needs to service them fully, as a one-stop shop.”

“For everything we recycle, we have several different options locally, both in the twin cities area, and in greater Minnesota, to market the recycled material. But to market successfully, everything we send out must meet or exceed industry specs, and we work hard at that. We’re not bidding against them on hauling contracts or hauling for disposal jobs,” he noted. “We process residential and commercial recyclables from haulers throughout MN and the surrounding states.”

DCRR, another of the Dem-Con businesses, is a C&D materials recovery facility that features an Erin Processing system to separate C&D debris, such as cardboard, wood, metals, and aggregates, which are recovered and recycled. DCRR has the distinction of being the first in the Midwest to have its recycling rate verified by a third party, The Recycling Certification Institute.

“The RCI is a 3rd party certification through an audit that determines that your recycling rates are real, verifiable and attainable,” he said. Recently, Dem-Con has been described as “One of the leading vertically integrated recyclers in the Midwest. The company also grinds untreated scrap wood for a variety of end-user markets. For this segment of the business, they use a stationary Rotochopper ECC 266 horizontal grinder. The ground wood is screened to produce a 5/8 inch mulch-like consistency. “This material is conveyed into a building where it is live loaded onto walking floor trailers and ready for market.”

The most recent addition to the Dem-Con Companies group is Dem-Con’s Metal Recycling business. DCMR opened the doors of their new building in July of 2015 as a full-service metal processing facility. “We accept ferrous and non-ferrous metals as well as autos. The facility is a great fit to Dem- Con’s existing environmental campus, helping to build the ‘one stop shop’ mentality to service all our customers’ needs,” he said.

Dem-Con also runs a state of the art, lined landfill. “We accept industrial and C&D waste, and the landfill provides an outlet for the residuals from on-site processing operations. This facility also provides an environmentally safe disposal option for asbestos, contaminated soil, and other non-hazardous waste materials.”

“We believe it’s important to educate the community and children about recycling and waste disposal.” To this end, the company recently opened an Education Room and an ‘End Markets Room’ that allows visitors a hands-on learning experience.

“We believe it’s important to show first-hand how recycling happens, and the importance of being a good steward of the environment,” continued Wetzell. “The program allows visitors to sort materials themselves to better understand what materials can and cannot be recycled.” School and community tours are given regularly.

Dem-Con has made a solid start on its mission: “to provide environmental solutions that are economically viable, sustainable and technically sound.” Judging by the results thus far, it would appear that they have only just begun.



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