GreenRock Recycling is a recent startup in Clinton, New Jersey, that markets construction and demolition materials for resale to residential, municipal and commercial customers, including standard and dyed mulch, topsoil, mason sand and screenings.
With its acquisition of a Mobirex MR 110 ZSi EVO2 impact crusher from Kleemann in late 2016, GreenRock is now producing a New Jersey Department of Transportation (DOT)-certified recycled concrete aggregate (RCA) and processed reclaimed asphalt pavement (RAP) that’s of great use to contractors in the Garden State.
“Our new Kleemann crusher makes a very nice, clean RCA that compacts well, looks like 1 1/2-in.-minus dense graded aggregate, yet is less than half the price,” says Mike Plushanski, general manager. “And our RAP is used mostly as a base material, which also is highly compactable and affordable.”
GreenRock was founded in 2012.
“Our permitted recycling initially was wood – as in tree parts only – including stumps, wood chips and logs,” Plushanski says. “But now we receive brick, blocks and concrete, which we comingle to make recycled concrete aggregate. And we receive clean asphalt to make RAP. We balance the cost of processing by charging tipping fees in addition to the product sales.”
In addition to recycling, GreenRock has a small shale quarry on the hilly property, which it rips to produce certified clean fill.
“We’re just trying to bring our site down to road grade so we have one nice, level property,” Plushanski says. “The shale can be used very much the same way as RAP, except that shale has more uses as New Jersey is very strict on how RAP is used. But as a certified clean fill, shale can be used anywhere.”
Replacing a small jaw
GreenRock’s new Mobirex crusher replaced a small, 1,000-tpd jaw crusher that was inherited from an existing construction business.
“Over five years we have grown like crazy, and that little crusher was going 40 hours a week and not putting a dent in the stockpiles,” Plushanski says. “Concrete was coming in so fast that the piles grew even as we were crushing. It also did not have the screening system, and that was part of the problem; we weren’t able to sell material, as flat, ‘pancake’ pieces larger than 2 in. would just drop through the jaw.
“We were unable to meet size specs, and we could not get DOT certification for 1 1/2-in., which a lot of contractors need for big jobs,” he adds. “We needed a higher-capacity crusher, and we needed to meet DOT standards. The Kleemann impact crusher was the way to go.”
Kleemann’s control system was one reason GreenRock went with the MR 110 Z Si EVO2.
“The Kleemann is so much more advanced than the other machine we demonstrated,” Plushanski says. “With the remote control I can adjust everything, including the distance of the curtains off the blow bars, or open up the return conveyor. If something goes wrong, you can shut down faster, and diagnose the problem and correct it.
“With the other machine, you had to walk up to a difficult-to-navigate computer screen,” he adds. “With the Kleemann, you just touch the part of the machine on the screen. It’s user-friendly.”
Another cost benefit is Kleemann’s diesel-electric drive system, according to Plushanski.
“Our old jaw crusher was burning 11 gallons per hour,” he says. “The other crusher we demoed was upwards of 14 gallons an hour. The Kleemann is burning 6 1/2 gallons an hour, with a 500-hp motor running. The fuel savings are huge.”
The independent prescreen within the Mobirex hopper also was a plus for GreenRock. Because GreenRock leaves all of the fines in the mix, permitting the fines to bypass the crusher internally increases wear parts longevity.
“The prescreen ahead of the impactor is so much more efficient than the simple holes of the other machine we looked at,” Plushanski says. “Being able to adjust the speed of it, making sure we are dropping all the fines out, we don’t have an ounce of fines more than should be going through the rotor. They are dropping right down to the main conveyor and out to the 1 1/2-in. screening system, and not beating up our blow bars.”
Alternatively, GreenRock processes RAP to 1 1/4-in. minus size, and it’s often used as parking lot or driveway base material. For RCA and RAP fines are retained to create a product similar to a dense graded aggregate, Plushanski says.
“We want a compactable base material, and for now choose not to remove fines out the side conveyor off the prescreen,” Plushanski says.
Timesaving startups
fly.
Startup of the crusher in the morning is made easy by the automation brought to GreenRock, especially the automatic closed-side gap setting adjustment for the MR 110 Z Si EVO2.
“You can do the zero-point adjustment all electronically,” Plushanski says. “Whatever size I set the curtain from the blow bars I know is accurate. We no longer crush 40 hours a week as we did with our old crusher. Instead we only need to crush one or two days a week, so every couple of days, when I open up, I will check the bars and set a new zero point.”
That so much of the machine is computer-controlled is a benefit to GreenRock, Plushanski adds.
“The computer operation is a major purchase point,” he says. “The other crusher we demoed had all mechanical adjustments. With the Kleemann, one morning when I was firing up, I realized I was still set up for RAP. I changed the curtain distance as we idled up for concrete. I changed the prescreen vibrating and hopper speed. I was able to do all three adjustments from the touchscreen, whereas the other crusher meant shut down and climbing up with a wrench. I would have been up there a half hour trying to dial it down, and somehow measure it.
“With the Mobirex, it takes me 30 seconds to adjust three parts of the machine, versus not being able to adjust the three parts all at once with the other machine,” he adds. “You couldn’t do the prescreen adjustment, and to just do the hopper and blow bar adjustment would have taken me a half hour with the machine off. With the Kleemann we are up and running without having to stop.”
Kleemann’s diesel-electric drive system also saves time at startup, especially on cold days.
“It’s nice not having to wait for the hydraulics to warm up,” Plushanski says. “It’s freezing cold up here half the year. In the mornings we don’t have to wait 25 minutes for the hydraulics to warm up. With the old crusher, we’d start it up, run a conveyor and go back to the office to finish our coffees while it warmed up. When we demoed the crusher fresh off the boat it was 9 degrees, and it was up and running in 15 minutes.”
Another time-saver is the easy setup and dismantling that the Mobirex offers.
“It’s easy to set up and take apart,” Plushanski says. “The conveyor-mount secondary screen system unplugs with quick disconnects. In 15 to 20 minutes I can drop it, change all the screens and put it back up, and recycle a different product.”
And its sheer mobility is a time saver as well. GreenRock moves the impactor to different stockpiles as it produces different products.
“I was here at 5:30 a.m., changed the screens and walked the crusher across the yard by 6 a.m.,” Plushanski says.
Aluminum shields around the magnet keep the scrap steel or iron discharge running free of jams, he adds.
“Around the magnet, Kleemann provides aluminum shields that don’t retain bits of wire or nails,” Plushanski says. “Nothing builds up because it can’t stick to the aluminum, but our old crusher would have had thousands of nails stuck to the frame where it had become magnetized. It was difficult to clean every day.”
Scrapers on the belts are another advantage that benefits GreenRock.
“It’s the little things that make a difference, like scrapers at the tops of each of the conveyors,” Plushanski says. “No adjustment is needed for them, and they get all of the material off of the belts. As a result I don’t have a 2-ft.-high mound of dust under the machine, which I have to clean up each day.
A steel pan feeder located under the crusher intercepts crushed material in advance of the conveyor, absorbing the shock and protecting the conveyor.
“We used to pierce belts like there was no tomorrow on our old jaw,” Plushanski says. “We’d spend $10,000 a year on belts that we otherwise would have no problem with. But these belts never get that abrasive impact.”
Tom Kuennen is a freelancer writer specializing in the construction, energy and mining fields. Visit his website at www.expresswaysonline.com.