Progress in processing

Huge investments have been made in the recycling industry in the last 25 years, with mixed results, Nat Egosi said in his opening remarks at the second annual MRF & Recycling Plant Operations Forum in Chicago Oct. 10, 2017.

Egosi led the one-day forum, which brought together 170 attendees, from plant and regional managers to owners, engineers, equipment suppliers and government officials. The Recycling Today Media Group hosted the event in cooperation with RRT Design & Construction, a Melville, New York-based consulting firm with significant experience in the material recovery facility (MRF) design sector. Egosi is president and CEO of RRT.

“Our focus is on the ‘process’ in the collect, process and ship scenario,” Egosi said.

The sessions at the forum focused on plant processes, from employee safety to separation of materials. MRF operators and equipment providers, among others, discussed ways to improve procedures, best practices for running sorting equipment, how to effectively manage tipping floors and retrofits as well as using data to improve operations.

The following is a summary of the event’s “Separating Do’s and Don’ts” sessions. These back-to-back panels that focused on fiber and containers, respectively, dug into best practices for three key equipment classes: screens, ballistic separators and optical sorters.

Separating Do’s and Don’ts

Egosi started the fiber panel by noting China’s ban on certain scrap imports, including mixed paper, was brought about mostly because of contaminated loads of imported baled recyclables, which is why cleaning up quality is a must.

“China is not very nice to us these days,” said Pieter Eenkema van Dijk, CEO of Van Dyk Recycling Solutions, Stamford, Connecticut, and a speaker on the fiber panel.

Van Dijk said he has seen two actions occurring in MRFs that are affecting the way recyclers sort paper: Some recyclers are changing screens to nonwrapping screens. Others have invested in optical sorting equipment.

“There’s a new way to approach single stream today, a completely different way,” Van Dijk said during the panel. “Instead of sending smaller material to screens, send it to an optical sorter. I think eventually we’re going away from screens because you can positively sort the paper, and negatives can go to optical.”

In reference to China’s import ban and its proposed 0.3 percent limit on contaminants, panelist Rich Reardon, managing director of Max-AI for Bulk Handling Systems (BHS), Eugene, Oregon, asked, “Who didn’t see this coming?”

Reardon said investing in plants and ensuring the entire system is “commissioned to perform” as it should is important. This includes “making sure the screen is set to the specification provided and that discs are in good shape,” he said.

As for using screens to collect more old corrugated containers (OCC) from the stream, Reardon suggested operators change screen openings in different zones.

“Should we be focusing on one mixed paper grade and pull out OCC, or can screens be modified?” Reardon asked. “You need to look at the opening on screens by looking at the balance on the system.”

The speakers said plastic film can make up about 5 percent of MRFs’ inbound streams. Reardon suggested using optical sorters and air to remove film. Bypassing a screen also is an option.

“We need to rethink our process flow to adapt to what we’re getting in the bin.” – Michael Drolet, Steinert US

Van Dijk said film “is a huge problem” and “it costs a fortune just to sort.”

Panelist David Marcouiller, executive vice president of sales engineering at Machinex Industries Inc., Plessisville, Quebec, confirmed the difficulty of removing film from the stream. “Film is hard to get out and, when you do, it takes good fiber with it.”

He said the bulk of labor in MRFs today is spent on the fiber line, pulling out film and OCC.

As for fiber quality concerns, Marcouiller said using ballistic separators also can be helpful. “As soon as you separate the material by size, you can really attack the problem in a different way,” he said.

When collecting material in colder climates, where snow and ice, and therefore wetness, thrive, speakers suggested lowering the incline of screens. Additionally, Marcouiller said agitating the material more often can make a real difference.

“Packer trucks are getting better at packing material … [You] need to agitate material throughout the system,” he said.

Containers

Speakers on the containers panel said it was a matter of space and capital investments in equipment that would permit MRFs to sort flexible packaging and glass, among other containers, more efficiently.

Nick Davis, senior cost estimator for CP Group, San Diego, said the industry is learning to adapt to these changes in the incoming material stream. This is especially important, Davis said, noting that MRFs’ inbound stream of flexible packaging is expected to increase by 3 percent to 5 percent in coming years.

“Flexible packaging is here and I don’t think it’s going away,” Davis said.

“There are a lot of different things to consider [to deal with this problem],” Davis added. “It will require rethinking of the MRF and how we recycle materials.”

A decade ago, the containers MRFs sorted were mostly used beverage containers (UBCs), said panelist Michael Drolet, solution sales manager for Steinert US, Walton, Kentucky. Today, inbound streams include UBCs, plastics Nos. 3-7, glass and aseptic cartons, among other containers.

“We need to rethink our process flow to adapt to what we’re getting in the bin,” Drolet said.

He said drum magnets in MRFs started as a trend about five years ago. “The right drum magnet will always be more expensive, but will give you cleaner steel.”

However, Davis recognized the potential consequences of accepting any and all materials at the MRF, saying, “We don’t have space to store every possible commodity. There are market economics and also physical economics.”

Speakers addressed the question, “Can I improve something to better introduce material to optical equipment?”

Panelist Scott Jable, director of North American sales for Stadler America LLC, Colfax, North Carolina, suggested adjusting the angle of the screens. “I always adjust the angle first; the steeper you run your screen, the less contamination.”

He said star screens and ballistic separators operate with the same purpose: trying to get 3D material to go airborne. But for these devices to work properly, they cannot be overrun with material.

“Try to run your system at what it was designed to,” Jable said. “If you overrun your screens, you’ll bury everything.”

He said most of the issues with optical sorters are mechanical. Overrunning the sorter and not cleaning valves or putting them in the wrong place can cause disruptions.

Davis said CP Group has seen a number of MRFs add optical sorters as an alternative to disc screens.

“Optical sorters, fed correctly, can do everything we’re asking them to do; it takes space and money,” he said. “Nobody has really been willing to spend that much money.”

Davis added, “There are a lot of competing issues working on the economic side, but optical sorters are going to continue to evolve.”

As for robotics, Davis said he sees this type of equipment and optical sorters as both competing and complementary to each other.

MRF operators will be charged with assessing the effectiveness of these new technologies in their facilities in the coming years to cut down on contamination and combat shifting end markets.

The author is associate editor of the Recycling Today Media Group and can be contacted at mworkman@gie.net. This article previously appeared in the December issue of Waste Today’s sister publication Recycling Today.