Electronics unraveled

Recycling company Müller-Guttenbrunn Group (MGG), headquartered in Amstetten, Austria, was founded in 1954 with a focus on scrap metal recycling. Not surprisingly, this emphasis on metals has expanded to include the growing stream of obsolete electronics generated throughout Austria and the company’s additional service areas.

Throughout the years, MGG has invested to develop and innovate its electronics recycling processes for the multiple streams of materials electronics represent.

Engineer Herbert Müller-Guttenbrunn founded the privately owned company, which is managed currently by third-generation family member Christian Müller-Guttenbrunn, who is CEO.

Across its various facilities, MGG recycles around 850,000 tonnes of materials per year, including ferrous and nonferrous metals and plastics.

The company operates nearly 20 facilities in Austria, the Czech Republic, Hungary, Romania and Switzerland.

In Austria, Metall Recycling Mü-Gu GmbH is the ferrous recycling arm of MGG, handling end-of-life vehicles, electronics, appliances and other types of metallic scrap. The company also operates a specialised recycling process for obsolete electronics, accepting nondepulluted and depolluted electronic scrap from external suppliers and from other MGG facilities for further processing.

Metran Rohstoff-Aufbereitungs GmbH, Austria, is the nonferrous metals recycling division of MGG, which similarly handles processed e-scrap from across the MGG portfolio of companies as well as from many external companies across Europe.

In 2004, the company formed the joint venture business MBA Polymers Austria in Kematen an der Ybbs, Austria, in partnership with U.K.-based MBA Polymers Inc. The production facility began commercial operations in 2006 and processes large volumes of plastics recovered from e-scrap supplied by electronics recyclers from all over Europe. It produces several types of plastic resins.

The comprehensive electronics recycling process MGG and its joint venture operation have created and updated over the past decade has been the subject of numerous presentations and tours. Attendees of the International Electronics Recycling Congress, which is held in January in Salzburg, have had multiple opportunities to tour MGG facilities, for example.

Chris Slijkhuis, public affairs director for MGG, explains that one of the goals over the years has been to achieve “recycling depth” across all of the materials collected and processed.

“We want to really dig deep to get recovery of the material as far as we can get. We believe this is basically the head and heart of recycling.”

Slijkhuis says MGG is Austria’s largest electronics recycler. The company has invested in upgrades and innovations to its process in recent years providing capacity and recovery that are nothing short of world-class, particularly when it comes to small domestic appliances, he adds.
 

Ferrous improvements

MGG’s specialised electronics recycling process, Slijkhuis says, involves four steps, some aspects of which were created and developed in-house.

The process begins at Metall Recycling Mü-Gu with depollution using a piece of equipment known as the Smasher, which the company first created in 2004 using a large drying drum sourced from a nearby apple concentrate factory, Slijkhuis says. “We took this drum and converted it to a machine to tumble the e-waste.”

Electronics placed in the Smasher are tumbled to facilitate the release of items such as batteries, capacitors, toner cartridges and printed circuit boards without damaging them.

The machine has been patented by MGG, and Slijkhuis says approximately 20 sites throughout Europe and the U.S. have since purchased the drum.

The Smasher 2.0, introduced in 2013, is a smaller unit designed to gently remove even more pollutants from electronics, including electronic motors and spools and wood, which is problematic for further separation steps.

Slijkhuis explains that the Smasher 2.0 tumbles electronics so that capacitors and other pollutants can be removed easily. The materials are released onto a conveyor belt, where the pollutants are removed by hand. “It’s a very efficient way of getting the pollutants out of the e-waste,” he says.

“Basically, all of the pollutants are being taken out. The result is then raw material for our shredder,” Slijkhuis says.

He adds that the Smasher 2.0 surpasses European Union (EU) minimum thresholds for capacitors and batteries removed per tonne of e-scrap processed during the depollution step.

“We are getting close to 2 kilograms per tonne of capacitors,” he says, “almost double the minimum standard.” For batteries, the Smasher 2.0 yields about 40% more than required.

A more recent but related ferrous-side innovation at MGG concerns the shredding process. From 2004 to 2011, Slijkhuis says the company scrutinised its shredding process with an eye for improvement, particularly regarding the recycling of small domestic appliances.

“We realised we could do better in terms of ferrous metals and avoiding the loss of copper and precious metals,” he says. Additionally, Slijkhuis says, MGG realised the plastic stream could be improved during the shredding process.

The company’s work in this area led to the 2012 introduction of the EVA shredder, which Slijkhuis says is a combination of several techniques on the market, arranged in a specific configuration, and followed by a multistage magnet system for ferrous removal, designed in conjunction with the EVA shredder.

Ultimately, the EVA shredder was designed to prevent the loss of copper and precious metals and to optimise the shredding of plastics for subsequent processing.

Slijkhuis explains that EVA is the German abbreviation for electronics recycling plant, elektronik verwertungs anlage. It is also named in honor of Eva Müller-Guttenbrunn, the daughter of MGG CEO Christian Müller-Guttenbrunn, he says.

The machine was built in a 17-metre-high building, where electronic scrap is tipped by bulk loaders. “Because the electronics are already depolluted, you can transport them as bulk-loaded material,” Slijkhuis says. The plant is situated next to a rail station, and much of the material is transported by rail. “We believe that in the future, getting this type of waste away from the road and to rail or ship is the better option,” he says. “This means raw materials can be shipped over long distances at lower prices and in really big quantities.”

Slijkhuis says the EVA shredder is designed to crush electronics very quickly to prevent excessive plastics breakage.

“One of the problems with e-waste,” he says, “[is] if you hit too strongly on the metals, they will be hammered into the plastics.”

Because plastics comprise about 30% of e-scrap, “We want to get them out as cleanly and quickly as we can, so that MBA Polymers can make a good separation,” Slijkhuis says.

In addition, he says, the EVA shredder uses an extremely efficient air treatment system, removing shredded material from the unit very quickly.

The multistage ferrous separation process that follows shredder uses a complex magnet separation system and produces a very clean stream of metal.

After that process, he adds, “We end up with a very clean ferrous and as little as possible copper and aluminium.”

He adds that the ferrous fraction produced at Metall Recycling Mü-Gu contains no more than 0.15% free copper.

“This is important because the copper is more valuable, and it’s also the fraction with which we want to keep the precious metals as well,” he says.

The copper and aluminum fraction is transported to sister company Metran for processing.
 

Nonferrous developments

Regarding the company’s nonferrous developments, Slijkhuis says the innovations at Metran have included a large number of improvements made since the company was founded in 1984.

He explains that the Metran division was created based on the company’s desire to further separate the growing volume of shredded metal streams it was creating instead of shipping them off to another recycler.

One of the company’s innovations includes what Slijkhuis describes as a highly efficient heavy media plant built in 2006. The machine has three drums in line followed by eddy current separation and sieves at the end of the process.

“We have been able to reduce the smallest size from 5 millimetres to less than 1.8 millimetres with continuous improvements on the FKT process that deals with the small sized material,” he says, adding that the system can separate copper particles well below that size.

“At the end of the process it gets to a very concentrated copper fraction, and a lot of our effort is really for copper and precious metals,” Slijkhuis says.

The facility uses both sifting and sensor sorting processes to yield these results, he explains.

Slijkhuis says the company’s sensor sorting process can sort by colour, separating green circuit boards from silver metals or separating yellow-orange coppers from yellow-red brasses.

Ultimately, the process yields about 10 different streams and many more substreams, Slijkhuis says.

Metran receives mostly bulk-loaded materials from MGG-owned facilities in Amstetten as well as from the company’s facilities in Hungary, the Czech Republic and Romania. Other companies also send their shredder residue to Metran for processing.

Plastics remaining from Metran’s process are then sent to MBA Polymers Austria. The joint venture was formed in 2004 to deal with the stream of plastics that Slijkhuis says accounts for about 25% to 30% of the e-scrap stream.

Slijkhuis relates how MGG’s CEO had the foresight to partner with MBA Polymers, a company that could contribute extensive experience in the plastics recycling field.

“The plastic part is an important part of the process,” he says. “We want to separate these materials as far as we can go, and that meant that we needed to add sorting processes for e-waste plastics.”

The mix of plastics comprises mostly acrylonitrile butadiene styrene (ABS), polystyrene (PS) or polypropylene (PP), but there also are plastics containing flame retardants, which are not recyclable and must be removed.

Slijkhuis says MBA’s process begins with removal of nonplastics before the material is sorted into by polymer type. The resulting products are compliant with the European Union’s (EU) Restriction of Hazardous Substances directive (ROHS) and Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation.

“We start off with a very complex waste,” he says, “and by the end of our process, we get to a raw material again that can be used in new electronics.”

Initially, the facility created ABS, high-impact polystyrene (HIPS) and PP resins primarily from obsolete electronics. In 2014, it also began producing polycarbonate (PC) and PC-ABS resins.

MBA Polymers Austria processes 50,000 tonnes of plastics annually.

Overall, Slijkhuis says MGG is achieving a 94% recycling and recovery rate for small domestic appliances. Of that, he says, 75% is recycled, while 19% is recovered as energy. That means the company currently is reaching EU recycling targets for 2018 when it comes to small domestic appliances, he says. It also means the company is achieving significant depth of recycling.

“So many companies that recycle electronics materials just do a tiny bit and send the material to someone else,” he says. “We try to get as much possible material out of it as we can.”

The author is managing editor of Recycling Today Global Edition and can be reached at lmckenna@gie.net.