One could argue all waste streams are troublesome. However, some are more difficult than others. There’s an organic focus to streams like FOGO and the (non-treated) wood content of C&D waste, whereby environmentally friendly solutions can be found. Yet, there are other streams, there are just plain ugly. Soft plastics – well, most plastics – immediately spring to mind. Another is tyres. And it is the latter that has caused many issues when it comes to disposal. One of the key prerequisites to making sure tyres are recycled, reused or disposed of correctly, is making sure they can be broken down properly. This is especially true for off-road tyres (OTR), even more so with those involved in industries like mining. Some of the tyres are huge – they can weigh hundreds of kgs and be anywhere from 1.5 metres to 4 metres high.
Eldan Recycling is a Danish-based company that offers specialised equipment that can help break down OTR tyres so they can be processed properly. Carsten Nielsen is the company’s Pacific area sales manager, who has been part of a recent process to help an Australian-based customer meet its needs when it comes to breaking down these huge tyres.
“We went into a collaboration with an Italian company over the contract to help the Australian client. The Italian company did the pre-cutting of the OTR tyres,” he said. “Even that is a quite big chunk of– we are talking about 100- to 150-kilo pieces. After the Italian company has done the pre-cutting, our equipment does the chopping down into even smaller pieces.”
Nielsen said that Eldan Recycling equipment is currently being used as several lines running in New South Wales, another in WA, and two-and-a-half lines running in Melbourne. The key, he said, is to make sure that the OTR tyre waste is small enough to be used and resold, and in some cases, exported as TDF (tyre derived fuel).
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“It can only be 150 mm or less because you can’t export bigger than 150 mm. That is illegal,” he said.
As wells as the rubber being used as TDF, there is another product in a tyre that can have high value depending on how it is extracted – the steel.
“Steel is a quite valuable product, because you can get anywhere between $200 to $300 a tonne if it’s cleaned correctly,” said Nielsen. “With our system the purity of the steel is up about 98 per cent. With other systems you might get 90 to 92 per cent purity, maybe even less. And for that product you might get between $20 to $50 a tonne due to the amount of C02 that will be produced. Our system allows clients to expand and clean the steel.”
How does the system work in practical terms? When a tyre is initially processed, the steel isn’t extracted separately; the pre chopping part of the system cuts it up with the rest of the tyre. Then a device called a rasper cuts it down to a certain size. When the tyres are cut, it has the effect of liberating the steel from the rubber.
“The steel might have a little bit of rubber attached to it when it comes out of the raspers,” said Nielsen.
“For example, let’s assume we have a 20 mm screen in the rasper – the material falls through; some of the rubber comes out with the steel attached, and some comes out clean and will be picked up by a magnet next to a screener where you are bouncing the rubber and the steel.”
He said that any steel that is free of rubber will fall through a screen and will go out on a vibratory outlet, and there is also have an air stream going up to remove the textile, which is another component of the OTR tyre. The rest is a mixture of rubber and steel.
“You have a double drum magnet that picks out the steel and the rubber will fall through,” said Nielsen. “But as you’re picking up the steel to a magnet, you might have some rubber between the magnet and the steel. So, you go to a secondary drum magnet where the steel is airborne because of the magnetic field. The rubber will fall down in between those two magnets.”
It is a combination of the screening, the blower for the textiles, and the double drum magnet for the steel that makes it so clean. However, once the initial action is completed, on the top layer of the screener there will still be some rubber and steel, which means it is still not clean enough. The product is then put back into the rasper to have one more rerun.
“You’re not throwing away any rubber, and you have a clean steel,” said Carsten.
Fit for purpose
Nielsen also points out that Eldan Recycling is hands on in all aspects of building a line that fits the purpose of its clients.
“We build everything,” he said. “Almost all of it is being designed and built in-house. With that being said, we are not producing the conveyors and the small stuff. We buy that from a sub supplier, who has been supplying us with belt conveyors for the past 20 years.”
The new WA facility was commissioned in November, and it has since produced its first 600 kgs of rubber granules. Eldan Recycling worked with the client to make sure everything was in place. Collaboration was the key, as there were several issues that needed to be taken into consideration.
“What is going to be the best building to get for the equipment?” said Nielsen. “It wasn’t a large footprint, so we had to ask ourselves, ‘Can we squeeze it all in? Can we reduce the footprint for the Eldan Recycling machines?’ Also, ‘Where was the best area for storing the tyres before they are processed?’”
This last part was important because all state EPAs have strict requirements about how many tyres can be stored, where, and for how long.
Nielsen said that the decision also had to be made as to how far down the OTR tyres were shredded.
“Do we produce granules, TDF, or do we produce powder?” said Nielsen. “And luckily for Elden, they wanted to do it all including going all the way down to powder. The powder is used for mainly for road, construction. We’re doing everything.”
Some of the OTR tyres can weight up to four tonnes. They are initially cut up by a MT-Rex cutter, which chops the tyres into manageable sizes. They are then feed into the line that Eldan Recycling has set up. The line can throughput about eight tonnes an hour with ODT tyres, and about 10-15 tonnes an hour with car tyres.
When it comes to back up service, Eldan Recycling monitors its gear online and the company is only a phone call away to help troubleshoot any issues. Nielsen says its service should never be underestimated.
“One of the reasons why we convinced our tyre client to buy from us is that we answer all their queries straight away,” he said. “They are working with salespeople who know their stuff. My background is up in supervisor for installs when I was way younger. Also, I’ve been working with the technical part all my life.
“Eldan Recycling offers a lot of quality stuff on the line. We have machines I installed in Australia almost 20 years ago that are still running strong, even after the line had to be relocated to another factory when the company moved.”
Finally, Nielsen said that Eldan Recycling always backs its products. This is outlined in the company’s contracts when it signs up new companies to install a line.
“When we make a contract for a line install – like we’ve done for this Australian client – we state that we can do a certain amount of tonnage,” he said. “With this purity, and a certain amount downtown for maintenance, our products get the job done.”