How do you recycle a mattress?

How do you recycle a mattress?

Well, there is the dumb way. This assumes that the springs are the valuable bit, and tosses the mattress into a shredder and pulls the shredded up steel off using magnets. Looks like this.

Mattress in a low speed shredder, image courtesy of American Recycler

You'd think that was a pretty clever way of going about it. You'd be wrong.

Sure, there's value in the steel, but there's also value in the foam (depending on markets) and the timber (to a lesser extent). Shredding the mattress destroys these elements.

It also jams up shredders. I have been to any number of "demonstrations" of new shredders that will apparently shred up a mattress. They're usually good for a couple before the spring steel clags the machine up. You want to laugh, because you knew it was going to happen, but you just feel sorry for the poor contractor who, at best, has just lost a whole heap of potential sales. At worst he's damaged his machine.

And then there's the clever way. This looks at the value of everything, including the space taken up in landfill, and pulls the mattress apart to maximise these values. It is men and women with sharp knives standing around a mattress on a wool classing tables, cutting it apart to separate out the springs from the foam from the fibre from the fabric. It looks like this:

Mattress recycling with a knife, image courtesy of MPR News

The steel obviously has a market (but preferably cut into metre square pieces so it doesn't jam the steel shredder), and the foam can go to things like carpet underlay. In Australia, the big player was and presumably still is Dunlop Flooring, part of Pacific Brands. Baled and shipped to Melbourne, it is reincorporated into new products.

Up until late last year, you could comfortably say that most Australian cities had a mattress recycler, however mattress cleaner and recycler Dreamsafe went into voluntary liquidation in November 2011. They had a lot of plants on the east coast. There are probably others.

In the west, the Eastern Metropolitan Regional Council runs one, but you can drop your mattress off at most waste facilities and they will take it to the EMRC. You'll pay $10-20 or so for the service, but seriously, for the sake of a pint or two of beer at a Perth pub, how could you not?

The lessons from scrap steel recycling

In yesterday's blog Scrap steel - the greatest recycling story ever?, I pointed out how significant scrap steel is as a recycling sector. The sheer size of scrap steel recycling through the Electric Arc Furnace obviously diverts large quantities of material from landfill, but it also saves immense quantities of energy and thus greenhouse gases.

Electric Arc Furnace, image courtesy of Made in China

 This is all good, but more interesting is what lessons can be learned. My view on why scrap steel is so heavily recycled is:

Steel is integral to industrial societies

Steel is used in so many applications, from consumer uses like cars, through to heavy duty industrial application such as reinforcing for concrete. Indeed, it is so pervasive that it could be said to define the current era. All of this means that there are a great many buyers each looking to use it in any number of applications. The market drives this.

Translating to other materials, it is vital to let markets drive recycling, a point I return to over and over. Recycling without a market is just another form of waste disposal. Markets thrive where there is competition, and so developing a myriad of uses for the materials within waste will encourage its recycling.

Steel from scrap is high quality and uses less energy to make than from iron ore

It always helps if product generated from recycled material is of high quality. It especially helps if there are energy savings (though these tend to net out through pricing of scrap steel when compared with other raw materials such as iron ore). 

Sometimes these attributes are inherent in the product. Steel, aluminium and glass all recycle into high quality products using less energy. Sometimes it is a decision made by the recycler. In deciding how to sort for materials, the quality of the end product is determined. Failing to remove steel (ie nails) from timber recycling plants means that the chip cannot be used for particle board manufacture.

Steel is a cornerstone of the American economy

The point here is similar but different to my first. Being linked into the dynamic, innovative American economy means that there will always be a seething mass of engineers and entrepreneurs looking to do better. This is one of the great features of the American culture, and why America recycles more than 80% of its steel, far better than any other economy.

Other materials have a great prospect if they too can hitch their wagon to a culture of innovation. You can imagine, for instance, palladium's use in electronics driving all sorts of recovery innovation. This will be the subject of a future blog.

Steel is easily extracted

Being magnetic, it is easy to remove steel. Similar processes can and are being invented for other products, but here is where materials processing engineers with some lateral thinking could be game changers. We need to support this, encourage it, drive it.

Steel is dense and easily transported

There is a lot of cost in moving space around. If you can get a lot of weight into that space, then you are increasing the transport efficiency. Less dense materials can be made more dense through compactors, and this must be (and is) a first step for any recycling operations.

Waste paper baler, photo courtesy of Alibaba

Steel is high value

Leaving perhaps the most important to last - steel has a value that is high and preserved as it moves through the economy. This enables a vast web of collectors consolidating to larger and larger entities, all profitable in their own right. The ecosystem thus created is vital. Container deposit schemes seek to create the same system of cascading value through legislation. Not as good as a natural market, but sometimes these sorts of steps are needed. Any long term recycling and upcycling venture must be financially worthwhile for all participants.

So my thoughts. I'd be keen for comments on how the success of scrap steel can be, and is being, translated to other materials.

Scrap steel - the greatest recycling story ever?

When we think of recycling, we tend to think of plastic, glass and paper. The sort of stuff we see around the home and put out into the recycling bin. This is important, but the real story in recycling is scrap steel.

Global trade in scrap steel, 1998-2010

The chart above shows immense tonnages of scrap steel used annually - over 500 million tonnes per year. The whole report "World Markets for Recovered and Recycled Commodities: The End of the “Waste Era”..." is fascinating, and well worth a read.

This is obviously not the same as the 1,000 million tonnes plus of iron ore traded each year, but not grossly less. A bit sobering for Australians accustomed to feeling that they are building the world out of the Pilbara.

So why is this? Why is scrap metal so successful when we can't do the same for plastics, rubber or all the other commodities. I don't quite know, and would love to hear ideas, but my take is:

• Steel is integral to industrial societies, and useful in so many applications. As a result, there are likely to be many buyers
• Scrap steel makes high quality steel with lower energy requirements through the Electric Arc Furnace
• Steel is a cornerstone of the American economy, and formed the basis of its industrial revolution. This in turn led to a massive eruption of energy and innovation which characterises the American economy
• Steel is easily extracted, being magnetic.
• Steel is dense, and so easily transported
• It's high value, and this value can be passed down the line to a network of collectors

The trick, and a problem worth considering, is how can this be translated into other commodities? 

What is the shift that is needed to make other commodities roar like steel? 

How can Garbologie disrupt the status quo to make new industries form and grow?