Aluminium Extra
go around . A project containing 100 % recycled aluminium will only mean more prime aluminium being used in another . As aluminium has a high scrap value , the majority re-enters the supply chain in this ‘ closed loop ’ scenario .
The Council for Aluminium in building has pioneered its own ‘ Closed Loop Recycling ’ scheme in the UK dedicated to the aluminium construction market . The scheme expects its members collect and recycle pre-consumer and post consumer scrap in the UK through the scheme members creating a ‘ closed loop ’ or a ‘ cradle to cradle ’ cycle which continues to reduce carbon embodiment keeping the material ‘ in-use ’ in the UK rather than losing this overseas .
The aim of the initiative is to encourage the recycling of aluminium alloys within the same alloy grades . For the CAB scheme we require that extrusion grades of aluminium , namely 6000 series alloys for the architectural aluminium market , are recycled back into the same 6000 series alloys . The same can be said for sheet aluminium recycling , namely with 1000 series alloys . It is important to reiterate that in a ‘ closed loop ’, an aluminium alloy can be recycled infinitely without loss of its specific characteristics .
Pre-consumer scrap can easily be recycled before it leaves the factory as it is often ‘ clean ’ and of a known alloy , post-consumer scrap on the other hand , is where the challenge lies . With the many thousands of tonnes of alloy extrusion and sheet used in our buildings across the UK , we now look towards the advantages of deconstruction , separation and recycling , and the ability to see view our built landscape as an ‘ urban mine ’ for future raw materials . As already stated , we have recycled aluminium over many decades , primarily as it has a high recycle value , but without a ‘ closed loop ’ we can ‘ lose ’ the specific grades we require to recycle the aluminium back into the same product type . If we can constrain recycling to specific alloy grades , we can recycle extrusions back into new extrusions and offer a true circular economy for our aluminium products in the UK construction industry .
Key to this capability is the advent of the handheld spectrometer for identifying the content of an aluminium alloy . Easily portable and very quick to use , grades can easily be checked prior to recycling . This means that the aluminium grades could easily be checked and identified on a building site prior to deconstruction . The quantity available on a given site can also be relatively easily calculated before removal , as aluminium extrusions and sheets are usually uniform in shape and easily measured . Skips for the scrap , clearly labelled for the identified grades being removed , can be obtained from recyclers to be placed on site for collection of this valuable post-consumer scrap .
The second challenge is to remove nonaluminium components from the aluminium frames of windows and curtain walling , such as hinges , handles , gaskets , screws and weather seals . Done manually , this could take some time , and we must also consider the removal
of thermal breaks made of materials such as polyamide and polyurethane . Fortunately , the technology has advanced considerably , and this process is completely automated . What is supplied back to the smelter is ‘ chipped ’ aluminium , with minimal contaminants such as paint and thermal breaks which are mostly removed in the process .
CAB ’ s Closed Loop Recycling Scheme is open to members as part of their membership package . While such closed loop recycling of construction materials is currently voluntary , government legislation could be introduced on ‘ embodied carbon ’ content in the future and main contractors are increasingly seeking evidence to demonstrate the sustainability credentials of their supply chain . Aluminium scrap is an important resource and we should maximise the quantity and quality of recovered aluminium scrap in the UK to build the circular economy of the future .
CAB encourages anyone working and supplying products within the construction aluminium supply chain to join CAB and ‘ join the discussion ’. Together we can shape the industry and portray the facts of this amazing material .
CAB and staff are on hand at the offices to answer any aluminium fenestration related questions . Information is regularly updated on the CAB website at www . c-a-b . org . uk . For association membership enquires please contact Jessica Dean at the CAB offices by email jessica . dean @ c-a-b . org . uk or by phoning on 01453 828851 .
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