Associations & Organisations
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 . Postconsumer scrap is where the challenge really lies . With the many thousands of tonnes of alloy extrusion and sheet used in our buildings across the UK , we should be looking towards the advantages of deconstruction , separation and recycling , and the ability to see our built landscape as an ‘ urban mine ’ for 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 , introducing other grades reduces its resale value . If we 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 whilst maintaining value .
One of the keys 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 post-consumer scrap .
The second challenge is to remove non-aluminium 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 can be completely automated . What is supplied back to the smelter is ‘ chipped ’ aluminium , with minimal contaminants such as paint and thermal breaks .
Aluminium scrap in this form can easily be reintroduced back into the UK aluminium smelting industry to meet the growing demand for aluminium . With just 5 % of the energy needed to recycle aluminium in this way compared to producing prime aluminium from bauxite , we can make best use of the embodied energy present in aluminium that exists in our building stock .
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 , requirements could be placed 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 .
Main contractors are recognising the scheme and more refurbishment projects where aluminium fenestration is being removed are now being recycled within the CAB Closed Look scheme . The scheme continues to gain momentum and anyone within the aluminium fenestration supply chain can become involved , contact us at CAB for further information on how you can join to help the circulatory of your aluminium .
www . c-a-b . org . uk
CLEARVIEW-UK . COM OCTOBER 2024
77