Closing the recycling loop on aluminium

| Manufacturing

Novelis automotive alloy innovation
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Andy Pye reviews progress on the use of recycled aluminium material at Jaguar Land Rover.

Energy-intensive aluminium, the main alternative to steel in the automotive industry, is becoming more popular with car manufacturers for its low weight (aluminium can be up to 50% lighter than steel), but has been held back by the need to secure a steady supply of recycled material.

In the wake of the VW scandal, pressure on car manufacturers to operate with an ever lighter environmental impact has intensified.

According to global producer Constellium, the use of aluminium in automotive applications is poised to explode over the next decade: the company estimates that the US market for aluminium rolled products to be used in body-in-white (BIW) could grow tenfold to approximately 1Mt in 2020. In Europe, the BIW market is expected to grow by approximately 12% a year to more than 600kt in 2020. And according to another manufacturer Alcoa, North American demand for aluminium body sheet will almost quadruple to 1.8Mt in the decade through to 2025. This increase in demand is being driven primarily by the role that aluminium can play in meeting increasingly stringent legislation regarding fuel economy and CO2 emissions.

Novelis is a producer of rolled aluminium. It manufactures formable and lightweight aluminium sheet products and pioneered many of the common aluminium alloys used in automotive manufacturing today – including 6111, 6016 and the original 5754 – in addition to its own Novelis Advanz family of alloys. These are used in more than 180 vehicles in current production, including the new aluminium-bodied Ford F-150 and Range Rover.

The company was formed as a Canadian spin-off from Alcan in January 2005, acquiring substantially all of the aluminium rolled products businesses held by Alcan prior to its acquisition of Pechiney in 2003, as well as certain alumina and primary metal-related businesses in Brazil formerly owned by Alcan and four rolling facilities in Europe that Alcan also acquired from Pechiney in 2003.  The company expects double-digit growth in the global use of automotive aluminium by the end of the decade.

But while the production of primary aluminiium is extremely energy-intensive, it can recover much of its tarnished image by being highly recyclable. Indeed, approximately 75% of the aluminium ever produced is still in use in some form today. And the production of recycled aluminium consumes only 5% of the energy needed to produce primary aluminium with broadly the same properties, significantly reducing the cost of using the material.

This fits in well eith EU Directives, which stipulate that 85% by weight of end-of-life vehicles (ELVs) must be reused or recycled, with a total material recovery rate of 95%. And lightweight competitors such as carbon-fibre reinforced plastic (CFRP) require relatively complicated recycling methods, in addition to being relatively expensive.

But all is not as simple as it seems. The pool of end-of-life scrap is limited, so if an automotive supplier wishes to increase its recycled aluminium content, it will be diverting that material from another application, which is not going to improve anything in terms of the environment. The quest for recycled-content metal in cars runs the risk of developing inefficient material flows. If carmakers were to eat up the actual global base of recycled aluminium, this could happen at the expense of other users and at ecological disadvantages for the overall footprint.

Suppliers and car manufacturers must therefore focus on ‘closing the loop’ by recycling their own process scrap. They also need to develop efficient sorting and re-melting technologies for recycling the scrap recovered from ELVs. Currently, the majority of aluminium scrap from ELVs is processed into casting alloys used to produce engine blocks, cylinder heads and gearboxes.

In the case of wrought alloys, this is effectively downcycling the material. Wrought alloys have a low tolerance to any impurities present in the aluminium scrap, owing to inefficient separation processes. As a result, these impurities need to be diluted with the addition of virgin wrought aluminium in order to produce a new wrought alloy. The establishment of closed-loop recycling programmes requires sizable investment, but the long-term advantages of these systems – both financial and ecological – are significant.

As long ago as 2002, UK-based aluminium pioneer Jaguar Land Rover (JLR) started using aluminium in vehicle bodywork to reduce weight, improve fuel consumption and curb tailpipe emissions. In 2008 JLR teamed up with Novelis for an InnovateUK project to investigate the potential for using recycled aluminium in vehicle manufacturing.

Eight years on, the REALCAR (REcycled ALuminium CAR) project has resulted in the development by Novelis of an innovative high strength aluminium alloy, RC5754, made from recycled aluminium taken from JLR’s press shops, where vehicle bodywork is cut and shaped. In 2015, the Jaguar XE became the first car in the world to use RC5754. This has since been introduced in the lightweight aluminium bodies of the All-New Jaguar XF and F-PACE models and will soon be rolled out in all new JLR passenger cars.

RC5754 contains up to 50%-by-weight of scrap recycled from its in-house processes. JLR had to invest in new equipment and train its operators in order to ensure that clean, segregated scrap was received at Novelis.

RC5754 can absorb higher levels of processed aluminium scrap than previous alloys, and will be used in all new Jaguar Land Rover models, including the Range Rover and the Jaguar XE, and will replace its NG 5754 grade. The OEM will also introduce this recycled alloy retrospectively into its current models. RC5754 does not possess exactly the same properties as the virgin material “equivalent”. The iron content of RC5754 is a little higher as a result of using secondary material. This means that JLR has had to do a lot of work to evaluate the material’s properties and to design around the differences.

According to JLR, the REALCAR project has so far reclaimed more than 50,000 tonnes of aluminium scrap – equivalent to 200,000 XE body shells – back into the production process last year, preventing more than 500,000 tonnes of CO2 equivalent from entering the atmosphere.

JLR has ambitious plans for its aluminium alloy – by 2020 it aims to use 75% recycled aluminium to make Jaguar and Land Rover vehicles. To satiate its demand for recycled aluminium alloy, JLR has put a closed-loop recycling programme in place at its Halewood, Castle Bromwich and Solihull press shops. Over £7 million has been invested installing intricate segregation systems to capture and distribute the aluminium scrap for re-melting, reducing waste, retaining higher quality and value in the material. And the company has put a programme in place to encourage its tier one stamping suppliers to adopt the same philosophy. In all, REALCAR involves 11 UK press shops.

But so far, less than half of the aluminium used by JLR comes from recycled sources. This shortfall is purely down to shortage of supply – for JLR to significantly increase the proportion of recycled aluminium it uses it needs to find another source of scrap metal.

“The limiting factor on the press shop scrap is how much scrap we generate,” Adrian Tautscher, group leader of sustainable aluminium strategies at JLR,” Tautscher told industry experts in London in July this year. “We are trying to reduce that all the time. To push our use of recycled aluminium closer to the 75% mark, we will have to seek scrap supply from elsewhere.”

According to Andy Doran, senior manager for sustainability and recycling at Novelis, one answer is to start using recycled aluminium alloy straight from end-of-life vehicles,. “If you want to increase the level of recycled aluminium, you can bring in open loop scrap, but ultimately end-of-life has got to be the driver for increasing recycling,” he said.

But while using old cars to make new cars makes perfect sense, putting this into practice is not that simple. While the first phase of the REALCAR project focused on developing a high-quality recycled aluminium alloy, the second phase, REALCAR 2, launched in 2013, is looking at at how to source more scrap from post-consumer waste treatment centres.

Geoff Scamans, a Professor of Metallurgy at Brunel University who worked on the REALCAR 2 project, said while it was technically possible to turn post-consumer aluminium waste into the RC5754 alloy, the team had encountered challenges during the sorting process. “We actually found that the separation technologies that we needed weren’t available in the UK,” he said.

This has now led JLR and its REALCAR partners to submit a funding bid to InnovateUK for a third phase of the REALCAR project, dubbed REALITY. It aims to work with the waste industry to develop new sorting technologies to divert scrap aluminium from old cars back to the factory. Details are being kept confidential InnovateUK makes its final funding decision in October. But Scamans hints that REALITY could involve collaboration with recycling experts Axion to research new technologies to tackle the separation and sorting process. “It’s closing the loop on the REALCAR project, it’s closing the loop on the scrap recycling,” he told the July gathering. “The whole idea of this is to see what we can do with end of life vehicle scrap.Theoretically, if JLR can find a way to effectively sort the scrap metal into high-grade aluminium alloy, it could start making vehicles using 100 per cent recycled aluminium.”

Learnings from the collaboration of Novelis and Jaguar Land Rover in developing this new product and the production of key components for the Jaguar XE sportscar are documented in “Collaboration for a Closed-Loop Value Chain,” a case study following the participation of Novelis and JLR in the University of Cambridge Institute for Sustainability Leadership’s Postgraduate Certificate in Sustainable Value Chains.

Whilst the case study focuses on the REALCAR project, its findings are applicable to the creation and transformation of all value chains and other collaborative circular economy projects. Companies in other sectors that embrace ‘circular’ supply chains/value chains can benefit from the understanding and application of the insights presented here.

Since 2011, Novelis has invested approximately $500m to expand the size of its recycling network, doubling its recycling capacity to 2.1Mt per year and raising the recycled content in its products from 30% to 46%. Much of this scrap comes from the automotive sector. The company’s goal is to sell products that contain 80% recycled content by 2020.

In October 2014, Novelis opened the world’s largest aluminium recycling centre. Located next to the company’s rolling mill in Nachterstedt, Germany, the $258m facility can process up to 400kt of aluminium scrap annually, turning it into high-value aluminium ingots to feed the company’s European manufacturing network.

The Nachterstedt facility features state-of-the-art technology for aluminium scrap sorting, de-coating, melting and casting. It gives Novelis the flexibility to process a wide range of scrap types, creating a more efficient closed-loop recycling system and increasing Europe’s domestic scrap consumption.

Andy Pye

Andy Pye

Andy Pye is a graduate of Cambridge University and has had a high profile career in the technical press as well as being a pioneer in web publishing.
Andy Pye

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About Andy Pye

Andy Pye is a graduate of Cambridge University and has had a high profile career in the technical press as well as being a pioneer in web publishing.

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