Rare earth magnets: progress towards a circular economy

With rare earth magnets becoming increasingly sought after for use in electric vehicle motors and other fast-developing sectors of industry, R&D activity focused on finding ways to recycle them from household waste is gaining momentum.

Rare earth magnets are much sought after in many modern engineering applications due to their strength and lightweight characteristics, as well their resistance to demagnetisation, which makes them more reliable. They are particularly well suited to demanding applications in hard-to-reach places, where it might be difficult to get electric power, such as offshore wind farms or other remote energy plants. Rare earth magnets are also commonly used in electric vehicle motors, smartphones and all kinds of computer hardware, including data storage systems.

Made from various rare earth elements, which are (despite their name) commonly found in the earth’s crust, the most sought-after rare earth magnets are Neodymium Iron Boron (NdFeB) and Samarium Cobalt (SmCo) magnets. Despite their prevalence, it is not easy to find rare earth elements in sufficient quantities at locations where extraction would be considered commercially viable.

China is by far the world’s leading exporter of rare earth elements, supplying over 100,000 metric tonnes of rare earth oxide equivalent per year. Other countries including Australia, India, Russia and the US are also active in this space, albeit to a much lesser degree. In a climate of geopolitical uncertainty and rising trade-war tensions, innovators in many western economies have been looking for ways to reduce reliance on overseas suppliers by recycling rare earth magnets from household waste.

Extracting rare earth magnets from waste materials, such as disused computer hard drives or discarded consumer appliances containing electric motors, is incredibly difficult. In mixed waste streams, electronic goods have to be sorted from other waste such as food, other recyclables and non-recyclables. The magnets are typically found hidden away in voice coil actuators of hard disc drives, which are often glued into position and coated in nickel, adding to the difficulty of extraction. After breaking the nickel casing, they must then undergo further processing to turn them into a powder, before they are suitable for reuse.

Over the past decade, a total of 83 patent families (which is a collection of patent applications covering the same or similar inventions) have been filed in patent offices around the world containing a reference to recycling rare earth magnets, with most being filed since 2015. The technologies described in these patents are focused in two main areas – breaking down the coatings that surround rare earth magnets and breaking down the magnets themselves. Based on the origin of these patent applications, the most prolific innovators are based in USA, UK, and China.

In the UK, the University of Birmingham has been involved in some world-leading research and development activity in the field of rare earth magnet recycling. With a focus on solving the problem of extraction, its European patent (EP2646584B1), granted in 2018, centres on a novel rotating bin, which is used to separate the powdered magnetic material from its casing.

Continuing its R&D activity in this area, the University has recently filed a further patent application – EP3317889 – which is focused on improved processing of recycled powdered magnetic material into new rare earth magnets, especially for high-speed motors, such as electric motors in electric vehicles.

Other patents owned by the Texas-based Urban Mining Company LLC describe an innovative and cost-effective technology used to recycle rare earth magnets from discarded electrical equipment and then reprocess them into so-called ‘smart magnets’. The company has also recently invested in the construction of a new manufacturing facility for this purpose in San Marcos, Texas.

As much of the innovation activity involved in recycling rare earth magnets has spun out of University research departments, the role of intellectual property protection in supporting its route to market is especially critical and can easily be overlooked. New technologies should be protected by a patent application at the earliest opportunity in order to avoid the risk of early disclosure, which in the worst-case scenario could render them unpatentable. Once protected, they can be further developed through industry collaborations where necessary, without the patent owner losing a share in any commercial benefits. Depending on how demand for rare earth magnet recycling develops in the future, it may be possible to license patented technologies to third parties, in exchange for royalty payments, bringing long-lasting commercial benefits to the organisation.

Despite rare earth magnets being found in almost all electric motors and electronic devices, they are remarkably difficult, and costly, to extract and reuse. Where there’s a will, there’s a way however, and as patent research reveals, innovators have now found a way to extract and reprocess these high-performance magnets in a way that is commercially viable.

By Gemma McGeough, patent attorney and advanced materials science specialist at European intellectual property firm, Withers & Rogers.

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