Gemma McGeough examines recent advances in recycling
Rare earth magnets continue to be hugely sought after for use in the development of electric vehicle motors and other advanced technologies. With the release of the IPCC climate change report, the recent COP26 conference, and Net Zero goals constantly in the minds of innovators, an increasing amount of R&D activity is focused on environmentally friendly solutions.
Among them is an innovative system for recycling rare earth magnets from household waste. Their strength and lightweight characteristics, as well as their resistance to demagnetisation, make them particularly desirable for other demanding applications in hard-to-reach places, such as offshore wind farms or other remote energy plants. Rare earth magnets are also commonly used in smartphones and computer hardware, including data-storage systems, meaning demand is high.
Despite their name, rare earth magnets are made up of various elements commonly found in the earth’s crust, with Neodymium Iron Boron (NdFeB) and Samarium Cobalt (SmCo) magnets the most sought after. Although common, finding deposits of these rare earth elements in sufficient quantities at locations where extraction would be considered commercially viable is challenging.
For years, China has been the world’s leading exporter, holding 57.57% of global production in 2020. The US, Myanmar and Australia are next in line, but they remain some distance behind. Geopolitical uncertainty, rising trade tensions and the pandemic have led innovators in western economies to look for ways to reduce reliance on overseas suppliers by recycling rare earth magnets from household waste, such as disused computer hard drives and discarded appliances containing electric motors.
However, the extraction process is incredibly difficult. First, electronic goods must be sorted from other waste such as food, other recyclables and non-recyclables. The magnets tend to be hidden away in voice coil actuators such as within hard disk drives, which are often glued into position and coated in nickel, making extraction even harder. Once the nickel casing has been broken, the magnets must undergo further processing to turn them into a powder, before they are suitable for reuse.
Over the past decade, around 90 patent families – a collection of patent applications covering the same or similar inventions – have been filed globally containing a reference to recycling rare earth magnets, with most being filed since 2015. Many of these patented technologies focus on two main areas: breaking down the surrounding coatings and breaking down the magnets themselves.
The University of Birmingham has carried out world-leading research and development activity in this field. Aiming to solve the problem of extraction, its European patent (EP2646584B1) centres on an innovative rotating bin, which separates the powdered magnetic material from its casing. Another patent filed by the university (EP3317889B1) focuses on improving the processing of recycled powdered magnetic material into new rare earth magnets, particularly for high-speed motors. With EVs a key part of achieving Net Zero emissions by 2050, this technology could be vital to their mass production.
Texas-based Urban Mining Company owns a patent that outlines a technology used to recycle rare earth magnets from discarded electrical equipment and reprocess them into ‘smart magnets’. The business states that the technology saves 11 tonnes of CO2 emissions for every tonne of magnet produced. This equates to a 30-50% reduction in the environmental impact of such processes, compared with traditional extraction methods.
University research departments have been leading much of the innovation activity in this area. As such, intellectual property protection is essential in supporting the route to market for these important technologies. Protecting an innovation with a patent application at the earliest opportunity avoids the risk of early disclosure, which has the potential to render it unpatentable.
Once protected, further development of the technology can take place through industry collaborations, without compromising any commercial benefits. It may also be possible to license patented technologies to third parties, should demand for rare earth magnet recycling continue to rise. This approach can bring long-lasting commercial benefits to the patent owner, with licenses given in exchange for royalty payments.
Although difficult and costly to extract and reuse, rare earth magnets remain an essential element of electric motors and electronic devices. For every problem, however, there is a solution, and as governments around the world focus on legislating to reduce carbon emissions, innovation in this area is likely to intensify and become even more sought after.
The author is a patent attorney and advanced materials science specialist at intellectual property firm Withers & Rogers