The University of Birmingham has been awarded €4 million to set up a pilot facility to reclaim rare earth metals from scrap.
The project will reportedly form part of the EU-funded Horizon 2020 project Sustainable Recovery, Reprocessing and Reuse of Rare-Earth Magnets in a Circular Economy (SUSMAGPRO) and will focus on recycling magnets made of neodymium, boron and iron.
According to the university, over the last 30 years the use of rare earth metals has increased exponentially, and demand is expected to rise to the tens of thousands of tonnes by 2030. China produces around 80% of the world’s rare earth metals, but currently less than 1% is recycled. The project aims to develop a complete European supply chain to produce 20 tonnes of recycled magnets a year by extracting the metal alloy powders.
Previous methods of extracting rare earth metals required disassembly and removal of the magnet, the research team say. However the new process uses hydrogen decrepitation hydrogen to break down magnetic metal alloys into a powder, which is more easily separated from the remaining components, thereby saving time, labour and money. During the process, developed at the university by Professor Rex Harris, hydrogen preferentially enters the rare earth metal, and causes an expansion in volume. The structure cannot cope with such a large volume expansion and ‘decrepitates’ as grains break away from the material forming a fine powder. A safe mixture of hydrogen and inert gas at a low pressure causes magnets to decrepitate within a few hours. The de-magnetized alloy is then removed by screening and can be reprocessed directly back into new magnets as an alloy powder.
‘Rare earth magnets are used in practically every application that uses electricity to produce motion, and underpin industries that are worth more than £1 trillion worldwide,’ said Professor Allan Walton, from the School of Metallurgy and Materials at the University of Birmingham and one of the inventors of the process. ‘However, both the price and supply have fluctuated considerably over recent years. This means there is considerable opportunity for cost-efficient technologies, which make recycling viable in the long-term.’
This story uses material from the University of Birmingham, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.
