Inspenet, August 18, 2023.
Scientists at the University of Edinburgh are working on developing a methodology to extract rare elements present in waste metal alloys, such as those from decommissioned wind turbines.
These rare metals, such as niobium, tantalum, and rhenium, play a crucial role in the strength and stability of high-demand equipment when alloyed with steel. However, its extraction is usually carried out abroad using methods that have a negative impact on the environment.
The project, funded by the Industrial Biotechnology Innovation Center (IBioIC), aims to recover these rare metals from end-of-life devices , including many of Scotland’s older wind turbines. With this initiative, manufacturers could reuse these elements to create new metal alloys instead of relying on importing materials mined elsewhere.
The extraction of rare metals
Currently, there is no alternative available for the extraction of these rare metals in the British territory, which leads to companies having to send the waste to one of the few existing facilities in Canada for processing.
Using scrap materials provided by Advanced Alloy Services, a Sheffield-based company specializing in the manufacture of high-temperature metals and alloys for industries including aerospace, oil and gas, as well as renewable energies, the research group has developed a sustainable process for the extraction of these resources.
The initial method involves the treatment of the alloying materials by a combination of chemicals of biological origin, which allows the different compounds to be separated. SEM’s innovative DRAM system then acts as a filter to make sure the residual liquids that result are safe for disposal, the scientists explain.
DRAM technology, originated from by-products generated during the distillation of single malt whiskey, was initially conceived to carry out the safe extraction of precious metals present in electronic waste.
Leigh Cassidy, SEM Chief Scientist, explains: “Metals such as niobium, tantalum and rhenium are essential for the integrity of steel-based components commonly used in wind turbines and other high-temperature engines, but most of the reserves continue to be extracted from the ground. Meanwhile, we have aging infrastructure reaching the end of its life cycle and substantial amounts of these rare metals that could be reused.”
“We have already worked with the University of Edinburgh on methods for the safe extraction of metals from e-waste and saw an opportunity to explore a similar technique to separate the different metals from alloys. If used on a large scale, this type of process could be a huge boost for UK manufacturing and unlock a new circular, sustainable supply chain where rare metals are recovered from existing alloys.”
Liz Fletcher, Director of Business Engagement at IBioIC, added: “SEM is a great example of a company taking a bio-based process and applying it across multiple industries to help companies achieve their environmental goals. Joining forces with academic experts, SEM has developed potentially revolutionary processes for the sustainable treatment of various types of waste. Industrial-scale recycling will be key to achieving net zero, while reducing the carbon footprint and environmental damage associated with imported raw materials.”