Audi is funding the research to examine the possibility of extracting tin, gallium and indium from incinerated household waste.
German auto manufacturer Audi’s Audi Environmental Foundation (AEF) has announced a collaboration with the Freiberg University of Mining and Technology to fund research into new recycling technologies to recover critical minerals.
The university is developing a technology to selectively extract critical minerals such as tin, gallium and indium from recycled electronics to increase sustainability.
While electronics containing valuable minerals are put into household waste and incinerated, the new technology that the university is developing would allow users to extract mineral ions from the resultant fly ash. This means that even when electronics are not correctly recycled, valuable minerals may still be recovered.
The technology works by the creation of specially shaped “tweezer” heads called ligands. These heads will be made from the molecules that bind to the precious metal ions.
Each head will collect one specific metal ion, be it gallium, indium or tin, and once collected an acid will be used to separate the molecule from the tweezer head. This will ensure that the minerals collected are still in a condition where they can be recycled into new technology, increasing sustainability.
“The challenge is to produce molecules that specifically bind the desired metal ions,” said Betty Leibiger, the doctoral student at the university who is developing the recycling technology.
“At this stage of the project, the focus is on developing a number of suitable tweezer heads, which will then be tested and further optimised on a small scale,” she continued. Once the process is optimised, experiments will be conducted on real fly ash. The university believes that the process can be scaled up once optimised.
This is the latest mineral-focused renewable investment from Audi. In February 2022, the carmaker announced that from 2026 onwards, it would only launch fully electric models. Furthermore, it aims for 100% of its cars sales to be of electric vehicles (EVs) from 2030 onwards.
The minerals being targeted in this recycling collaboration are vital elements in technologies such as semiconductors, fiber-optics and lithium-ion batteries crucial in EVs.