Everybody tends to accumulate old electronics at home: cell phones, mp3 readers, game consoles, videorecorders… but not everybody knows that these are domestic mines of precious metals. Tim Smedley explains us, together with some experts, the added value of old electronics as secondary source of critical and precious metals in an article published on April 8, 2020, on the BBC Future website. One of the interviewed experts is Dr. Ana Maria Martinez (SINTEF, Norway) who collaborates with the SOLVOMET group of SIM² KU Leuven in several projects… on critical metal recovery. In this news article Martina Orefice (SIM² KU Leuven) provides further background and highlights the collaborations of Ana Maria and her team in different EU Horizon 2020 projects on metal recovery.

Recently an article, entitled 'How to mine precious metals in your home', was published on the BBC Future website. The article encourages people to dig into the reservoirs of their old electric and electronic waste (WEEE), in these unprecedented times of global lockdown due to the COVID-19 outbreak.

The article features a number of interviewees: James Horne (WEEE forum), Marjolein Scheers (Umicore) and Ana Maria Martinez (SINTEF). Ana Maria and her team from SINTEF are partners of SIM2 KU Leuven in different EU Horizon 2020 projects: CROCODILE, PLATIRUS and TARANTULA, which have in common that they all target the recycling and/or recovery of (critical) metals from urban mines.

Recycling batteries, PGMs and refractory metals

In particular, the CROCODILE project aims to recycle batteries to recover cobalt, lithium, copper, graphite and other precious metals via a combination of mechanical, wet mechanical, and pyrometallurgical techniques.

Concurrently, the target of the PLATIRUS project is to recover platinum group metals (PGMs) – platinum, palladium, rhodium – and also gold from exhausted catalytic converters, while TARANTULA aims to recover refractory metals – tungsten, niobium and tantalum – and other precious metals such as gold and antimony from tailings, mine waste and carbide scrap as well as from concentrated ores.

In all three projects, KU Leuven works on the solid-liquid extraction of the metals (i.e., the leaching step) as well as on the liquid-liquid extraction (i.e., solvent extraction), mainly via solvometallurgical methods.

SINTEF contributes to the production of metals, salts, oxides and carbides via novel electrodeposition (CROCODILE and TARANTULA) routes and to the electrochemical and pyrometallurgical recovery of the valuable metals (PLATIRUS).

Ana Maria Martinez

The main expertise of Ana Maria Martinez is electrochemistry in high temperature molten salts and ionic liquids, including electrowinning, electrorefining and electrodeposition of metals and alloys. Co-author of >50 peer-reviewed papers for international journals, Ana Maria obtained a PhD in Chemistry at the University of Valladolid (Spain) before moving to Norway.

At SINTEF, she is also involved in the coordination of EU-funded projects and in the co-supervision of several PhD and MSc students of the Norwegian University of Science and Technology (NTNU). Recently, she broadened her interests to secondary raw materials.

The e-waste collection bottleneck

In the BBC Future article she provides a precise analysis with data and clear facts of what is the actual status of urban mining.

Ana Maria highlights that the main obstacle to the full rollout of urban mining and the circular economy is not of a technological nature but rather societal: recycling technologies exist (and have proven to be, in general, more sustainable than primary extraction routes) but we lack the feed materials, since consumers are reluctant to hand in their old electronics (yet).

Although experts are familiar with this problem, it is essential to highlight this issue towards a larger audience (as for instance targeted by the EIT AWARE project, which works together with school children – see video). Therefore, we appreciate and are thankful to Ana Maria Martinez for participating in this BBC Future article, which reaches millions of readers worldwide!

The laws of thermodynamics

On the other side, in the article, it is also reported that “Metals are infinitely recyclable without losing their properties”. Indeed, the quality of the product is not affected by (indirect) metal recycling. However, the second law of thermodynamics teaches us that there's no process with a 100% yield; some material is unavoidably lost in every recycling step. Hence, infinite recycling is not possible.

In this sense, it is meaningful to read the contribution of prof. Mark Reuter at the EU-wide event in Brussels on March 12, 2020, co-organised by SIM2 KU Leuven and a host of EU projects. During this seminar – “The green transition challenged by the metal supply chain – the eminent Prof. Markus Reuter (TUBAF & HZDR, Germany) clearly stated that circular economy cannot be a closed loop:

“The inconvenient truth of the circular economy is that the nexus energy–materials is a downward spiral. The best we can do is to mitigate this spiral and not to go down too fast.”

This is a further confirmation of how complex the holistic picture really is; or, as ecologists say:

“The total is more than the sum of the parts”.

It is exactly the complexity of the situation that demands that we all chip in and do our part…so don’t be lazy and go to discover the hidden treasures of your drawers and your basement! Ah, and of course, do not forget the most important step…at the end of the lockdown, take a loooong walk to bring all the collected WEEE to recycle!

Want to know more?

Lazy for today to dig into your domestic mine? Here there are some more articles and videos on urban mining and critical raw materials to read and watch…

What is exactly urban mining? And what is, for instance, its impact on the REE supply?

  • R. Cossu, I.D. Williams, Urban mining: Concepts, terminology, challenges, Waste Manag. 45 (2015) 1–3. doi:10.1016/J.WASMAN.2015.09.040.
  • K. Binnemans, P.T. Jones, T. Müller, L. Yurramendi, Rare earths and the balance problem: how to deal with changing markets?, J. Sustain. Metall. 8 (2018) 126–146. doi:10.1007/s40831-018-0162-8.

What is the above-mentioned solvometallurgy?

  • K. Binnemans, P.T. Jones, Solvometallurgy: an emerging branch of extractive metallurgy, J. Sustain. Metall. 3 (2017) 570–600. doi:10.1007/s40831-017-0128-2


The CROCODILE, PLATIRUS and TARANTULA projects received funding from the European Union's EU Framework Programme for Research and Innovation Horizon 2020. The Grant Agreement numbers of the projects are the following:  CROCODILE, 776473; PLATIRUS, 730224; TARANTULA, 821159, respectively. Likewise, the author and the supporting SIM² KU Leuven team (Jones, Onisei, Janusz & Dinu) acknowledge the EIT RawMaterials AWARE project: AWARE is a Wider Society Project funded by EIT Raw Materials. The views expressed in this article works reflect only the author's views, exempting the EC from any liability.

EIT RawMaterials AWARE video: The Electro-Recycling Hero