Salzgitter AG and Umicore's business unit Metal Deposition Solutions have jointly developed a process to recover the rare precious metal iridium from anodes used in the continuous electro-galvanizing process.
In this way, the partners are contributing to resource conservation and the circular economy.
In electro-galvanizing, so-called MMO anodes are used to deposit a thin zinc layer on steel strips for corrosion protection. Galvanized steel strips find use, for example, in the automotive and household appliance industries. The anodes, which are coated and customized by Umicore MDS through a specialized process, feature a precious-metal coating containing iridium as the primary component. These coatings must be renewed regularly. So far, existing coating residues could not be recycled cost-effectively before recoating.
Iridium is among the rarest non-radioactive metals and is considered a strategically critical raw material for transformation processes, such as an electrode material for hydrogen electrolyzers. Its annual global production volume is only 10,000 kg. This combination recently led to a massive upsurge in the price of the precious metal on the global market. Consequently, it is therefore even more relevant that new processes now make it possible to return iridium from coating residues to the material cycle.
Marc Debeaux“And this is exactly where our idea comes in, which – to put it simply – is about recovering the iridium used in the anodes,” says Dr. Marc Debeaux, expert for electroplating processes at Salzgitter Mannesmann Forschung GmbH. “Here, we are talking about up to one kilogram per year.”
In a joint project with the anode manufacturer Umicore Galvanotechnik GmbH, Salzgitter Flachstahl GmbH, and Salzgitter Mannesmann Forschung GmbH, processes and interfaces were developed to enable cost-efficient recycling of iridium.
"Recycling iridium is very demanding and difficult,” says Frank Friebel, Head of Electrocatalytic Electrodes at the Umicore business unit MDS. “At present, there are only a few providers on the market who specialize in this complex process. Thanks to our many years of expertise in precious metal recycling, we served as an intermediary. By conducting joint trials and developing internal processes, we ultimately succeeded in integrating the process into everyday operations at Salzgitter Flachstahl GmbH.”
Frank FriebelThe cooperation demonstrates how sustainable outcomes can be achieved through the targeted recovery of valuable materials, even outside core processes, and provides impetus for a more comprehensive circular economy.
Salzgitter AG ranks as one of Germany’s leading steel and technology groups. As a pioneer in the circular economy, we focus on sustainable innovation and the transformation of products and processes across our business units in steel production, processing, trading, and technology. Visit www.salzgitter-ag.com.
The Umicore Business Unit Metal Deposition Solutions (MDS) is part of the Umicore Group. The division comprises two business areas: electroplating and thin-film products. MDS ranks as one of the world's leading suppliers of products for coating surfaces with (precious) metals in the nano and micrometer range. Drawing on in-depth expertise from both areas, we combine the two highest-quality processes: Electroplating and PVD coatings. Visit https://mds.umicore.com
