circular economy : Tungsten recycling at BMW's Steyr engine plant: "Every gram counts"

© BMW Motoren GmbH Steyr, Werkskommunikation

As part of its sustainability strategy, the BMW Group places a special focus on raw materials that belong to the so-called conflict minerals. These include ores whose extraction and trade are often associated with violations of environmental and social standards. One example is tungsten: Once misjudged as a troublesome side effect of tin mining, as it "ate up the tin ore like a wolf" and thus got its name, it took several hundred years for the special properties of the hard metal to come to the fore: heavy as gold, hard as a diamond and tens of times more heat-resistant than iron.

Today it can be found, for example, in the vibration alarm of cell phones, in the filaments of light bulbs, and also in the drilling and milling inserts of industrial machines used in automobile production.

At the Steyr plant and at BMW Group plants in Germany, a closed material cycle has been set up for this special metal, in which the old drilling and milling inserts are collected and recycled. New screwing and milling tools are then produced from the secondary tungsten thus obtained. This reduces the demand for tungsten in the BMW Group plants in Austria and Germany by seven tons per year. Compared to the use of primary tungsten, energy consumption is also reduced by 70 percent and CO2 emissions by over 60 percent.

"The responsible use of natural resources plays a central role in our sustainability goals. We will significantly increase the proportion of recycled raw materials by 2030 and use raw materials several times in a circular economy. This applies to use in the vehicle, but also to value creation as a whole," said Andreas Wendt, BMW AG Board Member for Purchasing and Supplier Network, adding, "In this context, every gram counts for which we can ensure that it conserves natural resources and does not contribute to violations of environmental and social standards."

Scrap metal becomes new tools

The carbide tools used per year at the Steyr plant contain up to 3.5 tons of recyclable tungsten. In total, the BMW Group plants in Germany and Austria generate nearly nine tons of tool scrap per year, containing an average of over seven tons of recyclable tungsten.

Tools made of carbide are predominantly made of tungsten and are used, for example, at the BMW Group plant in Steyr for high-precision machining of e-drive housings. At the end of their useful life, they are mostly sold on as scrap. In June 2021, the BMW Group will successively start collecting this tool scrap at its plants in Germany and Austria and have it recycled at Wolfram Bergbau und Hütten AG in Austria. On average, the tool scrap contains over 80 percent tungsten, which is processed into secondary tungsten in powder form using a special method. The electricity used for this comes 100 percent from renewable, regional energy sources.

New tools can then be produced from the dark gray tungsten powder. In a pilot project, the BMW Group has already demonstrated this material cycle with a small amount of tool scrap and had the tool manufacturer Gühring KG in Berlin produce new drilling and milling inserts from the recycled tungsten. These drilling and milling inserts are already being reused in BMW Group plants.

Almost complete transparency across the "3TG" supply chain

Back in 2012, the BMW Group identified particularly critical raw materials and materials from a sustainability perspective in its materials strategy. The BMW Group continuously analyzes these prioritized raw materials and materials with regard to their impact on the environment and society along the entire supply chain.

The conflict minerals tin, tantalum, tungsten and gold, also known as "3TG" after their English initials (tin, tantalum, tungsten, gold), play a special role here. The BMW Group has set itself the goal of complete transparency across the 3TG supply chain and, together with its suppliers, has already achieved nearly 100 percent traceability for the 3TG minerals contained in components and tools in 2019.

The European Union has also already taken action: A new "Conflict Minerals Regulation" came into force at the beginning of 2021, which has tightened the requirements for importing the four conflict minerals tin, tantalum, tungsten and gold.

In addition, the BMW Group is working to steadily increase the proportion of certified smelters in the supply chain. The BMW Group's Conflict Minerals Team provides training, information and support to suppliers in this regard.

The BMW Group is a member of the Responsible Minerals Initiative (RMI) and is driving sustainable management of conflict minerals. To improve understanding of mineral processing, BMW Group Purchasing conducts selected annual on-site visits to European smelters. Wolfram Bergbau und Hütten AG is also a member of the Responsible Minerals Initiative.