Purer high-tech material: Freiberg researchers develop new filtration techniques for copper casting
The "PurCo" junior research group at TU Bergakademie Freiberg wants to offer innovative solutions with new filter and recycling techniques.
Copper is a popular material with particular electrical and thermal conductivity, high corrosion resistance, and an antibacterial effect. As demand increases, so do the requirements for the purity of copper. Impurities due to contents of gases (oxygen and hydrogen) as well as metallic and non-metallic inclusions can negatively influence the outstanding properties of the high-tech material and reduce its quality. New technologies and materials should prevent this in the future and enable purer copper for the industry. This is being researched by the BMBF-funded junior research group “PurCo - Purification of Copper - Contributions to copper filtration and recycling of copper scrap”. It bundles the competencies of the Institute for Ceramics, Refractories, and Composite Materials (IKFVW) and the Institute for Non-Ferrous Metallurgy and Pure Materials (INEMET) of the TU Bergakademie Freiberg.
Development of new filter materials
In the future, the filter materials to be developed will efficiently remove impurities through what is known as depth filtration and targeted reactions with the filter surface. To be able to evaluate the purity of copper, methods for the quantitative characterization of non-metallic inclusions and hydrogen in copper are being developed. The researchers working with Dr. Claudia Voigt can draw on a wealth of experience in Freiberg's research. After all, filters made of ceramic materials, such as foam ceramic filters, have already been successfully developed for the cleaning process in aluminum and steel casting.
Copper is produced and cleaned using refining electrolysis. However, this process is very complex and energy-intensive, and new impurities can be introduced during the following process steps in the foundries. Melt filtration offers optimization potential here: "The filters to be developed should keep the purity of the copper at a high level directly in the foundries and offer a relatively simple way of removing impurities," explains Dr. Claudia Voigt, head of the junior research group. The removal of impurities directly in the foundry reduces reject rates, thus saving energy and resources and reducing CO2 emissions.
Research will start from January 2022
The junior research group received the funding notification in mid-October 2021 and will start their research from January 2022 the project is funded for 4,5 years as part of the BMBF young talent competition "NanoMatFutur" with around 1,7 million euros. The junior research group is also supported by two companies in the copper processing industry, KME, and MMG. The two industrial sponsors provide samples and test options.