INEMET and ITC discovered inovative method for utilizing end-of-life carbon fibers (CF)

Ludwig Blenau ©TU Bergakademie Freiberg/C. Mokry
INEMET (TUBAF) and ITC (KIT) discovered a method for utilizing carbon fibers as reduction agents in metallurgical processes.

Carbon fibers are a high-tech, light weight, modern construction material used in e.g. aerospace applications, wind mill rotors and modern cars. While the installed amount already surpasses 170 kt/a and is likely to grow considerably in the future, the end-of-life utilization remains unclear. Even special waste incinerators cannot process CF.

Our current research shows, that CF can be used both energetically and as a reduction agent in high turbulence, high temperature molten pyrometallurgical processes. At 1450°C we are able to convert up to 90 wt. % of CF in a typical fayalitic copper slag (FeOx-SiO2-Al2O3-CaO-system), while simultaneously reducing up to 70 wt. % of the contained iron into a separable pig iron phase.

The remaining Fibers can be back-cycled and used in a second batch. The remaining iron-depleted slag can be used for glass fiber production. Our approach proves the feasibility to combine fayalitic slag valorization with carbon fiber consumption and produce two high grade construction materials out of waste streams

Here you can find the presentation "Alternative Carbon use for Fayalitic Slag Valorization" by M.Sc. Ludwig Blenau.