The presented study aims to prepare chemical resistant glass fibers out of fayalitic copper slag. By carbothermic reduction (CRT) the glass within the system SiO2-CaO-Al2O3 will be prepared with an iron oxide content as low as possible.

A primary copper slag (PCS) is used as an input material which is characterized by X Ray Fluorescence (XRF). After reduction by CRT a pig iron phase, which can be used in the steel industry [1], and a secondary copper slag (SCS) phase, which is used to prepare chemical resistant glass fibers, are generated. The CRT is carried out in a graphite crucible within an induction furnace by mixing the PCS with petrol coke as a reducing agent and CaCO3 as fluxing agent. In Figure 1 the generated materials are depicted. The iron content within the SCS can be reduced down to 1.17 wt% (as Fe2O3 + FeO). The glass fibers are drawn manually from re-molten SCS, characterized by light microscopy, XRD and SEM-EDX as well as alkali resistance tests.