A valorization process for fayalitic copper slags is presented. A primary copper slag is reduced via carbothermic reduction thus creating a pig iron phase and a secondary copper slag, which is used for glass fiber production. The carbothermic reduction is carried out with graphite pellets or carbon fibers as an alternative reduction agent in crucibles within a furnace using inductive heating. The experiments are prepared and evaluated using FactSage 8.1. Carbon is used with an excess of 10% of the calculated value. The effect of temperature variation and turbulence on the carbothermic reduction process are studied. Glass fiber drawing is realized manually after remelting the secondary copper slag. The threshold for successful glass fiber production lays at a FeOx content below 10 wt%. The produced pig iron phase as well as the resulting glass fibers are characterized, while their industrial applicability is discussed.