Abstract
Germanium (Ge) is a critical element with unique electronic and optical properties that enable its use in high-performance applications, including infrared optics, photovoltaic and optical fiber systems. Due to its limited abundance in Earth’s crust and its high dissipation rates, the development of efficient recovery processes from secondary resources has become increasingly important. The rapid expansion of optical fiber production accounts for more than 30% of global Ge consumption, positioning waste optical fibers as a significant secondary resource. Existing recovery methods for Ge from waste optical fibers have demonstrated efficiency at the laboratory scale. However, their reliance on strong acid such as HF and multi-step processing routes presents major challenges for industrial scalability and economic viability. In this context, microwave-assisted carbothermal reduction of GeO2 is proposed as an alternative approach for Ge recovery. Particular emphasis is placed on key microwave processing parameters including dielectric properties, microwave power, cavity configuration, sample geometry and exposure time which influence microwave heating. This study aims to establish the groundwork of high temperature microwave-assisted processing to enable a more sustainable and scalable pathway for Ge recovery from waste optical fibers.