Recovery of germanium from waste Optical Fibers by hydrometallurgical method

Abstract

With the rapid development of optical fiber communications industry, germanium as main raw materials of optical fiber cables become more important in recent years. Due to the scarcity and importance of germanium, we developing an effective recycling process of recovering germanium metal from waste fiber optic cables. The process was arranged to do pre-treatment, leach the fiber and extract the germanium from silicon. In the leaching step, the concentration of different acid, reaction time and liquid-solid ratio were investigated. At the solvent extraction process, the pH value, concentration of extractant and stripping agents, organic-aqueous ratio and reaction time were considered. In leaching step, germanium and silicon were dissolved in solution by sulfuric acid and hydrofluoric acid. Then, germanium was extracted by Trioctylamine (TOA) to the organic phase and silicon was remained in the aqueous by controlling the conditions. After then, Germanium was then stripped by sodium hydroxide. With the optimal conditions, the recovery of germanium could be up to 99%. After separation, germanium could be recycled to back to the industrial effectively.