Optimization of germanium enrichment from waste optical fibers: A validation experiment using a hybrid approach

Abstract A batch-type and lab-scale germanium recovery method was developed via a hybrid approach combining pyro– and hydrometallurgical reactions to prove the feasibility of mass production and economic recovery of germanium from waste optical fibers. More specifically, the extent of pyro-metallurgical separation reaction was carefully examined to determine by trial and error its completion time which was 2 h at 700 °C. The post pyro-metallurgical reaction product was leached at 50, 65, and 80 °C for a maximum 8 hr retention at each temperature, using an optimized composition of aqueous HCl solution: maximum germanium recovery of 26 ppm was thus experimentally substantiated by using the ICP-OES method. XRF analysis was performed on the post-hydrometallurgical leaching residue to detect any significant composition of remaining Ge: The confirmation of Si, Cl, and Na as sole residual elements thus cogently substantiated the complete separation of germanium in accordance with the present hybrid approach. The...