Using ion-exchange resin to recovery of germanium from waste optical fibers

Germanium tetrachloride and germanium dioxide which used in optical fiber demand rises significantly due to the rapid development of optical fiber communication in recent years. It has 3% germanium in the optical fiber that is enough high to recycle them. In this study, we use ion-exchange to separate germanium (IV) from high concentration of silicate ion selectively which is 30 times more than germanium. Germanium in solution was recovered on an anion-exchange resin after complexation with catechol. Experiment investigations were undertaken using quaternary ammonium resins: IRA-900 and IRA-958. The influence of pH, time and amounts of resin and catechol on the sorption capacity were investigated. We also compare the germanium adsorption efficiency without catechol because germanium in high pH value would turn to anion that the pk1 and pk2 of germanium acid is 9.01 and 12.3. According to the adsorption efficiency and leaching process, the operation at low pH value is better and more selective. And using hydrochloric acid eluted the germanium ions. The best condition of solution is at pH=6, 5 times as high as the germanium molarity of catechol, flow rate=35ml/h and use 0.1M hydrochloric acid to elute, then we can separate 99% germanium from silicate effectively. Obviously, it indicated that process was very a powerful technique for recovering germanium. Germanium (IV) is the lack of resources in the world, and it is also the scattered precious metal. Therefore, the waste optic fiber cable has recovered economic benefits and necessities.