The Recovery of Indium from ITO Etching Wastewater by Sorption Processes
| Autor: | Yin-Hsiu Hsiao, 蕭因秀 |
|---|---|
| Rok vydání: | 2009 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 97 Indium is a rare and high price metal. In recent years, the photovoltaic industry is prospering therefore nearly eighty percent of indium is used in ITO film. ITO is the most common transparent conductive material and essential to TFT LCD. In the etching process of TFT LCD manufacturing process, some ITO dissolved in waste etchant. Although the indium content in the ITO etching wastewater is ppm grade, it is worth recovering because the domestic photoelectric factory produces a large number of ITO etching wastewater every year. In this study, sorption is investigated to recovery indium from ITO etching wastewater. Some adsorbents such as activated carbon and ion exchange resin are used to do batch adsorption experiment, and we can find out the suitable adsorbent to enrich the indium concentration and improve the recycling value of ITO etching wastewater. The follow-up kinetic adsorption, isothermal adsorption, column adsorption and desorption experiments are helpful to realize the isotherm adsorption model, adsorption parameter, desorption parameter, and so on. In batch adsorption experiments, we find that anion exchange resins help recycling indium from ITO etching wastewater, and the results of kinetic adsorption experiments show that the reaction reaches to equilibrium after adsorbing ten hours. In the kinetic adsorption experiments, we also find the diffusion coefficient and know the rate limiting step is intraparticle diffusion. The anion exchange resin is also used to do isotherm adsorption experiments, and we find that it conforms to the Langmuir isotherm model. In column experiments, the result of adsorption capacities is similar to the result calculated by the Langmuir isotherm model. In desorption experiments, we find HCl is an efficient desorbing solution. The HCl solution is adjusted to 5M, the ratio of solid phase to liquid phase 1:50 which would release the amount of 90 percentage of indium from the anion exchange resin. Moreover, the desorption reaction reaches to equilibrium at least 20 hours. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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