Resource Recovery of Scrap Digital Video Disc

Autor: Yu-Hao Yang, 楊育豪
Rok vydání: 2005
Druh dokumentu: 學位論文 ; thesis
Popis: 93
The main purpose of this research is to recover the Polycarbonate (PC) plastic and silver from scrap digital video disk (DVD). The upper and lower PC plastics which composed of the DVD are manually separated. The removal efficiencies of surface coating layers (i.e., acrylic glue, protecting glue, silver, memory dye and advertisement ink) of these separated PC plastics by various leaching solution are investigated in this research. The recovery of silver which contained in the final leaching solution by replacement, electrical wining and precipitation methods is also studied in this research. The results of this study reveal that all the surface coating layers of the separated PC plastics can be 100% removed by using 6.0N Nitric acid as the leaching solution with a solid/liquid ratio of 3g/25ml, leaching time of 90 minutes and leaching temperature of 50℃ This leaching test is performed in an ultrasonic cleaning device. The silver coating which 100% leached into this leaching solution can be totally recovered by adding sodium chloride solution (10 ml leaching solution mixed with 0.05ml of 1M sodium chloride solution ) to form a AgCl precipitate. The PC plastic and AgCl precipitate recovered from aforementioned recycling processes can then be sold to the recyclers for further recycling treatments. This research also conducts a LCA (Life Cycle Assessment) study for DVD product by SimaPro 5.0. The results of this LCA study show that environment impact values for DVD’s manufacture stage, transportation stage, and usage stage are 0.864 mPt, 0.00261 mPt and 0.36 mPt, respectively. For DVD’s disposal stage, three solutions of incineration, landfill and recycling are investigated. The LCA study for the recycling solution of DVD is according to the best recycling processes obtained in this research. The environment impact values of incineration, landfill and recycling solutions obtained in this LCA study are 0.247 mPt, 0.223 mPt, and 1.56mPt, respectively. The larger environment impact value means a greater impact to the environment.
Databáze: Networked Digital Library of Theses & Dissertations
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