| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a process for efficiently separating and recovering plastics and aluminum from mixed plastics. <P>SOLUTION: In the process, PO, PS, and ABS are first separated from PET, PVC and aluminum using ethylene glycol (EG) as a wet gravity separation liquid which does not dissolve the mixed plastics, at a temperature close to the melting temperatures of the plastics, and subsequently the heavier solids such as PVC and aluminum remaining in the lighter components are separated by sedimentation in a mixed liquid consisting of water and ethylene glycol. EG in use is separated and recovered and EG lost in the process is replenished with recycling EG formed in the depolymerization process of PET. PET and PVC are further heated together with aluminum and are depolymerized in EG containing NaOH under an atmospheric pressure to form EG and sodium terephthalate, while PVC is dechlorinated and the resulting hydrogen chloride is reacted with NaOH to form NaCl. PO and PVC sticking to aluminum are dissolved by a solvent such as xylene, and solid aluminum is recovered removing the adherent solvent by drying. The mixed solution comprising PO, sodium terephthalate, NaOH, and the solvent is heated under vacuum to evaporate and separate the solvent which is recycled and reused. PO is separated from NaOH and sodium terephthalate by washing with water. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
