The epoxidation of ethylene with oxygen (O2) was catalyzed by using Ag/Al2O3. Recently, the demand amount of ethylene epoxy and ethylene glacial were creation year by year in the word. The traditional recovery methodology of heavy metal could not deal with the complex waste materials. As a result, we investigated the new method by plasma to recover the silver form the non-fresh Ag/Al2O3 catalyst. The non-fresh Ag/Al2O3 catalyst contained 8.16% of silver by the heavy metal analysis method. The silver contain was 8.19% in catalyst by conforming with SEM-EDS method. When the experimental samples were scanned by SEM, we found that most of silver was concentrated below the bottom and partly silver was covered in the slag. Since, we believe the non-fresh Ag/Al2O3 catalyst was fully fused at the high temperature (~1500 oC) in plasma oven. The recovery ratios individual were 64.2%、12.5%、59.8%、86.7% and 79.5% in the Ca10Ag10CS, Ca15Ag5CS, Ca15Ag5CS-2, Ca20Ag5CS and Ca25Ag5CS batches. Following the results, silver was separated with alumina oxide from the non-fresh catalyst. We calculated the recovery benefit by basing on the handle amount of 100 kg for one day and the 21 working days in one mouth. The economic profits of the recovery of plasma technique, 21 tons of non-fresh catalyst could be handled and N.T. 2,585,350 was obtained in one mouth. We have tried to apply the plasma technique in the waste PCB and non-fresh Co/Mo to recover the heavy metal (Cu and Co/Mo). Following the experiment result, the plasma technique could be applied in the recovery of waste PCB to recover copper. For the recovery of non-fresh Co/Mo, the reaction condition and parameters would be modified in the future.

Recovery Silver Metal,Plasma