| 摘要 |
<p>PURPOSE:To easily recover a valuable metal at a high recovery rate from a used catalyst for cleaning exhaust gases for which a metallic carrier is used by immersing the above-mentioned catalyst in an aq. alkaline compd. soln. to strip the coating layers thereof, thereby dissolving and extracting the valuable metal. CONSTITUTION:The used catalyst (monolithic catalyst) for cleaning exhaust gases for which the metallic carrier is used is immersed into the aq. soln. of at least one kind of the alkaline compd. selected from the hydroxides and carbonates of Na and K to embrittle the coating layers contg. the catalyst component (platinum group metal, etc.) The concn. of the aq. alkaline compd. soln. is preferably about 5-15% in case of NaOH. The coating embrittled coating layers are then stripped from the carrier and are dissolved by using the extracting liquid such as acid soln. (for example, aqua regia). The valuable metal is isolated by the conventional practice. The valuable metal is thereby easily recovered at the high recovery rate from the monolithic catalyst having the metallic carrier.</p> |
