| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method capable of efficiently and easily recovering various kinds of metals from the incineration fly ash produced when wastes of shredder dust, or the like, are incinerated or the molten fly ash produced when the incineration fly ash is further melted by a plasma, or the like. SOLUTION: An aqueous sulfuric acid solution of a pH <=4 is subjected to extraction treatment to elute copper, cadmium and zinc in this solution. An electrolysis is effected between an anode and a cathode in the separated solution obtained by the separation of solid from liquid of a fly ash-containing slurry. The cathode potential is gradually or stepwise changed in a negative direction, by which the copper, cadmium and zinc are discriminated and electrolytically deposited on the cathode. The residue remaining after the separation of the solid from the liquid is thereafter subjected to the extraction treatment with an extraction chemical solution to elute lead in this solution. The lead is electrolytically deposited from the separated solution obtained by the separation of the solid from liquid of the residue-containing slurry.</p> |
