| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method with which fly ash is stabilized and, removed lead is recovered by removing the lead contained in the fly ash at a low cost. SOLUTION: Sulfuric acid 3 is added into the fly ash 2 containing heavy metals such as lead, etc., discharged from an incinerator or a fusion furnace, and after extracting the heavy metals except the lead, solid-liquid separation 4 is executed. Subsequently, an alkali thiosulfate 8 is added into the residue 5 containing the lead obtd. by the solid-liquid separation, and after extracting the lead, solid-liquid separation 9 is executed. Further, sufiding agent 13 is added into the filtrate obtd. by the solid-liquid separation, and after making the lead insoluble, solid-liquid separation 14 is executed.</p> |
