IMMOBILIZATION METHOD FOR HEAVY METAL IN FLY ASH

PROBLEM TO BE SOLVED: To provide an inexpensive fly ash treatment method in a refuse incinerator capable of immobilizing heavy metals in fly ash by chemicals showing superior cost performance by using acidic exhaust gas water as the fly ash immobilization agent, and contributing to reduction of CO2discharge in exhaust gas, besides remarkable cost reduction. SOLUTION: In the subject immobilization method for heavy metals in fly ash, acidic component-containing gas is washed with an alkaline solution, pH of the solution is adjusted to 9-12.5, preferably 10.5-11.5, then the obtained salt-containing liquid is mixed with heavy metal-containing fly ash. COPYRIGHT: (C)2006,JPO&NCIPI