INSOLUBILIZATION METHOD AND DEVICE FOR HEAVY METAL-CONTAINING ASH

PROBLEM TO BE SOLVED: To provide a method by which heavy metals in heavy metal-containing ash are easily and efficiently subjected to insolubilization treatment at a low cost, and the elution thereof is prevented. SOLUTION: A solution of a thiosulfuric acid compound 2 is added to raw material heavy metal-containing ash 1, and kneading is performed in a first kneading stage 3. Thereafter, the raw material heavy metal-containing ash 1 is subjected to heating treatment in a first heating stage 4. Next, a solution of a bivalent or trivalent iron compound 10 is added to the raw material heavy metal-containing ash 1, and kneading is performed in a second kneading stage 11. Subsequently, the raw material heavy metal-containing ash 1 is subjected to heating treatment in a second heating stage 12, so that treated heavy metal-containing ash 5 is obtained. COPYRIGHT: (C)2005,JPO&NCIPI