| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for separating a useful heavy metal in fly ash from chlorine and recovering the heavy metal in such a form being reusable in a refining step. <P>SOLUTION: The treatment method has a washing step in which fly ash is washed to dissolve and remove chorine-containing soluble salts and to obtain a washed precipitate, a heavy metal separating step in which a sodium hydroxide solution is preferably added as an alkali agent to the washed precipitate to leach a heavy metal, the resulting slurry is diluted and then adjusted to pH 7-12 by adding a mineral acid and a heavy metal-containing precipitate is separated from a salts-containing solution, and optionally, a heat treatment step in which the heavy metal-containing precipitate is further heat-treated. <P>COPYRIGHT: (C)2003,JPO</p> |
