Title:
METHOD FOR TREATING HEAVY METAL-CONTAINING FLY ASH
Document Type and Number:
Japanese Patent JP3896442
Kind Code:
B2
Abstract:
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.
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.
Inventors:
Ryotsugu Ito
Hiroyuki Ono
Kenji Ichiyasu
Hiroyuki Ono
Kenji Ichiyasu
Application Number:
JP2001365916A
Publication Date:
March 22, 2007
Filing Date:
November 30, 2001
Export Citation:
Assignee:
DOWA ECO-SYSTEM Co., Ltd.
International Classes:
B09B3/00; C22B3/44; C22B7/02; C22B13/00; C22B15/00; C22B19/00; C22B19/20; C22B19/30; (IPC1-7): B09B3/00; C22B3/44; C22B7/02; C22B13/00; C22B15/00; C22B19/00; C22B19/30
Domestic Patent References:
| JP8141539A | ||||
| JP2000140795A | ||||
| JP2000212654A | ||||
| JP7214029A | ||||
| JP10141539A |
Foreign References:
| WO1998056464A1 |
Attorney, Agent or Firm:
Kenji Wada